Predicting the orientation of invisible stimuli from activity in human primary visual cortex

Haynes, John‐Dylan; Rees, Geraint

doi:10.1167/5.8.221

Cited by 187 publications

(283 citation statements)

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“…The main analyses were based on ROI decoding (Haynes and Rees, 2005;Kamitani and Tong, 2005), in which the voxels of a given ROI in native space were used for classification. ROI decoding followed the same cross-validation procedure as detailed for the searchlight analysis.…”

Section: Multivariate Analysesmentioning

confidence: 99%

Non-holistic coding of objects in lateral occipital complex with and without attention

et al. 2015

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A fundamental issue in visual cognition is whether high-level visual areas code objects in a part-based or a view-based (holistic) format. By examining the viewpoint invariance of object recognition, previous behavioral and neuroimaging studies have yielded ambiguous results, supporting both types of representational formats. A critical factor distinguishing the two formats could be the availability of attentional resources, as a number of studies have found greater viewpoint invariance for attended compared to unattended objects. It has therefore been suggested that attention is necessary to enable part-based representations, whereas holistic representations are automatically activated irrespective of attention. In this functional magnetic resonance imaging study we used a multivariate approach to probe the format of object representations in human lateral occipital complex (LOC) and its dependence on attention. We presented human participants with intact and half-split versions of objects that were either attended or unattended. Cross-classifying between intact and split objects, we found that the objectrelated information coded in activation patterns of intact objects is fully preserved in the patterns of split objects and vice versa. Importantly, the generalization between intact and split objects did not depend on attention. Our findings demonstrate that LOC codes objects in a non-holistic format, both in the presence and absence of attention.

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Section: Multivariate Analysesmentioning

confidence: 99%

Non-holistic coding of objects in lateral occipital complex with and without attention

et al. 2015

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“…Our motivation for extending the gene shaving method to fMRI data analysis is the inability of conventional fMRI data analysis to unravel the complex brain activity that natural sensory stimuli elicit [20]. Such complex brain activities often manifest in fMRI as spatially widely distributed and overlapping clusters of hemodynamic responses [19].…”

Section: Introductionmentioning

confidence: 99%

Identifying distributed and overlapping clusters of hemodynamic synchrony in fMRI data sets

Ghebreab

Smeulders

2010

Pattern Anal Applic

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Natural sensory stimuli elicit complex brain responses that manifest in fMRI as widely distributed and overlapping clusters of hemodynamic responses. We propose a statistical signal processing method for finding synchronous hemodynamic activity that directly or transiently reflects information about the experimental condition. When applied to fMRI data, the method searches for voxels with activation patterns exhibiting high coherence and simultaneously high variance across brain scans. The crux of the method is functional principal component analysis (fPCA) of activation patterns stored in a twodimensional data matrix, with rows and columns representing voxels and scans, respectively. Without external information, fPCA is performed directly on this data matrix. Otherwise, the data matrix is first transformed to highlight a specific source of variation, enabling fully or partially supervised fPCA with a single parameter determining the degree of supervision. We evaluated our method on a public benchmark of fMRI scans of subjects viewing natural movies. Our method turns out to be very suitable for flexibly uncovering distributed and overlapping hemodynamic patterns that distinguish well between experimental conditions or cognitive states.

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“…That is, do neural signals in primary sensory processing regions reflect the physical properties of the world or our conscious perception of it? Reports regarding the role of primary visual cortex in conscious vision have been mixed, with some reporting V1 responses reflect perceived reality (Kok & De Lange, 2014;Muckli et al, 2005;Murray, Boyaci, & Kersten, 2006;Watkins et al, 2006), while others report a better match with physical reality (Crick & Koch, 1995;Haynes & Rees, 2005;Mikellidou et al, 2016). However, patients suffering from blindsight (Azzopardi & Cowey, 1998;Weiskrantz, 1996) following a lesion to V1 offer compelling evidence that V1 is necessary for conscious visual perception.…”

Section: Consciousnessmentioning

confidence: 99%

“…These predictions can be explicitly tested with laminar fMRI. For example, Haynes and Rees (2005) showed that the orientation of a grating stimulus rendered invisible by brief presentation and backward masking could be decoded from patterns of activity in V1. Interactive models of consciousness predict that information about the visually presented stimulus that does not reach awareness should not be met by top-down responses for higher-level brain areas.…”

Section: Consciousnessmentioning

confidence: 99%

Laminar fMRI: Applications for cognitive neuroscience

et al. 2019

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Highlights Recent developments in high spatial resolution fMRI allow for functional imaging of human cortical layers (laminar fMRI)  Feedforward and feedback responses can be dissociated by their laminar profiles  In vivo measurements of feedforward and feedback responses in humans with laminar fMRI have many, far-reaching applications for cognitive neuroscience  We review recent laminar fMRI studies, and several areas of cognitive neuroscience that stand to benefit from this exciting technological development AbstractThe cortex is a massively recurrent network, characterised by feedforward and feedback connections between brain areas as well as lateral connections within an area. areas at a more fine-grained level than previously possible in the human species. In this review,we highlight recent studies that successfully used laminar fMRI to isolate layer-specific feedback responses in human sensory cortex. In addition, we review several areas of cognitive neuroscience that stand to benefit from this new technological development, highlighting contemporary hypotheses that yield testable predictions for laminar fMRI. We hope to encourage researchers with the opportunity to embrace this development in fMRI research, as we expect that many future advancements in our current understanding of human brain function will be gained from measuring lamina-specific brain responses.

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Predicting the orientation of invisible stimuli from activity in human primary visual cortex

Cited by 187 publications

References 0 publications

Non-holistic coding of objects in lateral occipital complex with and without attention

Non-holistic coding of objects in lateral occipital complex with and without attention

Identifying distributed and overlapping clusters of hemodynamic synchrony in fMRI data sets

Laminar fMRI: Applications for cognitive neuroscience

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