Disorders Of Attention Flashcards
What is anosodiaphoria?
Indifference to illness or disability
What is directional akinesia?
Impairments in directional motor programming
What is hypokinesia?
Motor impersistence
What did Heilman and Valenstein (1979) propose about neglect syndrome?
That neglect syndrome is a deficit in the orienteering response
What did Kinsbourne (1987) propose about neglect syndrome?
They framed neglect as an imbalance in hemispheric neural structures, biasing attention
What did Bisiach and Luzzatti (1978) demonstrate?
That patients with left neglect omitted left handed details of a familiar location
What did Bisiach et Al (1979) demonstrate?
Left neglect omitted left-sided details from static shape regardless of horizontal movement
What is anosognosia?
Denial of symptoms
What does the spotlight metaphor of attention propose?
> Highlight a particular location
Move attention from location to location
Zoom in, zoom out
Not necessarily locus of eye fixation
What are the limitations of the spotlight metaphor?
We can attend to 2 non-adjacent locations
What are the benefits of the spotlight metaphor?
> Highlights limited capacity of spatial attention
> Emphasis on spatial characteristics
What are the hemispherical specialisations wrt spatial processing?
> Left - processes the right side
> Right - processes left side and some right
What makes up neglect syndrome?
> Unilateral neglect
Extinction
Balint’s syndrome (dorsal simultagnosia)
What are the symptoms of Balint’s syndrome?
> Gaze apraxia
Optic apraxia
Visual simultagnosia
What is gaze apraxia?
The inability to voluntarily move gaze within the visual field
What is optic apraxia?
An impairment in visually guided movement
What is visual simultagnosia?
The inability to take in the entirety of a picture
What evidence is there that those with Balint’s syndrome can’t view images holistically?
> Studies with disaster images
Can only see one object in overlaps
Can tell line length difference if joined, can’t if not
Can group multiple objects by colour
What is unilateral neglect?
The failure to report, respond or orient to stimuli present contralateral to the site of the brain lesion
What is the aetiology of neglect?
> Stroke related neural damage
> Right hemispherical damage more likely to cause enduring neglect
What is neglect typically comorbid with?
> Anosognosia (symptom denial)
> Anosodiaphora (indifference to condition)
What evidence is there for anosognosia?
> Bisiatch (1988)
> Ramachandran (1996)
What did Bisiatch (1988) find?
Anosognosia in left side paralysis patients
What did Ramachandran find?
Anosognosia can extend to denying the symptoms of others
What are the clinical tests for neglect?
> Cancellation task
Line bisection task
Copying task
Free-drawing task
What is the leftwards spatial bias task?
Two bars graded white to black, one left to right, the other right to left. Healthy controls say black at left is darker, neglect patients say right
What is extinction?
The ability to identify a single stimuli presented to the left or right side, but have difficulty when two are presented simultaneously
What did Desimone and Duncan (1995) propose?
Different perceptual representations compete for attention, causes problems wrt extinction
What did Farah (1990) propose?
Balint’s syndrome is a type of double neglect
What are the features of Balint’s = Double neglect?
> Neglect usually right parietal damage, left space neglect
Balint’s is neglect on both side, but can see an object
Do not neglect portions of objects
What are the theoretical explanations for symptoms of neglect?
> Deficit of primary sensory input
Disorder of visuo-spatial attentional system
Disorder of mental representation of space
What evidence is there that neglect is not a primary sensory deficit?
Hemianopia patients do not show neglect and will redirect attention to their left side
What is the evidence for the attentional orienteering account of neglect?
> Failure to shift attention
> Automatically orient attention to the right
What are the stages of involved in shifting attention?
> Disengagement of attention
Movement and shifting of attention
Engagement of attention
What are the features of object based neglect?
> Neglect acts on each individual object in the visual field
> Neglect on left side of the object’s axis
What are the different spatial frames of reference?
> Personal space
Peri-personal space
Extra-personal space
What are typical symptoms of personal neglect?
> Failure to shave or groom on the left side
Failure to adjust glasses on the left
Failure to notice position of left limbs
What did Berti and Frassinetti (2000) find?
That peri-personal space can be extended with use of tools (such as pointer sticks)
What evidence is there that neglect is a disorder of mental representations of space?
Neglect can manifest in mental representations as well as the visual field. This is usually a double dissociation
What did Bisiatch and Luzzati (1978) suggest?
> Neglect inhibits ability to form mental representations
> Neglect in a result of attentional processes
What are the features of neglect?
> Failure to react or respond to contralesional information
Not a deficit of visual processing
Attentional deficit
Can effect perception, memory and imagery
Can be object or space based
What did Halligan and Marshall (1988) find?
> Neglect
Consciously unaware of left side
Subconsciously aware
Who demonstrated that patients with neglect can be influence by information on their left side, though not consciously aware of that?
Halligan and Marshall (1988)
What are the limitations of Halligan and Marshall (1988)?
> Always tested the same group
> Replication produced inconclusive results
What did McGlinchey-Berroth et al (1993) find?
> Priming study
Neglect
Priming present on both contralateral and ipsilateral sides
When asked to make conscious judgements, only ipsilateral priming
What are the overall limitations of neglect research?
> Significant individual differences
Several discrete subtypes associated with a variety of lesions
Neglect measures lack reliability
Lesions not precise or identical
