Cognitive Functions - Chapter 27 Flashcards
Where are cognitive functions orchestrated in the brain?
Association cortices
How is the cortex organized?
Internal structure, organization, connectivity/wiring
Sensorimotor organisms
Sensory organs reached, motor interactions
Cognition
“in between” info - memory, learning, attention, executive functions, consciousness
Eric Kandel
Cognitive neuroscience is the “New science of mind”
Whats the most ancient cortex?
Paleocortex (pyriform cortex - olfactory system)
3 layers
Neocortex(Motor cortex) - how many layers?
6 layers
How many layers in the Archiocortex?
4 layers
What are the 2 ways of characterizing cortex? What do they mean?
1)cytoarchitecture: where they are located
2)myleoarchitecture: how much myelin do the axons have
Canonical circuit
Layers of neurons passing info down 6 layers. All have primary input and output targets, Have vertical connections and horizontal connections. Cells with similar functions are aligned radially (Diagonally). Interneurons within layers give rise to axons that extend horizontally.
Where do layers 1-3 send outputs to?
Cortical areas. 3 is cortical areas on opposite hemisphere
Where do layers 4-5 send outputs to?
Subcortical structures (e.g striatum, superior colliculus)
Where does layer 6 send outputs to?
Thalamus
Korbinian Brodmann - Cytoarchitecture
“Regions of the brain with similar structures in both cell type layering could produce a specific function”
Histological staining techniques
What was the first area to be localized in the brain?
Broca’s area - speech
Brenda Milner
Memory - temporal lobe
Phineas gage
PFC
Wilder Penfield
Neurosurgical patients. Motor and sensory homunculi.
Neuropsychological testing
e.g test for memory
combined with functional neuroimaging + neuromodulation(TMS and IDCS)
Thalamic nuclei: Pulvinar
Parietal Association
Thalamic nuclei: medial dorsal
Frontal Association
Where does the majority of input come from?
Corticocortical connections
Input from same hemisphere
U - shaped fibers / long association fibers
Interhemispheric input
Long association through corpus callosum
Association cortices are modulated by what 4 nuclei? Where are they located? What do they promote?
Cholinergic - brainstem and basal forebrain: memory, learning, attention
Dopaminergic - midbrain: pleasure, salience, motivation, reward-learning
Noradenergic - brainstem: wakefulness, stress-reaction
Seratoninergic - brainstem: mood, memory processing, sleep
Delivering continuous pulses to a brain area activates or inhibits the function?
Inhibits
Define an association area
Each association area is defined by a distinct
Human Connectome Project
Mapping neuronal connections
Parietal lobe? Stuff in it?
Attention and perceptual awareness
Somatosensory cortex
Somatosensory association area
Speech
Taste
Reading
Temporal lobe? Stuff in it?
Categorization, recognition, semantic memory
Smell
Hearing
Auditory association area
Frontal lobe?
Planning and regulation of behavior (decision making and behavioral inhibition)
Frontal association area
Speech
Motor cortex
Stuff in the occipital lobe?
Visual association cortex
Vision
Lesion on right parietal association cortex
Severe left visual neglect
Left hemisphere parietal cortex lesion leads to…
Minimal right visual field neglect
Partial bilateral lesion to parietal association cortex
Severe right neglect
Which side of the parietal cortex gives spatial awareness for both the left and the right sides of my field?
Right side
Attention sensitive neurons fire when…
person pays attention
Wernicke’s Area
Lesion in temporal lobe - can’t understand what people are saying to them and what they are saying - language comprehension area
Ventral - WHAT pathway
Temporal association cortex - Agnosia
Ventral/inferior temporal surface
Agnosia
What pathway
Specific type of stimuli according to region
Anterior pole
Semantic Dementia - Cannot associate words with their meaning (Anomia)
Lesion to Visual Word For Area - Left Temporal Lobe:
Alexia
Lesion to right temporal lobe - Fusiform Face Area (FFA)
Prosopagnosia
Parahippocampal place area (PPA)
Place and scene processing
Apperceptive and Associative
IDK LOOK
Frontal Association Cortex
Self in relation to world - what is socially acceptable
select, plan and execute appropriate behavior
Lesion changes persons personality
Functional Deficits: Frontal Association Cortex
Cognitive disabilities, impaired restaint, disordered thought, perseveration and inability to plan appropriate action
Phineas Gage, basically became a dick and couldn’t plan ahead
Joe A , sexually inappropriate, couldnt plan for the future, not appropriate and lost initiative and creativity
Frontal Lobotomies
Wisconsin card sorting task
Frontal association cortex
Short term memory functions and planning - Frontal association cortex
Dorsolateraly
Value and decision making - Frontal Association Cortex
Ventromedially
Delayed response task
“Use remembered info to plan and guide appropriate sequences of behaviour
Large Scale Brain Networks
Interconnected networks function together
Cortex - explain
Wrinkled, two dimensional sheet of layered neurons
2 types of association cortices -3ary areas
Unimodal and multimodal
“regions of cortex where injury causes cognitive deficits that cannot be explained by impairment of sensory or motor function alone”
How does info flow in the CNS - give example
Sensory organs ->primary sensory areas ->secondary(sensory areas that are unimodal association cortices) and tertiary secondary ->multimodal association(here behavioural response gets organized)
prefrontal cortex->secondary motor areas->premotor cortex and supplementary motor area ->organize motor patterns ->primary motor cortex
top-down modulation
what I’ve already learned influences what I perceive
Parietal association cortex
Attention and awareness of the body and the stimuli around it
Integrates somatic, visual, acoustic and vestibular sensory info - spatial cognition and motor control of the eyes and extremities
Attention sensitive neurons
Prosopagnosia
Right temporal lobe (FFA)
Limbic Association Cortex
Learn from outcomes
Limbic - Orbital and ventromedial cortex
connected to amygdala and hippocampus - emotional processes
Hippocampal formation
Mediates formation of long-term memories and then transfers them to the neocortex(higher order functions)
