Merging visual features and temporal dynamics in sequential recommendation

Visual categorization is a human core cognitive capacity that depends on the development of visual category representations in the infant brain. The nature of infant visual category representations and their relationship to the corresponding adult form however remain unknown. Our results clarify the nature of visual category representations in 6- to 8-month-old infants and their developmental trajectory towards adult maturity in the key characteristics temporal dynamics, representational format, and spectral properties. Temporal dynamics change from slowly emerging, developing representations in infants to quickly emerging, complex representations in adults. Despite those differences infants and adults already partly share visual category representations. The format of infants' representations are visual features of low to intermediate complexity, whereas adults' representations also encoded high complexity features. Theta band neural oscillations form the basis of visual category representations in infants, and these representations are shifted to the alpha/beta band in adults.

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Differential temporal dynamics during visual imagery and perception

10.1101/226217 ◽

2017 ◽

Author(s):

Nadine Dijkstra ◽

Pim Mostert ◽

Floris P. de Lange ◽

Sander Bosch ◽

Marcel A. J. van Gerven

Keyword(s):

Visual Imagery ◽

Temporal Dynamics ◽

Stimulus Onset ◽

Neural Mechanisms ◽

Perceptual Processing ◽

Visual Features ◽

Complete Representation ◽

Visual Areas ◽

Temporal Generalization ◽

Human Participants

Visual perception and imagery rely on similar representations in the visual cortex. During perception, visual activity is characterized by distinct processing stages, but the temporal dynamics underlying imagery remain unclear. Here, we investigated the dynamics of visual imagery in human participants using magnetoencephalography. We show that, contrary to perception, the onset of imagery is characterized by broad temporal generalization. Furthermore, there is consistent overlap between imagery and perceptual processing around 150 ms and from 300 ms after stimulus onset, presumably reflecting completion of the feedforward sweep and perceptual stabilization respectively. These results indicate that during imagery either the complete representation is activated at once and does not include low-level visual areas, or the order in which visual features are activated is less fixed and more flexible than during perception. These findings have important implications for our understanding of the neural mechanisms of visual imagery.

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Recent advances in understanding object recognition in the human brain: deep neural networks, temporal dynamics, and context

F1000Research ◽

10.12688/f1000research.22296.1 ◽

2020 ◽

Vol 9 ◽

pp. 590

Author(s):

Susan G. Wardle ◽

Chris I. Baker

Keyword(s):

Neural Networks ◽

Object Recognition ◽

Human Brain ◽

Spatial Organization ◽

Deep Neural Networks ◽

Temporal Dynamics ◽

Brain Regions ◽

Visual Features ◽

Recent Advances ◽

Ambient Lighting

Object recognition is the ability to identify an object or category based on the combination of visual features observed. It is a remarkable feat of the human brain, given that the patterns of light received by the eye associated with the properties of a given object vary widely with simple changes in viewing angle, ambient lighting, and distance. Furthermore, different exemplars of a specific object category can vary widely in visual appearance, such that successful categorization requires generalization across disparate visual features. In this review, we discuss recent advances in understanding the neural representations underlying object recognition in the human brain. We highlight three current trends in the approach towards this goal within the field of cognitive neuroscience. Firstly, we consider the influence of deep neural networks both as potential models of object vision and in how their representations relate to those in the human brain. Secondly, we review the contribution that time-series neuroimaging methods have made towards understanding the temporal dynamics of object representations beyond their spatial organization within different brain regions. Finally, we argue that an increasing emphasis on the context (both visual and task) within which object recognition occurs has led to a broader conceptualization of what constitutes an object representation for the brain. We conclude by identifying some current challenges facing the experimental pursuit of understanding object recognition and outline some emerging directions that are likely to yield new insight into this complex cognitive process.

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Nonlinear Spatio-Temporal Dynamics and Chaos in Semiconductors

10.1017/cbo9780511524615 ◽

2001 ◽

Cited By ~ 136

Author(s):

Eckehard Schöll

Keyword(s):

Temporal Dynamics ◽

Spatio Temporal

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Effects of Monetary Incentives on Task Switching

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000146 ◽

2012 ◽

Vol 59 (4) ◽

pp. 216-226 ◽

Cited By ~ 36

Author(s):

Thomas Kleinsorge ◽

Gerhard Rinkenauer

Keyword(s):

Task Switching ◽

Temporal Dynamics ◽

Reward Processing ◽

General Level ◽

Monetary Incentives ◽

Switch Costs ◽

Expectancy Effect ◽

Reward Expectancy ◽

Trial Basis

In two experiments, effects of incentives on task switching were investigated. Incentives were provided as a monetary bonus. In both experiments, the availability of a bonus varied on a trial-to-trial basis. The main difference between the experiments relates to the association of incentives to individual tasks. In Experiment 1, the association of incentives to individual tasks was fixed. Under these conditions, the effect of incentives was largely due to reward expectancy. Switch costs were reduced to statistical insignificance. This was true even with the task that was not associated with a bonus. In Experiment 2, there was a variable association of incentives to individual tasks. Under these conditions, the reward expectancy effect was bound to conditions with a well-established bonus-task association. In conditions in which the bonus-task association was not established in advance, enhanced performance of the bonus task was accompanied by performance decrements with the task that was not associated with a bonus. Reward expectancy affected mainly the general level of performance. The outcome of this study may also inform recently suggested neurobiological accounts about the temporal dynamics of reward processing.

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