A03 Psychologists for Biopsychology

Question 1

Research support the role of exogenous zeitgebers on the regulation of the sleep/wake cycle for power of light

A03: Exogenous Zeitgebers

Answer 1

• Murphy et al (1998) demonstrated that light may be detected by skin receptor sites on the body even when the same information is not received by the eyes.
• Fifteen participants were woken at various times and a light pad was shone on the back of their knees. As such, the researchers managed to produce a deviation in the participant’s usual cycle of up to 3 hours.
• This suggests that light is a powerful exogenous zeitgeber that can extend its influence so greatly that it does not require detection by the eyes.

Question 2

A strength of the study of exogenous zeitgebers, particularly light, is its application to avoiding jet lag.

Answer 2

• Burgess et al (2003) found that exposure to bright light prior to an east-west flight decreased the time needed to readjust to local time on arrival.
• Participants exposed to continuous bright light shifted their circadian rhythm by 2.1 hours over the course of the study, and as a result, were brought closer to the local time conditions such that they would not experience jet lag.
• This is a strength because it demonstrates the power of exogenous zeitgebers and their utility in our everyday experiences.

Question 3

How does this benefit our economy positively?

Answer 3

• Furthermore, this research is particularly important for those who may fly frequently, for example, nurses. This is beneficial because it has real-life economic implications as research into the application of exogenous zeitgebers such as light can help increase productivity and efficiency, positively impacting the economy.

Question 4

Research support from animal studies about the significance of SCN.

A03: Endogenous Pacemakers

Answer 4

• The importance of the SCN has been demonstrated in research. Morgan (1955) bred hamsters so that they had circadian rhythms of 20 hours rather than 24.
• SCN neurons from these abnormal hamsters were transplanted into the brains of normal hamsters, which subsequently displayed the same abnormal circadian rhythm of 20 hours, showing that the transplanted SCN had imposed its pattern onto the hamsters.
• This research demonstrates the significance of the SCN and how endogenous pacemakers are important for biological circadian rhythms.

Question 5

Has not been replicated and has methodological issues; counter-point to Murphy.

A03: Exogenous Zeitgebers

Answer 5

• However, these findings have yet to be replicated and so we cannot conclude that they are reliable.
• Furthermore, the study has been methodologically criticised under the suggestion that there may have been light exposure to the participant’s eyes, acting as a confounding variable which limits the internal validity of the study.
• This limits the support that the research can give to the importance of exogenous zeitgebers.

Question 6

Circadian and ultradian rhythms seem to be connected and perhaps should not be seen as separate processes.

A03: Ultradian Rhythms

Answer 6

• Czeisler showed that the longest period of REM sleep coincides with the lowest point in the circadian body temperature cycle.
• This could mean that both processes use the same internal body clock known as the endogenous pacemaker.

Question 7

Research support the role of exogenous zeitgebers on the regulation of the sleep/wake cycle.

Menstrual cycle!

A03: Exogenous Zeitgebers & Infradian Rhythms

Answer 7

• Reinberg (1967) examined a woman who spent three months in a cave with only a small lamp to provide light. Reinberg noted that her menstrual cycle shortened from the usual 28 days to 25.7 days.
• This result suggests that the lack of light (an exogenous zeitgeber) in the cave affected her menstrual cycle, and therefore this is a strength as it demonstrates the effect of exogenous zeitgebers on infradian rhythms.

Question 8

Research support from Siffre’s case study.

A03: Exogenous Zeitgebers

Answer 8

• When Siffre returned from an underground stay with no clocks or light, he believed the date to be a month earlier than it was.
• This suggests that his 24-hour sleep-wake cycle was increased by the lack of external cues, making him believe one day was longer than it was. This highlights the impact of exogenous zeigebers on bodily rhythms.

Question 9

Support for the existence of exogenous zeitgebers –> Blind People

A03: Exogenous Zeitgebers

Answer 9

• Skene and Arendt (2007) claimed that the majority of blind people who still have some light perception have normal circadian rhythms whereas those without any light perception show abnormal circadian rhythms. This demonstrates the importance of exogenous zeitgebers (such as light) as a biological mechanism and their impact on biological circadian rhythms.

Question 10

Age differences affect circadian rhythms.

Answer 10

• For example, Siffre did the cave study again at the age of 60 and found that his internal clock ticked much more slowly when he was a young man, suggesting age can affect circadian rhythms.

Question 11

Real life applications into teenager’s academic performance.

A03: Circadian Rhythms

Answer 11

• Wolfson and Carskadon recommend that the school day start a couple of hours later to fit in with the typical teenage chronotype (sleep pattern).
• Hormonal shifts in the teenage body mean that getting to sleep becomes more difficult and therefore adolescent students tend to be rather sleepy at the start of the school day.
• Research into circadian rhythms has shown benefits for academic and behavioural performance when lessons start later in the day, including reduced dependence on caffeine

Question 12

Sweat rubbed on lips

Research support for exogenous zeitgebers and infradian rhythms

Answer 12

• Russell et al. (1980) found that female menstrual cycles became synchronised with other females through odour exposure. In one study, sweat samples from one group of women were rubbed onto the upper lip of another group.
• Despite the fact that the two groups were separate, their menstrual cycles synchronised.
• This suggests that the synchronisation of menstrual cycles can be affected by pheromones.
• Exogenous zeitgebers must be taken into consideration when investigating infradian rhythms and that perhaps a more holistic approach should be taken, as opposed to a reductionist approach that considers only endogenous influences.

Question 13

Research support for BRAC –> Violinists

Answer 13

• Ericsson et al. (2006) found that, among a group of elite violinists, practice sessions were usually limited to a duration of no more than 90 minutes at a time and the violinists frequently napped between practice sessions.
• The researchers also discovered the same pattern among other musicians, athletes, chess players and writers, supporting the existence of a 90-minute ultradian cycle of alertness and fatigue, during the waking day.

Question 14

Does not account for social cues

A03: Circadian Rhythms

Answer 14

• However, this research is flawed as it does not account for the existence of social cues. This is a limitation because shifting the start of the day is disruptive for parents and teachers, and it limits the number of extracurricular activities after school.
• Also, critics of the proposal suggest that a later school day would not actually reduce sleep deprivation, it would simply mean that teenagers would stay up later and still be exhausted!

Question 15

Research support for the existence of Circadian Rhythms…

Answer 15

• Sifre investigated the effect of the removal of light (exogenous zeitgeber) on the circadian rhythm of the sleep cycle and wake cycle.
• He spent 6 months in a cave without light and sound and continued to fall asleep and wake up on a regular schedule.
• His free-running biological rhythm settled to around 25 hours despite removing the exogenous zeitgeber, light, highlighting circadian rhythms persistence despite the removal of light (exogenous zeitgebers.)

Question 16

Provides an understanding of the adverse consequences that occur when they are disrupted (desynchronisation).

Answer 16

• Research has also pointed to a relationship between shift work and poor health - shift workers are 3x more likely to develop heart disease than people who work more typical work patterns (Knutsson, 2003).

Question 17

Phineas Gage: Case Study for Localisation of the Brain

Answer 17

• Shows the brain’s resilence
• An iron rod pierced through his brain and a ‘teacup’ of his brain exited the top of his skull.
• He still miraculously survived and was able to walk after 24 days, recovered physically and had slight memory loss but still was able to live for 12 years after.

Question 18

Research into disuption of circardian rhythms has positive implications on economy…

Answer 18

• This shows that research into the sleep/wake cycle may have real-world economic implications in terms of how best to manage worker productivity and prevent harmful effects of a disruption to circadian rhythms ensuring that in the long term, workers can prosper and positively impact the economy by being able to work more (without having to take off time for sickness) and be more efficient.

Question 19

Individual differences regarding circardian rhythms.

Answer 19

• Jeanne Duffy et al., 2001, revealed that some people have a natural preference for going to bed early and rising early (known as ‘larks’) whereas others prefer the opposite (‘owls’).

Question 20

Phineas Gage: Case Study for Brain Plasticity and Functional Recovery

Answer 20

• He had experienced huge changes to personality as result of damage to frontal lobe after experiencing an iron rod that pierced his skull.
• Before the accident, he was calm and reserved and after the accident, he became rude, hostile and quick tempered.
• Demonstrates that there are localised areas of brain as the area that Gage damaged links to reasoning, control and mood.

Question 21

Danelli

A03: A03: Plasticity and Functional Recovery of the Brain

Answer 21

• Case of 14 year old EB. At the age of 2 and a half, EB had hemispherectomy of the left side of his brain to remove a tumour (basically brain surgery).
• This removed the language areas of Broca’s and Wernicke’s Areas.
• After sturgey, EB lost all language abillity but was able to recover this language abillity after 2 years.
• FMRI scans actually showed that the right hemisphere followed a ‘left-like blueprint’ for language and could perform language tasks usually taken up by the right side of the brain.

Question 22

Research support for brain plasticity: Video Games

A03: Plasticity and Functional Recovery of the Brain

Answer 22

• Playing video games activates many different complex motor and cognitive demands.
• He compared a control group with a video game training group that was trained for two months in Super Mario. He found a significant increase in grey matter in brain areas such as the cortex, hippocampus and cerebellum, which was not evident in the control group who didn’t play Super Mario.
• Video game training resulted in new synaptic connections in brain areas such as spatial navigation and motor performance, which were skills that were important in getting better at the game.

Question 23

Research support for educational attainment affecting functional recovery.

A03: Plasticity and Functional Recovery of the Brain

Answer 23

• Schneider shows that a person’s educational attainment could influence the degree to which a person’s brain recovers its functionality.
• He found that the more time that brain injury patients had spent in education, the greater the chance that their brain had recovered to full functionality.
• For example, two fifths of patients who recovered to full functionality had more than 16 years of education compared to about 10% with patients who had less than 12 years of education.

Question 24

Research support from animal studies: Kitten & Functional Recovery

A03: Plasticity and Functional Recovery of the Brain

Answer 24

• Hubel and Wiesel sewed 1 eye of a kitten shut and analysed the response.
• The area of the visual cortex associated with the shuteye was still working and carried out processing information in the open eye.
• Demonstrates how the loss of function leads to compensatory activity in the brain (evidence of neural plasticity.)

Question 25

Research support from brain scans in normal participants.

A03: Lateralisation and Split-Brain Research

Answer 25

• Even in normal brains, the two hemispheres process information differently. For example, Fink et al used PET scans to identify which brain areas were active during a visual processing task.
• When ‘normal’ participants were asked to attend to global elements of an image (such as looking at a picture of a whole forest) regions of the right hemisphere were much more active.
• When required to focus in on the finer detail (such as individual trees) the specific areas of the left hemisphere tended to dominate.
• This suggests that, at least as far as visual processing is concerned, hemispheric lateralisation is a feature of the normal brain as well as the split-brain.

Question 26

Positive effects of brain plasticity: Research support from Taxi Drivers.

A03: Plasticity and Functional Recovery of the Brain

Answer 26

• Maguire’s research on London taxi drivers found that they had more volume of grey matter in the posterior hippocampus than those in a matched control group as taxi drivers must memorise a large variety of routes on the London map to become an efficient taxi driver.

Question 27

Brain Plasticity can also have negative consequences…

A03: Plasticity and Functional Recovery of the Brain

Answer 27

• However, brain plasticity can be negative. This is a limitation because the brain’s ability to rewire itself can sometimes have maladaptive consequences.
• For example, research from Medina shows that prolonged drug use has shown to result in poorer cognitive functioning as well as an increased risk of dementia later in life.

Question 28

Research support for brain plasticity from animal studies: Neurones and Environment

A03: Plasticity and Functional Recovery of the Brain

Answer 28

• Kempermann investigated whether an enriched environment could alter the number of neurones in the brain.
• He found evidence of an increased number of new neurones in the brains of rats housed in complex environments compared to rats housed in laboratory cages, specifically the hippocampus which is associated with the formation of new memories.

Question 29

Support for the existence of negative brain plasticity comes from the existence of pornography…

A03: Plasticity and Functional Recovery of the Brain

Answer 29

• Overuse of pornography can lead to creating negative functional and structural changes in the brain due to the damaging of dopamine receptors, leading to negative effects such as desensitisation to rewards.
• For example, Max Planck Institute for Human Development found a negative correlation between pornography use and the volume of the striatum, an area of the brain that makes up part of the reward system.

Question 30

Research support from animal studies regarding multi-tasking

A03: Lateralisation and Split-Brain Research

Answer 30

• Gazzaniga and Sperry’s research is supported by a study from Rogers which found that brain lateralisation improves our ability to multi-task.
• He saw that chickens were able to both gather food and be aware of predators at the same time. Using only one hemisphere to engage in a task leaves the other hemisphere free to engage in other functions.
• This shows that brain efficiency is improved by brain lateralisation and our hemispheres being able to work simultaneously.

Question 31

Brain is plastic –> lateralisation (hemispheres performing different functions from each other) not fixed.

A03: Lateralisation and Split-Brain Research

Answer 31

• Research has found language may not be restricted to the left hemisphere.
• Turk et al discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere, eventually leading to the ability to speak about the information presented to either side of the brain.
• Suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.

Question 32

A wide range of evidence to support the idea that different areas of the brain have different functions…

Answer 32

• Advances in brain imaging techniques like PET scans have allowed us to describe and discern neurological basis of mental processes/
• Tulving et al’s research involving tasks that required the use of episodic and semantic memory were able to show how these different types of long-term memory may be located on opposite sides of the pre-frontal cortex, whilst procedural memory may have been located in the cerebellum.
• Wide range of evidence to support the idea that different areas of the brain have different functions.

Question 33

Contradictory evidence on Broca’s findings…

A03: Localisation of Function

Answer 33

• 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.
• This is a limitation because 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.

Question 34

A03: What is evidence to support the existence of the somatosensory area performing its designated function?

Answer 34

• Robertson (1995) found that this area of the brain is highly adaptable, with Braille readers having larger areas in the somatosensory area for their fingertips compared to normal sighted participants, showing that the somatosensory area has a specific function for sensory information within the brain.

Question 35

A03: How does contradictory research show that men actually go through the same ‘tend and befriend’ response as women?

Answer 35

• Von Dawans et al (2012) challenge the view that, under stress, men respond only with fight or flight, whereas women are more prone to ‘tend and befriend’.
• It was found that acute stress can actually lead to greater cooperative and friendly behaviour, even in men. This could explain the human connection that happens during times of crisis such as the 9/11 terrorist attacks.
• One reason stress may lead to greater cooperative behaviour is because human beings are fundamentally social animals and is the protective nature of human social relationships that has allowed our species to thrive.

Question 36

A03: How does genetic data show that it is unlikely women have the same flight or fight response as men?

Answer 36

• Lee and Harley (2012) found the SRY gene, exclusively on the male Y chromosome, associated with aggression and priming for a fight-or-flight response to stress.
• They conclude that the absence of this gene in females, together with the action of oestrogen and oxytocin, mean that the response is not likely to occur in females - showing that the fight or flight response is not an adequate explanation for female responses.

Question 37

A03: What research shows that women actually have a different fight or flight response?

Answer 37

• Females adopt a ‘tend and befriend’ response in stressful/dangerous situations due to the release of oxytocin in response to stress (which is associated with maternal bonding and a mother’s natural protective urges)
• According to Taylor et al. (2000), women are more likely to protect their offspring (tend) and form alliances with other women (befriend), rather than fight an adversary or flee.
• Furthermore, the fight or flight response may be counterintuitive for women, as running (flight) may put their offspring at risk of danger.
• Women deal with stress through different system responses than fight or flight responses, in which they are more likely to ‘tend and befriend’ due to the excretion of oxytocin.

Question 38

A03: Why does the fight of flight response not tell the whole story?

Answer 38

• Gray argues that the first response to danger is to avoid confrontation.
• This is demonstrated by the ‘freeze response’, in which humans are hyper alert as they assess the situation and determine the best action to take for the particular threat that is imposed on them.
• Therefore, the ‘fight or flight response’ does not show an accurate representation of the body when faced with a threat.

Question 39

Individual differences are not taken into account…

A03: Localisation of Function

Answer 39

Research for this comes from Herasty who found that women have proportionally larger Broca’s and Wernicke’s areas than men, which can perhaps explain the greater ease of language use amongst women.

This is a limitation however because it suggests a level of beta bias in the theory: the differences between men and woman are ignored, and variations in the pattern of activation and the size of areas observed during various language activities are not considered.

Question 40

Individual differences in functional recovery…

A03: Plasticity and Functional Recovery of the Brain

Answer 40

While there is evidence for functional recovery, it is possible that this ability can deteriorate with age. Elbert et al. concluded that the capacity for neural reorganisation is much greater in children than in adults, meaning that neural regeneration is less effective in older brains. This may explain why adults find change more demanding than young people.

Therefore, to improve lateralisation and split-brain research we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma.