Chapter 1 Top-down facilitation of visual object recognition: object-based and context-based contributions

Fenske, Mark J.; Aminoff, Elissa; Gronau, Nurit; Bär, Markus

doi:10.1016/s0079-6123(06)55001-0

Cited by 173 publications

(152 citation statements)

References 84 publications

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“…Moreover, besides contributing to unconscious processing of manipulable, tool-like objects [78 -80], recent evidence [81] indicates that the dorsal pathway also directly supports their conscious processing. Moreover, besides these direct contributions to motion and object perception, recent approaches to visual object recognition [82][83][84][85][86] indicate that the dorsal M-pathway plays an important role in conscious vision by modulating the processing of activity in the early (V1-V4) stages of cortical processing. Without detailing the intricacies of the proposal [84,85], the gist of the proposal-a specific version of a 'frame-and-fill' approach to scene and object perception [83] and here modified from Fenske et al [84]-is illustrated in figure 4.…”

Section: The Roles Of Visual Processing In the Dorsal Pathwaymentioning

confidence: 99%

“…Top-down influences, besides playing major roles in attentional modulation of lower level visual processing [56], thus can also play a major role in the formation of conscious percepts. We [87] modified the model proposed by Fenske et al [84] by adding cascading re-entrant activations from the higher areas of the ventral cortical stream of processing to its lower ones, for the following reasons. First, reciprocal anatomical (feed-forward and feedback) connections exist between successive areas in the cortical streams of visual processing [88,89].…”

Section: The Roles Of Visual Processing In the Dorsal Pathwaymentioning

confidence: 99%

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Contributions of magno- and parvocellular channels to conscious and non-conscious vision

Breitmeyer

2014

Phil. Trans. R. Soc. B

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The dorsal and ventral cortical pathways, driven predominantly by magnocellular (M) and parvocellular (P) inputs, respectively, assume leading roles in models of visual information processing. Although in prior proposals, the dorsal and ventral pathways support non-conscious and conscious vision, respectively, recent modelling and empirical developments indicate that each pathway plays important roles in both non-conscious and conscious vision. In these models, the ventral P-pathway consists of one subpathway processing an object's contour features, e.g. curvature, the other processing its surface attributes, e.g. colour. Masked priming studies have shown that feed-forward activity in the ventral P-pathway on its own supports non-conscious processing of contour and surface features. The dorsal M-pathway activity contributes directly to conscious vision of motion and indirectly to object vision by projecting to prefrontal cortex, which in turn injects top-down neural activity into the ventral P-pathway and there ‘ignites’ feed-forward–re-entrant loops deemed necessary for conscious vision. Moreover, an object's shape or contour remains invisible without the prior conscious registration of its surface properties, which for that reason are taken to comprise fundamental visual qualia. Besides suggesting avenues for future research, these developments bear on several recent and past philosophical issues.

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Section: The Roles Of Visual Processing In the Dorsal Pathwaymentioning

confidence: 99%

Section: The Roles Of Visual Processing In the Dorsal Pathwaymentioning

confidence: 99%

Contributions of magno- and parvocellular channels to conscious and non-conscious vision

Breitmeyer

2014

Phil. Trans. R. Soc. B

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“…Feedback from dorsal subregions of frontal and parietal cortices, including IPS and FEF, is an attractive candidate (41)(42)(43). Numerous fMRI studies of attention implicate these high-level brain areas as key nodes in an attention network that provides dynamic modulation of visual cortex (7,(44)(45)(46).…”

Section: Memory Predictions Optimize Preparatory Visual Activity For mentioning

confidence: 99%

Long-term memory prepares neural activity for perception

Stokes

Atherton²,

Patai³

et al. 2011

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

136

148

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Past experience provides a rich source of predictive information about the world that could be used to guide and optimize ongoing perception. However, the neural mechanisms that integrate information coded in long-term memory (LTM) with ongoing perceptual processing remain unknown. Here, we explore how the contents of LTM optimize perception by modulating anticipatory brain states. By using a paradigm that integrates LTM and attentional orienting, we first demonstrate that the contents of LTM sharpen perceptual sensitivity for targets presented at memory-predicted spatial locations. Next, we examine oscillations in EEG to show that memory-guided attention is associated with spatially specific desynchronization of alpha-band activity over visual cortex. Additionally, we use functional MRI to confirm that target-predictive spatial information stored in LTM triggers spatiotopic modulation of preparatory activity in extrastriate visual cortex. Finally, functional MRI results also implicate an integrated cortical network, including the hippocampus and a dorsal frontoparietal circuit, as a likely candidate for organizing preparatory states in visual cortex according to the contents of LTM. O ur expectations shape how we see the world. From the earliest pioneers in perception (e.g., ref. 1), it has long been appreciated that past experience guides perceptual processing and decision-making. Indeed, the statistical regularities of the environment, extracted over past experience and coded in longterm memory (LTM), provide a rich source of predictive information that could be exploited to optimize perception for goal-directed behavior (2-4).Studies of selective attention provide an important framework for understanding the dynamic changes in neural processing that optimize perceptual analysis for goal-specific input. In particular, influential theories suggest that modulations in baseline neural activity in sensory cortex bias perceptual processing in favor of behaviorally relevant information (5-7). For example, a cue stimulus that provides information about the likely location of a target triggers a shift in baseline activity for neurons that represent the cued position (8-11), thereby increasing the neural sensitivity for subsequent stimulation at the attended region of space (10, 11). However, in everyday life, we rarely enjoy the benefit of explicit cues to guide our attention. More typically, we must rely on our own past experiences, stored in LTM, to build the predictions that shape perception for goal-directed behavior.Despite the obvious biological relevance of experience-based perceptual biasing, few studies have directly examined how memory influences attentional control. Studies of contextual cueing (2) demonstrate a close relationship between past experience and visual search efficiency: search times decrease with repeated exposure to the same stimulus configurations, even when repetitions are not explicitly processed (12). Contextual cueing effects are particularly compelling for detail-rich naturalistic scen...

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“…Visual object recognition results from the interplay of bottom-up processing of sensory information and taskspecific expectations, which act as top-down modulations onto incoming information [Fenske et al, 2006;Mesulam, 2008]. The former bottom-up sensory signals are mainly feed-forward signals originating in the primary and extrastriate visual cortex.…”

Section: Introductionmentioning

confidence: 99%

“…However, visual object recognition is not only affected by this bottom-up processing but also by top-down modulations. Such top-down processes are imposed, for example, by selectively attending to a specific stimulus or stimulus feature [Banich et al, 2000], expectations about the occurrence of specific objects [Li et al, 2009;Zhang et al, 2008], predictions about forthcoming objects [Fenske et al, 2006;Summerfield and Egner, 2009], or the monitoring of decision processes under uncertainty conditions [Ridderinkhof et al, 2004]. This higher level top-down modulation might facilitate the processing of attended, expected, or predicted objects though this facilitation might be based on different underlying brain mechanisms, such that attention might enhance and expectation might reduce visual processing in extrastriate object sensitive brain regions [see Summerfield and Egner, 2009].…”

Section: Introductionmentioning

confidence: 99%

Face recognition under ambiguous visual stimulation: fMRI correlates of “encoding styles”

Frühholz¹,

Godde²,

Lewicki³

et al. 2010

Human Brain Mapping

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Object categorization during ambiguous sensory stimulation generally depends on the activity of extrastriate sensory areas as well as top-down information. Both reflect internal representations of prototypical object knowledge against which incoming sensory information is compared. However, besides these general mechanisms, individuals might differ in their readiness to impose internal representations onto incoming ambiguous information. These individual differences might be based on what was referred to as "Schema Instantiation Threshold" (SIT; Lewicki et al. [1992]: Am Pshycol 47:796-801), defining a continuum from very rapid (low threshold) to a rather controlled application of internal representations (high threshold). We collected fMRI scans while subjects with low SIT ("internal encoders") and subjects with high SIT ("external encoders") made gender categorizations of ambiguous facial images. Internal encoders made faster gender decisions during high sensory ambiguity, showed higher fusiform activity, and had faster BOLD responses in the fusiform (FFA) and occipital face area (OFA) indicating a faster and stronger application of face-gender representations due to a low SIT threshold. External encoders made slower gender decisions and showed increased medial frontal activity, indicating a more controlled strategy during gender categorizations and increased decisional uncertainties. Internal encoders showed higher functional connectivity of the orbito-frontal cortex (OFC) to seed activity in the FFA which might indicate both more readily generated predictive classificatory guesses and the subjective impressions of accurate classifications. Taken together, an "internal encoding style" is characterized by the fast, unsupervised and unverified application of primary object representations, whereas the opposite seems evident for subjects with an "external encoding style".

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Chapter 1 Top-down facilitation of visual object recognition: object-based and context-based contributions

Cited by 173 publications

References 84 publications

Contributions of magno- and parvocellular channels to conscious and non-conscious vision

Contributions of magno- and parvocellular channels to conscious and non-conscious vision

Long-term memory prepares neural activity for perception

Face recognition under ambiguous visual stimulation: fMRI correlates of “encoding styles”

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