A theory of visual interpolation in object perception

We describe a new theory explaining the perception of partly occluded objects and illusory figures, from both static and kinematic information, in a unified framework. Three ideas guide our approach. First, perception of partly occluded objects, perception of illusory figures, and some other object perception phenomena derive from a single boundary interpolation process. These phenomena differ only in respects that are not part of the unit formation process, such as the depth placement of units formed. Second, unit formation from static and kinematic information can be treated in the same general framework. Third, spatial and spatiotemporal discontinuities in the boundaries of optically projected areas are fundamental to the unit formation process. Consistent with these ideas, we develop a detailed theory of unit formation that accounts for most cases of boundary perception in the absence of local physical specification. According to this theory, discontinuities in the first derivative of projected edges are initiating conditions for unit formation. A formal notion of relatability is defined, specifying which physically given edges leading into discontinuities can be connected to others by interpolated edges. Intuitively, relatability requires that two edges be connectable by a smooth, monotonic curve. The roots of the discontinuity and relatability notions in ecological constraints on object perception are discussed. Finally, we elaborate our approach by discussing related issues, some new phenomena, connections to other approaches, and issues for future research.     

Coping within couples: adjustment two years after forced geographic relocation

Is our understanding of how individuals adjust to stressful life events increased when we analyze their adjustment in ways that recognize that these individuals are also married couples? The data used to answer this question came from a unique “natural experiment” occasioned by the forced evacuation of the Israeli settlement of Ophira under the terms of the Camp David Accords. We found that the adjustment of individuals within couples became more similar across the relocation, that is, couples adapted as a “family system.” This occurred because the coping skills of one member of the couple “drove” the adjustment of both partners.     

Sleep in Alzheimer's disease and other dementing disorders

It is estimated that up to 10% of the elderly population have clinically significant cognitive deficits. The neuronal pathologies that underlie the dementing disorders cause both cognitive dysfunction and disturbances in normal sleep/wake patterns. Here we report the changes in sleep/wake patterns seen with increasing severity of Alzheimer's disease, probably the most common dementing disorder. In addition, studies examining sleep/wake patterns in a number of other dementing disorders are reviewed.     

Occupation and handedness: an examination of architects and mail survey biases

Handedness among architects was determined by mail survey. Contrary to previous reports, no evidence was found of an excess of left-handers among a sample of 236 fully qualified male architects and 78 male architectural students. A second study examined whether the use of mail surveys systematically biases the returns of handedness questionnaires. For this, questionnaires were sent to 1,017 university students. No evidence was found for a bias amongst those who did and did not reply to the initial questionnaire. These results strengthen the findings of the first study.     

The role of articulation in the parsing and retention of letter strings in tachistoscopic free recall

In Mewhort and Campbell's (1981) model of visual word recognition, a scan-parse mechanism transfer information from a character buffer to a short-term store and is largely responsible for the familiarity effects observed in tachistoscopic free recall. Although Mewhort and Campbell do not elaborate on the role of articulation in this task, they do suggest that the scan-parse mechanism acts prior to any involvement of articulatory processes (see Mewhort & Campbell, 1980). However, proponents of working memory (see Baddeley, 1986) are clear that articulation is necessary for the transfer of visual information to a phonological short-term store. In order to clarify the role of articulation in the parsing and retention of letter string, we asked subjects to undertake a tachistoscopic free-recall task, involving first- and fourth-order letter strings, with and without articulatory suppression and/or unattended speech. Unattended speech was observed to interfere with recall, but only when subjects were free to articulate the strings. This implies that subjects were retrieving information from the phonological store and that articulation is necessary for the registration of visual information in this store. The lack of interaction between order-of-approximation and suppression supports the view that the scan-parse mechanism acts independently of articulation. It appears, therefore, that letter strings are parsed at a stage preceding their transfer of the pharmacological store. Finally, the results indicate that subjects are able to draw directly on a representation of the parsed components of a letter string and may do so when phonological storage is difficult.(ABSTRACT TRUNCATED AT 250 WORDS)     

Social phobia: individual response patterns and the long-term effects of behavioral and cognitive interventions. A follow-up study

In this study the long-term effectiveness of Social Skills Training (SST) and Rational Emotive Therapy (RET), on social phobia was studied, as well as the differential influence of patient characteristics on treatment effectiveness. Fifty-seven patients were assessed 14 months after the post-test. Results showed that long-term effectiveness was independent of the response-pattern of the patients. Comparisons between methods, irrespective of the response-pattern of the patients, showed no differences in effectiveness in favor of either SST or RET. Explorative analysis indicated the potential predictive power for treatment-outcome of confederate ratings of overt behavior on the SSIT. Patients who needed additional treatment appeared to perform significantly worse on this measure at the pretest. No factors could be traced that predict relapse after a relatively successful treatment.     

Anxiety induced by cardiac perceptions in patients with panic attacks: a field study

In panic disorder bodily sensations appear to play an important role as a trigger for anxiety. In our psychophysiological model of panic attacks we postulate the following vicious circle: individuals with panic attacks perceive even quite small increases in heart rate and interpret these changes as being catastrophic. This elicits anxiety and a further increase in heart rate. To evaluate this model we conducted a field study of 28 subjects with panic attacks and 20 healthy controls. A 24 hr ambulatory ECG was recorded and the subjects were instructed to report any cardiac perceptions during this period and to rate the anxiety elicited by these perceptions. The incidence of cardiac perceptions was about the same in both groups, but only subjects with panic attacks reported anxiety associated with such perceptions. Analysis of the ECGs revealed that in both groups heart rate accelerations preceded cardiac perceptions. Following cardiac perceptions, the healthy controls showed a heart rate deceleration, whereas the subjects with panic attacks had a further acceleration. This heart rate increase after cardiac perceptions was positively related to the level of anxiety elicited by the perceptions. These results provide clear evidence in support of the vicious circle model of panic attacks.     

Treatment of panic attacks using cognitive therapy without exposure or breathing retraining

Cognitive treatment of panic attacks is based on the hypothesis that panic results from the catastrophic misinterpretation of bodily sensations, and that changing such misinterpretations will block the occurrence of panic. The treatment normally involves an integrated set of cognitive and behavioural techniques. In a consecutive series of panic patients, a multiple baseline across subjects design was used to investigate whether a modified form of treatment involving only cognitive procedures could reduce panic attack frequency. The results provide preliminary evidence that cognitive procedures directed at changing misinterpretations of bodily sensations can reduce panic attack frequency, and also that cognitive procedures which do not target misinterpretations may not reduce panic.     

Reasons for Living: Mood Effects Revisited1

To explore the relationship between mood and cognitive restraints to suicide, 98 undergraduates experienced the Velten mood-induction procedure to induce an elated, depressed, or neutral (unchanged) mood. They then completed the Multiple Adjective Affect Checklist, the Coopersmith Self-Esteem Inventory, and the Reasons for Living Inventory. Surprisingly, compared to neutral students, depressed students reported more overall reasons for living, greater feelings of responsibility to family, and more moral objections to suicide, and elated students reported more feelings of responsibility to family. Most responsive depressed students also had higher fear of suicide than others, and most responsive elated students had higher survival and coping beliefs than others. Results suggest that a mildly depressed mood caused students' increased reliance on cognitive beliefs about not committing suicide, and may indicate that mildly depressed persons might benefit from and be particularly receptive to cognitive interventions stressing beliefs about family and religious commitments.