Visual prediction of collision with natural and nonnatural motion functions

A movement with constant velocity looks fast in the beginning and later slows down, whereas a certain type of accelerated motion (natural motion) looks constant throughout. It was predicted that early occlusion of a constant motion would lead to overestimation of velocity whereas late occlusion would not. With natural motion, there would be no such difference. Constant and natural motions together with constant deceleration and constant acceleration motions were tested in a modified prediction-of-collision experiment. The results agree well with the predictions. It was concluded that the phenomena previously found are operative also in a more complex perceptual task where the observer’s attention is not focused on velocity directly. The visual system seems to achieve perception of partly occluded motion by applying a natural motion function rather than constant velocity. Acquaintance with the phenomena does not seem to alter the way they are perceived.     

A model for stochastic drift in memory strength to account for judgments of learning

Previous research has shown that judgments of learning (JOLs) made immediately after encoding have a low correlation with actual cued-recall performance, whereas the correlation is high for delayed judgments. In this article, the authors propose a formal theory describing the stochastic drift of memory strength over the retention interval to account for the delayed-JOL effect. This is done by first decomposing the aggregated memory strength into exponential functions with slow and fast memory traces. The mean aggregated memory strength shows power-function forgetting curves. The drift of the memory strength is large for immediate JOLs (causing a low predictability) and weak for delayed JOLs (causing a high predictability). Consistent with empirical data, the model makes a novel prediction of JOL asymmetry, or that immediate weak JOLs are more predictive of future performance than are immediate strong JOLs. The JOL distributions for immediate and delayed JOLs are also accounted for.     

Realism of Confidence,Modes of Apprehension,and Variable-Use in Visual Discrimination of Relative Mass

We investigated the role of movement in the perception of a novel affordance for wheelchair locomotion. Healthy adults without prior wheelchair experience judged the lowest lintel under which they could roll in the wheelchair. Prior to judgments, some participants were given brief (~2 min) practice at self-controlled wheelchair locomotion. There were 2 main results. First, participants who had this brief practice accurately judged their own minimum passage height (even when practice did not include passage under low lintels), whereas participants who had no practice gave inaccurate judgments. Second, prejudgment practice strongly influenced movement of the head and torso during judgment sessions. The results demonstrate that affordance perception can be learned through brief, indirect practice and suggest that such practice can inform exploratory movement.     

The power integration diffusion model for production breaks

The learning curve during repetitive production and the associated forgetting during production breaks are fundamental issues in the understanding of behavior. A model is suggested that combines 3 basic findings, namely, that single memory traces decay according to a power function of the retention interval, that aggregated memory traces can be combined by integration, and that the time to produce a unit can be described by a diffusion process on the memory trace. This power integration diffusion model is validated with empirical data, and the result fits better than 14 other published forgetting models.     

Achievement of specificational information usage with true and false feedback in learning a visual relative-mass discrimination task

Participants' usage of informational variables in learning visual relative-mass discrimination in collisions was tracked by means of PROBIT correlations. Four groups received feedback that was true or accorded with either of three nonspecificational cue variables. A majority in each group adopted the feedback, but several participants defied the false feedback. Unlike in previous research, the fit to data of the relative-mass invariant could not be bettered by post hoc linear combinations of the cues. Discriminability was lower in the use of the invariant. Analytic complexity was rejected as an explanation for discriminability differences. A "smart mechanism" for pickup of the relative-mass invariant was developed as an extension of G. Johansson's (1950/1994) vector model.     

Choice Blindness and Preference Change: You Will Like This Paper Better If You (Believe You) Chose to Read It!

Choice blindness is the finding that participants both often fail to notice mismatches between their decisions and the outcome of their choice and, in addition, endorse the opposite of their chosen alternative. But do these preference reversals also carry over to future choices and ratings? To investigate this question, we gave participants the task of choosing which of a pair of faces they found most attractive. Unknown to them, we sometimes used a card trick to exchange one face for the other. Both decision theory and common sense strongly suggest that most people would easily notice such a radical change in the outcome of a choice. But that was not the case: no more than a third of the exchanges were detected by the participants. We also included a second round of choices using the same face pairs, and two stages of post‐choice attractiveness ratings of the faces. This way we were able to measure preference strength both as choice consistency and by looking at measures of rating differences between chosen and rejected options. We found that the initially rejected faces were chosen more frequently in the second choice, and the perceived attractiveness of these faces was increased even in uncoupled individual ratings at the end of the experiment. This result is discussed in relation to Chen and Risen's recent criticism of the Free Choice Paradigm, as it shows that choices can affect future preferences. Copyright © 2013 John Wiley & Sons, Ltd.     

Latent Semantic Analysis Discriminates Children with Developmental Language Disorder (DLD) from Children with Typical Language Development

Journal of Psycholinguistic Research - Computer based analyses offer a possibility for objective methods to assess semantic-linguistic quality of narratives at the text level. The aim of the...     

Measurement of perceived oscillation

In earlier studies of perceived oscillation a comparison stimulus placed at a different distance and in a different direction from the observer than the Standard stimulus was used. The usual indicators were angles relating the turning positions, produced on a comparison stimulus, to a physical frame of reference, common for Standard and comparison. In three experiments where both Standard and comparison were “full-cuc,” the effect of different spatial arrangements was studied. Difference in distance did not affect the angles describing the response, nor did monocular or binocular vision, but difference in direction from the observer and the order of giving the two turning positions, combined with the position of the comparison stimulus before responding, had significant effects. The difference between Standard and comparison stimulus, which in an earlier series of experiments with artificial Standard stimuli had been rather large, was not very large for most conditions in the present experiments, where a real object was used as Standard stimulus. The correspondence was better, however, if another indicator, the angle describing the perceived extent of oscillation, was used. The spatial arrangements of Standard and comparison stimulus affect this indicator less than the indicators relating the perceived turning positions to the axes of the physical space.