Spatiotemporal object continuity in human ventral visual cortex

Abstract

Coherent visual experience requires that objects be represented as the same persisting individuals over time and motion. Cognitive science research has identified a powerful principle that guides such processing: Objects must trace continuous paths through space and time. Little is known, however, about how neural representations of objects, typically defined by visual features, are influenced by spatiotemporal continuity. Here, we report the consequences of spatiotemporally continuous vs. discontinuous motion on perceptual representations in human ventral visual cortex. In experiments using both dynamic occlusion and apparent motion, face-selective cortical regions exhibited significantly less activation when faces were repeated in continuous vs. discontinuous trajectories, suggesting that discontinuity caused featurally identical objects to be represented as different individuals. These results indicate that spatiotemporal continuity modulates neural representations of object identity, influencing judgments of object persistence even in the most staunchly ''featural'' areas of ventral visual cortex.functional MRI ͉ object persistence ͉ repetition attenuation ͉ spatiotemporal continuity ͉ visual tracking

Stimulus Predictability Reduces Responses in Primary Visual Cortex

“…V1 has been shown to respond less to coherent than to incoherent motion (McKeefry et al, 1997;Harrison et al, 2007;Bartels et al, 2008) and less to grouped than to randomly arranged objects (Murray et al, 2002). Furthermore, face-selective areas in ventral visual cortex have been shown to respond less when a face stimulus is repeated in a continuous trajectory (Yi et al, 2008), and responses of neurons in the superior temporal sulcus of the monkey brain were shown to be suppressed and to occur at shorter latencies when stimulation consists of predictable sequences of natural images (Perrett et al 2009). However, our study is the first to show that subtle changes in the spatiotemporal predictability of a stimulus affect stimulus processing in V1.…”

“…Therefore, it still remains to be determined whether reduced responses in V1 to predictable stimuli result from feedback, local processing in V1 or, what is likely to be the case, an interaction between feedback and local processing in V1 (Erlhagen, 2003). Yi et al (2008) observed that ventral visual cortex responds less to continuously than to discontinuously moving objects and attributed this effect to subjects perceiving continuously moving objects more as a single entity or gestalt. One could argue that the results presented here are due to a similar mechanism by claiming that predictable stimulus ensembles had a greater integrity as a gestalt.…”

Temporal dynamics of unimodal and multimodal feature binding

“…The mere fact that the object remains invisible may be tolerable with respect to perceived object constancy or persistency, but at some point this tolerance should end. Indeed, there is evidence that spatiotemporal continuity is crucial for object persistency (Gao & Scholl, in press;Mitroff & Alvarez, 2007;Yi et al, 2008) and that the impression of a continuously existing object begins to fade if visual objects disappear for more than half a second (Burke, 1952), at least in the absence of bridging events (see above). This implies that there might be a criterion for relating two temporally separated events-a criterion that determines whether the events are integrated or segregated.…”

Audio-visual synchrony and feature-selective attention co-amplify early visual processing

“…The motion of the train will lead to intermittent occlusions of the cars. Despite the spatial superposition, the visual system is able to interpolate occluded parts of the cars based on their trajectory and thus retains a sense of cars and trees being separate visual objects (Yi et al 2008;Franconeri et al 2012;Atmaca et al 2013). In our example, the moving cars correspond to the pulsing stimuli and the trees that constitute one visual object (Müller 2014, p. 132).…”