Cerebral cortex and mental health Flashcards
From which cortices does the association cortex take information?
- Primary and secondary sensorimotor cortices
- Brain stem
- Thalamus
To which cortices does the association cortex send information?
- Cerebellum
- Basal ganglia
- Hippocampus
Is there information flowing between the different association cortex?
Yes
What are the top-down effects on perception?
From higher level areas to modulate activity in primary sensory cortex
-> our expectations from context or prior experience can influence how we interpret ambiguous stimuli
How does the association cortex modulate top-down effects on our perception?
Integrates sensory and motor information
- to produce meaningful perception of the world around us
- allowing for abstract representation and flexible behaviour
What are the subdivisions of the association cortex?
- Posterior (parietal) association area
- Anterior (frontal) association area
- Limbic (temporal) association area
What is the posterior (parietal) association area responsible for?
- Attention
- Convergence of visual, auditory, somatosensory information
What is the anterior (frontal) association area responsible for?
- Planning
- Decision making
- Working memory
What is the limbic (temporal) association area responsible for?
- Long term memory
- Emotional responses
- > affect our behaviour
What are the executive functions?
- Generating
- Planning
- Monitoring
- Task-switching
- Inhibition
Who developed the Wisconsin card sort test?
What does it test?
Grand and Berg (1948)
- cognitive reasoning
- ability to adapt to changing rules
What does the Tower of Hanoi test?
- Cognitive abilities
- you have to plan several moves in advance
- > ability to plan
What does the Stroop test?
Inhibition
What does the N-back task test?
Working memory
- you have to remember which objects have been shown, tap the same object when it comes up
What are the 2 sources of evidence on executive functions and frontal lobe deficits?
- Neuroimaging (e.g. fMRI)
- Neuropsychological studies of acquired brain damage to frontal lobes (e.g. Phineas Gage)
What are the findings of fMRI studies on frontal lobe activity?
- Activation in frontal regions is greatest for novel tasks
- Decreases across the blocks of an inhibition task as the volunteers become more practised at the test
What characterises Autism spectrum disorder (ASD)?
> Impaired social and communicative development
> Rigid and repetitive behaviours and interests
> Poor performance on executive function tasks
- Tower of Hanoi, Wisconsin card sort test
> Dislike for change
> Preference for narrow routines and repetition
-> impairment in frontal functions necessary for adaptive responses to change and novelty
What is the Theory of mind?
The ability to recognise others’ thoughts, beliefs and desires, putting yourself in another person’s shoes
How is ASD associated to the Theory of mind?
- People with ASD tend to have difficulty understanding what others are thinking
- They often get confused by social situations and struggle with communication
What are the Theory of mind tasks?
- Animations (Frith-Happé triangles animations)
- Static cartoons
- Written stories
-> Cause healthy volunteers to think about other people’s thoughts
How do people with ASD often react to the Frith-Happé triangles animations?
Often see moving triangles and don’t attribute thoughts to them
What do fMRI results show when people with ASD complete the Theory of mind animations task?
Their brain activity differs from healthy controls in
- extra-striate cortex
- basal temporal
- superior temporal sulcus
- medial prefrontal
- even when they answer the questions correctly
What do brain scans suggest about the top-down effect in people with ASD?
Reduced top-down effect, especially when they’re looking at faces vs. other objects
What characterises the cerebral connectivity in ASD?
Atypical cerebral connectivity
- no circumscribed lesions, unlike patients with acquired frontal lobe damage
