Lecture 5 - Functions of the cortex Flashcards
What are sulci and gyri in the brain? What do they do?
- Sulci are sunken grooves
- Gryri are raised bumps that give the brain its textured appearance
- They increase cortical surface area
What are the four main lobes of the cortex and their general functions?
- Frontal lobe: Planning, attention, inhibition
- Parietal lobe: Somatosensory processing, speech, taste, reading
- Temporal lobe: Hearing, face recognition, memory
- Occipital lobe: Vision
Define grey and white matter in the brain
- Grey matter contains neuron cell bodies
- White matter consists of axons that connect different brain regions
Name and define the key anatomical (directional) terms
- Anterior (rostral): front
- Posterior (caudal): back
- Dorsal (superior): top
- Ventral (inferior): bottom
- Medial: toward the middle
- Lateral: toward the side
How did Wilder Penfield (1891-1976) contribute to neuroscience
Penfield’s work laid the foundation for modern neuroscience, particularly in
understanding epilepsy, memory, and brain function localization
What is executive function and which brain region is it associated with?
Executive function involves cognitive control processes like planning, problem-solving, inhibiting responses, and adapting behaviour. It is primarily associated with the frontal lobe
What does the Stroop What does the Stroop Task test, and what does poor performance indicate?
The Stroop Task tests response inhibition.
Poor performance (especially with incongruent colour-word trials) may indicate damage to the anterior cingulate gyrus (ACG), suggesting poor executive function
What is the Behavioural Assessment of the Dysexecutive Syndrome (BADS)?
It is a test assessing/measuring executive functions like shifting rules and searching strategies.
Examples:
- Rule shift cards: adapt to changing instructions
- Key search: draw a logical search path
What was the purpose and outcome of frontal lobotomies?
Frontal lobotomies aimed to reduce emotional disturbances by severing thalamocortical fibres. They caused blunted emotions and loss of cognitive control
What is V1 and what does it do?
V1 is the primary visual cortex in the occipital lobe. It processes basic information and sends it to V2-V5 for further analysis.
What does V4 do and what happens if it’s damaged?
V4 processes colour and complex shapes. Damage causes achromatopsia (loss of colour vision)
What is V5 responsible for and what is akinetopsia?
V5 processes motion. Akinetopsia is the inability to perceive motion due to V5 damage
What is Capgras syndrome and its neurological basis?
Capgras syndrome is characterised by a delusion where someone believes a loved one is an imposter. FFA (Face recognition) is intact but amygdala (emotional processing) is disrupted
What is prosopagnosia and what causes it?
Prosopagnosia is the impaired ability to recognise faces, often due to damage in the Fusiform face Area (FFA) in the ventral stream
What is posterior cortical atrophy (PCA), also called Benson’s syndrome?
PCA is a visual variant of Alzheimer’s with symptoms like alexia (word blindness), depth perception problems, and visual agnosia (inability to recognise or interpret objects/faces)
What are the two types of brain tissue?
- Grey matter (neuron cell bodies)
- White matter (myelinated axons)
What did Wilder Penfield and Boldrey (1937) discover? How did they do it?
Penfield and Boldrey (1937) contributed to the understanding of the human brain’s functional organization. They mapped the sensorimotor cortex, particularly the primary motor (precentral gyrus) and somatosensory (postcentral gyrus) areas of the brain through electircal stimulation in epilepsy patients
What are the motor and somatosensory homunculi?
They are visual representations of how body parts are mapped onto the cortex; more of the cortex is dedicated to areas requiring fine control/sensitivity (e.g., hands, face)
Give 5 causes of brain damage
- Traumatic Brain Injury (TBI): via accidents, sports
- Progressive diseases: e.g., Huntington’s Parkinson’s
- Stroke
- Surgery
- Infections
What are the effects of frontal damage?
- Personality changes
- Social disinhibition (e.g., Phineas Gage)
- Poor planning
- Odd behaviours
- Executive dysfunction
What is Pick’s Disease and which lobe does it affect?
Pick’s Disease is a type of frontotemporal dementia affecting the frontal lobe, causing behavioural and personality changes
Describe the Freeman-Watts Procedure
The Freeman Watts Procedure is a common method for lobotomies used to treat psychiatric disorders. It is controversial due to serious the ethical and medical consequences
What are the dorsal and ventral pathways?
- Dorsal (“where”): V1 –> V2 –> V3/V3A –> V5 –> Posterior Parietal Cortex (motion, spatial awareness)
- Ventral (“what”): V1 –> V2 –> V4 –> Inferotemporal Cortex (object/face recognition, colour)
What is V3/V3A responsible for?
Depth and motion
