Biopsychology Flashcards
(350 cards)
1
Q
The nervous system
Overview map
A
Nervous system
/. \
Peripheral. Central nervous system
Nervous system /. \
/. . Spinal cord. Brain
Somatic. Autonomic
nervous Nervous
system System
/. \
Sympathetic. Parasympathetic
Nervous system Nervous system
2
Q
The nervous system
What is the nervous system
A
Specialist network of cells in the human body and is our primarily internal communication system
3
Q
The nervous system
What are the two main functions of the nervous system
A
-collect process and respond to information in the environment
-coordinate the working of different organs and cells in the body
4
Q
The nervous system
What two systems is it divided into
A
-central nervous system
-peripheral nervous system
5
Q
The nervous system
What is the central nervous system made up of
A
The brain and spinal cord
6
Q
The nervous system
What is the brains main job
A
Ensure life is maintained
7
Q
The nervous system
What is the brain the centre of
A
All concours awareness where decision making takes place
8
Q
The nervous system
What is the cerebral cortex
A
Brains outer layer
9
Q
The nervous system
What’s special about the cerebral cortex in humans
A
Highly developed
10
Q
The nervous system
What separates humans from other animals
A
Higher mental functions
11
Q
The nervous system
How many hemispheres is the brain divided into
A
Two
12
Q
The nervous system
What is the spinal cord and extension of
A
The brain
13
Q
The nervous system
What is the spinal cord responsible for
A
reflex actions and facilitates transferral of messages to and from the brain to the PNS
14
Q
The nervous system
Why is there central nervous system important
A
Transfers messages to and from the environment
The core from which all physiology is controlled
Breathing resting heartbeat and sense all coordinated from CNS
15
Q
The nervous system
Why do biopsychologists look to the brain for behaviour
A
Most actions and reactions are generated from the CNS
16
Q
The nervous system
What is the peripheral nervous system
A
Extension beyond the CNS and transmits messages to the whole body from the brain
17
Q
The nervous system
What does the PNS do
A
Transmits messages via millions of neurons to and from the CNS
Collects info about pain and threat
18
Q
The nervous system
What two components is the PNS made of
A
Autonomic nervous system
Somatic nervous system
19
Q
The nervous system
What is the autonomic nervous system in the PNS
A
Involuntary/ automatic
20
Q
The nervous system
Where is the control centre fro the autonomic nervous system in the PNS
A
In the brain stem
21
Q
The nervous system
What does the Autonomic nervous system in the PNS do
A
-controls internal organs and glands of the body transmits and receives information from them
-governs vital functions such as breathing rate heart rate digestions and sexual arousals and stress responses
22
Q
The nervous system
Why is the autonomic nervous system in the PNS important for survival
A
Affects the reaction under threat and returns the body to normality (homeostasis) after a reactions
23
Q
The nervous system
What does the autonomic nervous system in the PNS divide into
A
Sympathetic system
Parasympathetic system
24
Q
The nervous system
What does the sympathetic system do
A
Increases activity
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The nervous system
What does the parasympathetic system do
Decreases or maintains bodily activities
26
The nervous system
What are biological changes associated with the sympathetic and parasympathetic response
Sympathetic state. Parasympathetic state
Increases heart rate. Decreases heart rate
Increases breathing rate. Decreases breathing rate
Dilates pupils. Constricts pupils
Inhibits digestions. Stimulates digestion
Inhibits saliva production. Stimulates saliva production
Contacts rectum. Relaxes rectum
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The nervous system
What does the somatic nervous system in the PNS
Controls voluntary movement under conscious control
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The nervous system
What does the somatic nervous system in the PNS control
Skeletal muscle movement
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The nervous system
What does the somatic nervous system in the PNS connect
The CNS and the senses
30
The nervous system
Where does the somatic nervous system in the PNS carry commands from
The motor cortex
31
The nervous system
What does the somatic nervous system in the PNS consist of
Sensory and motor neurons
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The nervous system
What does the somatic nervous system in the PNS transmit and receive
-transmits sensory info from the body/sense receptors to brain/CNS
-receives information from sensory receptors eg visual info
-receives info from spin eg temp of environment
-transmits info from brain via spinal cord to muscles/ receptors
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Endocrine system
What is the function of the endocrine system
Work alongside the nervous system to control/regulate vital physiological processes and functions in the body
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Endocrine system
Compared to the nervous system
Acts much more slowly
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Endocrine system
How does the endocrine system work
Has a series of glands through in the body which release chemicals (hormones)
These hormones are secreted into the bloodstream and regulate the activity of cells or organs
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Endocrine system
What does the endocrine system do
Provides a chemical system of communication via the blood stream
Communicates messages to the organs of the body
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Endocrine system
What could an imbalance of hormones lead to and example
Dysfunction eg high levels of cortisone may cause Cushings disease which can lead to a myriad of symptoms
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Endocrine system
Functions of the pituitary gland
Controls the release of hormones from all other endocrine glands in the body and can also directly produce and effect eg causes breast to lactate
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Endocrine system
Function of the adrenal gland
Important part of the fight or flight response as its facilitates the release of adrenaline which stimulates the heart rate contracts blood vessels and dilates air passages
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Endocrine system
Function of testes
Facilitate the release of testosterone which has been implicated in aggression
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Endocrine system
Function of ovaries
Facilitates the release of oestrogen and progesterone implicated in menstruation
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Endocrine system
Function of the thyroid gland
Secrets thyroxine, increase heart rate, creases metabolic rates and affects growth rates
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Endocrine system
Is behaviour thought to be influenced by hormones
Yes and each hormone throught to affect behaviour in a different way
44
Endocrine system
Which two systems often work in in parallel
The endocrine system and the autonomic nervous system
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Endocrine system
What is the fight or flight generated from
The autonomic nervous system (sympathetic branch)
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Endocrine system
What is the fight or flight response
Reflex response designed to help and individual manage physically when under threat and is also activated in times of stress as the body perceives stress to be a threat
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Endocrine system
What does the fight or flight response help the individual to do
React quicker than normals and facilitates optimal functioning -fight the threat or run away
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Endocrine system
How quick does the flight or fight response happen
In an instant as soon as the threat is perceived as its and automatic reaction in the body
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Endocrine system
First step of the fight or flight response
Stressor is perceived
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Endocrine system
Second step of the fight or flight response
Hypothalamus triggers activity in the sympathetic nervous system in the ANS from the normal resting parasympathetic state to and aroused sympathetic state
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Endocrine system
Third step of the fight or flight response
Stress hormone adrenaline released from the adrenal medulla into the blood stream
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Endocrine system
Fourth step of the fight or flight response
Physiological changes in body
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Endocrine system
Final happenings of the fight or flight response
Once threat has passed the body returns to the resting parasympathetic state and reduces the activities of the body which were increased by the sympathetic state
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Endocrine system
What physiological changes happen in response to the fight or flight response
Increases heart rate, faster breathing rate,muscle tension, pupil dilation, production of sweat, reduced functioning of the digestive and immune system
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Endocrine system
Why does the heart rate increase in the fight or flight response
To speed up the blood flow to vitals organs and improve the spread of adrenaline around the body
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Endocrine system
Why does the breathing rate get faster in the fight or flight response
To increase oxygen intake
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Endocrine system
Why does muscle tension happen in the fight or flight response
To improve reaction time and speed
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Endocrine system
Why do pupils dilate in the fight or flight response
To improve vision
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Endocrine system
Why is sweat priced in the fight or flight response
To facilitate temperature regulation
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Endocrine system
Why is the functioning of the immune and digestive system reduced in the fight or flight response
To save energy for prioritise functions eg running
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Structure and functions of neurons
How many neurons in the brain and spinal cord
100 billion in the brain
1 billlion in the spinal cord
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Structure and functions of neurons
What do neurons do
Receive informations and transmit it to other cells
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Structure and functions of neurons
What are the three types of neurons
Sensory
Relay
Motor
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Structure and functions of neurons
What is the function of the sensory neuron
Carry messages from the PNS to the CNS
Tell the brain about the external and internal environment by processing information taken from the senses
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Structure and functions of neurons
What is the function of the the relay neuron
Carry messages from one part of the CNS to another
Connect motor and sensory neurons
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Structure and functions of neurons
What is the function of a motor neuron
Connect the CNS to muscles and glands (effectors
Carry signals from the CNS which helps muscles and glands to functions
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Structure and functions of neurons
What does sensory neurons look like
Long dentrites and short axons
Have cell body sticking out from middle of axon
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Structure and functions of neurons what do relay neurons look like
Short dendrites and short axons
Looks kinda spidery
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Structure and functions of neurons
What do motor neurons look like
Short denrites and long axons
Cell body connected into dentrites
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Structure and functions of neurons
Blurt the structure
Label a diagram
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Structure and functions of neurons
Function of the cell body of the neuron
Contains the nucleus which houses genetic information for the cell
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Structure and functions of neurons
Functions of dentrite
Carry nerve impulses from neighbouring neurons towards the cell body
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Structure and functions of neurons
What the function of the axon
Carries the impulses away from cell body down length no the neuron
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Structure and functions of neurons
Function of myelin sheath
Fatty layer that covers axon
Protects axon
Speeds up electrical transmission
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Structure and functions of neurons
Function of nodes of ranvier
Breaks in myelin sheath
Speed up the transmission of the impulse by forcing it to jump across the axon
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Structure and functions of neurons
Function of the axon terminal
End of thr axon
Nerve impulse become chemical message to be passed onto post synaptic neuron
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Structure and functions of neurons
What is the neuron in resting state when compared to the outside
Negatively charged
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Structure and functions of neurons
What happens when a neuron is activated by a stimulus for a split second
Inside of cell becomes positively charged
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Structure and functions of neurons
What does the inside of the cell becoming positively charged for a spilt second cause
An action potential to occur which creates an electrical impulse that travels down the axon to the end of the neuron
80
Structure and functions of neurons
What is an action potential
A rapid change in charge across the axon that occurs when the neuron is firing
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Structure and functions of neurons
What is synaptic transmission
Process of transmitting chemical messages from neuron to neuron across the synaptic gap
82
Structure and functions of neurons
What s the synapse
Gap between neurons
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Structure and functions of neurons
What happens at the start of synaptic transmission
Electrical nerve impulse travels down the neuron and prompt the release of neurotransmitters at the presynaptic terminal
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Structure and functions of neurons
Where are neurotransmitters released from and into
Released form synaptic vesicles across the synapse to receptors
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Structure and functions of neurons
What do the receptors do
Covert to an electrical impulse to travel down post synaptic neuron
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Structure and functions of neurons
6 marks exam answer to describe the process of synaptic transmission
-Electrical impulses (action potentials) reach the presynaptic terminal
-Electrical impulses (action potentials) trigger release of neurotransmitters in the presynaptic neuron
-Neurotransmitters cross the synaptic cleft from the vesicle
-Neurotransmitters combine with receptors on the postsynaptic membrane
-Stimulation of the postsynaptic receptors by neurotransmitters result in either excitation or inhibition of the postsynaptic neuron
-Unused neurotransmitter molecules are absorbed back into the presynaptic neuron to be reused
87
Structure and functions of neurons
What happens to unused transmitter molecules and what’s this called
Absorbed back into the presynaptic neuron to be reused
Reuptake
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Structure and functions of neurons
What does reuptake regulate
Amount of neurotransmitters in the synapse and how much message their is
89
Structure and functions of neurons
What’s different about each neurotransmitter
There’s several dozen types which have been identifies and each has its own specific molecular structure that fits perfectly into the post synaptic receptor site (like lock and key)
90
Structure and functions of neurons
What has to happen for the message to be passed on
Neurotransmitters have to fit into the receptor on the next neuron
91
Structure and functions of neurons
Example of specialist function for neurotransmitter
Acetylcholine (ACh)
Stimulates muscle contraction and is key function motor control and movement
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Structure and functions of neurons
What are all neurotransmitters either
Excitatory or inhibitory effect of the neighbouring neurone (most can be both but GABA is purely inhibitory)
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Structure and functions of neurons
What does it mean is the neurotransmitters are excitatory
The post synaptic neuron is more likely to fire and impulse
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Structure and functions of neurons
Why is the neurotransmitter adrenaline excitatory
Causes excitation of the post synaptic neuron by increasing its positive charge and making it more likely to fire
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Structure and functions of neurons
What does it mean if the neurotransmitter is inhibitory
The post synaptic neuron is less likely to fire and impulse
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Structure and functions of neurons
Why is the neurotransmitter serotonin inhibitory
Causes inhibition in the receiving neuron( neuron becomes more negatively charged and less likely to fire )
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Structure and functions of neurons
What is true of the excitatory and inhibitory potentillas
They’re summed together
If the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to fire and if the net effect is excitatory the neuron will be more likely to fire
98
Structure and functions of neurons
Why is synaptic transmission only in one direction
Synaptic vesicle are only present from the presynaptic neuron and the receptors are only present on the post synaptic neuron
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Localisation of function
What happened in 1848 and what did it lead to
Phineas gage had an accident resulting in a rod going through his face and out of his head it lead to greater understanding of the brain structure
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Localisation of function
What is the holistic theory
Scientists used to support this and it was that all parts of the brain were involved in the processing of thought and action
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Localisation of function
What is localisation of function
Specific parts of the brain associated with specific functions and ifferent parts of the brain performing different tasks and are involved with different part of the body
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Localisation of function
What happens if a certain are of brain bets damaged
Function associated with that area will be affected
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Localisation of function
How many lobes is the brain made of
4
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Localisation of function
What 4 lobes is the brain made from
Frontal
Parietal
Temporal
Occiptal
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Localisation of function
Where is the frontal lobe
Front of the brain
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Localisation of function
Where is the parietal lobe
At the top in middle
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Localisation of function
Where is the temporal lobe
At the bottom in middle
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Localisation of function
Where is the occipital lobe
At the back of the brain
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Localisation of function
What is the cerebral cortex
Outer layer of both hemispheres
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Localisation of function
How thick is the cerebral cortex
3mm
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Localisation of function
What does the human cortex being develo mean
Separates humans from other animals
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Localisation of function
Appearance of cerebral cortex
Grey
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Localisation of function
What’s re the lobes named after
Bones which they lie beneath
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Localisation of function
What is each lobe associated with
Different functions
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Localisation of function
Where is the motor cortex
Back of the frontal lobe in both hemispheres
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Localisation of function
What does they motor cortex do
Controls movement in opposite side of body
Sends messages to the muscles via the brain stem and spinal cord
Important for complex movements and not basic actions
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Localisation of function
What do the areas within the motor cortex do
Control specific body parts
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Localisation of function
What would happen is there was damage to the motor cortex
May result in a loss over fine movements
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Localisation of function
Where is the somatosensory cortex
Front of both parietal lobes in both hemispheres
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Localisation of function
What does the somatosensory cortex lay next to in the brain
The motor cortex
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Localisation of function
What does the somatosensory cortex do
Sensation of the old
Where sensory information from the skin eg to such heat and pain is represented and processed
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Localisation of function
How does the area devoted to a certain body part in the somatosensory cortex affect it and example
Larger area devoted tot he body part the more sensitive
Eg receptors for face and hands occupy over half of the somatosensory cortex
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Localisation of function
Where is the visual cortex
Found in the occipital cortex one in each cortex
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Localisation of function
What is the visual cortex
Main visual centre
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Localisation of function
What does the visual cortex do
Process visual information such as colour and shape
Each eye sends information from the right visual field to the left visual cortex and vice versa
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Localisation of function
For the visual cortex what can happen if there’s damage to the left hemisphere
Produce blindness in part of the right visual field of both eyes
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Localisation of function
What does area VI seem necessary for and what does damage to this are mean
Necessary for visual perception
Damage to this are reported no vision of any kind: conscious vision, visual imagery while awake or in dreams
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Localisation of function
Where is the auditory cortex
In front of temporal lobe in both hemispheres
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Localisation of function
What does the auditory cortex do
Analyses speech based information
Processes information such as pitch and volume
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Localisation of function
What might damage to the auditory cortex produce
Partial hearing loss and the more extensive the damage the more extensive the loss of hearing
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Localisation of function
Where is Broca’s area
Bottom of the frontal lobs only in left hemisphere
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Localisation of function
What side is the language area and how do you remember
On left side
L eft = L anguage
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Localisation of function
When and what did Paul broca identify
Small area in left frontal lobe responsible for speech production
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Localisation of function
What does damage to the Broca’s area cause
Brocas aphasia
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Localisation of function
Symptoms of brocas aphasia
Speech is slow laborious and lacks fluency
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Localisation of function
Where is Wernicke’s area
Top of temporal lobe only in left hemisphere
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Localisation of function
What did Karl wernicke identify
Area as being responsible for language comprehension
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Localisation of function
What does damage to wernickes area result in
Wernickes aphasia
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Localisation of function
Symptoms of wernickes area
Patients often produce nonsense words that was fluent but meaningless
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Lateralisation of function
What is hemisphere lateralisation
Idea that both hemispheres are functionly different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other
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Lateralisation of function
Which side does each hemisphere control
Each hemisphere controls the opposite side of the body and visual field
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Lateralisation of function
If a function is dealt with by one hemisphere what is it said to be
Lateralised
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Lateralisation of function
Examples of left hemisphere functions
Analytic thought
Logic
Language
Reasoning
Science and math
Written
Number skills
Right handed control
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Lateralisation of function
Right hemisphere functions
Art awareness
Creativity
Imagination
Intuition
Insight
Left hand control
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Lateralisation of function
Where is language processed for most people
Left hemisphere
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Lateralisation of function
Language impact if stroke on left side of brain
Speech is affected
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Lateralisation of function
What is language subject to
Hemisphere lateralisation
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Lateralisation of function
Important functions of right hemisphere
Dominant for recognising emotions in other
Deals with spatial information
Drawling ability
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Lateralisation of function
Key focus for right hemisphere
Appears dominant in terms of recognising faces
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Lateralisation of function
What is the corpus callosum
Section that joins the two hemispheres
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Lateralisation of function
What happens in the corpus callosum
Messages travelling between two hemispheres pas through
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Lateralisation of function
What happens if the corpus callosum is damaged
Two hemispheres cannot communicate
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Lateralisation of function
Who did split brain research
Sperry (1968)
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Lateralisation of function
Who did sperry do split brain research on
Group of individuals who had their corpus callosum severed to control there epilepsy
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Lateralisation of function
What has split brain research been useful in
Understanding the role of each hemisphere and the extent to which they’re lateralised
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Lateralisation of function
Method for split brain research
1. Patient with severed corpus callosum stares at fixed dot in screen
2. Image or word projected to patent its right visual field (processed by the left hemisphere) or to patients left visual field (processed in right hemisphere )
3. Patient asked to describe what saw and if court draw it or touch the object.
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Lateralisation of function
Key finding for split brain research in describing what the patients saw
When shown in patients right visual field, patient could easily describe what they saw but if shown in left visual field patient could not describe what was seem and typically reported there was nothing there
Shows language mainly in left hemisphere
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Lateralisation of function
Key findings for split brain research in the left visual field
Although patients wouldn’t be able to verbally recall the object seen, they were able to close there eyes and raw it with there left hand or select a matching object from behind the screen
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Lateralisation of function
Evaluation of split brain research
2 strengths
Reliability
Applicability
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Lateralisation of function
Evaluation of split brain research
Reliability
Highly standardised procedure in lab
Replication is possible and obtain same results
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Lateralisation of function
Evaluation of split brain research
applicability
Produced impressive and sizeable body of research innings
Equipment and procedure enabled the findings of the two heliospheres to be studs in ways which weren’t possible before
Eg left hemisphere is language
More we understand about how our brain is lateralised the more we can help those with brain damage
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Lateralisation of function
Evaluation of split brain research
Two weaknesses
Generalisability
Validity
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Lateralisation of function
Evaluation of split brain research
Generalisability
Split brain patient unusual and only small sample of people
Only 11 participant took part in all vaioration sof study
All had history of epileptic seizures
As split brain patients are very rare may be difficult to find larger sample and therefore hard to generalise to whole populations
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Lateralisation of function
Evaluation of split brain research
Validity
Low ecological validity as techniques very artificial
Data was artificially produced in a real life situation information would be entering both eyes and therefore the person is able to compensate for having no corpus calllosum to transfer information across the hemispheres
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Localisation and lateralisation evaluation
Evidence for localisation
Tulving et al (1994)
Unique cases of neurological damage
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Localisation and lateralisation evaluation
Tulving eg al evidence for localisation
Conducted study of long term memory
Revealed that semantic and episodic memories reside in different part of the prefrontal cortex
Suggest they these area do the brain have different functions
This supports that the idea that many neurological functions are localised
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Localisation and lateralisation evaluation
Unique cases of neurological damage for localisation
Phineas cage suffered an accident in which a tamping iron took out a portion of his frontal lobe which resulted in a dramatic change in his personality
This case supports localisation theory as it suggests the frontal lobe may be responsible for regulating mood
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Localisation and lateralisation evaluation
Evidence for lateralisation
Heller and levy (1981)
Sperry(1968)
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Localisation and lateralisation evaluation
Heller and levy (1981) for lateralisation
Found that is a photo of a face is split so that each half is either smiling or neutral is shown to someone the emotion displayed on the left hand side of the picture is the emotion recognised by the participant
Suggest right hempisher seem to be particularly dominant for recognising emotions in other and highlight that the left visual field is processes by right hemisphere
Therefore evidence for lateralisation
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Localisation and lateralisation evaluation
Sperry (1981 for lateralisation
Split brainresearch
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Localisation and lateralisation evaluation
Evidence against lateralisation and localisation
Brain plasticity
In sense that when brain is damaged and particular function is lost, rest of brain seems to reorganise itself and try to recover lost function
Several documented cases of stroke victims recovering lost abilities
Against local and lateral bc same neurological action can be achieved even though the area of the brain responsible for the function has been damaged
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Localisation and lateralisation evaluation
Danelli et al (2013) against localisation and lateralisation
Reported case of a body who had virtually had all his left hemisphere re,over and managed to regain all most all of his language skills
Implies no localisation or lateralisation
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Brain plasticity
What is it
Brain has the ability to change throughout life
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Brain plasticity
Wnat happens to the brain during infancy
Experiences a rapid growth in the number of synaptic connections
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Brain plasticity
What happens to the brain at 2-3 years old
Peaks at 15000 number of synaptic growth
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Brain plasticity
What synaptic pruning
As we age rarely used synaptic connections are deleted and frequently used connections are strengthened
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Brain plasticity
Does it happens in childhood and adulthood
Used to be thought was restricted to developing brain in childhood and believed the adult brain would remain fixed and static in terms of function and structure by research suggest at any time neural connections can change or new connections can be formed as a result of learning and experience
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Brain plasticity
What factors can result in our brains changing
Occupation
Learning experience
Pastimes and hobbies
Drug use
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Brain plasticity
What is functional recovery
Form of neural plasticity following physical injury or damage through trauma where the brain is able to redistribute or transfer functions and in healthy brains areas may take over functions
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Brain plasticity
What the timeline of functional recovery
Process can occur quickly after trauma (spontaneous recover) then slow down after weeks/months
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Brain plasticity
What may be needed after functional recover
Rehabilitative therapy
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Brain plasticity
What happens in the brain during functional recovery
Brain is able to retire and reorganise itself by forming new synaptic connects close to the area of damage
Secondary neural pathways that would not typically used to carry out certain functions are activated or unmasked to enable functioning to continue
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Brain plasticity
What structural changes can occur in the brain
Axon sprouting
Recruitment of similar areas on the opposite side of the brain
Denervation supersensitivity
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Brain plasticity
What is axon sprouting
Growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
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Brain plasticity
Why can axon sprouting happen
When an axon is damaged its connections with a neighbouring neuron is lost
Helps replace a function
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Brain plasticity
When does axon sprouting only happen
Only if damaged axon and compensatory axon do similar jobs (otherwise problems may occur)
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Brain plasticity
Example of recruitment of similar areas on opposite side of the brain
If Broca’s area is damages on left side right side equivalent will carry out its functions
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Brain plasticity
What denervation super sensitivity
Occurs when axons aroused to a higher level to compensate for the ones lost
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Brain plasticity
What can denervation super sensitivity cause
Over sensitivity to messages such as pain which can increase pain levels
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Brain plasticity
What factors affect functional recovery
Perseverance
Physical exhaustion, stress and alcohol consumption
Age
Gender
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Brain plasticity
How does perseverance affect functional plasticity
Function may appear t be lost but this may be because the individual believes its unrecoverable and therefore doesn’t try
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Brain plasticity
Perseverance affect on functional recover example
Research shows when a monkey has a ‘deafferented’ limb (lost its sensory input) it will try not to use it
If functioning in other limb becomes damaged it has no option but to use it
Motor nerves are still connected to the limb but the sensory nerve damaged means the monkey doesn’t feel as if it can move the limb
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Brain plasticity
How does physical exhaustion stress an alcohol consumption affect functional recovery
When a function is recovered the function is used with considerable effort
May be fatigued by the effort
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Brain plasticity
How does age affect functional recovery
Deterioration of the brain in old age affects extent and speed of recovery
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Brain plasticity
Age affecting functional recovery example
Older patient (40+) gain less function compared to a young brain eg danelli et al (2013)
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Brain plasticity
Gender affect of functional recovery
Research suggest women recover better from brain injury as their function is not as lateralised
However research is mixed so conclusions are unclear
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Brain plasticity evaluation
strength
Practical application
198
Brain plasticity evaluation
Practical application
What has understanding the process involved in plasticity contributed to
Field of neurorehabilitation
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Brain plasticity evaluation
Practical application \
What do we now understand about spontaneous recovery
Tend to slow down after a number of weeks so forms of physical therapy may be required to maintain improvements in functioning
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Brain plasticity evaluation
Why is it a strength
Electrical stimulation of the brain may also be needed to counter the deficits in motor/cognitive functioning after a stroke.
This shows that although the brain has the ability to ‘fix itself’ to a point, this process requires further intervention to be completely successful.
The more we understand about this, the more effectively we can help those who need
201
Brain plasticity evaluation
Weaknesses
Factors affecting recovery
Validity of findings
202
Brain plasticity evaluation
Factors affecting recovery
The ability of the brain to recover varies according to the extent of the damage, the location of the damage, and the individual.
For this reason, each case varies and generalisations are difficult to make from case studies
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Brain plasticity evaluation
Validity of findings
In some cases there is no record of functioning level prior to the trauma
It is therefore difficult to know the extent to which the brain has recovered to pre-trauma levels.
This inability to come to firm conclusions lowers validity
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Brain plasticity evaluation
Functional recovery case study
Danelli et al (2013)
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Brain plasticity evaluation
Denelli et al (2013) story
At 2 ½ years old a boy had a large benign tumour removed from his left hemisphere (virtually all his left hemisphere was removed)
Lost all linguistic abilities
After intensive rehabilitation, language abilities started to improve at around 5yrs old
Over next 3 years they continued to improve until there were no language problems
At age 17, he had virtually the same level of language abilities as ‘normal’ controls
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Brain plasticity evaluation
Denelli et al (2013) results as plasticity
Seems that the right hemisphere had compensated for loss of left hemisphere (although there were still minor grammatical problems)
Shows functional recovery – the brain’s ability to redistribute or transfer functions
This is a form of plasticity
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Brain plasticity evaluation
research support for plasticity
Mechelli et al (2004)
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Brain plasticity evaluation
Mechelli et al (2004)
Research and results
Found a larger parietal cortex in the brains of people who were bilingual compared to matched monolingual controls
Suggests that this specific type of learning has led to changes in brain structure, demonstrating neural plasticity.
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Brain plasticity evaluation
Age and plasticity research
Bezzola et al (2012
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Brain plasticity evaluation
Bezzola et al (2012) research
Participants 40-60 year olds
40 hours of golf training
Used fMRI scans
Observed reduced motor cortex activity in novice golfers compared to a control group
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Brain plasticity evaluation
Bezzola et al (2012) results
Shows that neural plasticity does continue through the lifespan (not just younger people as they learn and gain new experiences)
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Brain plasticity evaluation
Negative plasticity research example
Medina et al (2007)
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Brain plasticity evaluation
Medina et al 2007 research
Prolonged drug use was shown to result in poorer cognitive functioning, as well as an increased risk of dementia later in life
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Brain plasticity evaluation
Medina et al 2007 results
Demonstrated how the brain’s ability to rewire itself can sometimes have maladaptive behavioural consequences
215
Studying the brain
What are the 4 ways
fMRIs
EEGs
ERPs
Post marten examinations
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Studying the brain
How do fMRIs work
Use magnetic field and radio waves to detect the changes in blood oxygenation and flow that occurs as a result of brain activity in specific parts of the brain
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Studying the brain
FMRIs
What happens when a brain area is more active
Consumes more oxygen and to meet this increase in demand blood flow is directed to this active area
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Studying the brain
What does fMRIS show from being in 3D
Shows which park of the brain are involved in a particular mental process
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Studying the brain
What are fMRIS important for
Understanding localisation of function
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Studying the brain ]
Strengths of fMRIs
Doesn’t rely on radiation
Virtually risk free, non invasive and straightforward to use
Produces opiates with height spatial resolution depicting detail by millimetre
Provided a clear picture of how brain activity is localised
Unlike post more them allows active brain to be investigates during specific activities/ tasks
Captures dynamic brain activity as opposed to post morgen which shows purely physiology
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Studying the brain
fMRIs weaknesses
Expensive compared to other neuroimaging techniques leading to small sample sizes reduced the validity of studies
Can only capture a clear image if person is completely still
Poor temporal resolution with around 5 second lag time behind image on screen and initial firing of brain activity
Can only measure blood flow in brain cannot home in on activity of individual neurons
fMRIs data is complex and can be open to interpretation
Unlike ERPs provide and indirect measure of neural activity
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Studying the brain
What is the post mortem technique
Involves the analysis of a persons brain following death
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Studying the brain
What is person having postmortem likely to have
Have had rare disorder or experienced unusual deficit in mental processes
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Studying the brain
Why are areas of damage examined after death
Establish likely cause of afflictions and may compare to neurotypical brain to ascertain extent of difference
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Studying the brain
Post mortem strengths
Evidence from post mortem was vital in providing a foundation for early understanding of key processes on the brain
Broca and Wernicke both relied on post-mortem studies to establish links between language, brain and behaviour evades before neuro-imaging became possible
Post-mortems improve medical knowledge and help generate hypotheses for future studies
Post mortem examinations enable deeper regions of the brain to be investigated than non-invasive techniques
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Studying the brain
Post mortem weaknesses
Causation is an issue with these investigations –observed damage to the brain may not be linked to the deficits under review, but some other unrelated trauma or decay
Post mortem scan be affected by changes which occur during/after death
Requires special permissions to be conducted, which often leads to small sample sizes
Post-mortems raise ethical issues of consent from the patient before death. Patients may not be able to provide informed consent e.g. the case of HM who lost his ability to form memories and was not able to provide such consent. Nevertheless post mortem research has been conducted on his brain.
Shows purely physiology as opposed to fMRIs which captures dynamic brain activity
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Studying the brain
How does an eeg work
Measure electrical activity within the brain via electrodes fixed to the scalp using a skull cap
Detect neuronal activity directly where the electrodes are placed
228
Studying the brain
What does the scan represent on an EEG
Represent the brainwave patterns that are generated from the section of millions of neurons providing an overall account of brain activity
229
Studying the brain
When are EEGs often used
By clinicians as a diagnostic tool as unusual a rhythmic patterns of activity may indicate neurological abnormalities
230
Studying the brain
EEGs strengths
EEGs have proved invaluable in the diagnosis of conditions such a epilepsy, a disorder characterised by random bursts of activity in the brain that can easily be detected on screen
It has contributed much to our understanding of the stages involved in sleep
Unlike fMRIs, EEG technology has extremely high temporal resolution (time lag is not an issue). Today’s EEG technology can accurately detect brain activity at a resolution of a single millisecond (and even less in some cases
EEGs are cheaper than fMRIs so larger samples can be used which can increase the validity of the data obtained
Unlike post mortems, allows active brain to be investigated during specific activities/tasks
231
Studying the brain
EEG weaknesses
Main drawback of EEGs lie in the generalised nature of the information received (that of many thousands of neurons).
EEGs have poorer spatial resolution than fMRIs
The EEG signal is not useful for pinpointing the exact source of neural activity and does not allow researchers to distinguish between activities originating in different but adjacent locations.
232
Studying the brain
What are ERPS
Use same apparatus as EEGs but record activity of activity as a stimulus from researcher
233
Studying the brain
EEG compared to ERP
EEGs in their raw form are a crude and overly general measure of brain activity. However within EEG data are all the neural responses associated with different events may be of interest to cognitive neuroscientists
Researchers have developed a way of teasing out and isolating their responses
Using a statistical averaging technique, all extraneous brain activity from the original EEG recording is filtered out, leaving only those responses that relate to e.g. presentation of a specific stimulus or performance of specific task
What remains are ERPs: types of brainwaves triggered by particular events
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Studying the brain
ERP strengths
ERPs bring much more specificity to the measurement of neural processes than could ever be achieved using raw EEG data.
As ERPs are derived from EEG data, they too have excellent temporal resolution which has led to their widespread use in the measurement of cognitive functions and deficits
Researchers have been able to identify many different types of ERP and describe the precise role of these in cognitive functioning
ERPs are cheaper than fMRIs so larger samples can be used which can increase the validity of the data obtained
Unlike post mortems, allows active brain to be investigated during specific activities/tasks
Unlike fMRIs, provide direct measure of neural activity
235
Studying the brain
ERP weaknesses
There is a lack of standardisation in ERP methodology between different research studies which makes it difficult to confirm findings
In order to establish pure data in ERP studies, background noise and extraneous material must be completely eliminated, and this may not always be easy to achieve.
ERPs have poorer spatial resolution than fMRIs
236
Biological rhythms
What are the three types
Ultradium rhythms
Circadium rhythms
Infradian rhythms
237
Biological rhythms
What are ultradium rhythms and example
Last less than 24 hours eg stages of sleep
238
Biological rhythms
What are circadian rhythms and example
Last 24 hours eg sleep/wake cycle
239
Biological rhythms
What are infradium rhythms and example
Last more than 24 hours
Eg menstrual cycle
240
Biological rhythms
What are biological rhythms
Distinct patterns of changes in body activity which conform to cyclical time periods
241
Biological rhythms
What are biological rhythms influenced by
Internal body clock and changes to the external environment
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Biological rhythms
What have biological rhythms
All living organisms plants animals and people are subject to biological rhythms and these exert important influence n the ways in which the body systems behave
243
Biological rhythms ]
What are all biological rhythms regulated and governed by
Endogenous pacemakers and exogenous zeitgebers
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Biological rhythms
What are endogenous pacemakers and example
Body’s internal biological clock
Mechanisms within the body that govern the internal biological bodily rhythms
Eg Suprachiasmatic nucleus
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Biological rhythms
what are exogenous zeitgebers and example
Environmental cue such that helps to regulate the biological clock in an organisms
Eg light and sound
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Biological rhythms
What type fo rhythm is the sleep wake cycle
Circadian
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Biological rhythms
What is the sleep wake cycle and what does it demonstrate
Feeling drowsy at night time and alert during the day
Demonstrates effect of daylight as an important zeitgebers
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Biological rhythms
Studies of sleep wake circadium rhythms
Siffres cave study
Aschoff and Wever (1976) NOT LEARNING
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Biological rhythms
What was Siffres cave study
Siffre spent several extended periods of time underground to study effects on own biological rhythms
Deprived of exposure to natural light or cues as to time or day but had all supplies such as food
Artificial light
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Biological rhythms
Findings from Siffres cave study
Biological rhythms just longer than usual 24 hours (25-30 hours )
Continued to fall asleep and wake up on regular schedule
Lost track of how m,any days he spent in the cave as he thought it was one month less
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Biological rhythms
Results from Siffres cave study
Suggests natural sleep wake cycle may be slightly longer than 24 hours
Natural light sources in the environment are vital for keeping the individual to a 24 hour cycle
Natural sleep wake cycle is adjusted by exogenous zeitgebers associated with put 24 hour day eg daylight and meal times
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Biological rhythms
Aschoff wever (1976) study
Convinced a group of participants to spend four weeks in a WW2 bunker deprived of natural light
All but one of the participants (whose sleep/wake cycle extended to 29 hours) displayed a circadian rhythm between 24 and 25 hours
suggests the ‘natural’ sleep/wake cycle may be slightly longer than 24 hours but is entrained (adjusted) by exogenous zeitgebers associated with the 24-hour day (daylight/mealtimes etc)
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Biological rhythms
What is the Suprachiasmatic nucleus (SCN)
Primary endogenous pacemaker which is influential in maintaining circadian rhythms
Tiny bundle of nerves located in the hypothalamus
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Biological rhythms
SCN role in sleeep wake cycle
Receives information about light even when eyes closed
enables our biological clock to adjust to changing patterns of daylight even when we sleep
The SCN passes information on day length and light that it receives to the pineal gland
During the night, the pineal gland increases production of melatonin
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Biological rhythms
What is melatonin and what ha it been suggested as a factor
Chemical that induced sleep and is inhibited during periods of wakefulness
Suggested as a causal factor in seasonal affective disorder
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Biological rhythms
Is the SCN found in animals and why has this facilitated research into the SCNs role
Yes
Human research would be difficult and u ethical
Argued generalisation can be made from animals to human
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Biological rhythms
Research into endogenous pacemakers
Decoursey et al (2000)
Ralph et al (1990)
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Biological rhythms
What was Decoursey eat al (2000) research
Destroyed SCN connections in the brain of 30 chipmunks and were returned to their natural habitat observed for 80 days
259
Biological rhythms
Fundings for Decoursey et L (2000)
Sleep wake cycle disappeared and by the end of the study a significant portion has been killed by predators
Chipmunks were awake and vulnerable t attack when they should’ve been attacked
Emphasises role of SCN in establishing and maintaining the circadian sleep wake cycle
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Biological rhythms
Ralph et al (1990) what
Removed SCN out of genetically abnormal hamsters which has 20 hour circadian rhythms and transplanted them into normal rats
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Biological rhythms
Ralph et al (1990) findings
After transplant circadian rhythms of normal rats shortened to 20 hours
Suggest SCN is pivotal in regulating the internal body clock
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Biological rhythms
How do exogenous zeitgebers work with pacemakers
Are a cue for endogenous pacemakers
Help regulate the body clock to the individual is synchronised with the environment
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Biological rhythms
Examples of exogenous zeitgebers
Noise, light seasons
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Biological rhythms
What entrainment
When there’s an adjustment of the body clock in line with three environment (biological clocks reset)
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Biological rhythms
Light as an exogenous zeitgebers
Key in humans
Resets body’s main pacemaker SCN
Can have an indirect influence on key processes in body controlling hormone secretion and blood circulation
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Biological rhythms
Social cues as exogenous zeitgebers
At 6 weeks baby’s circadian rhythm begins
At 16 weeks most babies are entrained
Schedules imposed by parents eg mealtime and bed times help this
Research suggest that adapting to local times for eating and sleeping is effective way of entraining circadian rhythms and beating jet lag
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Biological rhythms
Research for exogenous zeitgebers
Campbell and Murphy (1998)
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Biological rhythms
What Campbell and Murphy (1998)
Monitored temperature of 15 Volunteers who slept in a lab
Shone a beam log light onto the back of their knees during the night at a series of intervals
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Biological rhythms
Findings of Campbell and Murphy (1998)
Circadian rhythms disrupted by up to three hours
Shows not necessary for Leighton to just enter the eyes to have a physiological effect of biological rhythms
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Circadian rhythms
2 strengths
Shift work
Drug treatment timing
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Circadian rhythms
Strength -shift work
What has knowledge of circadian rhythm given us better understanding of
Adverse consequences of their disruption (desynchronisation)
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Circadian rhythms
Strength -shift work
Impact of night shift workers
Experience a reduced concentration around 6 in the morning so mistakes or accidents are more likely to happen
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Circadian rhythms
Strength -shift work
What has research shown for shift work
Shows link between shift work and poor health (3x more like to develop heart disease
Perhaps due to stress of adjust sleep wake cycle an poor quality sleep during the day
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Circadian rhythms
Strength -shift work
Why is this a strength
Research shows sleep wake cycle may have economic implication of how to bets man are worker productivity
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Circadian rhythms
Strength -drug treatment timing
Why does timing matter in re;action to circadian rhythm
Circadian rhythms coordinate a number of the body’s basic processes eg heart rate digestion or hormone levels which affects the action of drugs on the body and how well they’re absorbed or distributed
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Circadian rhythms ao3
2 strengths
Shift work
Drug treatments
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Circadian rhythms ao3
Strength shift work
How has this come from research of circadian rhythms
Knowledge has given us better understanding of adverse consequences of disruption (desynchronisation)
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Circadian rhythms ao3
Strength shift work
Impact of shift work
Experience period of reduced concentration around 6 in the morning so ore likely for accidents and mistakes
Research also shows link between shift wrk and poor health (3 times more likely to develop heart disease)
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Circadian rhythms ao3
Strength shift work
Why is this a strength
Research may have economic implications to best manage worker productivity’s
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Circadian rhythms ao3
Strength drug treatment
What body’s basic processes dies circadian rhythms control and why is this important
Heart rate digestion and hormone levels
Affects action of drugs on the body and how well they’re absorbed or distributed
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Circadian rhythms ao3
Strength drug treatment
What have been developed in relation to circadian rhythms
drug treatment guidelines to do with the timing of drug dosing for medication eg anti cancer or epileptic drugs
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Circadian rhythms ao3
Strength drug treatment
Why is this a strength
More we understand about biological rhythms and drugs the more effectively we can treat pep;e
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Circadian rhythms ao3
What else can you use as supporting evidence
Research eg recourses or Campbell and Murphy
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Circadian rhythms ao3
2 weakness
Validity
Generalisability
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Circadian rhythms ao3
Validity
Why might it not be valid in how research is done
Research often carried out in artificial conditions resulting in artificial behaviour
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Circadian rhythms ao3
Validity
Investigating sleep
Monitoring sleep can also have an effect on the sleep patterns of the participant. The sleep patterns recorded could therefore be a by-product of being monitored (not the effect of the zeitgeber or pacemaker)
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Circadian rhythms ao3
Validity
Poor control example
Eg siffre still had access to artificial light in the cave which may affect his biological clock
288
Circadian rhythms ao3
Validity
Why is this a weakness
Less certain that IV affected the DV
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Circadian rhythms ao3
Validity
Why might the research not be generalisable
Animals used in research
Using case studies and small samples
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Circadian rhythms ao3
Validity
Why does using animals in research affect the generalisability
Clear physiological differences which may in turn make generalising to humans problematic
291
Circadian rhythms ao3
Validity
Why dos using case studies and Small samples make generalising hard
People involved may not be repressive of the wider population which limits the etxent to which meaningful generalisation can be mad e
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Ultradian rhythms
How long are they
Last less than 24 hours
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Ultradian rhythms
Example
Stages of sleep / sleep cycle
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Ultradian rhythms
How many stages of sleep is there and how long approximately is each cycle
5
90 minutes
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Ultradian rhythms
What is each sleep stage characterised by
A different level of brainwave activity
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Ultradian rhythms
Which method of investigating would be used for sleep stages
EEG
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Ultradian rhythms
What happens if we don’t get enough sleep
Sleep deprivation
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Ultradian rhythms
Consequences of sleep deprivation
Memory and attention problems
Increased risk of motor vehicle acccidnts
Weakening of immune system
Increase in BMI due to increased appetite
Increased risk for depression and substance abuse
Increased risk for diabetes and heart problems
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Ultradian rhythms
Case study for sleep deprivation
In 1965 student randy Gardner stayed awake for 11 days and 24 minutes
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Ultradian rhythms
What happened to Andy Gardner
After two days of zero sleep, Gardner’s eyes struggled to remain focussed, he showed some signs of ataxia - an inability to repeat simple tongue twisters - and he found it difficult to identify objects based purely on touch
By day three, he became moody and uncoordinated, and by day five he started hallucinating
From there he experienced trouble concentrating, forming short-term memories, and became paranoid, and irritable
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Ultradian rhythms
Why is it a bad idea to not sleep
While Gardner ended up recovering from the experiment with no discernible long-term physical and mental defects, the rest of us might not be so lucky
A lot of us are trying to sustain ourselves on less sleep than our bodies need, and over several years, the health effects can be very serious.
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Ultradian rhythms
How long is sleep stage 1 and what wave type
Varies between 5 and 15 min
Alpha waves (slower and rhythmic) THEN THETA WAVES (EVEN SLOWER)
303
Ultradian rhythms
Activity and effects of sleep stage 1
Light sleep easily woken heart rate slows and muscles relax
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Ultradian rhythms
How long is sleep stage 2 and wave type
Varies between 5and 15 mins
Alpha waves (slower and more rhythmic ) then theta waves (even slower)
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Ultradian rhythms
Activity and effects of stage sleep 2
Body continues to relax still easy to wake sleep spindles
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Ultradian rhythms
How long is stage 3 sleep and wave type
Between 5 and 15 mins
Delta waves ( slower with greater amplitude )
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Ultradian rhythms
Activity and effects fo sleep stage 3
Deep sleep difficult to wake and less sleep spindles
308
Ultradian rhythms
Length and wave type of stage sleep 4
40 mins
Delta waves (slower with greater amplitude )
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Ultradian rhythms
Activity and effects of sleeep stage 4
Deep sleep difficult to wake and less sleep spindles
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Ultradian rhythms
Length and wave type of sleep stage 5 (REM sleeo)
15 mins initially and lengthens throughout the night with less Tim spent in other stages
Mixed frequency brain waves
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Ultradian rhythms
Activity and effects of sleep stage 5 (REM sleep)
Body is paralysed yet brain activity speeds up significantly (resembles the awake brain). Fast, jerky activity of the eyes under eyelids. High probability of dreaming. Irregular breathing and heart rate
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Ultradian rhythms Ao3
Strength
Research evidence of dement and kleitman (1957)
313
Ultradian rhythms Ao3
What did dement and kleitman (1957( do
Monitored sleep patterns of 9 adults in a lab
314
Ultradian rhythms Ao3
How did kleitman and dement )1957) measure brainwave activity
An EEG
315
Ultradian rhythms Ao3
In dement and kleitman (1957) what did the researchers control for
Effects of caffeine and alcohol
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Ultradian rhythms Ao3
What did the results of dement and kleitman (1957 show
REM highly correlated with the experience of dreaming h
Brain activity varied according to how vivid dreams are
Participants woken up during dreaming reported very accurate results of their dream
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Ultradian rhythms Ao3
Outcome of the dement and kleitman (1957)
Suggests sleep follows typical pattern throughout the night
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Ultradian rhythms Ao3
Problem
Validity
319
Ultradian rhythms Ao3
Example of problem with validity
Dement and kleitman (1957)
320
Ultradian rhythms Ao3
Self repot problems
May lie or be inaccurate
321
Ultradian rhythms Ao3
Lacking ecological validity
Not normal to be woken up and report dreams
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Ultradian rhythms Ao3
Artificial setting
Electrodes and labs disrupt sleep so may have caused result
323
Ultradian rhythms Ao3
Problems with generalisability
Small sample size
Limits extent to which results can be generalised
324
Infradian rhythms
Length
Last more than 24 hours
325
Infradian rhythms
Example
Menstural cyclen
326
Infradian rhythms
What is the menstural cycle governed by
Monthly changes in hormone levels which regulate ovulation
327
Infradian rhythms
What system is linked to the menstual cycle
Endocrine system
328
Infradian rhythms
What does menstrual cycle refer to
Time betweeen first day of a woman’s period and to day before next period and takes approximately 28 days
329
Infradian rhythms
Mentrua; cycle process
Rising levels of oestrogen cause the ovary to develop an egg and release it (ovulation)
After ovultion progesterone helps the womb lining get thicker preparing for preganancy
If pregnancy doesn’t occur, egg is absorbed into body and womb lining comes away and leaves body
330
Infradian rhythms
What els impacts menstrual cycle
Exogenous factors such as light,odours, other women’s cycle
331
Infradian rhythms
What are pheromones
Chemicals produced by an individual which act outside the individuals body Changing others behaviour
332
Infradian rhythms
studies
McClintock and stern (1998)
Reinberg(1967)
333
Infradian rhythms
What was the McClintock and stern (1998) study
Odourless compounds containing pheromones were transferred by the donor wiping. Pad on their armpit and the other women wiping the same pad on her top lip
334
Infradian rhythms
Results of McClintock and stern (1998(
If donor was in latter half of their menstrual cycle the woman’s cycle shortened]
If donor was at beginning of cycle woman’s cycle was lengthened
335
Infradian rhythms
What does the McClintock and stern (1998) study show
How the menstrual cycle of s woman can be altered by communication via pheromones and can synchronise
336
Infradian rhythms
What was a the Reinberg (1967) study
Woman spent three months in a cave with only the light of a small lamp
337
Infradian rhythms
Results of the Reinberg (1967 study
Days lengthened to 24.9 hours and menstrual cycle shortened to 25.7 days
338
Infradian rhythms
What dos the Reinberg (1967 study show
Level of light in the cave could’ve affected the woman’s menstrual cycle
How Infradian rhythms can be influenced by external zeitgebers
339
Infradian rhythms a03
2 strengths
Menstrual synchronicity
Evolutionary basis of the menstrual cycle
340
Infradian rhythms a03
What can explain menstural synchronicity
Effects of pheromones
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Infradian rhythms a03
Example of menstrual synchronicity
Groups of women lining together eg nuns have synchronised menstrual cycles
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Infradian rhythms a03
Sturdy to back menstrual synchronicity
McClintock and stern (1998)
343
Infradian rhythms a03
2 weaknesses
Methodological issues
Animal studies
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Infradian rhythms a03
Methodological issues in factors
Many other factors eg stress diet excercise can affect menstrual cycle so may act as confounding variables
345
Infradian rhythms a03
Methodological issues of sample
Often research has small samples
346
Infradian rhythms a03
Methodological issues other studies
Other studies have failed to find evidence of synchronicity
347
Infradian rhythms a03
Animal studies
Much knowledge of effects of pheromones on behaviour is derived from animal studies
348
Infradian rhythms a03
What does human behaviour remain as a result of animal studies
Evidence for effects of uman behaviour remains speculative and inconclusive
349
Infradian rhythms a03
What is unclear
How close women have to live together and for what period of time for menstrual synchronicity
350
Infradian rhythms a03
Why are animal studies a weakness
Big difference between animals and humans so hard to generalise
