Active control in interrupted dynamic spatial orientation: The detection of orientation change

Gibson (1966, 1979) suggested that an important property of perception is that the observer is active. Two experiments were conducted to examine the benefits of active observation in determining dynamic spatial orientation. Subjects were presented with displays simulating locomotion through a three-dimensional environment. Active observers continuously controlled locomotion, whereas passive observers viewed the display. During the trial, the display was blacked out for a brief period, followed by a static image that was at either the correct or the incorrect orientation following the blackout. Subjects were required to indicate whether they were positioned at the correct extrapolated orientation. The presence or absence of orientation change, the type of change (changes in rotation about the depth axis [roll], horizontal axis [pitch], or forward translation), the duration of the blackout, and the consistency of change were varied. In addition, the experiments used either a compensatory or a pursuit tracking task. Active observers had greater sensitivity than did passive observers in detecting a change for both tracking tasks. Subjects in both experiments exhibited greater sensitivity in detecting inconsistent changes (relative to consistent changes), suggesting that the dynamics specified by optical flow were incorporated in extrapolated orientation. In addition, sensitivity decreased with an increase in blackout duration. The results are discussed in terms of an extrapolation model of perception that incorporates the responses executed by active observers.     

Target and nontarget grouping in visual search

Results recently reported by Driver, McLeod, and Dienes (1992) are used to contrast three accounts of visual search—in particular, their mechanism for easy conjunction search. In the Driver et al. study, the target was defined by a conjunction of form and movement; the key manipulation was phase in both target and nontarget motion sets. Mechanisms working separately on each display element (inhibition from nontarget features, facilitation from target features) are unable to explain large effects of phase, since this is defined only by relationships between one element and another. As implemented in the guided search model of Cave and Wolfe (1990), local suppression between similar elements is also unable to account for the results. More promising is an approach based on perceptual grouping: Elements moving in phase can be selected (target motion) or rejected (nontarget motion) as a group. Rather than a bias against elements that are similar to or grouped with their neighbors, there is a bias to treat grouped elements together.     

A pointing technique for rapidly collecting localization responses in auditory research

A technique is described for rapidly collecting responses in auditory-localization experiments. Subjects indicate the perceived direction of the sound by pointing at a 20-cm-diam spherical model. In Experiment 1, the subjects judged the direction of a broadband signal, which could originate from any of 239 directions ranging through 360° of azimuth and between ?45° and +90° of elevation. Using this technique, the subjects responded 2–8 times more rapidly than previous subjects who used either a verbal-reporting technique or a head-pointing technique. Localization judgments were as accurate as they had been with verbal reports, but were not as accurate as judgments collected using the head-pointing technique. In Experiment 2, the signal was turned off and the experimenter read the spherical coordinates of the signal location to the subjects. The subjects pointed to these coordinates more accurately than they had judged the direction of the sounds in Experiment 1, suggesting that the response technique had not been the limiting factor in that experiment. Circumstances relevant to the choice of response techniques for auditory-localization experiments are discussed.     

IDAC computer interfacing for an undergraduate learning laboratory

A hardware and software interface system from International Data and Acquisition and Control, Inc. (IDAC) is reviewed. The IDAC system comes with spreadsheet software compatible for either Macintosh or IBM microcomputers. I prefer to use the IDAC hardware with my own software written in TrueBasic and spreadsheet macros. The entire system is easy to use and is currently in use for our undergraduate Learning Laboratory.     

Misalignment effects in 3-D versions of Poggendorff displays

Strong misalignment effects are found in three-dimensional (3-D) versions of Poggendorff displays viewed binocularly. The components of the standard 2-D Poggendorff figure—the parallels and the oblique segments—were presented in 3-D depth as a flat rectangular object with occluding edges and an oblique line situated behind the object. Three experiments investigated the misalignment effects under three different observation instructions: Subjects were told to look at the oblique (Experiment 1), at the rectangle (Experiment 2), or at the background (Experiment 3). Experiments 1 and 2 examined the effects on judgments of alignment of varying the distance in depth that separates the oblique from the rectangle. Experiment 3 examined the effects of varying the distance between the fixated background and the 3-D Poggendorff figure. Both standard and reversed misalignment effects were obtained. When the viewing condition produces crossed disparity for the oblique, perceived misalignment occurs in the usual Poggendorff direction, but it is reversed with uncrossed disparity. Moreover, the amount of misalignment is related to the amount of disparity, and it can be much stronger than is usual in the 2-D versions of the Poggendorff. The misalignment effects can be explained by binocular integration to produce a single cyclopean image.     

A test of interpersonal theory of depression in children and adolescents using a projective technique

Using a projective technique among child and adolescent psychiatric inpatients, we tested several hypotheses derived from Coyne's (1976b) interpersonal theory of depression. First, we predicted that depression would be associated with rejection, even controlling for the effects of aggression. Depression and rejection were associated only when aggression effects were covaried. Second, we hypothesized that the depression-rejection relation would display symptom specificity. Consistent with this hypothesis, we found that depression, but not anxiety, was related to rejection. Third, we assessed whether an index of interpersonal style—reliance on others—moderated the depression-rejection relation. Results suggested that depression and overreliance were both associated with high rejection scores, whereas the combination of low depression and low reliance on others was associated with low rejection scores. We found that results held across age groups. The implications of our findings for the interpersonal theory of depression in youngsters are discussed.     

The mediating role of anxiety in self-reported somatic complaints of depressed adolescents

This study examined the mediating role of anxiety in the self-reports of somatic complaints in 96 depressed adolescent inpatients. Sixty-four subjects with major depressive episodes and comorbid anxiety disorders (MDE-A) determined from the Diagnostic Interview for Children and Adolescents-Revised (DICA-R) reported significantly more somatic complaints than 32 adolescents having major depressive episodes without comorbid anxiety (MDE). An analysis of covariance demonstrated that, with anxiety symptoms controlled, MDE and MDE-A groups did not differ significantly in somatic complaints. A hierarchical multiple-regression analysis revealed that, with demographic and anxiety symptoms controlled, depressive symptoms did not contribute to the explanation or prediction of somatic complaints. The results suggest that anxious, but not depressive symptoms, are independently associated with somatic complaints. The results are discussed in light of new affective models of psychopathology.     

The comorbidities of adolescent problem behaviors: A latent class model

The correlations and comorbidities of a series of adolescent problem behaviors were studied in a sample of 739 New Zealand 15-year-olds. This analysis revealed the presence of strong comorbidities between different problem behaviors. The data were modeled using methods of unrestricted latent class analysis and this suggested that the best fitting model to describe the data was one which assumed that adolescent problem behaviors were described by four general classes of children. While the same general four-class model applied to males and females, there were marked gender differences in the rates of problems. Specifically, the predominant problem behaviors in females were those relating to an accelerated transition to adulthood marked by early sexual activity, alcohol abuse, and cannabis use whereas the predominant problems for boys were related to antisocial and law-breaking behaviors. Rates of children with no problems (85%) and with multiple problems (3%) were similar for boys and girls.This research was funded by grants from the Health Research Council of New Zealand, the Canterbury Medical Research Foundation, and the National Child Health Research Foundation.     

Enhancing possible selves in Mexican American students

This project assessed the modifiability of possible selves in young Mexican American children. Three intervention conditions were compared in a pre- and posttest design: child-only intervention, parent and child intervention, and a no-intervention control. Following eight intervention sessions, children in the two intervention groups showed significant gains in understanding the characteristics associated with becoming a good student and in recognizing the value of education in bringing about future occupational goals. Children in the intervention conditions also reported greater interest in becoming a physician, judge, or pilot — occupations they had directly experienced during training. The parent intervention phase contributed little to augmenting the positive results attributable to the child intervention component.This research was conducted under the auspices of NIH Grant HD-24003. We wish to thank Maritza Robles and the staff of the Bilingual program of the South Bend, IN, Corporation for their support.