AQA A level Psych - Biopsychology - Localisation of function

What does localisation of function mean in the context of the brain?

It refers to the idea that different parts of the brain perform different tasks and are involved with different parts of the body.

What is hemispheric lateralisation?

It is the division of the brain into two symmetrical halves, where certain physical and psychological functions are controlled by a particular hemisphere (lateralisation)

Which hemisphere of the brain controls activity on the right side of the body?

The left hemisphere.

What is the cerebral cortex?

The outer layer of both hemispheres of the brain, covering inner parts of the brain

How is the human cortex different from other animals?

Far more developed and appears grey due to location of cell bodies

What does increased grey matter in the brain suggest?

It indicates a greater density of neurons, which suggests higher levels of functioning.

Where are the language centres located in the brain?

Language is primarily restricted to the left side of the brain.

What did Broca (surgeon) identify in the 1880s?

A small area in the left frontal lobe responsible for speech production, known as Broca's area.

What is Broca's aphasia?

A condition characterised by slow speech and lack of fluency due to damage in Broca's area.

What did Wernicke describe?

People who had no problem producing language but difficulties understanding - speech fluent but meaningless

What did Wernicke discover about language processing?

He identified Wernicke's area in the left temporal lobe, responsible for language understanding, where damage results in Wernicke's aphasia.

What is characterised by Wernicke's aphasia?

Nonsense words

What 4 lobes can be cerebral cortex be split into?

Parietal, occipital, temporal, frontal

Back of the frontal lobe

Motor area which controls voluntary movement in the opposite side of the body

What occurs with damage to the motor area?

Loss of control over fine movements

Front of both parietal lobes

Somatosensory area where sensory info from skin is represented

Back of brain (occipital lobe)

Visual area where each eye sends info from right visual field to the right visual cortex

What occurs if there's damage in the left hemisphere (visual area)

Blindness in part of the right visual field in each eye

Temporal lobes

Auditory area which analyses speech-based info

Damage to auditory area

Partial hearing loss

What evidence supports the localisation of function regarding Broca's area?

Broca's patient 'Tan' could understand language but could only express the syllable 'tan,' and 8 similar patients had lesions in the left frontal hemisphere.

What led Broca to create Broca's area

Patients with damage to their right frontal hemisphere didn't have the same language problems. Led Broca to identify a 'language centre' in frontal lobe of left hemisphere

What happened to Phineas Gage?

Iron rod went through eye and brain. Part of the brain damaged in his accident was the area in frontal cortex associated with planning, reasoning and control

What significant change occurred in Phineas Gage after his accident?

His personality changed from mild-mannered to rude and hostile

What limitations exist in generalising findings from Phineas Gage's case?

His case is unique, and factors such as infection and trauma may have influenced his behavior changes.

What is a criticism of studies based on unique cases of brain damage?

They may lack generalisability, as individual cases may not represent broader population responses.

Plasticity

Fact that he survived and that his brain still functioned and allowed him to live for many more years suggests that his brain was able to reorganise itself and recover

Functional recovery theory

Suggests areas of the cortex could take over responsibility for specific cognitive functions following brain injury

How does plasticity and functional recovery in context of PG cast doubt on LOBF?

Suggesting that functions aren't localised to one region as other regions can take over specific functions following brain injury