Biopsychology Flashcards
AO3: Fight or flight gives a complete account of stress response
Gray (1988) proposes that before confronting or fleeing a stressor, most animals (including humans) display a freeze response
By freezing the animal is hyper-vigilant, alert to the slightest signs of danger This has an adaptive advantage as new info is sought allowing the best possible response to be made for a threat
AO3: Genetic basis of sex differences in fight or flight
- SRY gene promotes aggression = only
present on male Y chromosome - Females don’t have the Y chromosome + action of ostrogen and oxytocin may prevent fight or flight response
- Women’s responses may have evolved in context of being primary caregivers, where fight or flight could’ve put their offspring in danger
- Von Dawans et al. (2012) found, however, that both genders acute stress increased cooperative and friendly behaviour
AO3: Research support for localisation of function
- Peterson et al. (1998) carried out brain scans and found that Wernicke’s area was more active during a listening track and Broca’s area was more active during a reading task
This shows how the brain didn’t work holistically, but as reductionist parts.
There was higher activity in certain areas of the brain with certain tasks - Tulving et al. (1994) found that semantic and episodic memories were found in different parts of the prefrontal cortex. This provides support for the theory that neurological functions are localised
AO3: Evidence of equipotentiality theory
- The equipotentiality theory states that intact cortex areas can take responsibility from other cortex areas if they’ve been damaged
- This theory has been found in stroke patients who have been able to regain ability initially lost after their stroke
- According to localisation of function, this scenario is not possible
AO3: Understanding of communication between brain areas
- Wernicke claimed that different brain areas had specialist functions, however they must interact with each other in order to work (interdependent)
- Dronkers (2007) re-examined 2 patients brains that had Broca’s aphasia using MRI imaging
This revealed that other areas besides
Broca’s could’ve contributed to the loss of speech - This study suggests that learning and speech production are too complex to be localised and require support from other areas
AO3: Research support for functional recovery
-Researchers in the 1960s studied cases of stroke victims who had regained functions initially lost due to the stroke
- They discovered that when brain cells are damaged or destroyed functions may be recovered through the growth of new nerve endings which connect with other undamaged neurons to produce new neural circuits (axon sprouting).
In addition, neuronal unmasking where
‘dormant’ synapses (which exist anatomically but have not received enough input previously to be active) open connections to compensate for a nearby damaged area of the brain
- Other parts of the brain seemed to take over functions from the damaged or destroyed areas (recruitment of homologous areas to the opposite side of the brain).
AO3: Plasticity research support in humans
- Maguire et al. (2000) studied London taxi drivers to discover if there were any changes in their brain due to wide knowledge of navigation
- Researchers found a large amount of grey matter in the back of the hippocampus compared to control participants (hippocampus is largely involved in navigation)
- The larger the hippocampus was relative to the amount of time spent as a taxi driver
AO3: Plasticity research support in animals
- Kempermann et al. (1998) investigated whether enriched environments could alter the number of neurons in the brain
- They found that the number of neurons was relative to the complexity of the environments the rats were in
- Lots of neurons in hippocampus, which controls navigation
- Caution should be taken with animal studies as their cerebral cortex is more complex
AO3: Ability of multitasking for hemispheric lateralisation
- Rogers et al (2004) found that in domestic chickens, brain lateralisation is associated with ability to multitask (eat food and look for predators)
- Using only one hemisphere means that the other is free to engage in other tasks
- Shows enhancing brain efficiency in cognitive tasks
AO3: Split brain research lacks population validity
- Sperry’s research only included 11 participants as cutting the corpus callosum is a rare procedure
- Psychologists have argued that his research is a collection of case studies, so therefore cannot create general laws
- Results cannot be generalised to wider populations
AO3: Language may not be restricted to the left hemisphere
- Turk et al. (2002) discovered patient J.W
who suffered damage to the LH - Despite this, he developed the capacity to speak in the RH
- This led to the ability of speaking about info presented to either side of the brain
- This shows that lateralisation may not be fixed and can adapt following damage to certain areas
AO3: Research support in animals for SCN
Mutant hamster study
A group of hamsters with 20hr sleep wake cycles had their SCN removed and placed into brains of hamsters that had a 24hr sleep wake cycle
Hamsters with 24hr sleep wake cycle now showed a 20hr sleep cycle
AO3: Research support in humans for zeitgebers
Siffre stayed in a cave for 6 months with no sense of time and no natural light, with a phone linked to the surface 24/7
His sleep cycle lengthened to nearly 25 hours, with occasional 48hr fluctuations
Shows an internal mechanism providing a cycle, but light is required to keep the cycle at 24hrs exactly
AO3: Real life application for circadian rhythms
Night shift work
More accidents occur at night due to increased melatonin levels
Developed light boxes to mimic natural light, aswell as helping us to understand seasonal affective disorder
AO3: real life implications for ultradian rhythms
Helps us to diagnose health conditions such as narcolepsy, which involves REM disruption
This helps people to access healthcare for better quality of life
