Biopsychology - Localisation of Function Flashcards
What is the theory of localisation of function in the brain?
The theory states that different areas of the brain are responsible for different behaviours, processes, or activities.
What was the holistic theory of the brain?
Before localisation was supported, scientists generally believed that all parts of the brain were involved in processing thoughts and actions.
Who organised the localisation of function?
Broca and Wernicke organised localisation of function (cortical specialisation).
How is the brain divided?
The brain is divided into two symmetrical halves (left and right hemispheres). Some physical and psychological functions are controlled by a particular hemisphere.
What is the cerebral cortex?
The outer layer of both hemispheres is the cerebral cortex, like a tea cosy covering the inner parts of the brain. It is 3mm thick and separates us from lower animals.
What is the cortex of both hemispheres subdivided into?
The cortex is subdivided into four lobes: frontal, parietal, occipital, and temporal.
What is the function of the motor area?
Located in the frontal lobe, the motor area controls voluntary movement on the opposite side of the body. Damage to this area may result in a loss of control over fine movements.
What is the function of the somatosensory area?
Located at the front of the parietal lobe, it processes sensory information from the skin, such as touch, heat, and pressure. It is denoted by sensitivity, e.g., receptors for our face and hands occupy over half of the somatosensory area.
What is the visual area responsible for?
The visual area is located in the occipital lobe and receives and processes visual information. Each eye sends information from the right visual field to the left visual cortex and vice versa. Damage to the left hemisphere may produce blindness in the right visual field of both eyes.
What is the auditory area responsible for?
The auditory area is in the temporal lobe and analyses speech-based information. Damage may produce partial hearing loss; the more extensive the damage, the greater the loss.
What is the function of Broca’s area?
Broca’s area, located in the left frontal lobe, is responsible for speech production. Damage causes Broca’s aphasia, which is characterised by slow, laborious, and lacking fluency in speech.
What is the function of Wernicke’s area?
Wernicke’s area, located in the left temporal lobe, is responsible for language comprehension. Damage causes Wernicke’s aphasia, where patients produce nonsense words (neologisms) as part of their speech.
What is one evaluation point for localisation of function?
A compelling argument against LOF is plasticity. This supports the holistic theory, as after damage to one part of the brain (e.g., through accident), the rest of the brain appears to reorganise itself to recover lost function. Lashley described this as the law of equipotentiality, suggesting functions are not strictly localised.
What is another evaluation point for localisation of function?
Supporting evidence that neurological functions are localised: for instance, Petersen used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area during a reading task. This provides sound scientific evidence of localisation.
What is a further evaluation point for localisation of function?
Tulving revealed that semantic and episodic memories reside in different parts of the prefrontal cortex. Further evidence supports LOF, particularly in memory.
