Lecture 15 Flashcards
Identify other sensory areas
-vestibular cortex
-somatosensory cortex
-visual cortex
-auditory cortex
-olfactory cortex
Function of primary sensory cortex
-localise and identufy sensory stimuli e.g. hot, cold, patterns all details
raw elements of inputs
Function of primary motor cortex
-trigger and execute movement commands
Identify types of association cortex
-unimodal association cortex
-multimodal (or heteromodal association cortex)
Describe unimodal association cortex
-Areas adjacent to the primarty area (of same modaility)
-process information specific to single primary cortex: only responsible for higher processing of one modaility (e.g. sensation or motor)
Describe multimodal (or heterimodal association cortex)
-integrates many sensory modalities
-e.g. large portions of temporal, frontal and inferior parietal lobe
Describe two areas of motor-association cortex
-pre-motor cortex: lateral surface, anterior to primary motro cortex
-suplementary motro area: uperior and medial surface
Function of motor-association cortex
-involved in formulating motor programs for complex movements
Describe the somatotopic organisation motor and supplementay motor areas
-pre motor cortex runs adjecent (anteriorly to primary motor cortex) and similar to that of primary motor cortex: legs medial, then laterally the trunk, arm, face, hand, face, mouth
-supplementary motor area runs from primary motor cortex superior and medial: legs together than anteriorly arm, face
Describe the pre-motor cortex and supplementary area
-project primarily to the primary motor cortex: develop plan and go to primary motor cortex where execute response
-also project to brainstem and spinal cord
-Only 50% of corticospinal trcats are axons form the primary motor cortex: higher processing areas also have infleunce without going through primary motor cortex
Describe pre-motor cortex and function
responsible for coordinating muscle activity/movements across multiple joints in same limb
-stimulation causes muscle contractions at multiple joints (same limb)
-involved in preparation for voluntary movements (to be trigered later): Once movement continues, pre motor cortex no longer involved
-set related and directionally specific:
-affects contralateral limbs: neurons on one side influnce muscles on other side
Describe human evidence for premotor cortex function
Lesions to premotor cortex cause inability to initiate appropriate movement to an external cue, or co-ordinate multiple joint movements
-as soon as movement iniatiated it shuts off and primary motor cortex iniatites movemenst
-damage to pre-motor cortex- prevents palnning and cordination
Describe supplementary motor area
-programs complex sequences of movements
-bilateral co-ordination of movement
-Affect contra-lateral limbs
-Direct influence on proximal muecles
-influence on distal musckles via primary motor cortex
-interhemisoheric connections between supplementary motro areas
Human evidence of supplementary motor area function
-supplementary motor area involved in planning and performance of complex sequences of movements
-simple finger flexion (performance) involves primary sensory and motor areas,
-finger movement sequence (performance) involves supplementary area in addition to motor/sensory areas
-finger movement sequence (mental rehersal) only involving supplementary area
Describe deficits with supplementray motor area lesions
-deficits in manual co-ordination
-ionability to perform complex acts requrining sequences of muscle contractions or a planned strategy “apraxia” (poorly coordinated movements)
Describe location of somatosensory association cortex
found posterior to primary association cortex
Describe function of somatosensory association cortex
role in meaning and interpretation of sensory info, high level sensory processing of information
Describe agnosis
-“A normal percept stripped of all meaningh” , loss of knowledge, meaning of information, can describe basic level of information but can interpret at higher level
Describe condistions associated with somatosensory association cortex lesion
-stereoagnosia (astereognosis)- cant identify objects by touch, can describe generally
-agraphesthesia e.g. cant decsribe letter or shape on skin, thsi relys also on somatosensory pathways and language ability
Describe other agnosis for each sense i.e. visual
-visual agnoisa e.g. “at first sight, the man who mistook his wife for a hat”
