Perceptual assumptions and projective distortions in a three-dimensional shape illusion

We examine a shape illusion, in which the balconies of a building appear to tilt up or down, depending on the viewpoint. The balconies are actually level parallelogram shapes, but appear as tilted rectangles. We measured the illusory tilts observed when parallelogram shapes are viewed above the line of sight, using three-dimensional stimuli consisting of parallelograms of various tilts viewed at different orientations. Under perspective projection, parallelism and orthogonality are not preserved. However, perspective distortions alone cannot account for the perceived tilts measured in these experiments, since observers perceived illusory tilts even for stimuli in the frontoparallel plane. We introduce a model, based on the theory that observers assume ambiguously projected three-dimensional angles to be equal to 90 degrees, but revise their predictions on the basis of observation. In the model, perceived tilt is predicted as a weighted sum of the tilts predicted by the assumptions that the shape is rectangular, and that the shape is level (i.e. that the angle between the shape and the vertical backboard is equal to 90 degrees). We prove that it is mathematically impossible for a planar rectangle to share a projection with a nonrectangular parallelogram. A less restrictive assumption that just the two leading internal angles are equal to 90 degrees is suggested as an alternative, and it is further proven that this new configuration of angles leads to a unique perceived tilt. The relative weights in the model reflect the amount that each prediction is revised, and are shown to vary systematically with stimulus orientation. For some observers a better fit was found by replacing the level-tilt assumptions with an assumption that physical tilt was equal to the projected tilt.     

Functional characteristics of auditory temporal-spatial short-term memory: evidence from serial order errors

The functional characteristics of auditory temporal-spatial short-term memory were explored in 8 experiments in which the to-be-remembered stimuli were sequences of bursts of white noise presented in spatial locations separated in azimuth. Primacy and recency effects were observed in all experiments. A 10-s delay impaired recall for primacy and middle list items but not recency. This effect was shown not to depend on the response modality or on the incidence of omissions or repetitions. Verbal and nonverbal secondary tasks did not affect memory for auditory spatial sounds. Temporal errors rather than spatial errors predominated, suggesting that participants were engaged in a process of maintaining order. This pattern of results may reflect characteristics that serial recall has in common with verbal and spatial recall, but some are unique to the representation of memory for temporal-spatial auditory events.     

Vertical versus horizontal spatial compatibility: Right-left prevalence with bimanual responses

For two-choice tasks in which stimulus and response locations vary along horizontal and vertical dimensions, the spatial compatibility effect is often stronger on the horizontal than vertical dimension. Umiltà and Nicoletti [(1990) Spatial stimulus-response compatibility (pp. 89–116). Amsterdam: North-Holland] attributed this right-left prevalence effect to an inability to code vertical location when horizontal codes are present simultaneously. Hommel [(1996) Perception & Psychophysics, 43, 102–110] suggested instead that it reflects a voluntary strategy. This study reports four experiments that examine this issue. Experiment 1 was a conceptual replication of Hommel's Experiment 1, with responses made on a numeric keypad and subjects instructed in terms of the vertical or horizontal dimension. The results replicated Hommel's findings that showed a right-left advantage with horizontal instructions; however, with vertical instructions, we found a benefit of vertical compatibility alone that he did not. This benefit for vertical compatibility alone was eliminated in Experiment 2 using a varied practice schedule similar to that used by Hommel. Experiment 3 showed right-left prevalence and a benefit of vertical compatibility alone, even with varied practice and vertical instructions, when subjects responded on perpendicularly arranged handgrips. These benefits were eliminated in Experiment 4 using Hommel's method of urging subjects to respond only in terms of the instructed dimension. With bimanual responses, right-left prevalence is a robust phenomenon that is evident when comparing across vertical and horizontal instructions and, when the right-left distinction is relatively salient, within the vertical instructions condition alone. Received: 4 February 2000 / Accepted: 5 May 2000     

Psychopathy, criminal responsibility, and civil commitment as a sexual predator

Recent judicial decisions regarding commitment under sexual predator statutes and commentary addressing the legal significance of psychopathy provide an interesting opportunity to reflect upon the exculpatory significance of psychopathy and the appropriate relationship between criminal conviction and police power civil commitment. This paper examines the legal significance of psychopathy for the purposes of criminal responsibility and of civil commitment under sexual predator statutes. By examining the significance of psychopathy for each of these legal institutions, it clarifies our understanding of the legal significance of psychopathy and of the relationship between these institutions. This process illuminates the defensible functions and boundaries of each institution and clarifies the nature of the impairment that should qualify an individual for confinement by each. This analysis interprets criminal conviction and police power commitment, including sexual predator commitment, as integrated institutions of social control intended to provide a coherent approach to psychopaths as well as to others who require state intervention under the police power.     

Recollections of conflict with parents and family support in the personality disorders

This study examined the relationships between personality disorders and retrospective reports of family support and conflict with parents. Participants were 798 United States Air Force recruits who were participating in a larger program of research on the peer assessment of personality disorders. Correlational analyses revealed consistent but modest associations between personality disorder features and both measures of family adversity. Borderline, antisocial, and paranoid features maintained small, unique associations after controlling for the general component of personality disorder. Further analyses, however, showed that differences among the correlations between personality disorder traits and family adversity measures account for little explained variance. In general, it does not appear that individual personality disorders have unique relations with retrospective reports of family adversity. Instead, the relation between personality disorders and family adversity seems to depend on a component common to all personality disorders.     

Age-related changes in the control of attention in depth

In 2 experiments, the authors examined the control of spatial attention in depth in advanced age. Observers viewed 2 sets of lines that overlapped in two-dimensional (2-D) space but that were presented at different depth locations. An exogenous cue indicated the depth at which a colored target line would appear. On some trials, a distracting colored element was also presented. The luminance of this distracter varied from high to low. For both older and younger adults, distractors slowed reaction time less if they were at a different depth from the target. This effect was more robust for older adults with low-luminance distractors, indicating an important role for target features as well as attentional control. Adding another feature (i.e., color) that distinguished between target and distracter reduced the effects of slowing shown by the older observers and eliminated the cost of low-luminance distractors for all observers. The results suggest that attentional control in depth is maintained in aging.     

Maximizing therapeutic effects in treating sexual offenders in an Australian correctional system

In Australia, the community response to sexual offenders is marked by uncertainty as to whether offenders should be incarcerated as punishment or provided treatment in order to reduce the likelihood of re-offense. The incarceration of sexual offenders results in particular management, ethical, and political issues. Nevertheless incarceration can provide leverage to encourage the offender to participate in treatment while delivering punishment for wrongdoing and acting to protect the community. In the state of Victoria the CORE Sex Offender Programs have developed a statewide strategy in the public correctional system in order to assess, manage, and treat male sexual offenders. However, such offenders are notoriously reluctant to engage in treatment to address offending behaviors. A critical element of the strategy has been the Victorian Adult Parole Board, an entity that can determine that an offender needs to engage in treatment before he is considered for parole. Using the therapeutic jurisprudence framework as outlined by Wexler (1990), strategies to minimize the anti-therapeutic effects of the Victorian Adult Parole Board and maximize the therapeutic effects of the CORE Sex Offender Programs are highlighted.     

The Psychosocial Adjustment to Illness Scale--Self-Report: factor structure and item stability

The Psychosocial Adjustment to Illness Scale--Self-Report (PAIS-SR; Derogatis & Derogatis, 1990), a frequently used measure of adjustment in medically ill adults, was subjected to several exploratory factor analyses, with principal-axes factor extractions and varimax rotation procedures. The sample consisted of kidney, heart, liver, lung, and bone marrow transplant candidates (N = 280). The final analysis yielded a six-factor, 26-item instrument accounting for 59% of the variance. Coefficient alpha for the 26-item measure was .87, and internal consistency estimates for the factors ranged from .50 to .86. Strong correlations with other adjustment measures commonly used in the assessment of adults with chronic physical conditions support the validity of the PAIS-SR.     

Group preprogrammed systematic desensitization without the simultaneous presentation of aversive scenes with relaxation training

This study investigated the assumption that it is necessary to simultaneously present muscle relaxation and aversive scenes in order for decrements in anxiety to occur. Utilizing 70 high test anxious students, the following treatment groups were delineated: (a) preprogrammed systematic desensitization, (b) non-simultaneous (scenes presented prior to muscle relaxation), (c) relaxation, and (d) no-treatment control. Self-report measures of test and general anxiety as well as college grades constituted the dependent measures. The results indicated that there tended to be no significant differences between the preprogrammed systematic desensitization and non-simultaneous groups on the dependent measures and that the latter group tended to show significant decrements in anxiety and obtain better grades than the relaxation and no-treatment control groups. These findings question the necessity of simultaneously pairing muscle relaxation and aversive scenes in treating anxiety by this method.     

Reviews of current books

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