Putting spatial attention on the map: timing and localization of stimulus selection processes in striate and extrastriate visual areas

Martı́nez, Antı́gona; Russo, Francesco Di; Anllo-Vento, Lourdes; Sereno, Martin I.; Buxton, Richard B.; Hillyard, Steven A.

doi:10.1016/s0042-6989(00)00267-4

Cited by 259 publications

(232 citation statements)

References 62 publications

Supporting

Mentioning

195

Contrasting

Unclassified

Order By: Relevance

“…The backward progression of attentional effects from V4 to V1 is consistent with the findings of Mehta et al (24), who used a cross-modal attention design with a diffuse visual stimulus in monkeys, as well as the findings of Martinez et al (35) based on the timing of attentional effects on event-related potentials in humans. Other monkey studies have found smaller attentional effects in V1 than in V4 (3,4,6), although the latencies of attentional effects were not reported in those studies.…”

Section: Discussionsupporting

confidence: 88%

A backward progression of attentional effects in the ventral stream

Buffalo

Fries

Landman

et al. 2009

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

269

183

View full text Add to dashboard Cite

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...

show abstract

Section: Discussionsupporting

confidence: 88%

A backward progression of attentional effects in the ventral stream

Buffalo

Fries

Landman

et al. 2009

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

269

183

View full text Add to dashboard Cite

show abstract

“…With a time range of 100-120 ms, this modulation arose soon (i.e., 27 ms) after the onset of the initial feedforward-driven activity in V1 and very rapidly (11 ms) after the onset of activity in extrastriate areas. Importantly, it appeared much earlier than attention-related recurrent activity modulations in V1, which have been found to arise not until after 150-250 ms after stimulus onset (2)(3)(4)(5)19). The considerable difference in the time course of awareness and attention-related modulations suggests that both represent distinct recurrent processing operations in V1.…”

Section: Correlates Of Successful Target Identification (Tm Trials)mentioning

confidence: 87%

Rapid recurrent processing gates awareness in primary visual cortex

Boehler

Schoenfeld

Heinze

et al. 2008

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

150

127

View full text Add to dashboard Cite

Visual awareness has been proposed to depend on recurrent processing in early visual cortex areas including the primary visual cortex (V1). Here, we address this hypothesis with high spatiotemporal resolution magnetoencephalographic recordings in subjects performing a substitution masking paradigm. Neural activity reflecting awareness is assessed by directly comparing the neuromagnetic response elicited by effectively and ineffectively masked targets after the proportion of trials leading to masking was individually adjusted to match the proportion of trials without masking. This revealed a modulation of recurrent activity in the primary visual cortex rapidly after the onset of the feedforward sweep of processing in striate and extrastriate areas but significantly before the onset of attention-dependent recurrent modulations in V1. Our data provide direct support for the notion that (i) recurrent processing in V1 correlates with visual awareness and (ii) that attention and awareness involve distinct recurrent processing operations.magnetoencephalography ͉ visual attention ͉ visual awareness T here is considerable evidence suggesting that attention influences activity in early visual cortex areas, including the primary visual cortex via feedback-driven modulations (1-4). Data from single cell recordings in the monkey have revealed that such feedback may operate via selective rate enhancements in V1 that label the segmentation of relevant input for priority for further processing (5, 6). Conversely, there is evidence suggesting that attentional feedback operates by suppressing irrelevant input, thereby increasing the relative prominence of relevant input representations in V1 (7).Beyond its undoubted role for attentional selection, feedback processing from extrastriate to primary visual cortex has also been implicated as an important factor for mediating visual awareness (6,(8)(9)(10)(11). Empirical evidence for this claim has been provided by a number of experimental approaches. While recording from V1 neurons in the macaque, Lamme et al. (12) observed that backward masking by texture patterns did not influence the initial feedforward activity elicited by the figure but caused a suppression of the delayed figure-ground modulation of neural firing, the latter being assumed to be mediated by feedback connections. Furthermore, Super et al. (13) could show that the delayed modulation reflecting figure-ground segregation was reduced in V1 when the monkey failed to identify the figure-ground stimulus.Ress and colleagues (14, 15) report related observations with fMRI in human observers. They observed that better discrimination performance at visual detection thresholds correlated with a blood oxygenation level dependent (BOLD) response enhancement in primary visual cortex (14). This was the case even when subjectively perceived stimuli were physically absent (15). Although Ress and Heeger (15) discuss an explanation in terms of bottom-up fluctuations of sensory processing in V1, they also entertain the possibility tha...

show abstract

“…One inherent technical difficulty of all retinotopic methods is that of attention and fixation: even though performance of retinotopic mapping seems to be in part independent from attention [35], the individual needs to be able to fixate throughout the 25 minute examination time. It should be noted, however, that one to two polar angle mapping scans are sufficient for the ROI definitions of V1 and…”

Section: Discussionmentioning

confidence: 99%

Case Report: Practicability of functionally based tractography of the optic radiation during presurgical epilepsy work up

Schmitt

Kaufmann

Hoffmann

et al. 2014

Neuroscience Letters

View full text Add to dashboard Cite

Pre-operative tractography of the optic radiation (OR) has been advised to assess the risk for postoperative visual field deficit (VFD) in certain candidates for resective epilepsy surgery. Diffusion tensor imaging (DTI) tractography relies on a precise anatomical determination of start and target regions of interest (ROIs), such as the lateral geniculate nucleus (LGN) and the primary visual cortex (V1). The post-chiasmal visual pathway and V1 show considerable inter-individual variability, and in epilepsy patients parenchymatous lesions might further complicate this matter. A functionally based tractography (FBT) seems beneficial for precise OR identification. We assessed practicability of FBT for OR identification in a patient with occipital lobe epilepsy due to a temporo-occipital maldevelopmental tumor. The MRI protocol at 3 T included a T1-weighted sagittal 3D scan, a T2-weighted axial 2D scan and a DTI scan using an echo planar spin echo sequence. ROIs for fiber tracking of OR (LGN V1) were determined with T2*-weighted fMRI-based retinotopic assessment. After DTI pre-processing and fiber tracking, paths with similar properties were combined in clusters for visual presentation and OR localization. Retinotopic phase maps allowed for the identification of V1 and LGN for a precise DTIbased reconstruction of OR, which was distant to the patient's tumor. Location and structure of ORs were comparable in each hemisphere. FBT could thus influence the human research of the extrastriate visual pathway and the risk management of post-operative VFD in epilepsy surgery. , Heinze HJ AbstractPre-operative tractography of the optic radiation (OR) has been advised to assess the risk for postoperative visual field deficit (VFD) in certain candidates for resective epilepsy surgery. were determined with T2*-weighted fMRI-based retinotopic assessment. After DTI preprocessing and fiber tracking, paths with similar properties were combined in clusters for visual presentation and OR localization. Retinotopic phase maps allowed for the identification of V1 and LGN for a precise DTI-based reconstruction of OR, which was distant to the patient´s tumor. Location and structure of ORs were comparable in each hemisphere. FBT could thus influence the human research of the extrastriate visual pathway and the risk management of post-operative VFD in epilepsy surgery. Diffusion tensor imaging (DTI

show abstract

Putting spatial attention on the map: timing and localization of stimulus selection processes in striate and extrastriate visual areas

Cited by 259 publications

References 62 publications

A backward progression of attentional effects in the ventral stream

A backward progression of attentional effects in the ventral stream

Rapid recurrent processing gates awareness in primary visual cortex

Case Report: Practicability of functionally based tractography of the optic radiation during presurgical epilepsy work up

Contact Info

Product

Resources

About