Spatial Attention Does Not Strongly Modulate Neuronal Responses in Early Human Visual Cortex

Yoshor, Daniel; Ghose, Geoffrey M.; Bosking, William H.; Park, Sun; Maunsell, John H. R.

doi:10.1523/jneurosci.2944-07.2007

Cited by 62 publications

(50 citation statements)

References 29 publications

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“…The late interval response phases and the initial stimulus unselective response peaks (at about 50 msec) were of opposite polarity in the two animals. It should be noted that previous studies have also reported interindividual differences in visual cortical LFPs in monkeys (Anderson, Mruczek, Kawasaki, & Sheinberg, 2008;Taylor, Mandon, Freiwald, & Kreiter, 2005) and humans (Yoshor, Ghose, Bosking, Sun, & Maunsell, 2007). Possible causes of these interanimal variations in the shape of the LFP include differences in recording location (e.g., layer; Anderson et al, 2008), that is, foveal versus peripheral stimulus presentations or different cortical layer, in situ electrical properties of electrodes and, although less likely, differences in the location of the reference wires.…”

Section: Discussionmentioning

confidence: 91%

Dissociable Neural Effects of Long-term Stimulus–Reward Pairing in Macaque Visual Cortex

Frankó

Seitz

Vogels

2010

Journal of Cognitive Neuroscience

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It has been proposed that perceptual learning may occur through a reinforcement process, in which consistently pairing stimuli with reward is sufficient for learning. We tested whether stimulus-reward pairing is sufficient to increase the sensorial representation of a stimulus by recording local field potentials (LFPs) in macaque extrastriate area V4 with chronically implanted electrodes. Two oriented gratings were repeatedly presented; one was paired with a fluid reward, whereas no reward was given at any other time. During the course of conditioning the LFP increased for the rewarded compared to the unrewarded orientation. The time course of the effect of stimulus-reward pairing and its reversal differed between an early and late interval of the LFP response: a fast change in the later part of the neural response that was dissociated from a slower change in the early part of the response. The fast change of the late interval LFP suggests that this late LFP change is related to enhanced attention during the presentation of the rewarded stimulus. The slower time course of the early interval response suggests an effect of sensorial learning. Thus, simple stimulus-reward pairing is sufficient to strengthen stimulus representations in visual cortex and does this by means of two dissociable mechanisms.

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Section: Discussionmentioning

confidence: 91%

Dissociable Neural Effects of Long-term Stimulus–Reward Pairing in Macaque Visual Cortex

Frankó

Seitz

Vogels

2010

Journal of Cognitive Neuroscience

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“…Future investigations of the relative sensitivity of single units vs. LFPs are needed to clarify this issue. However, a long latency of attentional effects in V1 could explain why some studies found little or no significant average enhancement of response with attention in V1, because these studies generally used short stimulus presentations (3,6,37,38). Likewise, a long latency attentional effect in V1 provides an obvious explanation for why some imaging studies find robust effects of attention in V1 (13).…”

Section: Discussionmentioning

confidence: 99%

A backward progression of attentional effects in the ventral stream

Buffalo

Fries

Landman

et al. 2009

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

272

183

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The visual processing of behaviorally relevant stimuli is enhanced through top-down attentional feedback. One possibility is that feedback targets early visual areas first and the attentional enhancement builds up at progressively later stages of the visual hierarchy. An alternative possibility is that the feedback targets the higher-order areas first and the attentional effects are communicated "backward" to early visual areas. Here, we compared the magnitude and latency of attentional enhancement of firing rates in V1, V2, and V4 in the same animals performing the same task. We found a reverse order of attentional effects, such that attentional enhancement was larger and earlier in V4 and smaller and later in V1, with intermediate results in V2. These results suggest that attentional mechanisms operate via feedback from higher-order areas to lower-order ones.attention | Macaque | vision | feedback N europhysiologic and brain imaging studies in monkeys and humans have shown that attended stimuli evoke larger responses in visual cortex than unattended distracters (1-6), giving attended stimuli a competitive advantage for representation in the cortex (7). These top-down attentional effects are thought to be mediated in part by feedback from prefrontal and posterior parietal cortex (8-12) acting directly or indirectly on all visual areas in the dorsal and ventral stream, including V1. However, the mechanism of this feedback is unclear. In particular, a first-order question is whether the top-down feedback targets V1 [or even the lateral geniculate nucleus (LGN)] first and then is passed on successively to later areas, or whether it targets higher-order areas first and then is fed back to successively lower areas. Without an understanding of the basic functional anatomy of the attentional feedback, it will be difficult to make progress in unraveling the circuitry for attention.The magnitude and timing of attentional effects on visual responses in all of the different visual structures should, in principle, give insight into the direction of attentional effects along the visual pathways. However, a comparison of the magnitude of attentional effects across visual areas in different studies leads to a confusing picture. On the one hand, imaging studies in humans typically find that attentional effects on evoked responses become larger as one moves from V1 into higher-order areas (13,14). Several neurophysiologic studies in monkeys also often report small (4) or even nonexistent (6, 15, 16) attentional enhancement of firing rates to stimuli in the receptive fields (RFs) of V1 cells (17-19), compared with reliable findings of attentional effects in higher-order areas such as V4 in conventional target detection or discrimination paradigms. On the other hand, other primate studies report substantial attentional effects in V1 in complex tasks such as covertly tracking along curved lines with spatially directed attention (18). It has recently been demonstrated that even with a relatively simple selection task, very large at...

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“…Modulation in firing rates due to attention are known to be weak in early visual areas, increasing in strength over hierarchical levels (Mehta et al, 2000;Maunsell and Cook, 2002). Similarly, subdural LFP recordings in humans have shown that the effects of spatial attention in V1 on the event-related potential are rather small (Yoshor et al, 2007). The comparatively strong effects of temporal expectation and their global nature indicate that the underlying mechanisms differ from those of spatial attention.…”

Section: Discussionmentioning

confidence: 99%

Gamma Responses Correlate with Temporal Expectation in Monkey Primary Visual Cortex

Lima¹,

Singer²,

Neuenschwander³

2011

J. Neurosci.

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Gamma oscillations have been linked to selective attention. Here, we investigate the effects of expecting a behaviorally relevant event (a change in the fixation point) on the oscillatory patterning of the local field potential and spiking responses in V1. Three protocols were used. In the first protocol, fixation point change occurred at a fixed time point, enabling predictions on task timing. In the second, fixation point change occurred in trial blocks either early or late in the trial, allowing us to compare responses during epochs of low and high expectation. Finally, we used a cue to indicate the upcoming fixation point change. All protocols led to an increase in gamma oscillations associated with alpha suppression when the monkeys expected an event in time. These effects were spatially widespread, since comparable results were observed for both central and peripheral visual representations in V1. Our findings indicate that expectations associated with perceptual decisions, motor responses, or upcoming reward may have a strong effect on the primary visual cortex, causing global, spatially nonselective modulation of gamma activity.

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Spatial Attention Does Not Strongly Modulate Neuronal Responses in Early Human Visual Cortex

Cited by 62 publications

References 29 publications

Dissociable Neural Effects of Long-term Stimulus–Reward Pairing in Macaque Visual Cortex

Dissociable Neural Effects of Long-term Stimulus–Reward Pairing in Macaque Visual Cortex

A backward progression of attentional effects in the ventral stream

Gamma Responses Correlate with Temporal Expectation in Monkey Primary Visual Cortex

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