Lecture VI Flashcards
Attentional deficits are often due to damage to …, causing … and …
Frontoparietal network, causing visual neglect and Balint syndrome.
Many forms of neglect, but most common (2):
Hemispatial unilateral neglect
Ideational apraxia
Hemispatial unilateral neglect: … visual field neglect due to … damage.
… side neglect less common due to processing of … space in both hemispheres.
Left visual field neglect due to right inferior parietal damage.
Right side neglect less common due to processing of right space by both hemispheres.
Ideational apraxia: due to … damage, causing …
Left inferior parietal damage, causing misuse of tools.
Right inferior parietal damage causes …
Left inferior parietal damage causes …
Right inferior parietal damage causes hemispatial unilateral left neglect.
Left inferior parietal damage causes ideational apraxia.
Neglect is different from … (… damage) - neglect is more … and … is more …
Different from hemianopia (V1 damage).
Neglect more attentional, hemianopia more visual deficit.
Neglect patients can become … aware of stimulus in impaired visual field when …
Covertly aware, when stimulus is pointed out to them.
Treatment/coping mechanism for neglect.
Train to make saccades and motor movements to impaired part of visual field to cover everything with intact visual field.
Balint syndrome
- … and … apraxia when … is impaired.
- … damage to … and …
- … = …
Optic and oculumotor apraxia when motor guidance to objects is impaired.
Bilateral damage to dorsal posterior parietal cortex and lateral occipital cortex.
Simultanagnosia = can only attend to one object at a time.
Balint syndrome (3):
Simultanagnosia, optic ataxia, oculomotor apraxia.
Optic ataxia
See/recognize object but can’t grasp/turn/manipulate it.
Oculomotor apraxia (2):
Defect of controlled, voluntary, and purposeful eye movements.
Main difficulty is saccade initiation.
Dorsal posterior parietal lesion.
Balint syndrome.
Lateral occipital lesion.
Balint syndrome.
… lobe damage causes deficits in … - changing the allocation of attention.
… lobe damage causes deficits in … - initiating changes in attention.
Parietal lobe deficits in attention - allocation.
Frontal lobe deficits in control - initiation.
Frontoparietal network:
- frontal: …
- parietal: …
Frontal - initiating attention.
Parietal - changing attention.
Pathway cue to shift attention.
Cue triggers frontal - initiating attention - preparation - triggers parietal - shift attention.
TMS - active … (…/…)
Measure FFA and MT+ when attending … and …
Expectation: link between … and …/… strengthens depending on attentional focus.
Active frontal area (frontal eye fields/FEF).
FFA and MT+ when attending face area and motion direction.
Link between FEF and FFA/MT+ depending on attention.
Strong stimulation of FEF increased BOLD in … but not … when attending motion direction.
Strong stimulation of FEF increased BOLD in … but not … when attending gender of faces.
MT+ but not FFA in motion direction.
FFA but not MT+ in gender of faces.
Temporal characteristics to investigate causality (2):
First frontal then parietal.
fMRI is slow, use EEG.
Lateral PFC - …
FEF - …
Lateral intraparietal area/LIP - …
Lateral PFC - selecting relevant locations.
FEF - codes saccades endpoints.
Lateral intraparietal area/LIP - reorientating; evoke saccade.
Temporo-parietal junction (TPJ) integrates information (2):
From thalamus, limbic system, sensory systems.
From external environment and within body.
Visual search:
- easy: … (3).
- hard: … (3).
Easy visual search: bottom-up, pop-out, exogenous reorienting.
Hard visual search: top-down, conjuction/complex, endogenous reorienting.
Reorienting during both types of visual search is coded in the …, which lies between the … and …
Combines control of … and … attention.
Intraparietal sulcus, lies between TPJ and superior parietal lobule.
Combines control of exogenous and endogenous attention.
Default-mode network (DMN) (3):
Decreased activity in FP network.
Increased activity in DMN - posterior cingulate cortex (PCC).
Inverse coupling between FPN and DMN.
Sleep NTs (7):
ACh - memory consolidation, nucleus basalis.
5-HT - melatonin, sleep onset, internal clock, pineal gland, raphe nuclei.
Cortisol - awakening response, pituitary gland.
Glutamate - GABA, sleep duration.
Histamine - vigilance, alertness, hypothalamus.
Orexin/hypocretin - stable sleep, appetite, lateral hypothalamus.
Norepinephrine - arousal, locus coeruleus.
Awake - …
Begin sleep - …
Before REM - …
During REM - …
Awake - all active
Begin sleep - all less active
Before REM - norepinephrine active to activate REM
During REM - ACh active to improve memory
