The perceptual analysis of structure from motion for rotating objects undergoing affine stretching transformations

In two experiments, we evaluated the ability of human observers to make use of second-order temporal relations across three or more views of an apparent motion sequence for the perceptual analysis of three-dimensional form. Ratings of perceived rigidity were obtained in Experiment 1 for objects rotating in depth that were simultaneously subjected to sinusoidal affine stretching transformations along the line of sight or in a direction parallel to the image plane. Such transformations are theoretically interesting because they cannot be detected by analyses that are restricted to first-order temporal relations (i.e., two views), but they can be detected by more conventional analyses of structure from motion in which second-order temporal relations over three or more views are used. The current results show that human observers can perceive stretching transformations of a rotating 3-D object in a direction parallel to the image plane but that they fail to perceive stretching transformations along the line of sight. This result suggests that human observers can make use of some limited second-order temporal information. This finding was confirmed in Experiment 2, in which we investigated the effects of several specific optical consequences of sinusoidal stretching transformations applied in different directions. The results indicate that observers may be sensitive to the sign of acceleration, but that. they cannot make use of the precise magnitude of second-order relations necessary to recover euclidean metric structure.     

The symmetrical law of effect and the matching relation in choice behavior

In a concurrent-chains procedure, pigeons chose between outcomes that differed in the rate of response-independent delivery of food and electric shocks. The application of functional measurement techniques confirmed the matching relation—between choice and rate of reinforcement value—for two of three pigeons. Scale values of the outcomes were extracted for the two birds that conformed to matching, and the value of a single occurrence of shock per minute—in terms of negative food units—was estimated. A second experiment with concurrent chains provided a test of these parameter estimates. The close correspondence between predicted and obtained choice behavior found in Experiment II indicated that the estimates of outcome value were indeed reliable. Both experiments together support the contention that the effects on choice behavior of positive and aversive stimuli appear to be equal, though opposite in sign.     

EXPANDING INFANT MENTAL HEALTH TREATMENT SERVICES TO AT‐RISK PRESCHOOLERS AND THEIR FAMILIES THROUGH THE INTEGRATION OF RELATIONAL PLAY THERAPY

The expansion of infant mental health (IMH) to at‐risk preschoolers and their families has contributed to the integration of relational play therapy (RPT) into IMH treatment services for this population. Integrating RPT allows access to specialized play and expressive techniques specific to preschool and family development, which improves the clinical ability to meet the multiple and complex needs of at‐risk parent–child dyads and their families. This article will examine the RPT literature and explore the similarities and differences between IMH and RPT. In addition, two case studies will highlight a five‐phase, integrative clinical‐treatment process and provide insight into how IMH clinicians are integrating RPT models and maintaining adherence to the IMH treatment approach.     

The Nurturing Program: An Intervention for Parents of Children with Special Needs

Evidence-based psychosocial family interventions enhancing empathy and empowerment are particularly beneficial to families of children who have developmental disabilities. This study assessed the effectiveness of an intervention called the Nurturing Program for Parents and Their Children with Special Needs and Health Challenges (SNHC). Eighty-seven families were enrolled and randomly assigned to a control or treatment group. Forty-six families in the control group received individualized case management (CM) services and forty-one families in the treatment group were assigned to 12 sessions of the SNHC curriculum along with case management services. Before and after the intervention, participants in both conditions completed the Adult and Adolescent Parenting Index-2 assessing parents’ attitudes toward child rearing and the Family Empowerment Scale (FES) measuring family empowerment. Caregivers in the intervention condition improved in empathy towards children’s needs, F(1, 54)?=?4.52, p?=?.04; and all families, both control group and treatment group, improved their attitudes towards the use of corporal punishment by posttest, F(1, 54)?=?6.56, p?=?.013. Also, all caregivers increased in their empowerment over the course of the intervention, F(1, 50)?=?13.28, p?=?.001. Attrition, 22–26% among CM and 51–56% among SNHC+CM, limited generalizability as did participants not completing all SNHC sessions. Despite these limitations, findings suggest that early interventions catering to families of children with developmental disabilities have a positive impact on parenting. To varying degrees, both conditions provided caregivers with tools that positively affected the quality of the parent–child relationships and promoted empowerment.     

Fill‐in and infill errors in order memory

Many current models of memory are specified with enough detail to make predictions about patterns of errors in memory tasks. However, there are often not enough empirical data available to test these predictions. We report two experiments that examine the relative frequency of fill‐in and infill errors. In immediate serial recall tasks, subjects sometimes incorrectly recall item N too soon, placing it in position N?1. The error of interest is which item is recalled after this initial mistake. A fill‐in error is the tendency to recall item N?1 next, whereas an infill error is the tendency to recall item N+1 next. Both experiments reveal more fill‐in than infill errors, not only overall but at each possible error location throughout the list. The overall ratio is approximately 2:1. We conclude that none of the currently existing models adequately accounts for fill‐in and infill errors.     

Remembrance of places you passed: social spatial working memory in rats

Pairs of rats were tested in a radial-arm maze to determine whether the spatial choices made by one rat affect the subsequent spatial choices of the other rat. In a free-choice procedure, rats showed an increased tendency to choose the location that had most recently been chosen by a foraging partner but a decreased tendency to visit locations that the foraging partner had visited earlier. Forced-choice procedures were used to better control the social stimulus and the interactions between the rats. Under some conditions, locations were chosen later in the choice sequence of a subject rat if another rat had been observed choosing that location. Odor and other physical traces of the other rat's visits were ruled out as explanations for this effect. The results demonstrate the existence of working memory for locations visited by a familiar conspecific.     

Aging and visual 3-D shape recognition from motion

Two experiments were conducted to evaluate the ability of younger and older adults to recognize 3-D object shape from patterns of optical motion. In Experiment 1, participants were required to identify dotted surfaces that rotated in depth (i.e., surface structure portrayed using the kinetic depth effect). The task difficulty was manipulated by limiting the surface point lifetimes within the stimulus apparent motion sequences. In Experiment 2, the participants identified solid, naturally shaped objects (replicas of bell peppers, Capsicum annuum) that were defined by occlusion boundary contours, patterns of specular highlights, or combined optical patterns containing both boundary contours and specular highlights. Significant and adverse effects of increased age were found in both experiments. Despite the fact that previous research has found that increases in age do not reduce solid shape discrimination, our current results indicated that the same conclusion does not hold for shape identification. We demonstrated that aging results in a reduction in the ability to visually recognize 3-D shape independent of how the 3-D structure is defined (motions of isolated points, deformations of smooth optical fields containing specular highlights, etc.).     

Aging and the perception of speed

Two experiments were conducted to explore the potential effects of aging upon the perception and discrimination of speed. In the first experiment, speed difference thresholds were obtained for younger and older observers for a variety of standard speeds ranging from slow to fast. The second experiment was designed to evaluate the observers' ability to discriminate differences in the speed of moving patterns in the presence of significant amounts of noise (the noise was manipulated by limiting the lifetimes of individual moving stimulus elements). The results of both experiments revealed a significant deterioration in the ability of the older observers to perceive or detect differences in speed. While the presence of noise was found to affect the observers' discrimination performance, it affected both younger and older observers' thresholds in a proportionally equivalent manner-the older observers were no more affected by noise than the younger observers.