Training improves visual processing speed and generalizes to untrained functions

Abstract

Studies show that manipulating certain training features in perceptual learning determines the specificity of the improvement. The improvement in abnormal visual processing following training and its generalization to visual acuity, as measured on static clinical charts, can be explained by improved sensitivity or processing speed. Crowding, the inability to recognize objects in a clutter, fundamentally limits conscious visual perception. Although it was largely considered absent in the fovea, earlier studies report foveal crowding upon very brief exposures or following spatial manipulations. Here we used GlassesOff's application for iDevices to train foveal vision of young participants. The training was performed at reading distance based on contrast detection tasks under different spatial and temporal constraints using Gabor patches aimed at testing improvement of processing speed. We found several significant improvements in spatio-temporal visual functions including near and also non-trained far distances. A remarkable transfer to visual acuity measured under crowded conditions resulted in reduced processing time of 81 ms, in order to achieve 6/6 acuity. Despite a subtle change in contrast sensitivity, a robust increase in processing speed was found. Thus, enhanced processing speed may lead to overcoming foveal crowding and might be the enabling factor for generalization to other visual functions.

Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia

“…For such a framework to support "vision at a glance" (Hochstein and Ahissar, 2002;Kubilius et al, 2014), it would be reasonable to assume that such pre-attentive computations should occur fast and based on coarse spatial resolution, as is the case with the magnocellular pathway (Schmolesky et al, 1998;Lamme and Roelfsema, 2000) which appears to function normally in LG (Gilaie-Dotan et al, 2009, 2011. Another such processing route that might also be normal in LG (see place recognition in Table 2), might rely on peripheral form-based computations, which are suggested to respond transiently (Gilaie-Dotan et al, 2008) and rely on coarse spatial resolution (Levy et al, 2001(Levy et al, , 2004Dumoulin and Wandell, 2008). This might actually suggest that local-global effects are driven by peripheral coarse vision integrating over space, possibly relying on the same mechanisms as those for place recognition.…”

“…I also include in this group three functions (matching static faces based on identity or expression, reading heavily masked text, and recognizing complex Kanizsa figures) that LG was impaired in before training, and was not tested on after training, as I find that their perceptual demands resemble those of tasks that LG is still impaired in (face perception, and shape recognition from incomplete information), yet I cannot rule out a possible post-training improvement, had LG been retested on these functions post-training. Explicitly, this group includes contrast sensitivity (Polat et al, 2005;Gilaie-Dotan et al, 2009;Lev et al, 2015), near and far visual acuity (Gilaie-Dotan et al, 2009;Lev et al, 2015), crowding (Bonneh et al, 2004;Gilaie-Dotan et al, 2009;Lev et al, 2015), lateral interactions (Polat and Sagi, 1993;GilaieDotan et al, 2009;Lev et al, 2014Lev et al, , 2015, identifying contour in noise (Kovacs et al, 2000;Gilaie-Dotan et al, 2009;Lev et al, 2015), Table 2). …”

“…Visual inputs entering primary visual cortex (V1), the first stage of the visual cortical hierarchy, continue through intermediate visual areas (V2 and V3/VP) and into higher-order and more specialized visual and other multisensory regions [e.g. object-sensitive LOC (Malach et al, 1995;Grill-Spector et al, 1998), face-sensitive "FFA" (Kanwisher et al, 1997;McCarthy et al, 1997;Levy et al, 2001) and processes and even in visual awareness [e.g. motion perception (Zihl et al, 1983;Newsome and Pare, 1988;Salzman et al, 1992;Schiller, 1993;Gilaie-Dotan et al, 2013c), object, face and word perception (Behrmann and Kimchi, 2003;Barton, 2011;Konen et al, 2011;Behrmann and Plaut, 2014), and awareness (Lamme and Roelfsema, 2000;Silvanto et al, 2005;Silvanto, 2014)], investigating the contribution of intermediate visual regions to our visual perceptual experience lags behind and therefore remains unclear.…”

Behavioral, perceptual, and neural alterations in sensory and multisensory function in autism spectrum disorder

“…The vast majority of this work has been carried out within individual sensory systems, and has shown that very simple sensory-based judgments and abilities, such as Vernier acuity (vision), frequency discrimination (auditory) and two-point discrimination (tactile), can be greatly improved using training approaches in which subjects are receiving feedback on the basis of their ongoing judgments (Kaas et al, 2013; Lev et al, 2014; Zaltz et al, 2010; Zhou et al, 2006). Although fascinating, these studies have also reinforced that these training-based improvements rarely extend beyond the trained task.…”

Perceptual training yields rapid improvements in visually impaired youth

“…However, recent studies revealed a number of cases where perceptual learning can transfer to untrained tasks and stimuli910. In fact, a significant portion of the current research on perceptual learning is aimed toward elucidating conditions that facilitate generalization of perceptual training.…”