1210 Week 22

1210 Week 22

1. Lecture 1

   • Memory
     • learning - process of aquiring new information
     • memory - persistance of learning in a state that can be retrieved later
     • sensory immediate memory - milliseconds to seconds, iconic, audition and echoic
     • senses - sensory memory - short term - long term
     • flashbulb memories - emotionally charged event, very vivid, not highly accurate
     • olfaction and memory - certain smells invoke memories relating to the smell
     • music and memory - musical training/ music listening is thought to improve memory
     • memory training - daily memory training is thought to improve memory function
     • memory and age - memory function declines as you age
     • amnesia: anterograde - can't form new memories, retrograde - difficulty retrieving memories
     • patient H.M. - had a bilateral medial termoral lobectomy - before surgery had normal cognitive functioning intact short term, procedural and declarative memory after the surgery had anterograde declarative memory
     • synaptic plasticity: hippocampus - long term potentiation and depression in OA1 mediated by NMDA, major mechanisms for declarative memory, cerebellum - LTD, purkinje cells mediated by AMPA, major mechanisms for procedural learning
   • Short Term Memory
     • short term memory - seconds to hours holds about 7 items
     • working memory - limited capacity with the ability to perform mental operations
     • work memory model - central executive controls the visuospatial sketchpad and phonological loop
     • central executive - command and control centre, phonological loop - mechanism for acoustically coding information, visuospatial sketchpad - information storage in visuospatial codes
     • phonological loop - left supramarginal gyrus - area 4, left premotor region - area 6
     • visuospatial sketchpad - parietooccipital regions of both hemispheres but is right dominant
   • Long Term Memory
     • long term memory - days to years
     • long term declarative - explicit memory recalled by conscious effort, highly flexible, epidsodic - events/personal experiences, semantic - facts
     • formation occurs in the hippocampus, mammillary body, dorsal thalamus and rhinal cortex
     • storage is in the neocortex and frontal cortices on the dorsal lateral and anterolateral aspects
     • long term non-declarative - procedural/implicit memory, skills and assiciations at the unconscious level, rigid store, commonly involved in training reflexive motor and perceptual actions
     • procedural learning - non-associative: habituation - motor response decreases, sensitisation - motor response increases
     • procedural learning - associative: classical - change in passive motor response after association between 2 stimuli, instrumental/operant - change in active motor response after association between action and reward
     • brain systems that underlie procedural memory - basal ganglia, prefrontal cortex, amygdala, cerebellum and sensory cortex

2. Lecture 2

   • Speech
     • speech is produced by the lungs, pharynx, larynx, oral cavity and nasal cavity
     • language is localised and lateralised - left hemisphere
     • Broca's area - left frontal cortex, language production, aphasia - can't form words
     • Wernicke's area - left temporal cortex, understanding language, aphasia - can't form coherent sentences
     • conduction aphasia - lesions between the 2 areas, can't repeat words
   • Cognition
     • cognition occurs in the association cortex of the frontal, temporal and parietal lobes
     • association cortices receive input directly from the ipsilateral/interhemispheric cortico-cortical connections
     • association cortices receives processed information from the thalamus - pulvina and medial dorsal nuclei
     • associatation cortices receive subcortical imputs from dopaminergic neurones in the midbrain, NA/5-HT neurones in the reticular formation and cholinergic neurones in the brainstem and basal forebrain
     • generation of emotions involves evaluation of the event, experience of feeling and then expression of behavioural and physiological response
     • emotional response consists of behavioural, autonomic and hormonal changes
     • no one is fully sure which areas of the brain are involved in emotional processing but it includes the limbic system, amygdala, orbitofrontal cortex, cingulate gyrus, thalamus and ventral basal ganglia
     • executive control systems - oversees many complex activities and has to make desisions
     • the prefrontal cortex, dorsolateral PFC, ventromeidal PFC, anterior cingulate cortex, posterior parietal cortex and the basal ganglia from the ECS
     • dorsolateral prefrontal cortex - initiates and shifts behavious, inhibits behaviour and simulates behavioural consequences
     • ventromedial prefrontal cortex - inhibits socially inappropriate behaviour and controls sensitivity to the consequences of actions
   • Attention
     • attention - preferential processing of sensory information - allows for covert shifting and decreased reaction times but is subject to external influences
     • ADHD - inattention, hyperactivity, impulsiveness and affects the prefrontal cortex and basal ganglia
     • contralateral neglect syndrome - lesion to right parietal cortex, inability to attend to objects in a portion of space, failure to attend to stimuli presented on the opposite side to the lesion
     • balint's syndrome - lesion to parietal cortex, simultanagnosia, optic ataxia, ocular apraxia