Attention & inattention Flashcards
Distinguish between 2 types of attention
Selective attention (filtering the relevant out from the irrelevant) & sustained attention (maintaining processing on the current task = vigilance)
Goldberg (1998) found that the sensory response to a peripheral visual stimulus is enhanced when…
The monkey pays covert attention to it i.e. without making eye movements
Maintaining vigilance is an active process in as much as it requires protecting…
Current task demands from extraneous & intrinsic distractions
Mackworth found that sustained attention levels ___ over time, as indicated by impaired task performance
reduced
Sustained attention relies on ascending ___ projections from the locus coeruleus to the ventral attentional network
Noradrenergic (NA)
Me and you can experience attention lapses but what are the names of 3 specific disorders of attention? Hint: one is developmental, the other is degenerative & the final one affects young adults
ADHD, Parkinson’s diseases & Alzheimer’s disease, traumatic brain injury & schizophrenia
Name 3 syndromes of inattention which arise from focal brain lesions. Which is the rarest? Which arises from a posterior bilateral as opposed to unilateral lesion?
1) Neglect, 2) Extinction & 3) Simultagnosia. Simultagnosia. Simultagnosia
Extinction is characterised by a ___ bias in attention towards e.g. the right VF when….
directional. There is competition between the L & R VFs i.e. something is presented in both
What sets an extinction patient apart on the Posner task?
They suffer from an unusually large invalidity cost i.e. take much longer to reorient attention from the cued location to the actual, opposite location…WHEN the target location is the extinguished location (usually the left VF)
Do left (VF) extinction patients show unusual performance on valid trials of the Posner task or on invalid trials during which the cue directs attention towards the left VF?
No. No i.e. it is easy to move out of the cued extinguished location but it is difficult to move into it when it has not been cued
Name 2 examples in which the deficit of extinction can be overcome
1) When 2 balls are joined, extinction patients report seeing a whole barbell or dumbbell, 2) When pacmen images are arranged to form an illusory Kanisza square, patients report seeing more objects
Simultagnosia is a symptom of ___ syndrome and is characterised by only being able to see….
Balint’s syndrome. One object at a time when presented 2 or more
Humphreys (1994) argues that Balint’s syndrome is a form of __-___ ___. When presented with Luria’s star in white patients report seeing it, yet when…
Non-spatial extinction. Each triangle which forms the star is presented in a contrasting colour e.g. red vs. blue, then patients report seeing only one triangle, not their combination as a star
Ballint’s syndrome patients also perceive ___ ___ (feature misbinding) with extended free viewing i.e. not just with brief presentations as in controls
Illusory conjunctions
With time can neglect patients recover attention to their neglected VF (usually the left one)?
Yes
Give 4 visual perception tasks which reveal deficits in neglect, plus 2 more unusual & interesting tasks
Copying or painting, drawing from memory, reporting items from a room, searching for a target amongst distractors whilst your eye movements are tracked, searching tactically with your eyes shut whilst your hand movements are tracked, imagining Milan Square
What is amazing about the Milan Square study is that neglect patient ignore buildings which were…& now report buildings which were…
Previously reported when imagining viewing the square from the opposite end. Previously ignored
When neglect or extinction patients view a scene but do not report objects from e.g. the left VF, does V1 respond to objects in this left VF? This means that…
Yes. V1 activation does not equal conscious visual awareness
Name some components of neglect i.e. at which exact mechanism might the deficit lie? There may be a directional bias at any one of these levels
It may be a deficit in: 1) egocentric representation, 2) personal vs. extrapersonal space representation, hence the dissociation between these two in some cases, 3) object-centred representation (object-centred neglect), 4) selective attention, 5) spatial WM, 6) sustained attention, 7) motor ouputs, 8) imagery & 9) memory
Importantly neglect is an umbrella term for…
Lots of different patients with different precise lesion sites and so different dysfunctional mechanisms
Neglect patients are often ___ of their condition. Can the disorder be overcome with training?
Unaware. Yes but only in a stimulus-specific way i.e. there is no transfer to other everyday stimuli
Neglect has been found in many different frames of reference e.g. everything to the left of…
The head vs. eye vs. body midline may be ignored
N.B. neglect is not always as severe as an inability to consciously perceive the left side of space. Instead it may just be that…
RTs to stimuli presented in the L VF are increased
Object-centred neglect is very ___
rare
