A review of the evidence for a disengage deficit following parietal lobe damage

Losier, Bruno J.; Klein, Raymond M.

doi:10.1016/s0149-7634(00)00046-4

Cited by 175 publications

(120 citation statements)

References 41 publications

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“…A number of factors suggest that disengaging covert attention and withdrawing the gaze from a fixated stimulus are based on different underlying processes. First, neglect patients only exhibit deficient attentional disengagement when reacting to a contralesional stimulus following an ipsilesional distracter, while no deficit is observed in the reverse direction (Posner et al, 1987;Morrow and Ratcliff, 1988;Losier and Klein, 2001;Ptak and Schnider, 2006). Thus, in contrast to the present findings the disengagement deficit is clearly unidirectional.…”

Section: Discussioncontrasting

confidence: 91%

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A non-spatial bias favouring fixated stimuli revealed in patients with spatial neglect

Ptak

Schnider

Golay

et al. 2007

Brain

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The cardinal feature of spatial neglect is severely impaired exploration of the contralesional space, a failure resulting in unawareness of many contralesional stimuli. This deficit is exacerbated by a reflexive attentional bias toward ipsilesional items. Here we show that, in addition to these spatially lateralized failures, neglect patients also exhibit a severe bias favouring stimuli presented at fixation. We tested neglect patients and matched healthy and right-hemisphere damaged patients without neglect in a task requiring saccade execution to targets in the left or right hemifield. Targets were presented alone or simultaneously with a distracter that appeared in the same hemifield, in the opposite hemifield, or at fixation. We found two fundamental biases in saccade initiation of neglect patients: irrelevant distracters presented in the preserved hemifield tended to capture gaze reflexively, resulting in a large number of saccades erroneously directed toward the distracter. Additionally, distracters presented at fixation severely disrupted saccade initiation irrespective of saccade direction, leading to disproportionately increased latencies of left and right saccades. This latency increase was specific to oculomotor responses of neglect patients and was not observed when a manual response was required. These results show that, in addition to their failure to inhibit reflexive glances toward ipsilesional items neglect patients exhibit a strong oculomotor bias favouring fixated stimuli. We conclude that impaired initiation of saccades in any direction contributes to the deficits of spatial exploration that characterize spatial neglect.

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Section: Discussioncontrasting

confidence: 91%

“…Since attentional disengagement is an important component of spatial neglect (e.g. Morrow and Ratcliff, 1988;Losier and Klein, 2001;e.g. Posner et al, 1987), a critical question is whether attentional deficits can explain the present findings.…”

Section: Discussionmentioning

confidence: 99%

A non-spatial bias favouring fixated stimuli revealed in patients with spatial neglect

Ptak

Schnider

Golay

et al. 2007

Brain

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“…In a recent meta-analysis of results obtained in braindamaged patients with the Posner paradigm, Losier and Klein [110] took advantage of the greater statistical power of the cumulated evidence from several studies, and concluded that (1) the disengage de®cit is robust following peripheral cues, but not following central cues; (2) the disengage de®cit is large at shorter SOAs, and decreases as SOA increases; (3) the disengage de®cit is larger in patients showing signs of unilateral neglect. The ®rst two characteristics are typical of the operations of exogenous orienting; the third clearly links the disengage de®cit to unilateral neglect.…”

Section: A Directional De®cit Of Disengaging Attentionmentioning

confidence: 99%

Orienting of attention in left unilateral neglect

Bartolomeo

Chokron

2002

Neuroscience & Biobehavioral Reviews

284

137

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After right posterior brain damage, patients may ignore events occurring on their left, a condition known as unilateral neglect. Although de®cits at different levels of impairment may be at work in different patients, the frequency and severity of attentional problems in neglect patients have been repeatedly underlined. Recent advances in the knowledge of the mechanisms of spatial attention in normals may help characterizing these de®cits. The present review focuses on studies exploring several aspect of attentional processing in unilateral neglect, with particular reference to the dichotomy between`exogenous', or stimulus-related, and`endogenous', or strategy-driven, orienting of attention. A large amount of neuropsychological evidence suggests that a basic mechanism leading to left neglect behavior is an impaired exogenous orienting toward left-sided targets. In contrast, endogenous processes seem to be relatively preserved, if slowed, in left unilateral neglect. Other component de®cits, such as a general slowing of the operations of spatial attention, might contribute to neglect behavior. These results are presented and discussed, and their implications for hemispheric specialization in attentional orienting and for the mechanisms of visual consciousness are explored. q

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“…When a target occurs at an uncued location and attention has to be disengaged and moved to a new location, there is activity in the temporal parietal junction [5]. Lesions of the parietal lobe and superior temporal lobe have been consistently related to difficulties in orienting [7].…”

Section: Functional Anatomymentioning

confidence: 99%

Attentional Phenotypes for the Analysis of Higher Mental Function

Fossella

Posner

Fan

et al. 2002

The Scientific World JOURNAL

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We outline a strategy to relate normal cognitive processes to candidate genes. First, brain imaging is used to specify a cognitive process "attention" in terms of the neural networks involved. Next, evidence is presented showing that the operation of each network involves a dominant neuromodulator. Then we discuss development of a task designed to measure the efficiency of each network in normal individuals and consider evidence on the independence, reliability, and heritability of the networks. DNA from cheek swabs of subjects who performed the task are then used to examine candidate polymorphisms in genes related to the transmitters. We then examine the ability of these candidate alleles to predict the efficiency of relevant networks. This process has demonstrated that candidate genes are related to specific networks of attention to a greater degree than to overall performance as measured by reaction time and accuracy. These findings require replication and possible extension to other cognitive processes.

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A review of the evidence for a disengage deficit following parietal lobe damage

Cited by 175 publications

References 41 publications

A non-spatial bias favouring fixated stimuli revealed in patients with spatial neglect

A non-spatial bias favouring fixated stimuli revealed in patients with spatial neglect

Orienting of attention in left unilateral neglect

Attentional Phenotypes for the Analysis of Higher Mental Function

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