Brain plasticity

Plasticity

It can change and adapt over time

Synaptic pruning

Rarely used connections are deleted and frequently used connections are strengthened.

Maguire et al- brain plasticity

Studied brains of London taxi drivers and found significantly more grey matter in the posterior of the hippocampus than in a matched control group

This part of the brain is associated with the development of spatial and navigational skills.

A positive correlation was also found between the size of the posterior hippocampus and the time as a taxi driver.

This suggests that the brain is not fixed but rather plastic and can change and adapt based on experiences.

Draganski et al - further evidence

They imaged the brains of medical students 3 months before and after their final exams. Learning induced changes were seen to have occurred on the posterior hippocampus and the parietal cortex. As a result of studying for exams. The before and after provided a clear casual relationship showing that the learning had indeed induced changes within the brain showering that brain is not fixed but instead is plastic.

One weakness of brain plasticity

Brain plasticity is not always a positive thing and can lead to problems with functioning. The brains response to certain drugs in ur system is a form of plasticity and has highly negative consequences for the individual. Repeated drug use can change the reward system in the brain. This leads to a need for more drug use to get the same rewards. The addicts brain adapt in response to repeated drug use.

Functional recovery

Axonal sprouting and recruitment of homologous areas

Axonal sprouting

The growth of new nerve ending which connect with the undamaged nerve cells to form new neutral pathways

Recruitment of homologous areas

When a similar area of the brain on the opposite side is used to perform specific tasks. One example would be if Broca’s area was damaged the right side equivalent would carry out its functions. After a period of time, functionality may then shift back to the left side

Villablanca and hovda

strongest evidence for the ability of the brain to recover come from the most extreme brain abnormalities- a missing hemisphere.

They found that if a whole hemisphere is removed soon after birth then as an adult the person shows few behaviours and cognitive problems supporting the suggestion that brain is an active organ in its recovery, even from extreme brain deficits.

Split brain research - sperry

He studied 11 patients whose corpus collusion has been severed.

He asked participants to either describe what was seen or pick out from behind the screen by touch. A screen presented a word on one visual field and a different word to the different visual field.

When pps were asked to describe what was seen:

RVF - the patient can describe what is seen

LVF - the patient says there is nothing there because the right hemisphere doesn’t have a function of language.

When participant was asked to recognise by touch or draw what they had seen :

LVF - the patient cannot verbalise but can select the object behind the screen just by touch with the left hand or can draw the image with their left hand.