Towards Secure and Efficient Equality Conjunction Search over Outsourced Databases

Author(s):  
Weipeng Lin ◽  
Ke Wang ◽  
Zhilin Zhang ◽  
Ada Wai-Chee Fu ◽  
Raymond Chi-Wing Wong ◽  
...  
Author(s):  
Yin Li ◽  
Dhrubajyoti Ghosh ◽  
Peeyush Gupta ◽  
Sharad Mehrotra ◽  
Nisha Panwar ◽  
...  
Keyword(s):  

2019 ◽  
Vol 31 (5) ◽  
pp. 768-779 ◽  
Author(s):  
Justin Riddle ◽  
Kai Hwang ◽  
Dillan Cellier ◽  
Sofia Dhanani ◽  
Mark D'Esposito

Beta and gamma frequency neuronal oscillations have been implicated in top–down and bottom–up attention. In this study, we used rhythmic TMS to modulate ongoing beta and gamma frequency neuronal oscillations in frontal and parietal cortex while human participants performed a visual search task that manipulates bottom–up and top–down attention (single feature and conjunction search). Both task conditions will engage bottom–up attention processes, although the conjunction search condition will require more top–down attention. Gamma frequency TMS to superior precentral sulcus (sPCS) slowed saccadic RTs during both task conditions and induced a response bias to the contralateral visual field. In contrary, beta frequency TMS to sPCS and intraparietal sulcus decreased search accuracy only during the conjunction search condition that engaged more top–down attention. Furthermore, beta frequency TMS increased trial errors specifically when the target was in the ipsilateral visual field for the conjunction search condition. These results indicate that beta frequency TMS to sPCS and intraparietal sulcus disrupted top–down attention, whereas gamma frequency TMS to sPCS disrupted bottom–up, stimulus-driven attention processes. These findings provide causal evidence suggesting that beta and gamma oscillations have distinct functional roles for cognition.


2020 ◽  
Vol 20 (8) ◽  
pp. 30
Author(s):  
Igor S. Utochkin ◽  
Vladislav A. Khvostov ◽  
Jeremy M. Wolfe
Keyword(s):  

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.


2010 ◽  
Vol 2 (7) ◽  
pp. 538-538
Author(s):  
K. S. Frieder ◽  
M. Carrasco

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