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Object Processing (object + processing)
Selected AbstractsFrom Parts to Wholes: Mechanisms of Development in Infant Visual Object ProcessingINFANCY, Issue 2 2004Gert Westermann Visual object processing in infancy is often described as proceeding from an early stage in which object features are processed independently to a later stage in which relations between features are taken into account (e.g., Cohen, 1998). Here we present the Representational Acuity Hypothesis, which argues that this behavioral shift can be explained by a developmental decrease in the size of neural receptive fields in the cortical areas responsible for object representation, together with a tuning to specific object features. We evaluate this hypothesis with a connectionist model of infant perceptual categorization. The model shows a behavioral shift in featural to relational processing consistent with similar results observed in the infant categorization experiments of Younger (1985) and Younger and Cohen (1986). [source] Adult gaze influences infant attention and object processing: implications for cognitive neuroscienceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2005Vincent M. Reid Abstract Infants follow others' gaze toward external objects from early in ontogeny, but whether they use others' gaze in processing information about objects remains unknown. In Experiment 1, 4-month-old infants viewed a video presentation of an adult gazing toward one of two objects. When presented with the same objects alone a second time, infants looked reliably less at the object to which the adult had directly gazed (cued object). This suggests that the uncued object was perceived as more novel than the object previously cued by the adult's gaze. In Experiment 2, adult gaze was not directed towards any object. In this control experiment, infants looked at both objects equally in the test phase. These findings show that adult eye gaze biases infant visual attention and information processing. Implications of the paradigm for cognitive neuroscience are presented and the results are discussed in terms of neural structures and change over ontogeny. [source] Enhanced effectiveness in visuo-haptic object-selective brain regions with increasing stimulus salienceHUMAN BRAIN MAPPING, Issue 5 2010Sunah Kim Abstract The occipital and parietal lobes contain regions that are recruited for both visual and haptic object processing. The purpose of the present study was to characterize the underlying neural mechanisms for bimodal integration of vision and haptics in these visuo-haptic object-selective brain regions to find out whether these brain regions are sites of neuronal or areal convergence. Our sensory conditions consisted of visual-only (V), haptic-only (H), and visuo-haptic (VH), which allowed us to evaluate integration using the superadditivity metric. We also presented each stimulus condition at two different levels of signal-to-noise ratio or salience. The salience manipulation allowed us to assess integration using the rule of inverse effectiveness. We were able to localize previously described visuo-haptic object-selective regions in the lateral occipital cortex (lateral occipital tactile-visual area) and the intraparietal sulcus, and also localized a new region in the left anterior fusiform gyrus. There was no evidence of superadditivity with the VH stimulus at either level of salience in any of the regions. There was, however, a strong effect of salience on multisensory enhancement: the response to the VH stimulus was more enhanced at higher salience across all regions. In other words, the regions showed enhanced integration of the VH stimulus with increasing effectiveness of the unisensory stimuli. We called the effect "enhanced effectiveness." The presence of enhanced effectiveness in visuo-haptic object-selective brain regions demonstrates neuronal convergence of visual and haptic sensory inputs for the purpose of processing object shape. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Looking for faces: Attention modulates early occipitotemporal object processingPSYCHOPHYSIOLOGY, Issue 3 2004Andreas Lueschow Abstract Looking for somebody's face in a crowd is one of the most important examples of visual search. For this goal, attention has to be directed to a well-defined perceptual category. When this categorically selective process starts is, however, still unknown. To this end, we used magnetoencephalography (MEG) recorded over right human occipitotemporal cortex to investigate the time course of attentional modulation of perceptual processes elicited by faces and by houses. The first face-distinctive MEG response was observed at 160,170 ms (M170). Nevertheless, attention did not start to modulate face processing before 190 ms. The first house-distinctive MEG activity was also found around 160,170 ms. However, house processing was not modulated by attention before 280 ms (90 ms later than face processing). Further analysis revealed that the attentional modulation of face processing is not due to later, for example, back-propagated activation of the M170 generator. Rather, subsequent stages of occipitotemporal object processing were modulated in a category-specific manner and with preferential access to face processing. [source] | ||||||||||