Biopsychology Flashcards
What is the nervous system?
A specialised network of cells, it is the primary communication system which uses electrical and chemical signals.
What is the nervous system divided into?
Central nervous system (CNS) and the peripheral nervous system (PNS).
What is the CNS?
Brain and spinal cord.
What is the PNS divided into?
Somatic nervous system (SNS) and automatic nervous system (ANS).
What is the ANS divided into?
Sympathetic and parasympathetic.
What is the somatic nervous system?
System that controls conscious/voluntary activities. Made up of afferent and efferent neurons.
What is an afferent neuron?
Sensory neurons carrying sensory information.
What is an efferent neuron?
Motor neurons carrying instructions to effectors.
What is the PNS made from?
Nerves.
What is the autonomic nervous system?
Controls internal organs and glands (automatic responses).
What is the parasympathetic branch of the ANS?
Returns the body to routine, day to day activities (rest and digest).
What is the sympathetic branch of the ANS?
Stress related activities (fight or flight).
What do the parasympathetic and sympathetic branches do when operating together?
Maintain homeostasis.
What is the endocrine system?
Regulates all biological processes in the body, made up of glands and hormones, working alongside the nervous system.
Explain the process of the fight or flight response.
Stressor is perceived.
Signal sent to hypothalamus which activates the sympathetic branch of ANS.
Adrenal medulla (part of adrenal gland) releases adrenaline into the bloodstream and releases noradrenaline.
Pupils dilate, increased breathing and heart rate, muscle tension, glucose released.
After stressor is gone, parasympathetic branch of ANS dampens response and returns the body to testing state.
Name the types of neurons.
Sensory - carry messages from PNS to CNS, long dendrites, small axons.
Relay - connect sensory neurones to motor neurones, short dendrites, long axons.
Motor - connect CNS to effectors, short dendrites, long axons.
Explain the process of firing a neuron.
When resting, the inside of the neuron is negatively charged compared to the outside.
When activated, the neuron becomes positively charged for a second.
This causes an action potential to occur.
And this created an electrical impulse.
Explain chemical transmission between neurons.
Signals within a neurone are transmitted electrically, but between neurones is chemically. When the electrical impulse reaches the end of the neuron (presynaptic terminal), the release of a neurotransmitter is triggered from tiny sacs called presynaptic vesicles.
Bind to receptors or post synaptic neurone
Produce inhibitory or excitatory effects.
What are neurotransmitters?
Chemicals that diffuse across the synapse.
Where do axons take the electrical signals?
Towards the synapse.
Where do dendrites take the electrical signal?
Away from the synapse.
What is excitation?
When a neurotransmitter increase the positive charge of a postsynaptic neuron.
This makes an increased likelihood that the post synaptic neuron will pass the electrical impulse.
What is inhibition?
When a neurotransmitter increases the negative charge of a postsynaptic neuron.
This makes a decreased likelihood that the post synaptic neuron will pass on the electrical impulse.
What is summation?
Whether the post synaptic neuron fires or not. The excitory and inhibitory influences are summed up.
Ways of studying the brain
Post mortem - studying the brain after death, determine whether observed behaviour related to structural abnormalities.
Electroencephalogram (EEG) - measuring electrical activity in the brain, measuring wave patterns to help diagnose conditions.
Event-related potential (ERP) - isolating electrophysiological response of the brain to a specific sensory, motor or cognitive event, statistically analysing EEG data.
Functional magnetic resonance imaging (fMRI) - measure brain activity while a person is carrying out a task, detects radio waves from changing magnetic fields, detect which areas are rich in oxygen and therefore active.
Strengths of post mortem
Allows more detailed examination of anatomical and neurochemical aspects (not possible with non-invasive scanning techniques).
Develop understanding of schizophrenia - Harrison (2000) due to post mortem examinations, researchers have been able to identify structural differences and evidence for neurotransmitters which are associated with the disorder
Limitations of post mortem
Can lead to inaccurate findings - length of time between death and post mortem, drug treatments and age are all confounding influences. Findings might lack internal validity making it difficult to draw conclusions.
Retrospective - unable to follow up anything that arises from the examination, so conclusions drawn are often limited.
Strengths of EEG
High temporal resolution - takes a reading from an active brain making it more accurate.
Useful for clinical diagnosis - epileptic seizures can be picked up on an EEG so it can help to diagnose brain abnormalities.
Limitations of EEG
Can only detect activity in superficial regions of the brain, not deeper areas therefore information gained from EEGs is limited.
Poor spatial resolution (smallest feature that a scanner can detect) - cannot provide information on deeper regions of the brain so information is limited compared to fMRI.
Strengths of ERPs
Good temporal resolution - takes readings every millisecond so there is an accurate measurement of activity.
Non-invasive - allows more patients to have an ERP which improves understanding of conditions.
Limitations of ERPs
Poor spatial resolution - higher spatial resolution allows psychologists to discriminate between different brain regions with accuracy, unable to look at areas deeper in the brain.
Can only be interpreted by trained professionals, expensive, may minimise use of ERPs
Strengths of fMRI
Non-invasive, no risk of physical harm
High spatial resolution (the smallest feature that a scanner can detect) - greater accuracy
objective - volume of blood can be measured showing fact rather than opinion.
Limitations of fMRI
Poor temporal resolution (how quick it can detect changes) - unable to predict with a high degree of accuracy.
Small sample size in research - due to limited funding, difficult to generalise/low population validity.
Localisation of function
Functions such as movement, speech and memory are performed in distinct regions of the brain.
The opposite view is that the brain acts holistically.