Delayed Striate Cortical Activation during Spatial Attention

Noesselt, Toemme; Hillyard, S. A.; Woldorff, Marty G.; Schoenfeld, Mircea Ariel; Hagner, Tilman; Jäncke, Lutz; Tempelmann, Claus; Hinrichs, Hermann; Heinze, Hans‐Jochen

doi:10.1016/s0896-6273(02)00781-x

Cited by 259 publications

(270 citation statements)

References 46 publications

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“…This model accommodates two key observations: (i) it explains the relative enhancement of neural activity at attended locations, and how selectivity can be flexibly rerouted to favor new locations; and (ii) it explains the seeming paradox that attentional modulations in higher level areas appear earlier than in lower level areas (10,(51)(52)(53).…”

Section: Discussionmentioning

confidence: 64%

Direct neurophysiological evidence for spatial suppression surrounding the focus of attention in vision

Hopf

Boehler

Luck

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

225

184

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The spatial focus of attention has traditionally been envisioned as a simple spatial gradient of enhanced activity that falls off monotonically with increasing distance. Here, we show with highdensity magnetoencephalographic recordings in human observers that the focus of attention is not a simple monotonic gradient but instead contains an excitatory peak surrounded by a narrow inhibitory region. To demonstrate this center-surround profile, we asked subjects to focus attention onto a color pop-out target and then presented probe stimuli at various distances from the target. We observed that the electromagnetic response to the probe was enhanced when the probe was presented at the location of the target, but the probe response was suppressed in a narrow zone surrounding the target and then recovered at more distant locations. Withdrawing attention from the pop-out target by engaging observers in a demanding foveal task eliminated this pattern, confirming a truly attention-driven effect. These results indicate that neural enhancement and suppression coexist in a spatially structured manner that is optimal to attenuate the most deleterious noise during visual object identification.attention ͉ magnetoencephalography ͉ visual I t is a common experience that one is able to focus on relevant parts of a visual scene even when irrelevant parts of the scene are more salient. It has been suggested that this voluntary focusing is mediated by a biasing of competitive stimulus interactions in the visual cortex, which promotes preferential processing of relevant over irrelevant input (1-3). This competitive advantage can be achieved by enhancing the processing of relevant inputs or by attenuating the processing of irrelevant inputs. Evidence has accumulated that attention operates by means of both neural enhancement (4-7) and neural suppression (8-13). More recent data from functional MRI in humans indicate that enhancement and suppression may cooperate across the visual scene (14, 15), leading to an increase in selectivity in a push-pull-like manner (15). That is, a spatially organized combination of enhancement and suppression may effectively sharpen the demarcation of relevant from irrelevant inputs, particularly in cluttered visual scenes in which neural representations of relevant and irrelevant information may become mixed together (16, 17) .Many behavioral and electrophysiological studies of attention have indicated that attending to a location produces a monotonic gradient of processing efficiency around the attended location (18)(19)(20)(21)(22). In contrast, computational models motivated by the known anatomy and physiology of the primate visual system have predicted that the spatial distribution of cortical activity around the focus of attention may be more complex than a simple gradient. In particular, the selective tuning model (ST) of Tsotsos et al. (23,24) proposes an architecture of attentional selection that explicitly predicts a suppressive zone surrounding the focus of attention. In short, ST provides an acc...

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Section: Discussionmentioning

confidence: 64%

Direct neurophysiological evidence for spatial suppression surrounding the focus of attention in vision

Hopf

Boehler

Luck

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

225

184

View full text Add to dashboard Cite

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“…Because neural responses in the early visual areas are relatively insensitive to the repetition effect compared with those in the later visual areas Schacter and Buckner, 1998), the confounding of early visual signals into MEG data in the present study would obscure the NA effect occurring in higher visual areas. Given recent studies reporting that V1 area receives a delayed feedback signal from the higher visual cortex at a latency of 190 -230 msec (Noesselt et al, 2002;Halgren et al, 2003) in addition to the primary visual input from the thalamus, it would be difficult to exclude the early visual signals on the basis of signal latency. We therefore presented visual stimuli based on our random dot blinking (RDB) technique developed previously (Okusa et al, 1998).…”

Section: Methodsmentioning

confidence: 99%

Temporal Dynamics of Neural Adaptation Effect in the Human Visual Ventral Stream

Noguchi¹,

Inui²,

Kakigi³

2004

J. Neurosci.

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When the same visual stimulus is repeatedly presented with a brief interval, the brain responses to that stimulus are attenuated relative to those at first presentation [neural adaptation (NA)]. Although this effect has been widely observed in various regions of human brain, its temporal dynamics as a neuronal population has been mostly unclear. In the present study, we used a magnetoencephalography (MEG) and conducted a macrolevel investigation of the temporal profiles of the NA occurring in the human visual ventral stream. The combination of MEG with our previous random dot blinking method isolated the neural responses in the higher visual cortex relating to shape perception. We dissociated three dimensions of the NA: activation strength, peak latency, and temporal duration of neural response. The results revealed that visual responses to the repeated compared with novel stimulus showed a significant reduction in both activation strength and peak latency but not in the duration of neural processing. Furthermore, this acceleration of peak latency showed a significant correlation with reaction time of the subjects, whereas no correlation was found between the reaction time and the temporal duration of neural responses. These results indicate that (1) the NA involves the brain response changes in the temporal domain as well as the response attenuation reported previously, and (2) this temporal change is primarily observed as a rapid rising of "what" responses, rather than a temporal shortening of neural response curves within the visual ventral stream as considered previously.

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“…Why are these effects commonly observed with fMRI but not with other techniques? Recent studies that have combined the high spatial resolution of fMRI with the high temporal resolution of EEG and magnetoencephalography (Noesselt et al, 2002) have demonstrated that the effects of attention on V1 activity do not take place during the initial stimulusrelated response (ϳ60 -90 msec). Instead, longer-latency activity (in the time range of 150 -250 msec) was found to be strongly modulated by attention.…”

Section: The Effect Of Attention On Sensory Processingmentioning

confidence: 99%

Neuroimaging Studies of Attention: From Modulation of Sensory Processing to Top-Down Control

2003

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Delayed Striate Cortical Activation during Spatial Attention

Cited by 259 publications

References 46 publications

Direct neurophysiological evidence for spatial suppression surrounding the focus of attention in vision

Direct neurophysiological evidence for spatial suppression surrounding the focus of attention in vision

Temporal Dynamics of Neural Adaptation Effect in the Human Visual Ventral Stream

Neuroimaging Studies of Attention: From Modulation of Sensory Processing to Top-Down Control

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