Uninformative visual experience establishes long term perceptual bias

Abstract

Visual appearance depends upon the resolution of ambiguities that arise when 2D retinal images are interpreted as 3D scenes. This resolution may be characterized as a form of Bayesian perceptual inference, whereby retinal sense data combine with prior belief to yield an interpretation. Under this framework, the prior reflects environmental statistics, so an efficient system should learn by changing its prior after exposure to new statistics. We conjectured that a prior would only be modified when sense data contain disambiguating information, such that it is clear what bias is appropriate. This conjecture was tested by using a perceptually bistable stimulus, a rotating wire-frame cube, as a sensitive indicator of changes in the prior for 3D rotation direction, and by carefully matching perceptual experience of ambiguous and unambiguous versions of the stimulus across three groups of observers. We show for the first time that changes in the prior—observed as a change in bias that resists reverse learning the next day—is affected more by ambiguous stimuli than by disambiguated stimuli. Thus, contrary to our conjecture, modification of the prior occurred preferentially when the observer actively resolved ambiguity rather than when the observer was exposed to environmental contingencies. We propose that resolving stimuli that are not easily interpreted by existing visual rules must be a valid method for establishing useful perceptual biases in the natural world.

Cue-Recruitment for Extrinsic Signals after Training with Low Information Stimuli

“…In the new study the visual system was forced to resolve the ambiguity using a less reliable stereo signal, and to maintain the percept without the benefit of continued disambiguating information. Previous studies found that low-information stimuli can cause stronger learning [4], [17], [20] and cause learning to occur in cases where it did not occur otherwise [5]–[7]. The result from Experiment 1 confirms the potency of low-information stimuli in promoting the recruitment of difficult-to-learn cues.…”

“…The differences in learning due to controlled factors, such as the new signal to be learned, whether the session started with ambiguous trials [4], [17], [20], or whether the object was moving, were large; whereas effects are robust to changes in other factors, such as overall size of the display [4], [17], [20]. Factors that are intrinsic to the perceptual system play a role.…”

Persistent states in vision break universality and time invariance

“…the perturbation experiment); on the other hand, state change seems to sometimes occur in total absence of external visual stimulation (the short-term temporal dynamics experiment). Results showing the importance of endogenous (43) and initial (44) perceptual decisions to subsequent cue learning may be germane to these issues.…”

A trained perceptual bias that lasts for weeks

“…In other words, does the learning reflect the operation of a functionally useful mechanism, one that would normally act to improve perception, and thus the organism's fitness or “achievement” (Brunswik, 1954)? While one instance of long term learning cannot decide this question, the long-lasting nature of the learning is at least consistent with learning how to disambiguate an otherwise ambiguous visual stimulus so as to be prepared the next time it occurs, in the service of fast and accurate perception (Harrison & Backus, 2010b). …”