Effects of Memory Load in Attentional Processes: Visual Search in Space and Time

2008 ◽  
Author(s):  
Beatriz Gil-Gomez de Liano ◽  
Juan Botella
Author(s):  
Angela A. Manginelli ◽  
Franziska Geringswald ◽  
Stefan Pollmann

When distractor configurations are repeated over time, visual search becomes more efficient, even if participants are unaware of the repetition. This contextual cueing is a form of incidental, implicit learning. One might therefore expect that contextual cueing does not (or only minimally) rely on working memory resources. This, however, is debated in the literature. We investigated contextual cueing under either a visuospatial or a nonspatial (color) visual working memory load. We found that contextual cueing was disrupted by the concurrent visuospatial, but not by the color working memory load. A control experiment ruled out that unspecific attentional factors of the dual-task situation disrupted contextual cueing. Visuospatial working memory may be needed to match current display items with long-term memory traces of previously learned displays.


2021 ◽  
Author(s):  
Heida Maria Sigurdardottir ◽  
Hilma Ros Omarsdóttir ◽  
Anna Sigridur Valgeirsdottir

Attention has been hypothesized to act as a sequential gating mechanism for the orderly processing of letters in words. These same visuo-attentional processes are assumed to partake in some but not all visual search tasks. In the current study, 60 adults with varying degrees of reading abilities, ranging from expert readers to severely impaired dyslexic readers, completed an attentionally demanding visual conjunction search task thought to heavily rely on the dorsal visual stream. A visual feature search task served as an internal control. According to the dorsal view of dyslexia, reading problems should go hand in hand with specific problems in visual conjunction search – particularly elevated conjunction search slopes (time per search item) – which would be interpreted as a problem with visual attention. Results showed that reading problems were associated with slower visual search, especially conjunction search. However, problems with reading were not associated with increased conjunction search slopes but instead with increased conjunction search intercepts, traditionally not interpreted as reflecting attentional processes. Our data are hard to reconcile with hypothesized problems in dyslexia with the serial moving of an attentional spotlight across a visual scene or a page of text.


2005 ◽  
Vol 17 (5) ◽  
pp. 788-799 ◽  
Author(s):  
Radek Ptak ◽  
Nathalie Valenza

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.


2000 ◽  
Vol 7 (2) ◽  
pp. 292-300 ◽  
Author(s):  
E. S. Olds ◽  
W. B. Cowan ◽  
P. Jolicoeur
Keyword(s):  

2015 ◽  
Vol 8 (2) ◽  
pp. 21-35 ◽  
Author(s):  
B.B. Velichkovsky ◽  
A.I. Izmalkova

The structure of working memory has components responsible for the storage of verbal and visualspatial information; despite the fairly detailed study of the functions and mechanisms of their work, the question of their mutual influence is still open. Studies on the verbal working memory load influence on visual search performance (a task requiring the use of visual-spatial working memory resources) it was found that the load on the verbal working memory leads to increased efficiency of target detection. The results of the analysis of oculomotor activity during visual search also point out that the implementation of such tasks under verbal working memory load is accompanied by an increase in cognitive tension and of the degree of search automaticity. The results may indicate the interaction of verbal and visual-spatial working memory components that share non-specific cognitive resources.


2018 ◽  
Vol 30 (12) ◽  
pp. 1902-1915 ◽  
Author(s):  
Nick Berggren ◽  
Martin Eimer

Mental representations of target features (attentional templates) control the selection of candidate target objects in visual search. The question where templates are maintained remains controversial. We employed the N2pc component as an electrophysiological marker of template-guided target selection to investigate whether and under which conditions templates are held in visual working memory (vWM). In two experiments, participants memorized one or four shapes (low vs. high vWM load) before either being tested on their memory or performing a visual search task. When targets were defined by one of two possible colors (e.g., red or green), target N2pcs were delayed with high vWM load. This suggests that the maintenance of multiple shapes in vWM interfered with the activation of color-specific search templates, supporting the hypothesis that these templates are held in vWM. This was the case despite participants always searching for the same two target colors. In contrast, the speed of target selection in a task where a single target color remained relevant throughout was unaffected by concurrent load, indicating that a constant search template for a single feature may be maintained outside vWM in a different store. In addition, early visual N1 components to search and memory test displays were attenuated under high load, suggesting a competition between external and internal attention. The size of this attenuation predicted individual vWM performance. These results provide new electrophysiological evidence for impairment of top–down attentional control mechanisms by high vWM load, demonstrating that vWM is involved in the guidance of attentional target selection during search.


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