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The proactive brain and the fate of dead hypotheses.

Tal A, Bar M - Front Comput Neurosci (2014)

Bottom Line: In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition.Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection.Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered.

View Article: PubMed Central - PubMed

Affiliation: The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel.

ABSTRACT
A substantial portion of information flow in the brain is directed top-down, from high processing areas downwards. Signals of this sort are regarded as conveying prior expectations, biasing the processing and eventual perception of incoming stimuli. In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition. Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection. We propose that such predictions are rapidly inhibited in the brain after a competing option has been selected. Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered.

No MeSH data available.


Framework for top-down visual processing. LSF information is rapidly projected from preliminary occipital visual areas to the OFC. Based on this rudimentary display, predictions are formed and projected downwards to IT regions, where they coincide with the slower ventral visual stream of processing and facilitate recognition. In this illustration, an image of hairdryer supposedly prompts predictions of a drill, a gun, a hairdryer and a boomerang.
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Figure 1: Framework for top-down visual processing. LSF information is rapidly projected from preliminary occipital visual areas to the OFC. Based on this rudimentary display, predictions are formed and projected downwards to IT regions, where they coincide with the slower ventral visual stream of processing and facilitate recognition. In this illustration, an image of hairdryer supposedly prompts predictions of a drill, a gun, a hairdryer and a boomerang.

Mentions: According to the proposed framework, the OFC uses rudimentary versions of an input to rapidly activate familiar object categories resembling it. These activations act as hypotheses of the input’s identity, subsequently combined with HSF bottom-up processing in temporal regions to facilitate recognition (Bar et al., 2006; Figure 1). LSF-based “initial guesses” assist, therefore, in narrowing down the search space of identity matching. An image of a tennis racket, by this account, will evoke a cursory image in the OFC, which will cause a signal corresponding to a racket, a guitar, a spoon and other object prototypes sharing a relatively similar outline, to be subsequently passed downwards. Finding the best match between these options and additional bottom-up incoming information will constitute recognition. Combining bottom-up with top-down signals in this manner has indeed been demonstrated to yield optimal efficiency in a computational model of visual recognition (Graboi and Lisman, 2003). Bottom-up information confines the hypothesis space to a selected subset of options, which are then passed back downwards to subsequently confine the breadth of lower-level processing required.


The proactive brain and the fate of dead hypotheses.

Tal A, Bar M - Front Comput Neurosci (2014)

Framework for top-down visual processing. LSF information is rapidly projected from preliminary occipital visual areas to the OFC. Based on this rudimentary display, predictions are formed and projected downwards to IT regions, where they coincide with the slower ventral visual stream of processing and facilitate recognition. In this illustration, an image of hairdryer supposedly prompts predictions of a drill, a gun, a hairdryer and a boomerang.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4219452&req=5

Figure 1: Framework for top-down visual processing. LSF information is rapidly projected from preliminary occipital visual areas to the OFC. Based on this rudimentary display, predictions are formed and projected downwards to IT regions, where they coincide with the slower ventral visual stream of processing and facilitate recognition. In this illustration, an image of hairdryer supposedly prompts predictions of a drill, a gun, a hairdryer and a boomerang.
Mentions: According to the proposed framework, the OFC uses rudimentary versions of an input to rapidly activate familiar object categories resembling it. These activations act as hypotheses of the input’s identity, subsequently combined with HSF bottom-up processing in temporal regions to facilitate recognition (Bar et al., 2006; Figure 1). LSF-based “initial guesses” assist, therefore, in narrowing down the search space of identity matching. An image of a tennis racket, by this account, will evoke a cursory image in the OFC, which will cause a signal corresponding to a racket, a guitar, a spoon and other object prototypes sharing a relatively similar outline, to be subsequently passed downwards. Finding the best match between these options and additional bottom-up incoming information will constitute recognition. Combining bottom-up with top-down signals in this manner has indeed been demonstrated to yield optimal efficiency in a computational model of visual recognition (Graboi and Lisman, 2003). Bottom-up information confines the hypothesis space to a selected subset of options, which are then passed back downwards to subsequently confine the breadth of lower-level processing required.

Bottom Line: In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition.Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection.Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered.

View Article: PubMed Central - PubMed

Affiliation: The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel.

ABSTRACT
A substantial portion of information flow in the brain is directed top-down, from high processing areas downwards. Signals of this sort are regarded as conveying prior expectations, biasing the processing and eventual perception of incoming stimuli. In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition. Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection. We propose that such predictions are rapidly inhibited in the brain after a competing option has been selected. Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered.

No MeSH data available.