3. (year 12-13)

the fight or flight response and stress

when faced with a stressor, the sympathetic nervous system triggers changes to prepare the body for action

fight or flight process

• increased heart rate/breathing rate - speed up blood flow/oxygen intake

• pupil dilation to improve vision

• sweat production to facilitate temperature regulation

• reduced functioning of digestive/immune systems to redirect and save energy

evolutionary perspective

acute stress responses are adaptive because they help humans survive immediate threats or predators

negative health impacts today

modern stressors rarely require physical running or fighting

high adrenaline

can lead to fatty deposits, hardening of arteries and increased risk of CHD

high cortisol

suppresses the immune system, making individuals more vulnerable to infections

localisation of the brain function

theory that specific functions/process’s are localised to and can be found in specific locations in the brain

where has the hippocampus/pre-frontal cortex been implicated to link to/linked to

hippocampus - implicated in the processing of memory

pre frontal cortex - linked to impulse control and executive functioning

what does the LOF model refute

previous assumptions that the brain is a singular component that carries out all functions shared

how can LOF be measured

MRI

fMRI

PET

how many hemispheres are there in the brain

2 hemispheres - covered by a thin layer known as the cerebral cortex

the lobes are responsible for specific functions within that hemisphere

what are the 4 lobes

frontal

temporal

parietal

occipital

frontal lobe

motor cortex - responsible for movement

prefrontal cortex - executive functioning

Broca’s area - speech production

temporal lobe

auditory area - auditory processing e.g. hearing

Wernicke’s area - language comprehension

hippocampus - memory and spatial navigation

parietal lobe

somatosensory cortex - touch sensation e.g. heat/pain

body orientation - understanding whether an object is on left or right of you

aids learning e.g. writing

occipital lobe

visual area - processing of visual info e.g. sight

understanding of distance and recognition of faces and objects

other brain components

cerebellum - balance and coordination

brain stem - controls involuntary responses

evolution of localisation of function in the brain

Phineas gage - personality changes caused by damage to the frontal lobe

limitations of LOF

Lashley - rats who had their cortex removed were still able to navigate and memorise routes so cognitive functions are shared across the cortex

what connects the two brain hemispheres

corpus callosum

what does “the brain is contralateral “ mean

right side of the brain controls the left side of the body and vice versa

stroke on left hemisphere will be PHYSICALLY evidence on right hand side of body

hemispheric lateralisation

division of functions between the 2 hemispheres

left hemisphere

generally lateralised to the processing of language

Broca and Wernicke’s area are found here

stroke in left hemisphere is likely to result in impaired speech

right hemisphere

generally lateralisaed to the processing of visual information, imagination and creativity

spatial information is lateralised to the right hemisphere

Broca’s area (read over)

• Paul Broca was a surgeon and neurologist interested in speech disorders.

• His patient, Louis Leborgne (nicknamed Tan), could only say the word “Tan” due to his neurological condition.

• Tan also had complete paralysis on the right side of his body.

• After Tan died in 1861, Broca performed a brain autopsy and discovered a lesion in the left frontal lobe. The rest of the brain was undamaged.

• Broca concluded that the left frontal lobe is responsible for speech production.

• This led to the term Broca’s aphasia, describing difficulty producing speech.

Wernicke’s area

• Around 10 years after Broca, Carl Wernicke identified patients who could speak fluently but struggled to understand language.

• He examined their brains and found damage to the left temporal lobe, close to the auditory area.

• This damage caused fluent but meaningless speech.

• Wernicke’s aphasia describes difficulty understanding language and accessing the correct words.