Biopsychology

Question 1

The nervous system

Answer 1

A specialised network of cells in the human body and is our primary internal communication system. Is based on electrical and chemical signals. It has 2 main functions: to collect, process and respond to information in the environment, and to co-ordinate the working of different organs and cells in the body.
is divided into the CENTRAL Nervous System and the PERIPHERAL nervous system.

Question 2

The nervous system
central nervous system

Answer 2

The CNS is a subsystem of the nervous system which consists of the brain and spinal cord. This is the origin of all complex commands and decisions.
The brain is the centre of all conscious awareness and is covered by the cerebral cortex (outer layer). It is divided into 2 hemispheres.
The spinal cord is an extension of the brain. It passes messages to and from the brain and connects nerves to the PNS. It is also responsible for reflex actions.

Question 3

The nervous system
peripheral nervous system

Answer 3

The PNS transmits messages via millions of neurons to and from the CNS. The PNS is then subdivided into the AUTONOMIC nervous system and the SOMATIC nervous system.

Question 4

The peripheral nervous system
Somatic nervous sytem

Answer 4

SNS governs muscle movement and receives information from sensory receptors. Transmits information from receptor cells in the sense organs to the CNS. It receives information from the CNS that directs muscles to act.

Question 5

The peripheral nervous system
Autonomic nervous system

Answer 5

ANS governs vital functions in the body such as breathing, heart rate digestion etc. Transmits information to and from internal organs. It is automatic as it all happens involuntarily. It is further divided into the SYMPATHETIC nervous system and the PARASYMPATHETIC nervous system

Question 6

Autonomic nervous system
Sympathetic nervous system

Answer 6

The Sympathetic nervous system changes the ANS from its resting state to become aroused in stressful situations. Eg increases heart rate and dilates pupils.

Question 7

Autonomic nervous system
Parasympathetic nervous system

Answer 7

The parasympathetic nervous system helps to return the body to its resting (parasympathetic) state. this acts as antagonistic to the sympathetic nervous system. eg decreases heart rate and constricts pupils.

Question 8

The endocrine system
Glands and hormones

Answer 8

The endocrine system works alongside the nervous system to control vital bodily functions. The endocrine system works slower than the nervous system but has more widespread and powerful effects. Various glands in the body produce hormones, which are secreted into the bloodstream and affect any cell in the body that has a receptor for the particular hormone. Most hormones affect more than one body organ, leading to diverse responses. The main endocrine gland is the pituitary gland in the brain. It is known as the master gland because it controls the release of hormones from all other endocrine glands in the body.

Question 9

The endocrine system
Fight or flight

Answer 9

The endocrine system and the ANS work in parallel with one another. When a stressor is perceived the hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the ANS. This changes it from its resting state to its physiologically aroused sympathetic state. All of this happens in an instant as soon as the threat is perceived such as increased heart rate. This is an acute response and an automatic response in the body. Once this has happened the parasympathetic nervous system returns the body to its resting state. This acts as a brake and reduces activity in the body that was increased by the sympathetic branch.

Question 10

Fight or flight response
Role of adrenaline

Answer 10

The stress hormone adrenaline is released from the adrenal medulla into the bloodstream. Adrenaline triggers physiological changes in the body, like increased heart rate, which creates the physiological arousal needed for the fight or flight response.

Question 11

The structure and function of neurons

Answer 11

The cell body contains a nucleus which contains the genetic material of a cell. Branch-like structures protrude from the cell called dendrites and carry nerve cell impulses from neighbouring nerve cells towards the cell body. The axon carries nerve impulses away from the cell body down the length of the neuron. This is covered in a fatty layer of the myelin sheath to speed up the electrical transmission. This is segmented by nodes of Ranvier so impulses have to ‘jump’ across the gaps. There are terminal buttons at the end of the axon that communicates with the next neuron across a synapse.
When a neuron becomes activated by a stimulus, it causes an action potential. This creates an electrical impulse that travels down the axon towards the end of a neuron.

Question 12

The function of and structure sensory neurons

Answer 12

These carry messages from the PNS to the CNS. They have long dendrites and short axons.

Question 13

The function and structure of Relay neurons

Answer 13

These connect the sensory neurons to the motor or other relay neurons. they have short dendrites and short axons.

Question 14

The function and structure of Motor neurons

Answer 14

These connect the CNS to the effectors such as muscles and glands. They have short dendrites and long axons.

Question 15

Synaptic transmission

Answer 15

Neurons communicate with each other within groups called neural networks. each neuron is separated by a synapse. Signals within neurons are transmitted electrically, but signals between neurons are transmitted chemically. When the electrical impulse reaches the end of the neuron (Presynaptic terminal) it triggers the release of neurotransmitters from tiny sacs called synaptic vesicles.

Question 16

Synaptic transmission
Neurotransmitters

Answer 16

Neurotransmitters are chemicals that are diffused across the synapse to the next neuron in the chain, where it is received by the postsynaptic receptor site in the dendrites. The chemical message is then converted back to electrical. Each neurotransmitter has its own specific molecular structure that fits perfectly into the postsynaptic receptor site, similar to a lock and key.

Question 17

Synaptic transmission
Excitation

Answer 17

When a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron. This increases the likelihood that the postsynaptic neuron will pass on the electrical impulse (to fire). Whether a postsynaptic neuron will fire is decided by summation. If the net sum on the neuron is excitatory it will be more likely to fire.

Question 18

Synaptic transmission
Inhibition

Answer 18

When a neurotransmitter, such as serotonin, increases the negative charge of the postsynaptic neuron. This decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse (to fire). Less likely to fire if the net sum is more inhibitory.

Question 19

Localisation of function

Answer 19

During the 19th century, scientists such as Broca and Wernicke discovered that certain areas of the brain are associated with particular physical and psychological functions. Before this the holistic theory of the brain was widely supported, that all parts of the brain were involved in the processes of thought and action. They argued for the localisation of function theory, that certain parts of the brain perform certain tasks. This means that is a specific area is damaged, the functions of that part will also be affected.

Question 20

Localisation of function
Motor centre

Answer 20

At the back of the frontal lobe (in both hemispheres) is the motor centre. This controls voluntary movement on the opposite side of the body. Damage to this area in the brain may result in loss of control over fine movements.

Question 21

Localisation of function
Somatosensory centre

Answer 21

At the front of both parietal lobes is the somatosensory area. This is where sensory information from the skin is represented. The amount of somatosensory area devoted to a specific body part denotes its sensitivity, for example, receptors for our face and hands occupy over half of the somatosensory area.

Question 22

Localisation of function
Visual centre

Answer 22

In the occipital lobe at the back of the brain is the visual area or visual cortex. each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex. This means that damage in the left hemisphere can lead to blindness in the right eye.

Question 23

Localisation of function
Auditory centre

Answer 23

The temporal lobes house the auditory area, which analyses speech-based information. Damage may produce hearing loss. Specific damage to a certain area of the temporal lobe known as Wernicke’s area may affect the ability to comprehend language.

Question 24

Localisation of function
Language centres
BROCA AND WERNICKE AREA

Answer 24

Language is restricted to the left hemisphere of the brain in most people. In the 1880s, Broca identified a small area of the left frontal lobe responsible for speech production. Damage to BROCA’S AREA causes Broca’s aphasia which is characterised by slow speech that lacks fluency. His most famous patient was ‘Tan’ because that was the only syllable he could say.
Around the same time, Wernicke discovered people who could produce speech fluently but was meaningless and couldn’t understand the speech of others. He identified WERNICKE’S AREA in the left temporal lobe as being responsible for language understanding. People who have Wernicke’s aphasia will often produce nonsense words as part of their speech.

Question 25

Hemispheric lateralisation

Answer 25

The idea is that the two hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other. Language is lateralised as both Broca’s area and Wernicke’s area are in the left hemisphere. The RH can only produce rudimentary words but contributes to emotional context. This has led to the suggestion that the LH is the analyser but the RH is the synthesiser . In the case of vision, both eyes receive light from the left visual field and the right visual field. The LVF of both eyes is connected to the RH and the RVF of both eyes is connected to the LH.
The motor area of the brain is cross-wired despite not being lateralised, so the RH controls the left side and the LH controls the right side.

Question 26

Hemispheric lateralisation
Split brain research

Answer 26

A ‘split-brain’ operation involves severing the connections between the RH and LH, mainly the corpus callosum. Sperry (1968) devised a system to study how two separated hemispheres deal with, for example, speech and vision. People who had a split-brain operation were studied using a special set-up in which an image could be projected to a participant’s RVF (processed by the LH) and the same, or different, image could be projected to the LVF (processed by the RH. Presenting the image to one hemisphere of a split-brain participant meant that the information cannot be conveyed from that hemisphere to the other. When a picture of an object was shown to a participant’s RVF (linked to LH), the participant could describe what was seen. But they could not do this if the object was shown to the LVF (RH) - they said there was ‘nothing there. This is because, in the connected brain, messages from the RH are relayed to the language centres in the LH, but this is not possible in the split brain. Although participants could not give verbal labels to objects projected to the LVF, they could select a matching object out of sight using their left hand (linked to RH). The left hand was also able to select an object that was most closely associated with an object presented to the LVF (for instance, an ashtray was selected in response to a picture of a cigarette). If a pinup picture was shown to the LVF there was an emotional reaction (e.g. a giggle) but the participants usually reported seeing nothing or just a flash of light.
These observations show how certain functions are lateralised in the brain and support the view that the LH is verbal and the RH is ‘silent but emotional.

Question 27

Plasticity

Answer 27

The brain has the ability to change throughout life. During infancy, the brain experiences rapid growth in the number of synaptic connections it has, peaking at about 15,000 per neuron at 2-3 years of age (Gopnik et al. 1999). This is about twice as many as there are in the adult brain. As we age, rarely-used connections are deleted and frequently-used connections are strengthened (synaptic pruning). People once thought that the adult brain was not capable of change but we now understand that synaptic pruning enables lifelong plasticity where new neural connections are formed in response to new demands on the brain.

Question 28

Research into plasticity

Answer 28

Maguire et al. (2000) studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in a matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training, London cabbies must take a complex test called ‘The Knowledge, which assesses their recall of the city streets and possible routes. Maguire et al. found that this learning experience alters the structure of the taxi drivers’ brains. They also found that the longer the taxi drivers had been on the job, the more pronounced the structural difference (a positive correlation).

Question 29

Functional recover after trauma

Answer 29

Following physical injury, or other forms of trauma such as a stroke, unaffected areas of the brain are often able to adapt and compensate for those areas that are damaged. The functional recovery that may occur in the brain after trauma is an example of neural plasticity.
Healthy brain areas may take over the functions of those areas that are damaged, destroyed or even missing. Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or months. At this point, the individual may require rehabilitative therapy to further their recovery

Question 30

Functional recovery
During recovery

Answer 30

The brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage. Secondary neural pathways that would not typically be used to carry out certain functions are activated or ‘unmasked’ to enable functioning to continue, often in the same way as before (Doidge 2007). This process is supported by a number of structural changes in the brain including:
* Axonal sprouting - the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
* Denervation supersensitivity - this occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. However, it can have the negative consequence of oversensitivity to messages such as pain.
Recruitment of homologous (similar) areas on the opposite side of the brain. This means that specific tasks can still be performed. An example would be if Broca’s area was damaged on the left side of the brain, the right-sided equivalent would carry out its functions. After a period of time, the functionality may then shift back to the left side.

Question 31

Ways of studying the brain
fMRI

Answer 31

Functional magnetic resonance imaging (fMRI) works by detecting the changes in both blood oxygenation and flow that occur as a result of neural (brain) activity in specific parts of the brain. When a brain area is more active it consumes more oxygen and to meet this increased demand, blood flow is directed to the active area (known as the haemodynamic response). fMRI produces three-dimensional images (activation maps) showing which parts of the brain are involved in a particular mental process and this has important implications for our understanding of localisation of function.

Question 32

Ways of studying the Brain
EEG

Answer 32

An electroencephalogram (EEG) measures electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap. The scan recording represents the brainwave patterns that are generated from the action of thousands of neurons, providing an overall account of brain activity. EEG is often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity may indicate neurological abnormalities such as epilepsy, tumours or some sleep disorders.

Question 33

Ways of Studying the brain
ERPs

Answer 33

Although EEG has many scientific and clinical applications, in its raw form it is a crude and overly general measure of brain activity. However, within EEG data are contained all the neural responses associated with specific sensory, cognitive and motor events that may be of interest to cognitive neuroscientists. As such, researchers have developed a way of teasing out and isolating these 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, say, the presentation of a specific stimulus or performance of a specific task. What remains are event-related potentials (ERPs) - types of brainwaves that are triggered by particular events.
Research has revealed many different forms of ERP and how, for example, these are linked to cognitive processes such as attention and perception.

Question 34

Ways of Studying the brain
Post mortem examination

Answer 34

This is a technique involving the analysis of a person’s brain following their death.
In psychological research, individuals whose brains are subject to a post-mortem examination are likely to be those who have a rare disorder and have experienced unusual deficits in cognitive processes or behaviour during their lifetime. Areas of damage within the brain are examined after death as a means of establishing the likely cause of the affliction the person experienced. This may also involve comparison with a neurotypical brain in order to ascertain the extent of the difference.

Question 35

Localisation theory supported by neurosurgery

Answer 35

One strength of localisation theory is that damage to areas of the brain has been linked to mental disorders.
Neurosurgery (surgery on the brain) is a last resort method for treating some mental disorders, targeting specific areas of the brain which may be involved. For example, cingulotomy involves isolating a region called the cingulate gyrus which has been implicated in OCD. Dougherty et al. (2002) reported on 44 people with OCD who had undergone a cingulotomy. At post-surgical follow-up after 32 weeks, about 30% had met the criteria for a successful response to the surgery and 14% for a partial response.
The success of these procedures suggests that behaviours associated with serious mental disorders may be localised.

Question 36

Localisation theory supported by brain scans

Answer 36

Another strength is evidence from brain scans that supports the idea that many everyday brain functions are localised. For instance, Petersen et al. (1988) used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task. Also, a review of long-term memory studies by Buckner and Petersen (1996) revealed that semantic and episodic memories reside in different parts of the prefrontal cortex. These studies confirm localised areas for everyday behaviours.
Therefore objective methods for measuring brain activity have provided sound scientific evidence that many brain functions are localised.

Question 37

Localisation of language is questioned (localisation theory WEAKNESS)

Answer 37

One limitation is that language may not be localised just to Broca’s and Wernicke’s areas.
A recent review by Dick and Tremblay (2016) found that only 2% of modern researchers think that language in the brain is completely controlled by Broca’s and Wernicke’s areas. Advances in brain imaging techniques, such as fMRI, mean that neural processes in the brain can be studied with more clarity than ever before. It seems that language function is distributed far more holistically in the brain than was first thought. So-called language streams have been identified across the cortex, including brain regions in the right hemisphere, as well as subcortical regions such as the thalamus
This suggests that rather than being confined to a couple of key areas, language may be organised more holistically in the brain, which contradicts localisation theory.

Question 38

Research support for hemispheric lateralisation

Answer 38

One strength is research showing that even in connected brains the two hemispheres process information differently. For example, Fink et al. (1996) used PET scans to identify which brain areas were active during a visual processing task. When participants with connected brains were asked to attend to global elements of an image (such as looking at a picture of a whole forest) regions of the RH were much more active. When required to focus in on the finer detail (such as individual trees) the specific areas of the LH tended to dominate.
This suggests that at least as far as visual processing is concerned, hemispheric lateralisation is a feature of the connected brain as well as the split brain.

Question 39

LH and RH role questioned (WEAKNESS of hemispheric lateralisation)

Answer 39

One limitation is the idea that the LH as analyser and RH as synthesiser may be wrong. There may be different functions in the RH and LH, but research suggests people do not have a dominant side of their brain which creates a different personality. Nielsen et al. (2013) analysed brain scans from over 1000 people aged 7 to 29 years and did find that people used certain hemispheres for certain tasks (evidence for lateralisation). But there was no evidence of a dominant side, i.e. not artist’s brain or mathematician’s brain.
This suggests that the notion of right- or left-brained people is wrong.

Question 40

More research support for split brains

Answer 40

One strength is support from more recent split-brain research. Gazzaniga (Luck et al. 1989) showed that split-brain participants actually perform better than connected controls on certain tasks. For example, they were faster at identifying the odd one out in an array of similar objects than normal controls. In the normal brain, the LH’s better cognitive strategies are ‘watered down’ by the inferior RH (Kingstone et al. 1995).
This supports Sperry’s earlier findings that the left brain’ and ‘right brain’ are distinct.

Question 41

Low generalisability of split-brain research

Answer 41

One limitation of Sperry’s research is that causal relationships are hard to establish. The behaviour of Sperry’s split-brain participants was compared to a neurotypical control group. An issue though is that none of the participants in the control group had epilepsy. This is a major confounding variable. Any differences that were observed between the two groups may be the result of the epilepsy rather than the split brain.
This means that some of the unique features of the split-brain participants’ cognitive abilities might have been due to their epilepsy (though Fink’s research, supports Sperry’s conclusions).

Question 42

Plasticity may be life long (STRENGTH)

Answer 42

One strength is that brain plasticity may be a life-long ability. In general, plasticity reduces with age. However, Bezzola et al. (2012) demonstrated how 40 hours of golf training produced changes in the neural representations of movement in participants aged 40-60. Using fMRI, the researchers observed increased motor cortex activity in the novice golfers compared to a control group, suggesting more efficient neural representations after training.
This shows that neural plasticity can continue throughout the lifespan.

Question 43

Plasticity may have negative consequences (WEAKNESS)

Answer 43

One limitation of plasticity is that it may have negative behavioural consequences. Evidence has shown that the brain’s adaptation to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia (Medina et al. 2007).
Also, 60-80% of amputees have been known to develop phantom limb syndrome - the continued experience of sensations in the missing limb as if it were still there. These sensations are usually unpleasant, painful and are thought to be due to cortical reorganisation in the somatosensory cortex that occurs as a result of limb loss (Ramachandran and Hirstein 1998).
This suggests that the brain’s ability to adapt to damage is not always beneficial.

Question 44

Real world application of functional recovery

Answer 44

One strength of functional recovery research is its real-world application. Understanding the processes involved in plasticity has contributed to the field of neurorehabilitation. Simply understanding that axonal growth is possible encourages new therapies to be tried. For example, constraint-induced movement therapy is used with stroke patients whereby they repeatedly practise using the affected part of their body (such as an arm) while the unaffected arm is restrained.
This shows that research into functional recovery is useful as it helps medical professionals know when interventions need to be made.

Question 45

Variables that affect people’s differing levels of recovery (WEAKNESS)

Answer 45

One limitation of functional recovery is that level of education may influence recovery rates. Schneider et al. (2014) revealed that the more time people with a brain injury had spent in education - taken as an indication of their ‘cognitive reserve’ - the greater their chances of a disability-free recovery (DR). 40% of those who achieved DFR had more than 16 years of education compared to about 10% of those who had less than 12 years of education.
This would imply that people with brain damage who have insufficient DFR are less likely to achieve a full recovery.

Question 46

fMRI doesn’t rely on the use of radiation (STRENGTH)
fMRI produces clear pictures

Answer 46

One key strength of fMRI is, unlike other scanning techniques such as PET, it does not rely on the use of radiation. If administered correctly it is virtually risk-free, non-invasive and straightforward to use. it also produces images that have very high spatial resolution, depicting detail by the millimetre, and providing a clear picture of how brain activity is localised. This means that fMRI can safely provide a clear picture of brain activity.

Question 47

fMRI is expensive and has low temporal resolution (WEAKNESS)

Answer 47

fMRI is expensive compared to other neuroimaging techniques.
It has poor temporal resolution because there is around a 5-second time-lag behind the image on screen and the initial firing of neuronal activity. This means fMRI may not truly represent moment-to-moment brain activity.

Question 48

EEG has high temporal resolution and has real-world application (STRENGTH)

Answer 48

EEG has been useful in studying the stages of sleep and in the diagnosis of conditions such as epilepsy, a disorder characterised by random bursts of activity in the brain that can easily be detected on screen. Unlike fMRI, EEG technology has an extremely high temporal resolution. Today’s EEG technology can accurately detect brain activity at a resolution of a single millisecond (and even less in some cases). This shows the real-world usefulness of the technique.

Question 49

EEG has generalised data produced (WEAKNESS)

Answer 49

The main drawback of EEG lies in the generalised nature of the information received (that of many thousands of neurons). The EEG signal is also not useful for pinpointing the exact source of neural activity. Therefore it does not allow researchers to distinguish between activities originating in different but adjacent locations.

Question 50

ERPs are more specific and have high temporal resolution (STRENGTH)

Answer 50

The limitations of EEG are partly addressed through the use of ERPs. These 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 measurements, they have excellent temporal resolution, especially when compared to neuroimaging techniques such as MRI. This means that ERPs are frequently used to measure cognitive functions and deficits such as the allocation of attentional resources and the maintenance of working memory

Question 51

ERPs are not standardised and may be hard to achieve (WEAKNESS)

Answer 51

Critics have pointed to a lack of standardisation in ERP methodology between different research studies which makes it difficult to confirm findings. A further issue is that, in order to establish pure data in ERP studies, background ‘noise’ and extraneous material must be completely eliminated. This is a problem because it may not always be easy to achieve.

Question 52

Post-mortem evidence was vital in the early understanding of brain processes.

Answer 52

Post-mortem evidence was vital in providing a foundation for early understanding of key processes in the brain. Broca and Wernicke both relied on post-mortem studies in establishing links between language, brain and behaviour decades before neuroimaging ever became a possibility. Post-mortem studies were also used to study HM’S brain to identify the areas of damage, which could then be associated with his memory deficits. This means post-mortems continue to provide useful information.

Question 53

Post-mortem evidence may not explain causation and raises issues of consent (WEAKNESS)

Answer 53

Causation is an issue within these studies, however. Observed damage to the brain may not be linked to the deficits under review but to some other unrelated trauma or decay. A further problem is that postmortem studies raise ethical issues of consent from the individual before death. Participants may not be able to provide informed consent, for example in 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. This challenges the usefulness of post-mortem studies in psychological research.