Lecture 16 Flashcards
Describe function of pariental association cortex
-integrates visual, somatosensory, vestibular and auditory inputs- many modalities together
-Outputs include motor association area
Describe how primary and association areas are represented
- represented bilaterally, there are some assymetries in functional specialisation
Descibe primary function of dominant hemisphere
-skilled motor formulation (praxis), formuting complex movements, most people this is left hemisphere, right is nondominant
Describe apraxia
-damage to motor asssociation areas, or parietal association cortex or dominant hemisphere (usually left)
-inability to perform complex sequences of movements: due to dmage to left parietal cortex, loss of praxis
-tested using skilled tasks (combining hair, eating with utensils: unable to integrate sensory information e.g. eating apraxia)
Describe functions of non-dominant hemisphere
more artistic, functions in visual-spatial analysis and spatial attention, usually right hemisphere
Describe hemi-spatial neglect (hemi-neglect)
-Damage to right parietal association cortex or frontal cortex cuases inability to attend to sensory information on the contralateral side, e.g. stroke affecting right hemisphere
Describe effects of damage to hemispheres with hemineglect
-Left hemisphere attends to some info on right space, no responsibility to attend to left space
-Right hemisphere responsible to attend to things in entire space, more concentrated on left side
-Damage to left hemisphere dont see effects, right side can attend to both sides.
-If damage right hemisphere loss ability to attend to info on left space, some ability to attend to right due to left hemisphere
Describe types of neglect tested
-Sensory neglect (visual, tactile, or auditory)
-Motor-intentional neglect- ability to attend to movements
-Combination of sensory and motor neglect
-conceptual neglect
-usually see combination of motor and sensory neglect
Describe double simultaneous stimulation tests
-test for extinctions i.e. tactile extinction, motor extinction
E.g. tractile:
Touch touch right hand, do you feel? yes
Touch left hand, do you feel? yes
Touch both simultaniously and only feels right
E..g motor:
Raise both arms- left drops dont attend to things on the left, neglect in motor function on one side
-Test for neglect i.e. visual neglect
e.g. paper and pen test with picture, usually only describe objects on right side
Describe conceptual neglect
Neglect things in left space, mental imagery affected by neglect, depends on how person oriented e.g. coming down street one way describe things on right side, from oppoosite direction, describe things on right.
-loses ability to attend to internal representation of envirnment
Describe types of conceptual neglect
-anosognosia- no awareness of hemi-neglect/- plegia, not able to recognise deficit or weakness in one side of body e.g. the sound of one hand clapping, person thought they were moving same on both sides despite deficit on one side
-hemiasomatognosia- limbs ‘dis-owned’, doesnt recognise limb as their own e.g. the man who fell out of bed
Describe damage with dressing apraxia
dressing apraxia due to right parietal lesion
Describe alien hand
-Damage to corpus collosum and/or supplementary motor area (non-dominant hemisphere- right),
-hand out of control, usually left hand
-acts autonomously, mischievously, often counteracts own intentions e.g. unbotton with right, button back up with left
-some evidence legs may be involved
Describe hypothesis of alien hand
-when left side split from right, more emotional right side acts out and left side more anaytical cant keep in check
