Differences Between Objects and Nonobjects in Visual Extinction: A Competition for Attention

1996 ◽  
Vol 7 (3) ◽  
pp. 177-180 ◽  
Author(s):  
Robert Ward ◽  
Susan Goodrich
Keyword(s):  
Visual Attention ◽  
Parietal Cortex ◽  
Visual Fields ◽  
Detection Task ◽  
Attentional Selection ◽  
Selective Visual Attention ◽  
Visual Extinction ◽  
Simple Detection ◽  
Left And Right

We used visual extinction as a method for investigating the influence of objects on selective visual attention Two subjects demonstrating extinction following damage to right parietal cortex were tested in a simple detection task The task required only that subjects detect the presence or absence of any item in the left and right visual fields Both subjects showed an advantage for good objects in the impaired field However, this advantage for good objects held only in the presence of a simultaneous stimulus in the undamaged field We suggest that objects are not simply easier to detect than nonobjects, instead we argue that objects are stronger competitors for attentional selection

Hemisphere-specific Parietal Contributions to the Interplay between Working Memory and Attention

2021 ◽  
pp. 1-14
Author(s):  
Anastasia Kiyonaga ◽  
John P. Powers ◽  
Yu-Chin Chiu ◽  
Tobias Egner
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Attention ◽  
Parietal Cortex ◽  
Dual Task ◽  
Search Behavior ◽  
Brain Regions ◽  
Task Demands ◽  
Attentional Demands ◽  
Left And Right

Abstract To achieve our moment-to-moment goals, we must often keep information temporarily in mind. Yet, this working memory (WM) may compete with demands for our attention in the environment. Attentional and WM functions are thought to operate by similar underlying principles, and they often engage overlapping fronto-parietal brain regions. In a recent fMRI study, bilateral parietal cortex BOLD activity displayed an interaction between WM and visual attention dual-task demands. However, prior studies also suggest that left and right parietal cortices make unique contributions to WM and attentional functions. Moreover, behavioral performance often shows no interaction between concurrent WM and attentional demands. Thus, the scope of reciprocity between WM and attentional functions and the specific contribution that parietal cortex makes to these functions both remain unresolved. Here, we took a causal approach, targeting brain regions that are implicated in shared processing between WM and visual attention, to better characterize how those regions contribute to behavior. We first examined whether behavioral indices of WM and visual search differentially correlate with left and right parietal dual-task BOLD responses. Then, we delivered TMS over fMRI-guided left and right parietal sites during dual-task WM–visual search performance. Only right-parietal TMS influenced visual search behavior, but the stimulation either helped or harmed search depending on the current WM load. Therefore, whereas the left and right parietal contributions were distinct here, attentional and WM functions were codependent. Right parietal cortex seems to hold a privileged role in visual search behavior, consistent with prior findings, but the current results reveal that behavior may be sensitive to the interaction between visual search and WM load only when normal parietal activity is perturbed. The parietal response to heightened WM and attentional demands may therefore serve to protect against dual-task interference.

scholarly journals The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

2009 ◽  
Vol 21 (10) ◽  
pp. 1946-1955 ◽  
Author(s):  
Lorella Battelli ◽  
George A. Alvarez ◽  
Thomas Carlson ◽  
Alvaro Pascual-Leone
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Visual Tracking ◽  
Magnetic Stimulation ◽  
Posterior Parietal Cortex ◽  
Parietal Lobe ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Visual Fields ◽  
Brain Regions ◽  
Visual Extinction ◽  
Interhemispheric Competition

Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of visual space when targets are simultaneously present in the ipsilesional visual field, a form of visual extinction. Visual extinction may arise due to an imbalance in the normal interhemispheric competition. To directly assess the issue of reciprocal inhibition, we used fMRI to localize those brain regions active during attention-based visual tracking and then applied low-frequency repetitive transcranial magnetic stimulation over identified areas in the left and right intraparietal sulcus to asses the behavioral effects on visual tracking. We induced a severe impairment in visual tracking that was selective for conditions of simultaneous tracking in both visual fields. Our data show that the parietal lobe is essential for visual tracking and that the two hemispheres compete for attentional resources during tracking. Our results provide a neuronal basis for visual extinction in patients with parietal lobe damage.

On the Relation between Visual Spatial Attention and Visual Field Asymmetries

1992 ◽  
Vol 44 (3) ◽  
pp. 529-555 ◽  
Author(s):  
T. A Mondor ◽  
M.P. Bryden
Keyword(s):  
Visual Field ◽  
Visual Attention ◽  
Visual Fields ◽  
Stimulus Onset ◽  
Right Visual Field ◽  
Structural Factors ◽  
Letter Identification ◽  
Functional Capabilities ◽  
Visual Spatial ◽  
The Right

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.

Selective visual attention in patients with frontal lobelesions or Parkinsons disease

1999 ◽  
Vol 37 (5) ◽  
pp. 595-604 ◽  
Author(s):  
Sonia S Lee ◽  
Krista Wild ◽  
Caroline Hollnagel ◽  
Jordan Grafman
Keyword(s):  
Visual Attention ◽  
Parkinsons Disease ◽  
Selective Visual Attention

Opposite biases in salience-based selection for the left and right posterior parietal cortex

2006 ◽  
Vol 9 (6) ◽  
pp. 740-742 ◽  
Author(s):  
Carmel Mevorach ◽  
Glyn W Humphreys ◽  
Lilach Shalev
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Posterior Parietal ◽  
Left And Right ◽  
Selection For

scholarly journals Cuttlefish use stereopsis to strike at prey

2020 ◽  
Vol 6 (2) ◽  
pp. eaay6036 ◽  
Author(s):  
R. C. Feord ◽  
M. E. Sumner ◽  
S. Pusdekar ◽  
L. Kalra ◽  
P. T. Gonzalez-Bellido ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Information ◽  
Convergent Evolution ◽  
Visual Fields ◽  
Three Dimensional ◽  
Visual Information Processing ◽  
Depth Information ◽  
Cephalopod Species ◽  
Left And Right

The camera-type eyes of vertebrates and cephalopods exhibit remarkable convergence, but it is currently unknown whether the mechanisms for visual information processing in these brains, which exhibit wildly disparate architecture, are also shared. To investigate stereopsis in a cephalopod species, we affixed “anaglyph” glasses to cuttlefish and used a three-dimensional perception paradigm. We show that (i) cuttlefish have also evolved stereopsis (i.e., the ability to extract depth information from the disparity between left and right visual fields); (ii) when stereopsis information is intact, the time and distance covered before striking at a target are shorter; (iii) stereopsis in cuttlefish works differently to vertebrates, as cuttlefish can extract stereopsis cues from anticorrelated stimuli. These findings demonstrate that although there is convergent evolution in depth computation, cuttlefish stereopsis is likely afforded by a different algorithm than in humans, and not just a different implementation.

Selective Visual Attention: Selective Cuing, Selective Cognitive Processing, and Selective Response Processing

1994 ◽  
pp. 26-80 ◽  
Author(s):  
G. Mulder ◽  
A. A. Wijers ◽  
K. A. Brookhuis ◽  
H. G. O. M. Smid ◽  
L. J. M. Mulder
Keyword(s):  
Visual Attention ◽  
Cognitive Processing ◽  
Selective Visual Attention
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