Individual differences in learning to perceive length by dynamic touch: Evidence for variation in perceptual learning capacities

Recent studies of perceptual learning have explored and commented on variation in learning trajectories. Although several factors have been suggested to account for this variation, thus far the idea that humans vary in their perceptual learning capacities has received scant attention. In the present experiment, we aimed at providing a detailed picture of the variation in this capacity by investigating the perceptual learning trajectories of a considerable number of participants. The learning process was studied using the paradigm of length perception by dynamic touch. The results showed that there are substantial individual differences in the way perceivers respond to feedback. Indeed, after feedback, the participants' perceptual performances diverged. We conclude that humans vary in their perceptual learning capacities. The implications of this finding for recent discussions on variation in perception are explored.     

Unmarried, nonresident fathers' involvement with their infants: a risk and resilience perspective.

The authors used a subsample of fathers (n = 652) who participated during the 1-year follow-up of the Fragile Families and Child Wellbeing study to assess the influence of risk and resilience factors on unmarried, nonresident fathers' involvement with their infants. They examined the additive, multiplicative, and moderating models of risk and resilience in relation to paternal involvement. Fathers' relationship to the child's mother was conceptualized as a risk or resilience factor. Fathers in acquaintance relationships with the mother and fathers who scored higher on the additive risk index were less involved in child care. Fathers who scored higher on the additive resilience index were more involved in child care. There was a multiplicative effect of relationship status and the risk index on fathers' involvement. The findings point to the importance of programs that address risk and resilience conditions affecting nonresident fathers in interaction with the quality of relationships they have with their children's birth mother.     

The application of the Things I Worry About Scale to a sample of at-risk American adolescents: an examination of psychometric properties

To date, published studies regarding the Things I Worry About Scale have been conducted exclusively in Northern Ireland and have included relatively homogeneous samples of students. The present study reexamined the psychometric properties of the scale using data collected from a sample of at-risk adolescents in the United States. The factor structure of the instrument was examined to determine the reliability of the instrument with a culture other than that with which the instrument was developed, and salient group differences were identified and discussed. The cross-cultural applicability of the instrument and the stability of the factor structure were explored and found to be relatively robust. However, differences were identified which were specifically related to the emergence of a highly salient component representing a very pessimistic view of what the future held. The results suggest the need for confirmatory factor analytical studies and further examination of the utility of the instrument with diverse populations.     

3-D processing in the Poggendorff illusion

In the Poggendorff illusion two collinear oblique lines, separated by two vertical lines, appear to be misaligned. 3-D processing of the oblique but not the vertical lines is considered to cause this apparent misalignment. We investigated whether more explicitly triggering 2-D versus 3-D interpretations of the different parts of Poggendorff-like displays would influence the apparent misalignment. In Experiment 1, we found that compared to 2-D controls, 3-D interpretations of the vertical parts did not influence apparent misalignment, while for the oblique parts 3-D processing resulted in more apparent misalignment than 2-D controls. In Experiment 2, the amount of contour convergence of the oblique parts was manipulated resulting in the 3-D blocks, but not the 2-D line patterns, to be perceived as receding in depth. Now, apparent misalignment increased the more the 3-D blocks were perceived as receding in depth. We conclude that apparent misalignment in Poggendorff-like displays can be influenced by different interpretations of its separate parts, while keeping the local junctions between the different elements the same.     

Precision and power grip priming by observed grasping

The coupling of hand grasping stimuli and the subsequent grasp execution was explored in normal participants. Participants were asked to respond with their right- or left-hand to the accuracy of an observed (dynamic) grasp while they were holding precision or power grasp response devices in their hands (e.g., precision device/right-hand; power device/left-hand). The observed hand was making either accurate or inaccurate precision or power grasps and participants signalled the accuracy of the observed grip by making one or other response depending on instructions. Responses were made faster when they matched the observed grip type. The two grasp types differed in their sensitivity to the end-state (i.e., accuracy) of the observed grip. The end-state influenced the power grasp congruency effect more than the precision grasp effect when the observed hand was performing the grasp without any goal object (Experiments 1 and 2). However, the end-state also influenced the precision grip congruency effect (Experiment 3) when the action was object-directed. The data are interpreted as behavioural evidence of the automatic imitation coding of the observed actions. The study suggests that, in goal-oriented imitation coding, the context of an action (e.g., being object-directed) is more important factor in coding precision grips than power grips.     

A bottleneck in face identification: repetition priming from flanker images

There is evidence that face processing is capacity-limited in distractor interference tasks and in tasks requiring overt recognition memory. We examined whether capacity limits for faces can be observed with a more sensitive measure of visual processing, by measuring repetition priming of flanker faces that were presented alongside a face or a nonface target. In Experiment 1, we found identity priming for face flankers, by measuring repetition priming across a change in image, during task-relevant nonface processing, but not during the processing of a concurrently-presented face target. Experiment 2 showed perceptual priming of the flanker faces, across identical images at prime and test, when they were presented alongside a face target. In a third Experiment, all of these effects were replicated by measuring identity priming and perceptual priming within the same task. Overall, these results imply that face processing is capacity limited, such that only a single face can be identified at one time. Merely attending to a target face appears sufficient to trigger these capacity limits, thereby extinguishing identification of a second face in the display, although our results demonstrate that the additional face remains at least subject to superficial image processing.     

Beliefs and data on the relationship between consistency and accuracy of eyewitness testimony

Two studies concerned with consistency and accuracy of eyewitness testimony were conducted. In Study 1 potential jurors indicated the degree to which they considered that various witness on‐stand behaviours indicated testimonial accuracy. Witness statements that were inconsistent with previous statements were considered to be the strongest indicators of inaccuracy. Study 2 examined the relationship between consistency and accuracy of testimony. Witnesses viewed a film of a robbery and were interviewed twice (2 weeks apart) about the crime in a 4 (interview format)×2 (interview occasion) design. Regardless of whether consistency was operationalised in terms of direct contradictions between interviews, or degree of agreement on detail across interviews, no more than 10% of the variance in overall accuracy rate was explained by any individual measure. Number of contradictions and overall agreement between interviews did, however, make additive contributions to prediction of overall accuracy. Also, higher correlations between contradiction‐based consistency measures and interview two accuracy rate were detected. Neither consistency nor accuracy for specific testimonial dimensions were predictive of accuracy on the other dimensions, or overall accuracy. Copyright © 1999 John Wiley & Sons, Ltd.     

What Should A “Gibsonian Neuroscience” Look Like? Introduction to the Special Issue

Abstract

Ecological psychology has been criticized for ignoring the brain in its theory formation. In recent years, however, a number of researchers have started asking ecologically-inspired questions about the ways in which not only the embodied activity of the organism in its environment, but also the particulars of the organism's nervous system matter. This work has typically appeared in neuroscience journals, thereby potentially escaping the attention of ecological psychologists. The current article introduces a Special Issue of Ecological Psychology that aims to correct this problem. This issue brings together one empirical and six theoretical articles that develop ideas about the contributions of the nervous system to perception-action. We briefly review each of the articles, identify common themes, and point out the surprising variety in theoretical positions. It is hoped that this Special Issue will help guide discussions amongst ecological psychologists and (ecological) neuroscientists as they confront the question “What should a ‘Gibsonian neuroscience’ look like?”