Human visual perceptual organization beats thinking on speed

What is the degree to which knowledge influences visual perceptual processes? This question, which is central to the seeing-versus-thinking debate in cognitive science, is often discussed using examples claimed to be proof of one stance or another. It has, however, also been muddled by the usage of different and unclear definitions of perception. Here, for the well-defined process of perceptual organization, I argue that including speed (or efficiency) into the equation opens a new perspective on the limits of top-down influences of thinking on seeing. While the input of the perceptual organization process may be modifiable and its output enrichable, the process itself seems so fast (or efficient) that thinking hardly has time to intrude and is effective mostly after the fact.     

Effects of asynchrony on symmetry perception

The effect of temporal image segmentation on symmetry perception was investigated by means of stimuli composed of one part surrounding another. The two parts could be presented synchronously or with a temporal offset (20–100 ms), and each part could be either symmetrical or random. The task was to discriminate completely symmetrical (S) stimuli (in Experiment 1) or completely random (R) stimuli (in Experiment 2) from partially symmetrical (PS) stimuli in which one part was symmetrical and the other random. The R stimuli showed an asynchrony effect but the S stimuli did not. Furthermore, in both experiments, the PS stimuli showed an asynchrony effect when the symmetrical part was presented last but not when the symmetrical part was presented first (independent of whether it was the surrounded part or the surrounding part). Both results suggest that symmetry is strong enough to override this kind of temporal image segmentation.     

Interactions between constituent single symmetries in multiple symmetry

As a rule, the discriminability of multiple symmetries from random patterns increases with the number of symmetry axes, but this number does not seem to be the only determinant. In particular, multiple symmetries with orthogonal axes seem better discriminable than multiple symmetries with nonorthogonal axes. In six experiments on imperfect two-fold symmetry, we investigated whether this is due to extra structure in the form of so-called correlation rectangles, which arise only in the case of orthogonal axes, or to the relative orientation of the axes as such. The results suggest that correlation rectangles are not perceptually relevant and that the percept of a multiple symmetry results from an orientation-dependent interaction between the constituent single symmetries. The results can be accounted for by a model involving the analysis of symmetry at all orientations, smoothing (averaging over neighboring orientations), and extraction of peaks.     

Bayesian confusions surrounding simplicity and likelihood in perceptual organization

In the study of perceptual organization, the Occamian simplicity principle (which promotes efficiency) and the Helmholtzian likelihood principle (which promotes veridicality) have been claimed to be equivalent. Proposed models of these principles may well yield similar outcomes (especially in everyday situations), but as argued here, claims that the principles are equivalent confused subjective probabilities (which are used in Bayesian models of the Occamian simplicity principle) and objective probabilities (which are needed in Bayesian models of the Helmholtzian likelihood principle). Furthermore, Occamian counterparts of Bayesian priors and conditionals have led to another confusion, which seems to have been triggered by a dual role of regularity in perception. This confusion is discussed by contrasting complete and incomplete Occamian approaches to perceptual organization.     

Nocturnal emissions: a failure to replicate

A time series of nocturnal emissions was presented in The American Journal of Psychology in 1904. The anonymous author of this remarkable article provided the time series to support his contention that his nocturnal emissions exhibited a seasonal pattern of variation. Specifically, he claimed to have heightened emissions during spring and summer, with dampened emissions later. The basis for this claim was a time series graph of average emissions by month across an 8-year period. The purpose of this article is to reanalyze these data with statistical procedures developed in the past century to validate the original conclusion drawn by the author. After analyses of the data with several state-of-the-art methods, no statistical support was found for a seasonal pattern of nocturnal emissions.     

Insight into children's prosocial lies: Comment on Warneken and Orlins

In their article, Warneken and Orlins ( 2015 ) provide insight into children's prosocial lie‐telling. Their work adds to a growing body of literature regarding the development of prosocial behaviour and indicates that young children will tell ‘white lies’ in order to improve the mood of others. This work has important implications for forensic contexts that we note.