Orientation-selective adaptation improves perceptual grouping

Abstract

#The role of visual pattern adaptation, and learning, in spatial integration was investigated. Observers reported whether a grid of identical tilted bars was perceived as rows or columns (perceptual grouping task). Performance was measured multiple times during a session to determine effects of repeated exposure to the stimuli. To test for possible effects of learning on the within-session dynamics, observers repeated the experiment on five days. We found that repeated performance produced rapid within-day improvements, which were largely transient and were not retained on subsequent days. In addition, exposure to stimuli with equal orientation contributed to the within-session improvement, whereas stimuli having an orientation differing by 458 from the original orientation diminished the improvement previously obtained in the same session. Practice with the task over days resulted in faster improvements. The transient nature of these exposure-driven improvements and their susceptibility to interference by stimuli designed to reduce adaptation suggest that adaptation was their main cause. Finally, to investigate the effects of adaptation on internal noise and on spatial integration, we employed an externalnoise paradigm, showing that internal-noise reduction resulted from adaptation. Internal noise was reduced only when spatial integration was effective, suggesting that adaptation improved perception of global stimulus properties. Overall, our results suggest that the grouping task benefits from an adaptation process that rapidly adjusts the visual system to the statistics of the visual stimuli. We suggest that this effect is achieved through spatial decorrelation of neural responses. With practice, those adjustments are made faster.

Identifying Long- and Short-Term Processes in Perceptual Learning

“…In cognitive learning, Rickard (2007) postulated that between-session delay could cause both forgetting and enhanced potential for new learning and therefore rapid relearning. Pinchuk-Yacobi and Sagi (2019) attributed rapid within-session learning to adaptation because of its transient nature. We found that the magnitude of relearning was indeed negatively correlated with between-session effects (off-line gain or forgetting) in the contrast detection, vernier-offset discrimination, face-view discrimination, visual shape search, and auditory-frequency discrimination tasks (see Table S7).…”

A decision-time account of individual variability in context-dependent orientation estimation

“…Generally, contextdependent changes in visual processing are thought to be functionally useful, despite some debate regarding details (Clifford, 2014;Kohn, 2007;Snow, Coen-Cagli, & Schwartz, 2017;Solomon & Kohn, 2014;Webster, 2011). Possible benefits include (a) self-calibration, constancy, or correction of a reference "norm" (Andrews, 1964;Day, 1972;Dekel & Sagi, 2019a;Gibson & Radner, 1937;Webster, 2011), (b) optimization of the neural code, such as improved gain of computational units, improved coding sensitivity to likely events, or decorrelation to remove coding redundancies (Benucci, Saleem, & Carandini, 2013;Coen-Cagli, Kohn, & Schwartz, 2015;Pinchuk-Yacobi & Sagi, 2019;Snow et al, 2017;Wei & Stocker, 2017), and (c) enhanced attentional selection of novel or surprising events (such events are presumably more likely to be important and hence deserve more attention). However, these and other alternatives are not necessarily mutually exclusive (e.g., orientation biases may reflect both self-calibration and decorrelation, Clifford, Wenderoth, & Spehar, 2000), and are not necessarily dependent on the neural implementation (e.g., divisive normalization may underlie both code optimization and attentional selection, Carandini & Heeger, 2012).…”

Contrast adaptation improves spatial integration

“…Notably, unlike other studies using passive adaptation, in our experiments the adapted stimuli were task related, and the observers were asked to make an explicit judgment regarding each of them. Previous studies showed that passive adaptation is sufficient to cause adaptation-dependent sensitivity improvements (Greenlee & Heitger, 1988;Pinchuk-Yacobi & Sagi, 2019). However, top-down influences such as task relevance and attention can enhance the effects for some types of adaptation but not for others (Festman & Ahissar, 2004;Pinchuk-Yacobi et al, 2016).…”