Lesson 6 – Localisation of Function Flashcards
What is the localisation of function?
Localisation of function- refers to principle that functions (language, memory, hearing 👂 etc) have specific locations within 🧠
Where is the visual 👀 cortex located?
Visual 👀 cortex is in occipital lobe of BOTH hemispheres of 🧠
How is visual information passed to the visual cortex?
1) Visual processing starts in retina where light 💡 enters and strikes photoreceptors
2) Nerve impulses from retina transmitted to 🧠 via optic nerve
3) Majority terminate in thalamus (acts as relay station- passing info onto visual cortex)
Where is the auditory cortex located?
Auditory 👂 cortex lies within temporal lobe in BOTH hemispheres of 🧠
How is auditory 👂 information passed to the auditory cortex?
1) Auditory pathway begins in cochlea in inner 👂 where sound waves 🌊 converted to nerve impulses
2) Nerve impulses travel via auditory nerve to auditory cortex
3) Basic decoding occurs in 🧠 stem
4) Thalamus carries out further processing before impulses reach auditory cortex
What is the motor cortex responsible for?
Motor cortex responsible for generation of voluntary motor movements
Where is the motor cortex located?
Located in frontal lobe of BOTH 🧠 hemispheres
What does the somatosensory cortex detect?
Detects sensory events arising from different regions of the body
Where is the somatosensory cortex located?
Located in the parietal lobe of BOTH hemispheres
How does the somatosensory cortex work?
Using sensory info from skin- somatosensory cortex produces sensations of touch, pressure, pain and temperature- localises to specific parts of body
How many language centres are there?
2
What are the 2 language centres?
1) Broca’s Area
2) Wernicke’s Area
What was wrong with patients who had issues with their Broca’s area?
They had difficulty producing language/speech (Expressive Aphasia-caused by damage to Broca’s area- affects language production but NOT understanding)
Where is the Broca’s area located?
LEFT hemisphere of frontal lobe
How specifically is speech affected with expressive aphasia?
Speech lacks fluency and patients have difficulty with certain words which help sentences function (e.g. ‘it’ and ‘the’)
Where is the Wernicke’s area located?
LEFT hemisphere of temporal lobe
What was wrong with patients who had damaged their Wernickes area?
Receptive Aphasia- could speak BUT unable to understand language … responses ✖️ make sense BUT fluency of language was normal
How many lobes does the brain have and what are they?
1) Frontal lobe
2) Parietal lobe
3) Temporal lobe
4) Occipital lobe
Where are the lobes located in the brain?
See page 2 of L6 Notability Biopsychology Notes
What are the evaluation points of Localisation of Function?
👎- Equipoteniality theory (Lashley- 1930)- higher mental functions ✖️ localised- intact areas of cortex take over responsibility for specific cognitive function following injury to area normally responsible
👎- Dronkers et al. (2007)- re-examined preserved 🧠 of 2 Broca’s patients- MRI scans revealed that several areas of 🧠 damaged- damage to Broca’s area cause temporary speech disruption BUT ✖️ usually result in severe disruption of language- language ⬆️ widely distributed skill than originally 💭
👎- Bavelier et al. (1997)- found individual differences in which 🧠 areas activated when person engaged in silent 📖- observed activity in right temporal lobe, left frontal lobe and occipital lobe
👎- may be how 🧠 areas communicate with each other ⬆️ important than specific 🧠 regions
- Dejerine (1892)- reported patient ✖️ read 📖 due to damage between visual cortex and Wernicke’s area
