Biopsych: Localisation Of Brain Flashcards
What is the localisation of functions in the brain?
Prior research believes in the holistic explanation, where all parts of the brain are involved in all processing. Yet localisation of functions means that certain areas of the brain are responsible for certain processes, behaviours and activities.
What are hemispheres in the brain?
- the brain is divided into 2 symmetrical halves, the left and right hemisphere
- some functions are dominated by 1 hemi (lateralisation)
- activities on the left side of the body is controlled by the right hemi and vice versa
- the outer layer of both hemis is called the cerebral cortex, a 3mm layer covering the inner parts of the brain
- this separates us from animals as the cortex is developed and appears grey (grey matter)
What is the visual cortex?
The occipital lobe processes vision. What is seen in the left visual field, is processed in the occipital lobe in the right hemi and vice versa. The left visual field is what the left of both eyes see, so damage in the occcipital lobe in the left hemi would cause blindness in the right visual field of each eye.
What is the Auditory cortex?
The temporal lobes process the auditory info, allowing us to perceive sound in the environment. Signals are sent from the auditory cortex to other parts of the brain to process high level info -e.g. to the Wernickes area to understand comprehension
What is the motor cortex?
Sits in the back of the frontal lobe in both hemis. Controls voluntary behaviour, similar to the visual cortex, the left hemi processes movements by the right side of the body and vice versa. Damage to this area of the brain would result in a loss of control of the fine movements.
What is the Somatosensory Cortex?
Processes sensory info from the body (e.g. heat, pressure, touch). This area is present in both hemis and is separated from the motor cortex of the brains central sulcus. Each part of this cortex is allocated to a part of body, some of the body takes up more area on the somatosensory cortex.
What is the language centres of the brain?
Language is processed only by the left hemi
What is the Broca’s area?
In the frontal lobe, found in an area of the brain that was responsible for speech production. Damage causes aphasia, which is slow and laborious speech that lacks fluency. This can be seen in the case study of Tan
What is the Wernicke’s Area?
Wernicke researched into the patients that could speak fine but lacked the ability to understand and comprehend speech. Language they produced was fluent but meaningless. Wernicke coined an area in the temporal lobe, Wernicke’s area, in charge of language comprehension. Also coined Wernickes aphasia.
What did Peterson et al do to support localisation of function in the brain?
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, suggesting that these areas of the brain have different functions. Both are active where they should be. Although this lacks ecological validity.
How did Tulvings long term memory study support this theory?
Rereleased that semantic and episodic memories reside in different parts of the prefrontal cortex. Also lacks ecological validity.
How did Dougherty et al’s study support this localisation of functioning theory?
Reported on 44 people with OCD who had undergone a cingulotomy (a neurosurgical procedure that involves lesioning of the cingulate gyrus). At post-surgical follow up after 32 weeks, a third had met the criteria for successful response to the surgery and 14% for partial response. Suggests LofF has practical applications in the development of more advanced treatments for serious mental conditions.
- lacks pop density as only ptps with OCD and quite a small sample
- lacks ecological validity.
What did Lashley find to refute LofF?
He removed areas of the cortex (between 10-50%) in rats that were learning a maze. No area was proven to be more important than any other in terms of the rats ability to learn the maze. The process of learning appeared to require every party of the cortex, rather than being confined to a particular area. Suggests intelligence is too complex to restrict to certain areas, suggesting LofF as more simple. Might not have the same response with humans, lacks ecological validly and unethical.
How does the case study of Phineas Cage refute the theory?
When the brain has become damaged, and a particular function has been compromised or lost, the brain appears to reorganise itself to recover the lost function. However lack of control over variable and cannot generalise as highly unique
