Lecture 5 - Functions of the Cortex

Question 1

Describe the structure of Cortex

Answer 1

• 2 hemispheres
• Sulci = sunken
• Gyrus = bumps
• Grey matter: learning, connections between neurones
• White matter: axons, connections within neurones

Question 2

What are the key terms in term of location?

Answer 2

• Anterior = front
• Posterior = back
• Dorsal = top
• Ventral = bottom
• Medial = middle
• Lateral = outward

Question 3

What did Penfield do?

Answer 3

• Electrodes on brain to stimulate different parts
• No pain sensors
• Can label and map cortexes

Question 4

What is the difference between primary and association cortexes?

Answer 4

• Primary = direct input from senses
• Association = integrates info, understands things from primary cortex
• Sensations become more complicated when you move from primary areas to association areas
• Brain can interpret things that are not there e.g phantom limb syndrome
• Frontal cortex = planning of behavioural responses

Question 5

What are the different lobes and their functions?

Answer 5

• Frontal lobe: planning, reasoning, attention/inhibition, made of association areas, CONTAINS MOTOR CORTEX
• Parietal lobe: Somatosensory cortex - sensory info and primary sensory input. Speech, taste, reading
• Occipital lobe: info from eyes - visual
• Temporal Lobe: hearing, smell association area is making sense of language. Medial temporal lobe = learning & memory

Question 6

What is Cognitive Neuropsychology?

Answer 6

• Injury in brain leading to deficits

Question 7

What are examples of brain damage?

Answer 7

• Traumatic: brain bounces around
• Progressive: Neurones in brain die, gets worse over time
• Surgery: lobotomy
• Bacterial Infection
• Strokes: lack of oxygen to brain due to blockages

Question 8

What are some of the odd behaviours displayed when the frontal lobe is damaged?

Answer 8

• Cannot inhibit emotions properly
• Characteristic behaviour: someone had to remove faeces with her hands and threw prosthetics
• Phineas Gage: personality changes and loss of social inhibition
• Pick’s Disease: type of dementia: parts of brain shrink due to lack of cells

Question 9

What is executive function?

Answer 9

• Top-down regulation of behaviour/cognition inc. problem solving
• Can be seen through stroop effect: have to inhibit natural response to read

Question 10

What happened in the stroop test for patients with damage to different areas in the frontal lobe?

Answer 10

• Damage to Anterior CIngulate Gyrus (ACG) = poor performance
• Unable to inhibit reading the word
• Poor executive function

Question 11

What is BADS

Answer 11

• Behavioural assessment of the Dysexecutive Syndrome
• Designed to assess range of executive functioning
• Consists of 6 tests inc. rule shift card, patients struggle with shifting rules and will perservere with old rules

Question 12

What is the ventral stream?

Answer 12

• Primary Visual Cortex to Posterior parietal cortex if asking where, and to inferotemporal cortex if asking why
• Part of association cortex of visual system, to recognise objects and faces

Question 13

What happens if you damage the ventral stream?

Answer 13

• Capgras syndrome: think someone you know is an imposter
• Connection between person and emotional aspect is disconnected, recognition available but affection is not present
• Prosopagnosia: impaired recog of familiar faces - ventral route impaired and retrieval of contextual info not available

Question 14

What are the deficits associated with lesions in the parietal lobe?

Answer 14

• Benson’s Syndrome: another form of dementia - patients judge aspects of space - impairs ‘where’ pathway
• Stroke: Ischemic - stops due to blood clot. Most common is middle cerebral artery (MCA)
• Visual Neglect: drawing half of things