The contribution of covert attention to the set-size and eccentricity effects in visual search.

Author(s):  
Marisa Carrasco ◽  
Yaffa Yeshurun
2001 ◽  
Author(s):  
Jason S. McCarley ◽  
Matthew S. Peterson ◽  
Arthur F. Kramer ◽  
Ranxiao Frances Wang ◽  
David E. Irwin

Author(s):  
Athanasios Drigas ◽  
Maria Karyotaki

Motivation, affect and cognition are interrelated. However, the control of attentional deployment and more specifically, attempting to provide a more complete account of the interactions between the dorsal and ventral processing streams is still a challenge. The interaction between overt and covert attention is particularly important for models concerned with visual search. Further modeling of such interactions can assist to scrutinize many mechanisms, such as saccadic suppression, dynamic remapping of the saliency map and inhibition of return, covert pre-selection of targets for overt saccades and online understanding of complex visual scenes.


2019 ◽  
Vol 162 ◽  
pp. 8-19 ◽  
Author(s):  
Jennifer Hemström ◽  
Andrea Albonico ◽  
Sarra Djouab ◽  
Jason J.S. Barton

2002 ◽  
Vol 14 (7) ◽  
pp. 980-993 ◽  
Author(s):  
Emanuela Bricolo ◽  
Tiziana Gianesini ◽  
Alessandra Fanini ◽  
Claus Bundesen ◽  
Leonardo Chelazzi

In visual search, inefficient performance of human observers is typically characterized by a steady increase in reaction time with the number of array elements—the so-called set-size effect. In general, set-size effects are taken to indicate that processing of the array elements depends on limited-capacity resources, that is, it involves attention. Contrasting theories have been proposed to account for this attentional involvement, however. While some theories have attributed set-size effects to the intervention of serial attention mechanisms, others have explained set-size effects in terms of parallel, competitive architectures. Conclusive evidence in favor of one or the other notion is still lacking. Especially in view of the wide use of visual search paradigms to explore the functional neuroanatomy of attentional mechanisms in the primate brain, it becomes essential that the nature of the attentional involvement in these paradigms be clearly defined at the behavioral level. Here we report a series of experiments showing that highly inefficient search indeed recruits serial attention deployment to the individual array elements. In addition, we describe a number of behavioral signatures of serial attention in visual search that can be used in future investigations to attest a similar involvement of serial attention in other search paradigms. We claim that only after having recognized these signatures can one be confident that truly serial mechanisms are engaged in a given visual search task, thus making it amenable for exploring the functional neuro-anatomy underlying its performance.


2008 ◽  
Vol 14 (6) ◽  
pp. 990-1003 ◽  
Author(s):  
BRANDON KEEHN ◽  
LAURIE BRENNER ◽  
ERICA PALMER ◽  
ALAN J. LINCOLN ◽  
RALPH-AXEL MÜLLER

AbstractAlthough previous studies have shown that individuals with autism spectrum disorder (ASD) excel at visual search, underlying neural mechanisms remain unknown. This study investigated the neurofunctional correlates of visual search in children with ASD and matched typically developing (TD) children, using an event-related functional magnetic resonance imaging design. We used a visual search paradigm, manipulating search difficulty by varying set size (6, 12, or 24 items), distractor composition (heterogeneous or homogeneous) and target presence to identify brain regions associated with efficient and inefficient search. While the ASD group did not evidence accelerated response time (RT) compared with the TD group, they did demonstrate increased search efficiency, as measured by RT by set size slopes. Activation patterns also showed differences between ASD group, which recruited a network including frontal, parietal, and occipital cortices, and the TD group, which showed less extensive activation mostly limited to occipito-temporal regions. Direct comparisons (for both homogeneous and heterogeneous search conditions) revealed greater activation in occipital and frontoparietal regions in ASD than in TD participants. These results suggest that search efficiency in ASD may be related to enhanced discrimination (reflected in occipital activation) and increased top-down modulation of visual attention (associated with frontoparietal activation). (JINS, 2008, 14, 990–1003.)


2010 ◽  
Vol 104 (5) ◽  
pp. 2433-2441 ◽  
Author(s):  
Richard P. Heitz ◽  
Jeremiah Y. Cohen ◽  
Geoffrey F. Woodman ◽  
Jeffrey D. Schall

The goal of this study was to obtain a better understanding of the physiological basis of errors of visual search. Previous research has shown that search errors occur when visual neurons in the frontal eye field (FEF) treat distractors as if they were targets. We replicated this finding during an inefficient form search and extended it by measuring simultaneously a macaque homologue of an event-related potential indexing the allocation of covert attention known as the m-N2pc. Based on recent work, we expected errors of selection in FEF to propagate to areas of extrastriate cortex responsible for allocating attention and implicated in the generation of the m-N2pc. Consistent with this prediction, we discovered that when FEF neurons selected a distractor instead of the search target, the m-N2pc shifted in the same, incorrect direction prior to the erroneous saccade. This suggests that such errors are due to a systematic misorienting of attention from the initial stages of visual processing. Our analyses also revealed distinct neural correlates of false alarms and guesses. These results demonstrate that errant gaze shifts during visual search arise from errant attentional processing.


Perception ◽  
10.1068/p5276 ◽  
2005 ◽  
Vol 34 (3) ◽  
pp. 305-318 ◽  
Author(s):  
Endel Põder

The effect of attention on the detection and identification of vertically and horizontally oriented Gabor patterns in the condition of simultaneous masking with obliquely oriented Gabors was studied. Attention was manipulated by varying the set size in a visual-search experiment. In the first experiment, small target Gabors were presented on the background of larger masking Gabors. In the detection task, the effect of set size was as predicted by unlimited-capacity signal detection theory. In the orientation identification task, increasing the set size from 1 to 8 resulted in a much larger decline in performance. The results of the additional experiments suggest that attention can reduce the crowding effect of maskers.


2020 ◽  
Author(s):  
Joseph MacInnes ◽  
Ómar I. Jóhannesson ◽  
Andrey Chetverikov ◽  
Arni Kristjansson

We move our eyes roughly three times every second while searching complex scenes, but covert attention helps to guide where we allocate those overt fixations. Covert attention may be allocated reflexively or voluntarily, and speeds the rate of information processing at the attended location. Reducing access to covert attention hinders performance, but it is not known to what degree the locus of covert attention is tied to the current gaze position. We compared visual search performance in a traditional gaze contingent display with a second task where a similarly sized contingent window is controlled with a mouse allowing a covert aperture to be controlled independently from overt gaze. Larger apertures improved performance for both mouse and gaze contingent trials suggesting that covert attention was beneficial regardless of control type. We also found evidence that participants used the mouse controlled aperture independently of gaze position, suggesting that participants attempted to untether their covert and overt attention when possible. This untethering manipulation, however, resulted in an overall cost to search performance, a result at odds with previous results in a change blindness paradigm. Untethering covert and overt attention may therefore have costs or benefits depending on the task demands in each case.


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