Biopsych

Question 1

The PNS is subdivided into 2 more systems.
What are these 2 systems?

Answer 1

The PNS is further subdivided into the autonomic nervous system (which controls involuntary, vital functions of the body, such as maintaining heart rates and breathing rates) and the somatic nervous system (which receives information from sensory receptors belonging to each of the 5 senses, and results in effectors being stimulated by the CNS, via motor neurones).

Question 2

*The autonomic nervous system is also subdivided into 2 further systems
What are these systems

Answer 2

The autonomic nervous system is also subdivided into the sympathetic and parasympathetic branches. These branches work as part of an antagonistic pair during the ‘rest and digest’ response, and are crucial in producing the physiological arousal needed to maintain the fight or flight response.

Question 3

Name some of the effects of the parasympathetic system.

Answer 3

Decreases heart rate
Decreases breathing rate
Increases digestion
Causes vasodilation
Causes pupil constriction
release of acetylcholine

Question 4

Name some of the effects of the sympathetic system.

Answer 4

The sympathetic nervous system increases Increases heart rates
Increases breathing rate
Causes vasoconstriction
Causes pupil dilation
Slows down processes like digestion

Question 5

What is commonly known as the ‘master gland’ because it controls the release of hormones from all other glands in the body?

Answer 5

The pituitary gland

Question 6

Describe the fight or flight response

Answer 6

1.The body senses and becomes aware of a stressor in the environment
2.Through sensory receptors and sensory neurones in the PNS, this information is sent to the hypothalamus in the brain which coordinates a response and triggers
increased levels of activity in the sympathetic branch of the ANS.
3.Adrenaline is released from the adrenal medulla in the adrenal glands, and is transported to target effectors, via the blood and through the action of the endocrine system
4. This results in the rectum contracting, saliva production being inhibited and a greater breathing rate
5. Once the stressor is no longer a threat, as part of an antagonistic pairing, the hypothalamus triggers less activity in the sympathetic branch and more activity in the parasympathetic branch of the ANS

Question 7

Describe the somatic nervous system

Answer 7

Controls skeletal muscles for movement
Voluntary system (under conscious control)

Question 8

Describe the autonomic nervous system

Answer 8

Controls internal organs or glands
Involuntary system

Question 9

What structures make up the reflex arc?

Answer 9

Relay neurone, sensory neurone, motor neurone

Question 10

What does the localisation theory suggest?

Answer 10

• Localisation theory suggests that certain areas of the brain are responsible for certain processes,
  behaviours and activities.

Question 11

Describe the motor area

Answer 11

The motor area = Separated from the auditory area by the central suclus and found in the frontal lobe, this area is involved in regulating and coordinating movements. Lesions or damage in the motor area result in an inability to control voluntary fine motor movements.

Question 12

Describe the auditory area

Answer 12

• The auditory area = An area of the temporal lobe, located on the superior temporal gyrus, which is responsible for processing auditory information and speech. Lesions or damage in the auditory area causes hearing loss, whereas damage to specific parts of the auditory area (Wernicke’s area) results in Wernicke’s aphasia

Question 13

Describe the visual area

Answer 13

The visual area = An area in the occipital lobe which is responsible for processing visual information

Question 14

Describe the somatosensory area

Answer 14

The somatosensory area = An area of the parietal lobe which processes information associated with the senses e.g. touch, heat, pressure etc. “These regions receive neuronal input from specific nuclei of the thalamus that correspond with the handling of sensation along the lines of touch, pain, temperature and limb position”. Lesions in this area result in a loss of ability to denote sensitivity to particular bodily areas.

Question 15

Describe the Broca’s area

Answer 15

Broca’s Area = Responsible for speech production and located in the frontal lobe, usually in the left hemisphere. Lesions or damage results in Broca’s aphasia, characterised by difficulty forming complete sentences and understanding sentences, as well as failing to understand the order of words in a sentence and who they are directed towards i.e. I, you, we, him, me etc.

Question 16

Describe the Wernicke’s area

Answer 16

Wernicke’s Area = Responsible for speech comprehension and located in the temporal lobe (the left temporal lobe for most people). Lesions or damage (e.g. through stroke and trauma) results in Wernicke’s aphasia, which is characterised by the use of nonsensical words (called syllogisms), no awareness of using incorrect words, but no issues with pronounciation and intonation.

Question 17

What is the left hemisphere of the brain associated with?

Answer 17

Overall, the left hemisphere of the brain is associated with language production and comprehension. Therefore, language is an example of a cognitive ability which is both localised and lateralised (to the left hemisphere).

Question 18

What is Plasticity?

Answer 18

• Plasticity = Refers to the brain’s ability to physically and functionally adapt and change in response trauma, new experiences and learning. Neuroplasticity was demonstrated by Maguire et al (2006). The idea of plasticity opposes the previous theory that there is a ‘critical window’ for synaptic and neuronal connection formation, which occurred during the first 3 years of life, after which no new neuronal connections would be formed (Gopnik et al).

Question 19

How do we control the strength and number of neuronal connections in our brains?

Answer 19

We control the strength and number of neuronal connections in our brains through the process of synaptic pruning i.e. 4“the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions”.

Question 20

Describe Maguire et al’s study

Answer 20

After studying the brains of London taxi drivers, Maguire et al. found a larger grey matter volume in the mid-posterior hippocampi ( and a lower volume in the anterior hippocampi) of their brains, alongside a positive correlation between an increasing grey matter volume and the longer the individuals had been taxi drivers. The researchers concluded that “a complex spatial representation, which facilitates expert navigation and is associated with greater posterior hippocampal gray matter volume, might come at a cost to new spatial memories and gray matter volume in the anterior hippocampus”. This may be because the hippocampus is associated with spatial awareness; an ability which taxi drivers must have when they complete The Knowledge test.

Question 21

Give two strengths for the localisation theory

Answer 21

+ Supporting evidence for localisation of brain function = Tulving et al demonstrated, using PET scans, that semantic memories were recalled from the left prefrontal cortex, whilst episodic memories were recalled from the right prefrontal cortex. This shows that different areas of the brain are responsible for different functions, as predicted by localisation theory. This idea was further supported by Petersen et al , who found that Wernicke’s area activation is required for listening tasks, whereas Broca’s area is required for reading tasks. This confirms the idea that Wernicke’s area is involved in speech comprehension, whilst Broca’s area is responsible for speech production.
+ Supporting Case Studies = Phineas Gage was injured by a blasting rod which intersected the left side of his face, tearing through his prefrontal cortex. The damage involved both left and right prefrontal cortices in a pattern that, as confirmed by Gage’s modern counterparts, causes a defect in rational decision making and the processing of emotion”. Such case studies, particularly those showing marked differences after trauma, demonstrate the idea that some areas of the brain are responsible for specific functions. However, with the use of case studies, the subjectivity of the conclusions drawn and the unusual sample, alongside a lack of control over confounding and extraneous variables, must also be considered.

Question 22

Give a weakness of the localisation theory

Answer 22

— Contradictory Theory = The opposite to localisation theory would be a holistic view of brain function, suggesting that each function requires several brain areas to be activated and that these functions are not restricted to these areas. For example, after removing 20-50% of the cortices belonging to rats, found that no specific brain area or lesion was associated with learning how to traverse through a maze. This suggests that intelligence, or even learning, is too complex and advanced a cognitive ability to be restricted to certain areas of the brain. Therefore, this suggests that localisation theory may provide a better explanation for ‘simple’, rather than complex, brain functions. (Lashley’s research)

Question 23

Define plasticity

Answer 23

Plasticity = Refers to the brain’s ability to physically and functionally adapt and change in response trauma, new experiences and learning. Neuroplasticity was demonstrated by Maguire et al (2006).

Question 24

How do we control the strength and number of neuronal connections in our brains?

Answer 24

We control the strength and number of neuronal connections in our brains through the process of synaptic pruning i.e. “the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions”

Question 25

Summarise the Maguire et al study.

Answer 25

After studying the brains of London taxi drivers, Maguire et al. found a larger grey matter volume in the mid-posterior hippocampi ( and a lower volume in the anterior hippocampi) of their brains, alongside a positive correlation between an increasing grey matter volume and the longer the individuals had been taxi drivers. The researchers concluded that 5“a complex spatial representation, which facilitates expert navigation and is associated with greater posterior hippocampal gray matter volume, might come at a cost to new spatial memories and gray matter volume in the anterior hippocampus”. This may be because the hippocampus is associated with spatial awareness; an ability which taxi drivers must have when they complete The Knowledge test.

Question 26

What is functional recovery?

Answer 26

Functional recovery is the ability of the brain to transfer the functions of areas damaged through trauma, to other healthy parts of the brain, thus allowing for normal functioning to carry on.

Question 27

How is functional recovery carried out?

Answer 27

This is enabled through the law of equipotentiality (where secondary neural circuits surrounding the damaged area become activated), axonal sprouting (formation of new synapses and strengthening of axonal connections between damaged and healthy areas), reformation of blood vessels (as part of the haemodynamic response, where activated areas experience a higher blood deoxygenation level) and recruiting homologous areas on the opposite side of the brain. Showing that function is not always lateralised to specific hemispheres

Question 28

Give an example of functional recovery.

Answer 28

A second example of functional recovery would be the case of Jodi Miller, whose entire right hemisphere was removed in an attempt to control her epileptic seizures. However, through the mechanisms of neuroplasticity, she was still able to control the right side of her body through the use of cerebral spinal fluid. This demonstrates positive plasticity, because the neuroplasticity results in desirable or positive consequences.

Question 29

Give two strengths of the Plasticity and Functional Recovery of the Brain

Answer 29

+ Evidence supporting the positive and negative effects of neuroplasticity = Much research has been carried out into the phenomenon of plasticity. Positive plasticity has been demonstrated by the case study of Jodi Miller, who has shown the power of recruiting homologous areas on the opposite side of the brain, axonal sprouting and the reformation of blood vessels. Therefore, there is evidence supporting not only the existence of, but also the uses of plasticity.

+ Neuroplasticity occurs in animals too = Hubel and Weisel (1970) sutured the right eye of kittens, who are blind from birth, for a period of 6 months, opening the eyes and several points and monitoring brain activity in the visual cortex. The researchers found that, although the right eye was closed, there was still activity in the left visual cortex, corresponding to the development of occular dominance columns. This was demonstrated by how “during the period of high susceptibility in the 7 fourth and fifth weeks eye closure for as little as 3-4 days leads to a sharp decline in the number of cells that can be driven from both eyes”. This therefore supports the idea that areas of the brain receiving no input can take over the function of highly stimulated areas, despite originally having different functions.

Question 30

Give a weakness of the Plasticity and Functional Recovery of the Brain

Answer 30

— There are limits to spontaneous and functional recovery = Although after trauma the brain activates secondary neural circuits which contribute towards reinstating normal function (law of equipotentiality), the brain can only ‘repair’ itself up to a specific point, after which motor therapy or electrical stimulation is needed to increase recovery rates. For example, Lieperta et al (1998) found that after constraint-induced movement therapy, the motor performance of stroke patients improved significantly. Therefore, this suggests that functional recovery cannot be relied upon to reinstate normal function.

Question 31

What is Hemispheric lateralisation?

Answer 31

Hemispheric lateralisation = The idea that each hemisphere (half) of the brain is mainly responsible for certain behaviours, processes and activities. This is in contrast with the holistic theory of brain function, which suggests that function is distributed across the whole brain (i.e. is global).

Question 32

Summarise Sperry and Gazzanigas split brain research

Answer 32

• Each visual field has two sides - left and right. The right hemisphere controls the left side of the
body, and vice versa.
• Sperry and Gazzaniga (1968) conducted split-brain research on 11 epileptic patients. In order to
control their seizures, these patients underwent surgical lesioning of the corpus callosum, which meant information processed by one hemisphere cannot be relayed to the other hemisphere. Therefore, it is possible to expose a single hemisphere to certain stimuli in split-brain patients, and thus infer the functions of each hemisphere.
• The patients had one of their eyes covered.
The stimuli was flashed onto a screen for one-tenth of a second. This prevented both visual fields of the eye being exposed to the information, so only one hemisphere would process it. Therefore, their
research was conducted under strictly controlled conditions, through the use of a laboratory experiment

Question 33

Describe the procedure of sperry and gazanigas split brain research

Answer 33

1. Describing what you see = If the stimulus word was exposed to the right visual field, then it would
   be processed by the left hemisphere and the patient would say the word. This is because the left hemisphere contains the ‘language centres’ of the brain and so allows for speech. However, if the same stimulus word was exposed to the left visual field, then it would be processed by the right hemisphere and the patient would write the word using their left hand. This is because the right
   hemisphere contains the visuo-spatial centres of the brain, allowing for the physical act of writing.
   The patient would not be able to give a verbal description of the word, because the right hemisphere contains no language centres.
2. Matching words or faces = The right hemisphere appeared to dominate the ability to match a list
   of faces to a given stimulus. This is due to the right hemisphere containing the brain’s visuo-spatial
   centres, thus allowing for the visual identification and processing of the faces.
3. Recognizing objects placed into the hands = If an object was placed into the patient’s right hand, they would be unable to identify that it is there, because the information would be processed by the left hemisphere which only has language centres, and no visuo-spatial centres. Therefore, if an object was placed into the patient’s left hand, they would be able to identify the object and
   choose a similar one from a hidden bag, due to the action of the visuo-spatial centres.

Question 34

Give a weakness of split brain research (lack of control with sample selection)

Answer 34

Lack of control with the sample selection = The epileptic patients had been taking anti-epilepsy medications for extended and different periods of time, which may have affected their ability to recognise objects and match words, due to causing cerebral neuronal changes. Secondly, although all patients had undergone a commissurotomy, there may have been differences in the exact
procedures e.g. differing extent of the lesioning of the corpus callosum. This would have affected the degree to which the two hemispheres could relay information between themselves. Therefore, these two confounding variables had not been controlled, meaning that the lateralised functions may be examples of unreliable causal conclusions.

Question 35

Give a strength of split brain research

Answer 35

+ Clearly demonstrated lateralisation of function = Split-brain research was pivotal in establishing the differences in functions between the two hemispheres, and so opposing the holistic theory of brain function. The left hemisphere was demonstrated as being dominant for language tasks, due to containing language centres, whereas the right hemisphere was demonstrated as being dominant for visuo-spatial tasks. Therefore, this suggests that the left hemisphere is the analyser, whereas the right hemisphere is the synthesiser, and so there are marked differences between the two.

Question 36

Give a weakness of split brain research (The differences in function may not be so clear-cut)

Answer 36

— The differences in function may not be so clear-cut = With evidence making the drastic distinctions
that the left hemisphere is responsible for language (analyser) whilst the right is responsible for visual-spatial tasks (synthesiser), this has given the public the false impression that the two hemispheres are ‘opposite’ in function and that they can receive such labels. However, as suggested by Pucetti (1980), there have been cases of split-brain patients who are left-handed but produce and comprehend speech in the right hemisphere, which opposes the predictions made by lateralisation theory.
Therefore, it is important not to jump to conclusions and to appreciate that, through recruitment of homologous areas on the opposite side of the brain, each hemisphere is not restricted to specific function