Priming of Color and Position during Visual Search in Unilateral Spatial Neglect

We examined priming of visual search by repeated target location or color in two patients with left visual neglect and extinction, following strokes centered on the right inferior parietal lobe. Both patients, like the healthy controls we tested, showed intact priming, with performance speeded when either the location or color of a singleton target was repeated over successive trials in a standard search condition (Experiment 1). This was observed both from and to targets on the contralesional (left) side. Moreover, priming of search was still observed even when a return of fixation back to display-center was required between successive trials (Experiment 2). When briefer displays were used (Experiment 3), the patients often failed to detect left targets. This situation revealed an important dissociation: Whereas location priming only arose from preceding left targets that had been consciously detected, color priming (possibly arising within the intact ventral stream) did not depend on awareness of the preceding target. There was considerable color priming from missed targets. These findings demonstrate relatively intact priming of visual search by color and location in patients with right parietal damage, and also reveal that location priming may differ from color priming in requiring awareness.

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Damage to the right superior longitudinal fasciculus in the inferior parietal lobe plays a role in spatial neglect

Neuropsychologia ◽

10.1016/j.neuropsychologia.2009.05.010 ◽

2009 ◽

Vol 47 (12) ◽

pp. 2600-2603 ◽

Cited By ~ 69

Author(s):

N. Shinoura ◽

Y. Suzuki ◽

R. Yamada ◽

Y. Tabei ◽

K. Saito ◽

...

Keyword(s):

Parietal Lobe ◽

Spatial Neglect ◽

Superior Longitudinal Fasciculus ◽

Inferior Parietal Lobe ◽

The Right

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Unilateral Spatial Neglect

10.1093/oxfordhb/9780199675111.013.012 ◽

2014 ◽

Cited By ~ 5

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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“No Pain No Gain”: Evidence from a Parcel-Wise Brain Morphometry Study on the Volitional Quality of Elite Athletes

Brain Sciences ◽

10.3390/brainsci10070459 ◽

2020 ◽

Vol 10 (7) ◽

pp. 459 ◽

Cited By ~ 1

Author(s):

Gaoxia Wei ◽

Ruoguang Si ◽

Youfa Li ◽

Ying Yao ◽

Lizhen Chen ◽

...

Keyword(s):

Cortical Thickness ◽

Parietal Lobe ◽

Elite Athletes ◽

National Level ◽

Brain Regions ◽

Sense Of Agency ◽

Healthy Controls ◽

Inferior Parietal Lobe ◽

Brain Morphometry ◽

Volitional Behavior

Volition is described as a psychological construct with great emphasis on the sense of agency. During volitional behavior, an individual always presents a volitional quality, an intrapersonal trait for dealing with adverse circumstances, which determines the individual’s persistence of action toward their intentions or goals. Elite athletes are a group of experts with superior volitional quality and, thereby, could be regarded as the natural subject pool to investigate this mental trait. The purpose of this study was to examine brain morphometric characteristics associated with volitional quality by using magnetic resonance imaging (MRI) and the Scale of Volitional Quality. We recruited 16 national-level athletes engaged in short track speed skating and 18 healthy controls matched with age and gender. A comparison of a parcel-wise brain anatomical characteristics of the healthy controls with those of the elite athletes revealed three regions with significantly increased cortical thickness in the athlete group. These regions included the left precuneus, the left inferior parietal lobe, and the right superior frontal lobe, which are the core brain regions involved in the sense of agency. The mean cortical thickness of the left inferior parietal lobe was significantly correlated with the independence of volitional quality (a mental trait that characterizes one’s intendency to control his/her own behavior and make decisions by applying internal standards and/or objective criteria). These findings suggest that sports training is an ideal model for better understanding the neural mechanisms of volitional behavior in the human brain.

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The Inferior Temporal Lobe Mediates Distracter-Resistant Visual Search of Patients with Spatial Neglect

Journal of Cognitive Neuroscience ◽

10.1162/0898929053747676 ◽

2005 ◽

Vol 17 (5) ◽

pp. 788-799 ◽

Cited By ~ 18

Author(s):

Radek Ptak ◽

Nathalie Valenza

Keyword(s):

Visual Search ◽

Temporal Lobe ◽

Parietal Lobe ◽

Spatial Neglect ◽

The Other ◽

Current Evidence ◽

Search Performance ◽

Mixed Condition ◽

Attentional Processes ◽

Core Deficit

Although impaired visual search is a core deficit of patients with spatial neglect, current evidence is not conclusive about the mechanisms underlying this failure. We present evidence from 14 neglect patients searching for a target defined by two perceptual features that visual search is mediated by mechanisms of attentional competition. Participants were tested in three search conditions with constant target and distracter positions: Distracters did not share any feature with the target; distracters shared one feature with the target; two distracters shared one feature and one distracter shared the other feature with the target (mixed condition). Whereas search performance of healthy participants was comparable across conditions, neglect patients had a significant contralesional slowing in the mixed condition compared with the other two conditions. A detailed lesion analysis revealed that involvement of the parietal lobe did not predict the degree of distractibility in visual search. In contrast, neglect patients with high distractibility had more frequent damage to the inferior temporal lobe, suggesting a preliminary role of this region for competitive attentional processes involved in visual search of spatial neglect patients.

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A study on the right unilateral spatial neglect in left hemispheric lesions - The difference between right-handed and left-handed post stroke patients.

The Japanese Journal of Rehabilitation Medicine ◽

10.2490/jjrm1963.27.363 ◽

1990 ◽

Vol 27 (5) ◽

pp. 363-373

Author(s):

Shinichiro MAESHIMA ◽

Nobuyuki DOHI ◽

Toshio KAJIWARA ◽

Yoshimi KONDO ◽

Etsuko MAESHIMA ◽

...

Keyword(s):

Spatial Neglect ◽

Stroke Patients ◽

Unilateral Spatial Neglect ◽

Post Stroke ◽

Left Handed ◽

The Difference ◽

The Right

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Validity and reliability of standing balance control measurement on the left unilateral spatial neglect model

Brazilian Journal of Motor Behavior ◽

10.20338/bjmb.v15i3.247 ◽

2021 ◽

Vol 15 (3) ◽

pp. 167-179

Author(s):

Abdul C. Meidian ◽

Song Yige ◽

Syahmirza I. Lesmana ◽

Kazu Amimoto

Keyword(s):

Postural Balance ◽

Balance Control ◽

Standing Balance ◽

Spatial Neglect ◽

Validity And Reliability ◽

Control Measurement ◽

Unilateral Spatial Neglect ◽

Head Mounted Display ◽

The Right ◽

Healthy Participants

BACKGROUND: The present study developed a head-mounted display with the visual direction of a web camera modified to the right as a left unilateral spatial neglect (USN) model with respect to postural balance control. AIM: We aimed to estimate the validity and reliability of center of pressure (CoP) measurements in static standing balance (SSB) and dynamic standing balance (DSB) of healthy participants were using the USN model and to examine whether this model's use influenced postural balance control. METHOD: A portable CoP force plate was used to quantify postural balance control in 64 healthy participants as the model. The CoP displacement of the non-USN and USN models in the medial-lateral (ML) and anterior-posterior (AP) planes, CoP length, and bilateral load ratio in SSB and DSB to the right (R) and left (L) were evaluated. RESULTS: Regression analysis indicated that most CoP measurements have excellent concurrent validity. Bland–Altman plots showed good agreement between the non-USN and USN models in the CoP measurements. Test-retest reliability estimation between two times measurements varied in the frontal and sagittal planes. A Comparison of the results demonstrated that the CoP-AP and CoP length changed (-1.40% and 7.67%, respectively) significantly in SSB (P<0.05). Moreover, the CoP-AP changed very significantly in DSB-R and DSB-L (-1.50% and 1.86%, respectively) in opposite directions (P<0.01) when the subjects performed as the model. CONCLUSION: CoP measurements are valid and reliable to quantify standing balance control in both non-USN and USN models that appear to modulate changes in postural adaptation and adjustment.

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Parietal Lobe Lesions Disrupt Saccadic Remapping of Inhibitory Location Tagging

Journal of Cognitive Neuroscience ◽

10.1162/089892904323057245 ◽

2004 ◽

Vol 16 (4) ◽

pp. 503-509 ◽

Cited By ~ 69

Author(s):

Ayelet Sapir ◽

Amy Hayes ◽

Avishai Henik ◽

Shai Danziger ◽

Robert Rafal

Keyword(s):

Visual Search ◽

Reference Frame ◽

Inhibition Of Return ◽

Parietal Lobe ◽

Visual Environment ◽

Eye Position ◽

Intraparietal Sulcus ◽

Healthy Controls ◽

Neural Substrate ◽

Saccadic Remapping

Maintaining a coherent percept of the visual scene while eye position continuously changes requires that saccades be accompanied by remapping of the visual environment. We studied saccadic remapping in patients with unilateral lesions in the intraparietal sulcus and healthy controls, using inhibition of return (IOR)—an inhibitory tag that enables efficient visual search. In healthy controls, IOR was found at both retinal and environmental locations of the cue, indicating that the inhibitory tag had been remapped into environmental coordinates. In contrast, right parietal patients demonstrated IOR only at the retinal location of the cue, indicating that the intraparietal sulcus is involved in remapping of the environment after eye movements to afford a stable, environmentally based reference frame. Note that patients did not show environmental IOR in either visual field. These results also suggest that this region may be the neural substrate for encoding inhibitory spatial tags in an environmentally based reference frame.

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Immersive virtual prism adaptation therapy with depth sensing camera: A feasibility study with functional near infrared spectroscopy in healthy adults

10.1101/2021.04.07.438873 ◽

2021 ◽

Author(s):

Sungmin Cho ◽

Won-Seok Kim ◽

Jihong Park ◽

Seung Hyun Lee ◽

Jongseung Lee ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Right Hemisphere ◽

Prism Adaptation ◽

Spatial Neglect ◽

Depth Sensing ◽

Functional Near Infrared Spectroscopy ◽

Unilateral Spatial Neglect ◽

The Right

Unilateral spatial neglect (USN) is common after stroke and associated with poor functional recovery. Prism adaptation (PA) is one of the most supported modality able to ameliorate USN but underapplied due to several issues. Using immersive virtual reality and depth-sensing camera, we developed the virtual prism adaptation therapy (VPAT) to overcome the limitations in conventional PA. In this study, we investigated whether VPAT can induce behavioral adaptations and which cortical area is most significantly activated. Fourteen healthy subjects participated in this study. The experiment consisted of four sequential phases (pre-VAPT, VPAT-10°, VPAT-20°, and post-VPAT) with functional near-infrared spectroscopy recordings. Each phase consisted of alternating target pointing and resting (or clicking) blocks. To find out the most significantly activated area during pointing in different phases (VPAT-10°, VPAT-20°, and Post-VPAT) in contrast to pointing during the pre-VPAT phase, we analyzed changes in oxyhemoglobin concentration during pointing. The pointing errors of the virtual hand deviated to the right-side during early pointing blocks in the VPAT-10°and VPAT-20°phases. There was a left-side deviation of the real hand to the target in the post-VPAT phase. The most significantly activated channels were all located in the right hemisphere, and possible corresponding cortical areas included the dorsolateral prefrontal cortex and frontal eye field. In conclusion, VPAT may induce behavioral adaptation with modulation of the dorsal attentional network. Future clinical trials using multiple sessions of a high degree of rightward deviation VPAT over a more extended period are required in stroke patients with unilateral spatial neglect.

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