Biopsychology Last Min Rev Flashcards
Localisation of function
Different parts of the brain perform different tasks and are involved with different parts of the body
Lateralisation
Some physical and psychological functions are controlled or dominated by a specific hemisphere
Frontal lobe
Motor area which controls voluntary movement in the opposite side of the body
Parietal lobe
Somatosensory area where sensory information is processed from the skin
Occipital
Visual area
Temporal lobe
Auditory area which analyses speech based information
Damage to brocas area
Causes brocas aphasia which is when speech is slow, laborious and lacking in fluency
Damage to Wernickes area
People who has no problem producing speech but had difficulty understanding it (wernickes aphasia)
Evidence of localisation from neurosurgery
Cingulotomy isolates the cingulate gyri which has links to ocd. Dougherty 2002 reported 44 people with ocd who had undergone a cingulotomy and 32 weeks after, 30% had met the criteria of a successful response and 14% partial response
Evidence of localisation from brain scans
Petersen used brain scans to demonstrate how Wernickes area was active during a listening task and Brocas was active during a reading task. A review of long term memory studies show that semantic and episodic memories reside in different parts of the prefrontal cortex
Challenge to localisation of brain function
Lashley removed areas of the cortex from rats that were learning a maze. No area was proven to be more important than any other area in terms of the rats ability to learn, so learning is holistic
Challenge to language localisation
Not just brocas and wernickes area, only 2% of modern researchers believe it is. Advances in brain scans such as fmri mean neural processes can be studied with more clarity than before so language may be more holistic
Hemispheric lateralisation
The idea that two halves of the brain function different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other
Split brain research
Sperry 1968, 11 people with split brain were studied using a special set up in which an image was projected to RVF and the same or different image projected to LVF. In a normal brain info would travel the corpus collosum and present a complete image of visual field. Found when image was RVF they could visualise the image but couldn’t with LVF, they couldn’t verbalise but could select a matching object in a line up. Shows the LH is visual
Evidence for lateralisation in connected brain
Two hemispheres process info different. PET scans identified which brain areas were active during a visual processing task. RH was more active looking at the whole picture and LH for finer details.
Limitation of lateralisation in brain
There may be different functions of LH and RH research suggests there is not a dominant side of the brain which creates a different personality. LH being the analyser and RH as synthesiser is wrong.
More recent split brain research support
Luck 1989 showed that split brain participants performed better than control on certain tasks such as faster at identifying an odd one out. Shows in a normal brain the LHs better cognitive strategies are watered down by inferior RH
Generalisation issues with split brain
Sperrys findings were compared with a neurotypical control group where none had epilepsy. This acts as a confounding variable. Any differences between the groups could be due to the epilepsy and not split brain
Plasticity
Brains tendency to change and adapt as a result of experience and new learning. Involves growth of new connections
Synaptic pruning
Rarely used connections are deleted and frequently used connections are strengthened
Research into plasticity
Maguire 2000 studied brains of London taxi drivers and found more vol of grey matter in the posterior hippocampus than in a matched control group. This part is associated with spatial and navigational skills. Cabbies must take the knowledge which assesses recall of streets, learning this alters the structure of the drivers brain. The longer they had the job, the more pronounced the structural difference (pos correlation)
Functional recovery
Following damage due to trauma, the brains ability to redistribute or transfer functions usually performed by damaged areas to other undamaged areas
What happens during functional recovery
Unmasking of secondary neural pathways that would not typically be used to carry out certain functions are activated.
Axonal sprouting
growth of new nerve endings which connect with other undamaged nerves to form new neuronal pathways
