Biopsychology: Localisation of the Brain Flashcards
what is localisation?
Broca and Wernicke argued that localisation of functions is the idea that different parts of the brain perform different tasks and are involved with different parts of the body. if a certain part becomes damaged, the function associatedd with that area will be affected
what are the hemispheres?
the brain is divided into 2 hemispheres that our functions are controlled by a particular hemisphere (lateralisation). activity on the left-hand side of the body is controlled by the right hemisphere and vice versa.
what’s the cerebral cortex?
the outer layer of the hemispheres. it’s 3mm thick and seperates us from other animals . the cortex appears grey due to the location of cell bodies.
what are the 4 lobes?
frontal, parietal, occipital and temporal
what’s the different centres?
motor = frontal lobe, controls volunatry movement in the opposite side of the body. somatosensory = parietal lobe, sensory information from the skin is represented. visual = occipital lobe, information captured by the eye is sent to the opposite visual cortex. auditory = temporal lobe, analyses speech-based information.
what are the language areas?
Broca’s area = frontal lobe in the left hemisphere, responsible for speech production. (patient called Tan, all he could say). Wernicke’s area = temporal lobe in the left hemisphere, responsible for language comprehension
what’s the brain scan evidence for localisation? (A03)
Petersen 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 these areas have different functions. Tulving revealed that semantic and episodic memories reside in different parts of the prefrontal cortex. a number of highly objective methods of measuring brain activity exist, providing scientific evidence.
what’s neurosurgical evidence for localisation? (A03)
the practise of surgically removing areas of the brain to control aspects developed in the 1950s. Freeman developed lobotomies which were brutal and imprecise. Now it’s occassionaly used in extreme cases. Dougherty reported 44 OCD patients who had undergone a cingulotomy. post-surgery, 1/3 had met the criteria for a successful procedure. this strongly suggests behaviour associated with mental disorders are localised.
how does plasticity contradict localisation?
when the brain has become damaged through illness or accident and a function is lost, the rest of the brain appears to reorganise itself in an attempt to recover the lost function. this proves that areas of the brain don’t have specific functions if they can work together to make up for the damaged area.
