Biopsychology Flashcards
(106 cards)
1
Q
How is the nervous system divided?
A
It has 2 parts: Central NS and Peripheral NS.
2
Q
Define Central NS and name its different parts.
A
It’s body’s control unit.
1. Spinal cord 2. Brain stem 3. Brain
3
Q
Explain what is the spinal cord.
A
Column of nerves between the brain and peripheral NS. Responsible for reflex actions.
4
Q
Explain what is the brain stem.
A
Connects the brain to the spinal cord.
5
Q
Explain what is the brain.
A
Receives information from sensory receptors and sends messages to muscles and glands.
It’s divided into 3 major parts:
1. hindbrain (lower part) 2. midbrain 3. forebrain
6
Q
Define Peripheral NS and name its different parts.
A
It’s the body’s link to the outside world. It transmits information to and from the CNS.
1. Autonomic NS 2. Somatic NS.
7
Q
Explain what is the Autonomic NS.
A
It regulates involuntary bodily processes; operates automatically, unconsciously.
Divided in sympathetic and parasympathetic NS.
8
Q
Define sympathetic and parasympathetic NS.
A
Sympathetic NS: prepares body for action and stress “fight or flight”.
Parasympathetic NS: calms body and helps it conserve energy.
9
Q
Explain what is the Somatic NS.
A
Carries sensory information from sensory organs to the CNS and relays motor (movement) commands to muscles, consciously.
10
Q
What is the nervous system?
A
Primary internal communication system, a specialised network of cells in our body.
11
Q
Which are the 2 parts of the forebrain?
A
Diencephalon and the cerebral hemispheres.
12
Q
What does the diencephalon contain?
A
Thalamus and Hypothalamus.
13
Q
Describe the function of the hypothalamus.
A
Controls basic functions such as hunger, thirst, sexual behaviour; also controls the pituitary gland
14
Q
Define Sensory neurones.
A
They convey information about sensory stimuli: vision, touch, etc. towards the brain.
15
Q
Define Motor neurones.
A
They convey instructions for physical operations: e.g. muscle movement, digestion, etc.
16
Q
Define Relay neurons.
A
They connect different parts of the CNS.
17
Q
What are neurotransmitters?
A
They send information from one neuron to another. These diffuse across the synaptic gap and bind to specialised receptor sites on the post-synaptic neuron.
18
Q
Explain what is the synaptic gap.
A
The gap between the pre and post-synaptic neurons.
19
Q
What is the structure of a typical neuron?
Learn diagram + synapse
A
Dendrites → (It has a nucleus) → Cell body → Axon → Myelin Sheath ( Schwann’s cells) → Node of Ranvier → Axon Terminals.
20
Q
Explain the excitatory action of NTT at synapses.
A
Makes a nerve impulse MORE likely to be triggered.
21
Q
Explain the inhibitory action of NTT at synapses.
A
Makes a nerve impulse LESS likely to be triggered.
22
Q
What is the Localisation of function in the brain?
A
Theory that different areas of the brain are responsible for different behaviours, processes or activities. It contrasts with the holistic theory of the brain.
If a certain area of the brain becomes damaged, the function associated with that area will also be affected.
23
Q
Define brain localisation.
A
Link between brain structures and their functions.
24
Q
How many hemispheres is the brain divided into?
A
2, left and right.
25
What is the motor area?
A region of the frontal lobe involved in regulating movement.
26
What is the visual area?
A part of the occipital lobe that receives and processes visual information.
27
What is the auditory area?
It is located in the temporal lobe and concerned with the analysis of speech-based information.
28
Evaluate localisation of function.
| Strength
+ Evidence to support: Broca’s aphasia is an impaired ability to produce language; in most cases, this is caused by brain damage in Broca’s area.
Wernicke’s aphasia is an impairment of language perception, demonstrating the important role played by this brain region in the comprehension of language.
29
Evaluate localisation of function.
| 2 weaknesses
- Lashley proposed the equipotentiality theory, which suggests that the basic motor and sensory functions are localised, but that higher mental functions are not. He claimed that intact areas of the cortex could take over responsibility for specific cognitive functions following brain injury.
- Dronkers et al. (2007) conducted an MRI scan on Tan’s brain, to try to confirm Broca’s findings. Although there was a lesion found in Broca’s area, they also found evidence to suggest other areas may have contributed to the failure in speech production. These results suggest that the Broca’s area may not be the only region responsible for speech production and the deficits found in patients with Broca’s aphasia could be the result of damage to other neighbouring regions.
30
What is hemispheric lateralisation?
It suggests that the brain’s 2 hemispheres are not exactly alike and have different specialisms.
31
Explain the Split Brain Research. (Sperry, 1968)
| Aim and procedure.
Aim: To assess the abilities of separated brain hemispheres.
Procedure: Participants sat in front of a board with a horizontal rows of lights and were asked to stare at the middle point. The lights then flashed across their right and left visual field. Participants reported lights had only flashed up on the right side of the board
32
Explain the Split Brain Research. (Sperry, 1968)
| Findings.
Findings: When their right eye was covered and the lights were flashed to the left side of their visual field they claimed not to have seen any lights at all. However, when asked to point at which lights had lit up they could do.
33
What happened when a picture of an object was shown to a patient's right visual field?
Patient could easily describe what was seen but couldn't pick it out or draw it.
34
What happened when a picture of an object was shown to a patient's left visual field?
The patient could not describe what was seen, and typically reported there was nothing there.
35
EVALUATION OF SPLIT BRAIN RESEARCH
The analyser and the synthesiser
Research suggests that the left hemisphere is the analyser whilst the right hemisphere is the synthesiser - a key contribution to our understanding of brain processes.
36
EVALUATION OF SPLIT BRAIN RESEARCH
Methodological strengths
The experiments involving split brain patient's made use of highly specialised and standardised procedures.
37
EVALUATION OF SPLIT BRAIN RESEARCH
Theoretical basis
Sperry's work prompted a debate about the degree of communication between the two hemispheres in everyday functioning.
38
What is plasticity?
Brains tendency to change and adapt (functionally and physically) as a result of experience and new learning.
39
Define synaptic pruning.
During infancy, the brain experiences a rapid growth in the number of synaptic connections. As we age, rarely used connections are deleted and frequently used connections are strengthened.
40
What is functional recovery?
Idea that following physical injury or other forms of trauma, unaffected areas of the brain can adapt to compensate for those that are damaged.
41
What is Broca's area?
An area of the frontal lobe in the left hemisphere (of most people) responsible for speech production.
42
What is Wernicke's area?
An area of the temporal lobe (encircling the auditory cortex) in the left hemisphere (in most people) responsible for language comprehension.
43
What case study supports localisation of function?
Phineas Gage
44
Briefly describe the case study of Phineas Gage.
Whilst working on a rail road an accident with explosive led to a metre-length pole going through Gage's left cheek, passing behind his left eye and exiting his skull taking a portion of his brain with it -most of his left frontal lobe. Gage survived and the effect he suffered was a drastic personality change from a calm and reserved man to someone who was quick-tempered and rude.
45
What is Functional magnetic resonance imaging (fMRI)?
A brain scanner which measures increased blood flow to brain sites when individuals are asked to perform cognitive/physical tasks. Increased blood flow indicates increased demand for oxygen in that area.
This produces 3D images showing which parts of the brain are involved in a particular mental process, important for our understanding of localisation of function.
46
What is a strength of fMRI?
• Non-invasive – No insertion of instruments unlike PET and no exposure to radiation.
47
What are 2 limitations of fMRI?
* fMRI only measures blood flow – it cannot home in on the activity of individual neurons so it’s hard to tell exactly what brain activity is being represented on the screen.
* Expensive – Other neuroimaging techniques such as EEG may be cheaper and it can only capture a clear image if the person stays still.
48
What is Electroencephalogram (EEGs)?
Measures electrical activity in the brain using electrodes attached to the scalp, and measures
how electrical activity in the brain varies over time/in different states. EEG readings can detect epilepsy and Alzheimer’s.
49
What are 3 strengths of EEGs?
* Records brain activity over time.
* Non-invasive.
* Cheaper than fMRI thus making them more available.
50
What are 3 limitations of EEGs?
* EEGs only monitor electrical activity in outer layers of the brain, so, cannot reveal electrical activity in deeper brain sites.
* Not highly accurate – electrical activity detected in several regions of the brains simultaneously.
* Uncomfortable – Hard for the patients as electrodes are attached to their head.
51
What are Event-related potentials (ERPs)?
Very small voltage changes in the brain triggered by specific events or stimuli which are measured using an EEG. Measures small voltages of electrical activity when a stimulus is presented.
52
What are 3 strengths of ERPs?
* ERPS provide a continuous measure of neural activity in response to a stimulus.
* Derived from EEG – Excellent temporal resolution compared to fMRI.
* Non-invasive.
53
What are 3 limitations of ERPs?
* ERPS only monitor electrical activity in outer layers of the brain, therefore, cannot reveal electrical activity in deeper brain sites.
* Extraneous stimuli must be eliminated in order to collect pure data, the participant may react to background noise or a difference in temperature.
* Lack of standardisation in methodology between studies.
54
What are Post-mortem examinations?
Brains from dead individuals who displayed cognitive abnormalities whilst alive can be dissected to check for structural abnormalities/damage.
55
What are 3 strengths of Post-mortem examinations?
* Allow for detailed examinations and measurement of deep brain structures.
* Brain tissue can be examined in detail.
* Highly applicable.
56
What are 2 limitations of Post-mortem examinations?
* The issue of causation – The deficit a patient displays during their lifetime may not be linked to the deficits found in the brain, they may be the result of another illness.
* Ethical issues – Deceased people are not able to provide informed consent such as HM because of his lack of short term abilities.
57
Define hormones.
Chemical messengers secreted from the glands in body which cause changes in our body/behaviour.
58
What is the network of gland called?
The endocrine system.
59
What is the main hormone of the Thyroid (EG) and its effects?
Thyroxine - Regulates metabolic rate and protein synthesis.
60
What is the main hormone of the Adrenal
| medulla (EG) and its effects?
Adrenaline and noradrenaline - Fight or flight response: increased heart rate, blood pressure, release of glucose and fats (for energy)
61
What is the main hormone of the Adrenal
| cortex (EG) and its effects?
Corticosteroids - Release of glucose and fats for energy; suppression of the immune system.
62
What is the main hormone of the Testes (EG) and its effects?
Testosterone - Male sexual characteristics, muscle mass.
63
What is the main hormone of the Ovaries (EG) and its effects?
Oestrogen - Female sexual characteristics, menstruation, pregnancy.
64
What is the main hormone of the Pineal (EG) and its effects?
Melatonin - Sleep-wake cycle.
65
Define pituitary gland.
Master gland and controls release of hormones from many of the glands. Its divided into the anterior and posterior
66
Describe the anterior pituitary (Hormones released, name it).
ACTH: Stimulates release of corticosteroids during flight-flight response.
67
Describe the posterior pituitary (Hormones released, name it).
Oxytocin: Uterine contractions during childbirth.
68
What is the fight or flight response?
Sequence of activity within the body that is triggered when the body prepares itself for defending or attacking (fight) or running away to safety (flight).
69
Define stress.
Stress is experienced when a person’s perceived environmental, social and/or physical demands exceed their perceived ability to cope.
70
What are the 2 major systems involved in the fight or flight response?
The Sympathomedullary Pathway – deals with acute (short-term, immediate) stressors.
The Pituitary-Adrenal System – deals with chronic (long-term, on-going) stressors.
71
What does the adrenal medulla do?
It a secretes the hormone adrenaline.
72
Explain what adrenaline is.
It gets the body ready for a fight or flight response. Physiological reaction includes increased heart rate.
73
Explain the Hypothalamic Pituitary-Adrenal (HPA)
| System.
- The stressor activates the Hypothalamic Pituitary Axis.
- The hypothalamus stimulates the pituitary gland.
- The pituitary gland secretes adrenocorticotropic hormone (ACTH).
- ACTH stimulates the adrenal glands to produce the hormone corticosteroid.
- The adrenal cortex releases stress hormones
called cortisol.
74
What are biological rhythms?
Distinct patterns of changes in body activity that conform to cyclical time periods. They're influenced by internal body clocks as well as external changes in the environment.
75
What are endogenous pacemakers (EP)?
Internal biological clocks/mechanisms.
76
What are exogenous zeitgebers (EZ)?
Changes in the environment/external cues.
77
Give 2 examples of biological rhythms.
- The sleep/wake cycle.
| - Menstrual cycle.
78
What are the 3 types of biological rhythms? How do they differ?
1. Circadian rhythm
2. Infradian rhythm
3. Ultradian rhythm
They differ in terms of the time they last.
79
Explain what circadian rhythms are and give 2 examples.
They last around 24 hours.
- sleep/wake cycle
- core body temperature
80
Explain the sleep/wake cycle.
- An important EZ on the sleep/cycle is light.
- This is also governed by an internal EP, called suprachiasmatic nucleus (SCN).
- The SCN lies above the optic chiasm which provides information from the eye regarding the level of brightness to the SCN which uses this information to coordinate the activity of the entire circadian rhythm system.
81
Explain the core body temperature circadian rhythm.
This fluctuates over a 24hour period. It peaks mid-afternoon at about 37.1 C and throughs in the early hours at about 36.7 C.
82
Explain research on the sleep/wake cycle.
| Siffre (1962)
He conducted a case study using himself as the participant. He spent 6 months in a cave with no natural light or cues as to the day or time. When he woke he used artificial light.
His internal body clock was allowed to 'free run' and settled into a sleep/wake cycle of 25-30 hours. He lost track of days he'd been in the cave. He believed it to be one month less than he actually stayed in. He stayed for 170 days.
This suggests that natural light sources in the environment are vital for keeping the individual to a 24 hour cycle.
83
Explain research on the sleep/wake cycle.
| Aschoff and Wever (1976)
They studied a number of volunteers that agreed to spend time cut off from the outside world in a disused WWII bunker in Munich. After a month or so cut off from external cues they adopted a 25h daily cycle. This again shows the importance of natural light for this circadian rhythm.
84
Give 2 strengths of research on circadian rhythms.
- It provides an understanding of the adverse consequences that occur when they are disrupted (desynchronisation) E.g. Night workers
- It has been used to improve medical treatments. E.g. aspirin.
85
What is 1 limitation of circadian rhythms?
Generalisation is difficult, small samples are used. E.g. Siffre was just one person.
86
Define Infradian rhythms. Give 2 exapmles.
These take longer than 24 hours to complete.
| - Menstrual cycle and seasonal affective disorder (SAD)
87
Explain the menstrual cycle.
It lasts about 1 month. It's governed by a monthly change of hormone levels that regulate ovulation.
During each cycle, rising levels of the hormone oestrogen causes ovulation, then the hormone progesterone helps the womb lining to grow thicker, readying the womb for pregnancy.
88
What is the endogenous and external control on synchronising the menstrual cycle?
```
Endogenous control: the cycle is under the internal control of hormones. These cause a number of physiological changes within the body.
External control (zeitgebers): the cycle can be influenced by external factors, i.e. living with other women. Most likely mechanism for this is by the action of pheromones.
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89
Define pheromones.
Chemical substance similar to hormones but which carry messages between individuals of the same species.
90
Explain research on the menstrual cycle by Kathleen Stern and Martha McClintock (1998).
They demonstrated how menstrual cycles may synchronise as a result of the influence of pheromones.
They studied 29 women with a history of irregular periods. Samples of pheromones were collected from 9 of the women at different stages of their menstrual cycle, via a pad and placed in their armpit. The pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants. On day 1, pads from the start of the menstrual cycle were applied to all women, on day 2 a pad from 2nd day of cycle...
Findings: On 68% of occasions, women experiences changes to their cycle which brought them closer to the cycle of the 'odour donor'.
Conclusion: This study shows that the menstrual cycle of a woman can be altered by communication via pheromones.
91
Evaluate the menstrual cycle synchrony.
| 1 strength
- It may be explained natural selection. It has some evolutionary advantages. Bentley (2000) believed that synchronisation between women living in close proximity would ensure that women would conceive and give birth at similar times. This would be beneficial since they could share breastfeeding.
This suggests that synchronisation may be an adaptive strategy.
92
Evaluate the menstrual cycle synchrony.
| 1 limitation
- Their methodological shortcomings. Many factors affect the menstrual cycle. e.g. stress, diet...
93
Explain what is seasonal affective disorder (SAD).
Depressive disorder which has a seasonal pattern onset, the main symptoms which are similar to depression is persistent low mood, general lack of activity and interest in life. These are triggered in the winter months.
Psychologists have hypothesised that the hormone melatonin is implicated in the cause of SAD. During the night , the pineal gland secrets melatonin until down when there is an increase in light.
94
What is one of the most effective treatments for SAD?
Light therapy, a box which simulates very strong light to reset the body's internal clock. It helps about 80% of people.
However, this can produce headaches and eye strain.
95
Define what ultradian rhythms are.
They last less than 24 hours and occur more than once a day
96
What did psychologists find about the stages of the sleep cycle? Name them.
There are 5 stages.
- Stages 1 and 2: a person can easily be woken up. In 1 Alpha waves, then in 2 changes in pattern (sleep spindles) happen and K-complexes.
- Stages 3 and 4: deep sleep, delta waves.
- Stage 5 REM sleep: body is paralysed + brain activity resembles that of someone awake. Theta waves.
97
Evaluation of research into ultradian rhythms.
| 2 Strengths
- It has improved understanding of age-related changes in sleep.
Sleep scientists have observed that SWS reduces with age. According to Eve and Cauter et al. (2000), the sleep deficit may explain various issues in old age, such as alertness. (UR have practical value)
- Lab environment in most studies.
98
Evaluation of research into ultradian rhythms.
| Limitation
- Personal differences.
Tucker et al (2007) found large differences between participants in terms of the duration of each slope stage, particularly stages 3 and 4. They suggest that these differences are biologically determined.
99
Is the circadian rhythm determined by internal mechanisms or external factors?
Research suggests that it's a combination of EPs and EZs, these interact with each other to control and fine-tune biological rhythms.
100
Describe the main EP that affects the sleep/wake cycle: The suprachiasmatic nucleus (SCN).
Tiny bundle of nerve cells located in the hypothalamus in each hemisphere of the brain.
101
Give supporting evidence for the importance of EPs.
| Decoursey et al.
The SCN connections were destroyed in the brains of 30 chipmunks that were then returned to their natural habitat and observed for 80 days. The sleep/wake cycle of the chipmunks disappeared.
102
Give supporting evidence for the importance of EPs.
| Ralph et al.
Bred 'mutant' hamsters with a 20 hour sleep/wake cycle. When SCN cells from the foetal tissue of mutant hamsters were transplanted into the brains of normal hamsters, the cycles of the second group defaulted to 20 hours. This suggests the SCN is pivotal in regulating the internal body clock.
103
Evaluation of research into SCN.
| Limitation
It may obscure other body clocks.
Damiola et al (2000) demonstrated how changing feeding patterns in mice could alter the circadian rhythms of cells in the liver by up to 12h, whilst leaving the rhythms of the SCN unaffected. This suggests other complex influences on the sleep/wake cycle.
104
How do social cues affect the sleep/wake cycle?
In infants the s/w cycle is very random. At about 6 weeks of age, the circadian rhythms begin and, by 16 weeks, it's entrained by the schedules and routines imposed by parents.
105
Evaluation of EZs.
- Generalising from animal studies.
- Ethics in animal studies.
- Animal studies of the sleep/wake cycle: existence of the pineal gland in chipmunks and hamsters means that generalising can e made to the human brain.
- Animals are exposed t considerable harm. e.g. DeCoursey
106
Evaluation of EZs.
- They don' have same effects in all environments.
- Evidence to contradict.
- Summer/winter in different places, how it affects sleep patterns.
- Miles et all (1977) recount the study of a young man, bling from birth, who had an abnormal circadian rhythm of 24.9h. Despite exposure to social clues such as regular mealtimes, his sleep/wake cycle could no be adjusted.
