“Nonspatial” Attentional Deficits Interact with Spatial Position in Neglect

2017 ◽  
Vol 29 (5) ◽  
pp. 911-918 ◽  
Author(s):  
Dongyun Li ◽  
Christopher Rorden ◽  
Hans-Otto Karnath
Keyword(s):  
Strong Evidence ◽  
Temporal Dynamics ◽  
Spatial Position ◽  
Spatial Neglect ◽  
Spatial Bias ◽  
Attentional Deficits ◽  
Attentional Deployment ◽  
Attentional Performance ◽  
Trunk Position ◽  
Contralesional Side

A widely debated question concerns whether or not spatial and nonspatial components of visual attention interact in attentional performance. Spatial neglect is a common consequence of brain injury where individuals fail to respond to stimuli presented on their contralesional side. It has been argued that, beyond the spatial bias, these individuals also tend to exhibit nonspatial perceptual deficits. Here we demonstrate that the “nonspatial” deficits affecting the temporal dynamics of attentional deployment are in fact modulated by spatial position. Specifically, we observed that the pathological attentional blink of chronic neglect is enhanced when stimuli are presented on the contralesional side of the trunk while keeping retinal and head-centered coordinates constant. We did not find this pattern in right brain-damaged patients without neglect or in patients who had recovered from neglect. Our work suggests that the nonspatial attentional deficits observed in neglect are heavily modulated by egocentric spatial position. This provides strong evidence against models that suggest independent modules for spatial and nonspatial attentional functions while also providing strong evidence that trunk position plays an important role in neglect.

scholarly journals Spatial distance of target locations affects the time course of both endogenous and exogenous attentional deployment.

2020 ◽  
Author(s):  
Frederik Geweke ◽  
Emilia Pokta ◽  
Viola S. Störmer
Keyword(s):  
Time Course ◽  
Temporal Dynamics ◽  
Spatial Distance ◽  
Exogenous Attention ◽  
Endogenous Attention ◽  
Attentional Deployment ◽  
Current Task ◽  
Time Courses ◽  
Task Goals ◽  
Target Locations

Spatial attention can be deployed exogenously, based on salient events in the environment, or endogenously, based on current task goals. Numerous studies have compared the time courses of these two types of attention, and have demonstrated that exogenous attention is fast and transient and endogenous attention is relatively slow but sustained. In the present study we investigated whether and how the temporal dynamics of exogenous and endogenous attention differ in terms of where attention is deployed in the visual field, in particular at locations nearby or far from fixation. Across a series experiments, we measured attentional shift times for each type of attention, and found overall slower deployment of endogenous relative to exogenous attention, in line with previous research. Importantly, we also consistently found that it takes longer to deploy attention at more distant locations relative to nearby locations, regardless of how attention was instigated. Overall, our results suggest that the temporal limits of attentional deployment across different spatial distances are similar for exogenous and endogenous attention, pointing to shared constraints underlying both attentional modes.

Abnormal temporal dynamics of visual attention in spatial neglect patients

Nature ◽  
1997 ◽  
Vol 385 (6612) ◽  
pp. 154-156 ◽  
Author(s):  
Masud Husain ◽  
Kimron Shapiro ◽  
Jesse Martin ◽  
Christopher Kennard
Keyword(s):  
Visual Attention ◽  
Temporal Dynamics ◽  
Spatial Neglect

scholarly journals Directed Attention in Gilles de la Tourette Syndrome

1998 ◽  
Vol 11 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Nellie Georgiou ◽  
John L. Bradshaw ◽  
Jim G. Phillips
Keyword(s):  
Tourette Syndrome ◽  
Task Demands ◽  
Expectancy Effects ◽  
Directed Attention ◽  
Attentional Deficits ◽  
Direct Gaze ◽  
Attentional Performance ◽  
Overall Performance ◽  
Directing Attention ◽  
Unexpected Stimulus

Gilles de la Tourette syndrome (TS) is a basal ganglia (BG) disorder, associated not only with hyperkinetic movements but also with attentional impairments. This experiment sought to ascertain whether overt direct visual attention would influence tactile attentional performance in TS, via the use of a vibrotactile choice reaction time procedure involving biased probabilities of event occurrence. Participants were required to look (i.e., direct gaze) either at the hand receiving the most (expected) vibrations, or the hand less often stimulated (the unexpected), for both crossed and uncrossed arm postures. Contrary to our predictions, gaze did not influence attentional performance in TS patients. Furthermore, patients were found not to be sensitive to distributions of event probability; that is, they did not demonstrate normal expectancy effects like controls. Attentional deficits in TS (as in Parkinson’s disease, another BG disorder) may pertain more to difficulties in holding rather than in shifting the focus of attention. Moreover, directing attention towards the unexpected locus in the crossed arm posture improved overall performance in both patients and controls, suggesting that increased task demands (e.g., crossed arm posture), and/or unexpected stimulus location, may be alleviated by directed attention. These impairments may stem from dysfunction in the circuits linking the frontal lobes with the BG.

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

Brain ◽  
2007 ◽  
Vol 130 (12) ◽  
pp. 3211-3222 ◽  
Author(s):  
R. Ptak ◽  
A. Schnider ◽  
L. Golay ◽  
R. Muri
Keyword(s):  
Spatial Neglect ◽  
Spatial Bias

Working Memory in Unilateral Spatial Neglect: Evidence for Impaired Binding of Object Identity and Object Location

2021 ◽  
Vol 33 (1) ◽  
pp. 46-62
Author(s):  
Haggar Cohen-Dallal ◽  
Nachum Soroker ◽  
Yoni Pertzov
Keyword(s):  
Working Memory ◽  
Right Hemisphere ◽  
Spatial Neglect ◽  
Object Location ◽  
Object Identity ◽  
Response Scale ◽  
Unilateral Spatial Neglect ◽  
Localization Errors ◽  
Retention Intervals ◽  
Contralesional Side

Working memory (WM) is known to be impaired in patients with stroke experiencing unilateral spatial neglect (USN). Here, we examined in a systematic manner three WM components: memory of object identity, memory of object location, and binding between object identity and location. Moreover, we used two different retention intervals to isolate maintenance from other mnemonic and perceptual processes. Fourteen USN first-event stroke patients with right-hemisphere damage were tested in two different WM experiments using long and short retention intervals and an analog response scale. Patients exhibited more identification errors for items displayed on the contralesional side. Localization errors were also more prominent in the contralesional side, especially after a long retention interval. These localization errors were often a result of swap errors, that is, erroneous localizations of correctly identified contralesional objects in correctly memorized locations of ipsilesional objects. We conclude that a key WM deficit in USN is a lateralized impairment in binding between the identity of an object and its spatial tag.

scholarly journals Prefrontal glucose metabolism in medication-resistant major depression

2015 ◽  
Vol 206 (4) ◽  
pp. 316-323 ◽  
Author(s):  
Cheng-Ta Li ◽  
Tung-Ping Su ◽  
Shyh-Jen Wang ◽  
Pei-Chi Tu ◽  
Jen-Chuen Hsieh
Keyword(s):  
Prefrontal Cortex ◽  
Glucose Metabolism ◽  
Cortical Function ◽  
Attentional Deficits ◽  
Prefrontal Cortical ◽  
Positron Emission ◽  
Attentional Performance ◽  
Resistant Depression ◽  
Regional Cerebral Glucose Metabolism ◽  
Depressive Episodes

BackgroundMedication-resistant depression (MRD) is associated with poorer attentional performance and immense socioeconomic costs.AimsWe aimed to investigate the central pathophysiology of MRD, previously linked to impaired prefrontal cortex function.MethodA total of 54 participants (22 with MRD, 16 with non-resistant depression, 16 healthy controls) were recruited. Non-MRD status was confirmed by a prospective 6-week antidepressant trial. All medication-free participants underwent a go/no-go task to study prefrontal cortical function (attention) and positron emission tomography scans to study regional cerebral glucose metabolism (rCMglu) at rest.ResultsThe MRD group had worse attentional ratings and decreased rCMglu compared with the non-MRD and control groups. Attentional performance was positively associated with prefrontal cortex rCMglu. The prefrontal cortex differences between MRD and non-MRD groups remained after adjusting for past depressive episodes (F(1,35) = 4.154, P = 0.043).ConclusionsPronounced hypofrontality, with the associated attentional deficits, has a key role in the neuropathology of medication-resistant depression.

Is attention related with pathological personality in siblings of psychotic patients?

2011 ◽  
Vol 26 (S2) ◽  
pp. 1455-1455
Author(s):  
L. Moreno ◽  
J. Valero ◽  
A.M. Gaviria ◽  
A. Labad
Keyword(s):  
Selective Attention ◽  
Sustained Attention ◽  
Psychotic Disorders ◽  
Hierarchical Cluster ◽  
Personality Factors ◽  
Healthy Controls ◽  
Vulnerability Factors ◽  
Schizotypal Personality ◽  
Attentional Deficits ◽  
Attentional Performance

IntroductionImpaired sustained and selective attention have been seen as vulnerability factors to psychotic disorders. Relatives of psychotic patients are a risk population for psychosis, and previous studies have shown that they displayed more attentional deficits compared with healthy controls. Additionally, relatives have more pathological personality and schizotypy, the least considered also to be the expression of the genetic vulnerability to schizophrenia. There are few studies that relate attention to personality factors in relatives of psychotic patients.AimsTo compare attentional performance of siblings of psychotic patients with those of healthy controls, taking into account their pathological and schizotypal personality.MethodsThe Spanish version of the SPQ and the DAPP-BQ were administered to a sample of 51 subjects that were divided into four groups by a hierarchical cluster analysis: siblings with high pathological personality (SHPP), siblings with low pathological personality (SLPP), controls with high pathological personality (CHPP), and controls with low pathological personality (CLPP). In all the subjects we assessed a sustained attention index (SUA) and a selective attention index (SEA). We compared the performance of the four groups on these attentional indexes.ResultsWe found that SHPP had worse performance on sustained attention compared with CLPP. Specifically this difference was in the reaction time item of the SUA.ConclusionsThe high schizotypy and pathological personality had an influence on sustained attentional performance in the siblings of patients with psychosis, but not in the healthy controls.

scholarly journals A demonstration of endogenous modulation of unilateral spatial neglect: The impact of apparent time-pressure on spatial bias

2007 ◽  
Vol 14 (1) ◽  
pp. 33-41 ◽  
Author(s):  
MELANIE S. GEORGE ◽  
JACKIE S. MERCER ◽  
ROBIN WALKER ◽  
TOM MANLY
Keyword(s):  
Time Pressure ◽  
Spatial Neglect ◽  
Spatial Bias ◽  
Secondary Effects ◽  
Short Term ◽  
Spatial Systems ◽  
Unlimited Time ◽  
Cortical Regions ◽  
The Impact ◽  
Subjective Arousal

Unilateral neglect, a lack of awareness for one side of space, is a common and debilitating consequence of stroke. Previous work has identified a relationship between enduring left neglect and diminished general alertness and shown that increasing alertness can temporarily reduce the severity of the spatial bias. In that research, alertness was modulated by loud tones or with pharmacological stimulants. Here we examine whether cognitive, endogenously driven changes can produce similar short-term improvements. Time-pressure is associated with increased subjective arousal and increased activation in cortical regions associated with alertness. Here five patients completed a spatial cancellation task with and without instructions regarding a time limit. Significant reductions in neglect severity were observed when patients believed that they were acting under time-pressure, despite the conditions being equivalent in the actual (unlimited) time available. Functional imaging work has highlighted the secondary effects that damage to networks mediating alertness can have on structurally intact spatial systems. The results here suggest that activation of presumably spared function in these damaged networks can induce moment-by-moment changes in spatial function and, crucially, that this can be achieved using entirely endogenous means. (JINS, 2008,14, 33–41.)

Unilateral Spatial Neglect

2014 ◽  
Author(s):  
Giuseppe Vallar ◽  
Nadia Bolognini
Keyword(s):  
Right Hemisphere ◽  
Parietal Lobe ◽  
The Body ◽  
Spatial Neglect ◽  
Motor Action ◽  
Unilateral Spatial Neglect ◽  
Semantic Level ◽  
The Right ◽  
Neglect Dyslexia ◽  
Contralesional Side

Left unilateral spatial neglect is the most frequent and disabling neuropsychological syndrome caused by lesions to the right hemisphere. Over 50% of right-brain-damaged patients show neglect, while right neglect after left-hemispheric damage is less frequent. Neglect patients are unable to orient towards the side contralateral to the lesion, to detect and report sensory events in that portion of space, as well as to explore it by motor action. Neglect is a multicomponent disorder, which may involve the contralesional side of the body or of extra-personal physical or imagined space, different sensory modalities, specific domains (e.g. ‘neglect dyslexia’), and worsen sensorimotor deficits. Neglect is due to higher-order unilateral deficits of spatial attention and representation, so that patients are not aware of contralesional events, which, however, undergo a substantial amount of unconscious processing up to the semantic level. Cross-modal sensory integration is also largely preserved. Neglect is primarily a spatially specific disorder of perceptual consciousness. The responsible lesions involve a network including the fronto-temporo-parietal cortex (particularly the posterior-inferior parietal lobe, at the temporo-parietal junction), their white matter connections, and some subcortical grey nuclei (thalamus, basal ganglia). Damage to primary sensory and motor regions is not associated to neglect. A variety of physiological lateralized and asymmetrical sensory stimulations (vestibular, optokinetic, prism adaptation, motor activation), and transcranial electrical and magnetic stimulations, may temporarily improve or worsen neglect. Different procedures have been successfully developed to rehabilitate neglect, using both ‘top down’ (training the voluntary orientation of attention) and ‘bottom up’ (the above-mentioned stimulations) approaches.

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