BIOPSYCHOLOGY - Localisation Of Function Flashcards
At face value, what three parts is the brain divided into?
the forebrain (front part of the brain), midbrain (middle part of the brain) and hindbrain (back part)
What are the 4 regions of the brain?
- cerebrum
- diencephalon
- brain stem
- cerebellum
Function of the CEREBRUM
- located in the forebrain as the largest part of the brain split into two hemispheres
- both hemispheres communicate to each other via corpus callosum
- contains 4 lobes (frontal, occipital, temporal, parietal)
frontal lobe function
involved in thoughts and production of speech
occipital lobe function
involved with processing of images
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temporal lobe function
dealing with cognitive skills
parietal lobe function
deals with sensory information
Function of the DIENCEPHALON
- found inside the cerebrum above the brain stem
- responsible for sensory function, food intake and sleep cycle
- split into 4 sections (thalamus, hypothalamus, epithalamus, subthalamus)
Function of the CEREBELLUM
- found below and behind the cerebrum and attached to the brainstem
- controls motor function, balance, and interpretation of information sent to brain via senses
Function of the BRAINSTEM
- governs blood pressure
- breathing
- heartbeat
- some reflexes
- motor and sensory neurons pass through the brainstem, so impulses can travel between the brain and spinal cord
What is localisation of function
the principle that specific functions such as language or memory have specific locations in the brain
Function of the somatosensory cortex
- recieves sensory input from receptors in the skin including touch, pain, pressure and temperature from all areas of the body surface
- located in the parietal lobe of the brain
- top of the body is represented at the bottom of the SC and vice versa
- amount of somatosensory area dedicated to a body part reflects its sensitivity
- face and hand take up over half of the somatosensory area
Function of the motor cortex
- responsible for the generation of voluntary movements
- located in back of frontal lobe
- both hemispheres have a motor cortex and function contralaterally
- different parts of the motor cortex control different parts of the body
- these parts are arranged logically e.g. part controlling foot is next to part controling leg
input + damage
Visual and auditory centres
- recieves input directly from eyes and ears
- damage to them can lead to blindness and deafness
Function of the visual centre
- primary visual centre located in the occipital lobe
- secondary visual areas provide additional processing to convert sensation into perception
- …because damage to SVAs does not lead to blindness but a loss of aspects of visual perception such as…
- Prosopagnosia (loss of ability to recognise and identify faces)
- Achromatoposia (loss of the ability to see in colour)
Function of the auditory centre
- concerned with hearing
- lies within the temporal lobes in both hemispheres where the auditory cortex is located
- auditory pathways begin in the inner ear where soundwaves are converted to nerve impulses…
- which travel via auditory nerve to the auditory cortex
name the two language centres
Brocas area and Wernickes area
Function of Broca’s Area
- named after Paul Broca
- …who treated a patient named Tan who could understand spoken language but could not speak or put his thoughts down in writing
- located in the posterior portion of the frontal lobe of the left hemisphere
- believed to be important for SPEECH PRODUCTION
- damage to the Broca’s area is known as Broca’s aphasia
Function of Wernicke’s Area
- area of the brain dedicated to understanding language
- located in the posterior portion of the left temporal lobe
- damage to W’s A is Wernicke’s aphasia
Wernicke’s proposition for language centres
- language involves separate motor and sensory regions located in different cortical regions
- motor: Broca’s area close to the area controlling the mouth, tongue and vocal chords
- sensory: Wernicke’s area close to regions of the brain responsible for auditory and visual input
- there is a neural loop known as the ARCUATE FASICULUS running between Broca’s and Wernicke’s area
Strengths of localisation of function
- brain scan evidence
- case study evidence
- support from aphasia studies
Brain scan evidence AO3 localisation of function
Peterson et al used brain scans to show how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task. This suggests that language is localised to these two areas and this has high validity because it is backed up by objective scientific evidence.
Case study evidence AO3 localisation of function
Phineas Gage suffered an accident where his frontal lobe was forced out of his brain by a pole. This caused a complete change of personality which suggests that our personality may be localised to the frontal lobe. Science has since shown that the frontal lobe governs mood.
Support for aphasia studies AO3 localisation of function
- aphasia is the inability to produce or understand speech
- studies have shown that people who suffer damage to the Broca’s area suffer expressive aphasia
- studies have shown that people who suffer damage to the Wernicke’s area suffer receptive aphasia
- therefore supports brain localisation
