scholarly journals Dissecting the neural focus of attention reveals distinct processes for spatial attention and object-based storage in visual working memory

2018 ◽  
Author(s):  
Nicole Hakim ◽  
Kirsten C. S. Adam ◽  
Eren Gunseli ◽  
Edward Awh ◽  
Edward K. Vogel

AbstractComplex cognition relies on both online representations in working memory (WM) said to reside in thefocus of attention, and passive offline representations of related information. Here, we dissect the focus of attention by showing that distinct neural signals index the online storage of objects and sustained spatial attention. We recorded EEG activity during two tasks that employed identical stimulus displays while the relative demands for object storage and spatial attention varied. We found distinct delay-period signatures for an attention task (which only required spatial attention) and WM task (which invoked both spatial attention and object storage). Although both tasks required active maintenance of spatial information, only the WM task elicited robust contralateral delay activity that was sensitive to mnemonic load. Thus, we argue that the focus of attention is maintained via a collaboration between distinct processes for covert spatial orienting and object-based storage.

2019 ◽  
Vol 30 (4) ◽  
pp. 526-540 ◽  
Author(s):  
Nicole Hakim ◽  
Kirsten C. S. Adam ◽  
Eren Gunseli ◽  
Edward Awh ◽  
Edward K. Vogel

Complex cognition relies on both on-line representations in working memory (WM), said to reside in the focus of attention, and passive off-line representations of related information. Here, we dissected the focus of attention by showing that distinct neural signals index the on-line storage of objects and sustained spatial attention. We recorded electroencephalogram (EEG) activity during two tasks that employed identical stimulus displays but varied the relative demands for object storage and spatial attention. We found distinct delay-period signatures for an attention task (which required only spatial attention) and a WM task (which invoked both spatial attention and object storage). Although both tasks required active maintenance of spatial information, only the WM task elicited robust contralateral delay activity that was sensitive to mnemonic load. Thus, we argue that the focus of attention is maintained via a collaboration between distinct processes for covert spatial orienting and object-based storage.


2018 ◽  
Vol 30 (2) ◽  
pp. 256-266 ◽  
Author(s):  
Dirk van Moorselaar ◽  
Joshua J. Foster ◽  
David W. Sutterer ◽  
Jan Theeuwes ◽  
Christian N. L. Olivers ◽  
...  

Current theories assume a functional role for covert attention in the maintenance of spatial information in working memory. Consistent with this view, both the locus of attention and positions stored in working memory can be decoded based on the topography of oscillatory alpha-band (8–12 Hz) activity on the scalp. Thus far, however, alpha modulation has been studied in isolation for covert attention and working memory tasks. Here, we applied an inverted spatial encoding model in combination with EEG to study the temporal dynamics of spatially specific alpha activity during a task that required observers to visually select a target location while maintaining another independently varying location in working memory. During the memory delay period, alpha-based spatial tuning functions shifted from the position stored in working memory to the covertly attended position and back again after the attention task was completed. The findings provide further evidence for a common oscillatory mechanism in both the selection and the maintenance of relevant spatial visual information and demonstrate the dynamic trade-off in prioritization between two spatial tasks.


2019 ◽  
Author(s):  
Roger W. Strong ◽  
George Alvarez

Attentional tracking and working memory tasks are often performed better when targets are divided evenly between the left and right visual hemifields, rather than contained within a single hemifield (Alvarez & Cavanagh, 2005; Delvenne, 2005). However, this bilateral field advantage does not provide conclusive evidence of hemifield-specific control of attention and working memory, as it can be explained solely from hemifield-limited spatial interference at early stages of visual processing. If control of attention and working memory is specific to each hemifield, maintaining target information should become more difficult as targets move between the two hemifields. Observers in the present study maintained targets that moved either within or between the left and right hemifields, using either attention (Experiment 1) or working memory (Experiment 2). Maintaining spatial information was more difficult when target items moved between the hemifields compared to when target items moved within their original hemifields, consistent with hemifield-specific control of spatial attention and working memory. However, this pattern was not found for maintaining identity information (e.g., color) in working memory (Experiment 3). Together, these results provide evidence that control of spatial attention and working memory is specific to each hemifield, and that hemifield-specific control is a unique signature of spatial processing.


2019 ◽  
Author(s):  
Daria Kvasova ◽  
Salvador Soto-Faraco

AbstractRecent studies show that cross-modal semantic congruence plays a role in spatial attention orienting and visual search. However, the extent to which these cross-modal semantic relationships attract attention automatically is still unclear. At present the outcomes of different studies have been inconsistent. Variations in task-relevance of the cross-modal stimuli (from explicitly needed, to completely irrelevant) and the amount of perceptual load may account for the mixed results of previous experiments. In the present study, we addressed the effects of audio-visual semantic congruence on visuo-spatial attention across variations in task relevance and perceptual load. We used visual search amongst images of common objects paired with characteristic object sounds (e.g., guitar image and chord sound). We found that audio-visual semantic congruence speeded visual search times when the cross-modal objects are task relevant, or when they are irrelevant but presented under low perceptual load. Instead, when perceptual load is high, sounds fail to attract attention towards the congruent visual images. These results lead us to conclude that object-based crossmodal congruence does not attract attention automatically and requires some top-down processing.


2012 ◽  
Vol 24 (12) ◽  
pp. 2363-2371 ◽  
Author(s):  
Paolo Capotosto ◽  
Maurizio Corbetta ◽  
Gian Luca Romani ◽  
Claudio Babiloni

TMS interference over right intraparietal sulcus (IPS) causally disrupts behaviorally and EEG rhythmic correlates of endogenous spatial orienting before visual target presentation [Capotosto, P., Babiloni, C., Romani, G. L., & Corbetta, M. Differential contribution of right and left parietal cortex to the control of spatial attention: A simultaneous EEG-rTMS study. Cerebral Cortex, 22, 446–454, 2012; Capotosto, P., Babiloni, C., Romani, G. L., & Corbetta, M. Fronto-parietal cortex controls spatial attention through modulation of anticipatory alpha rhythms. Journal of Neuroscience, 29, 5863–5872, 2009]. Here we combine data from our previous studies to examine whether right parietal TMS during spatial orienting also impairs stimulus-driven reorienting or the ability to efficiently process unattended stimuli, that is, stimuli outside the current focus of attention. Healthy volunteers (n = 24) performed a Posner spatial cueing task while their EEG activity was being monitored. Repetitive TMS (rTMS) was applied for 150 msec simultaneously to the presentation of a central arrow directing spatial attention to the location of an upcoming visual target. Right IPS-rTMS impaired target detection, especially for stimuli presented at unattended locations; it also caused a modulation of the amplitude of parieto-occipital positive ERPs peaking at about 480 msec (P3) post-target. The P3 significantly decreased for unattended targets and significantly increased for attended targets after right IPS-rTMS as compared with sham stimulation. Similar effects were obtained for left IPS stimulation albeit in a smaller group of volunteers. We conclude that disruption of anticipatory processes in right IPS has prolonged effects that persist during target processing. The P3 decrement may reflect interference with postdecision processes that are part of stimulus-driven reorienting. Right IPS is a node of functional interaction between endogenous spatial orienting and stimulus-driven reorienting processes in human vision.


2021 ◽  
Author(s):  
Ming-Ray Liao ◽  
Andy Jeesu Kim ◽  
Brian A Anderson

Reward learning has been shown to habitually guide spatial attention to regions of a scene. However, the neural mechanisms that support this bias in spatial orienting are unknown. In the present study, participants learned to orient to a particular quadrant of a scene (high-value quadrant) to maximize monetary gains. This learning was scene-specific, with the high-value quadrant varying across different scenes. During a subsequent test phase, participants were faster at identifying a target if it appeared in the high-value quadrant (valid), and initial saccades were more likely to be made to the high-value quadrant. fMRI analyses during the test phase revealed learning-dependent priority signals in the bilateral caudate tail and superior colliculus, frontal eye field, substantia nigra, and insula, paralleling findings concerning feature-based value-driven attention. In addition, ventral regions typically associated with scene selective and spatial information processing, including the hippocampus, parahippocampal gyrus, and temporo-occipital cortex, were also implicated. Taken together, our findings offer new insights into the neural architecture subserving value-driven attention, both extending our understanding of nodes in the attention network previously implicated in feature-based value-driven attention and identifying a ventral network of brain regions implicated in rewards influence on scene-dependent spatial orienting.


2002 ◽  
Vol 16 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Heikki Hämäläinen

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.


2001 ◽  
Vol 15 (1) ◽  
pp. 22-34 ◽  
Author(s):  
D.H. de Koning ◽  
J.C. Woestenburg ◽  
M. Elton

Migraineurs with and without aura (MWAs and MWOAs) as well as controls were measured twice with an interval of 7 days. The first session of recordings and tests for migraineurs was held about 7 hours after a migraine attack. We hypothesized that electrophysiological changes in the posterior cerebral cortex related to visual spatial attention are influenced by the level of arousal in migraineurs with aura, and that this varies over the course of time. ERPs related to the active visual attention task manifested significant differences between controls and both types of migraine sufferers for the N200, suggesting a common pathophysiological mechanism for migraineurs. Furthermore, migraineurs without aura (MWOAs) showed a significant enhancement for the N200 at the second session, indicating the relevance of time of measurement within migraine studies. Finally, migraineurs with aura (MWAs) showed significantly enhanced P240 and P300 components at central and parietal cortical sites compared to MWOAs and controls, which seemed to be maintained over both sessions and could be indicative of increased noradrenergic activity in MWAs.


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