Suicidality among high school students in Hong Kong, SAR

Suicide is the leading cause of death in Hong Kong SAR for the youth aged 15-24. This study examined the prevalence of suicidality among secondary school students in Hong Kong using a representative, territory-wide sample of 2,586 students. Suicidal behaviors can be conceptualized as a spectrum of self-destructive behaviors. Cumulative logit model analysis indicated that a range of factors, such as unhappy family life, were associated with increasing levels of suicidality. Use of illicit drugs, inhalants, and tobacco differentiated attempters from ideators. The implications of the research findings are discussed.     

Sequence effects in the categorization of tones varying in frequency

In contrast to exemplar and decision-bound categorization models, the memory and contrast models described here do not assume that long-term representations of stimulus magnitudes are available. Instead, stimuli are assumed to be categorized using only their differences from a few recent stimuli. To test this alternative, the authors examined sequential effects in a binary categorization of 10 tones varying in frequency. Stimuli up to 2 trials back in the sequence had a significant effect on the response to the current stimulus. The effects of previous stimuli interacted with one another. A memory and contrast model, according to which only ordinal information about the differences between the current stimulus and recent preceding stimuli is used, best accounted for these data.     

Modeling age and retest processes in longitudinal studies of cognitive abilities

Mixed effects models were used to examine the separate effects associated with age and retest on changes in various cognitive abilities. Individuals (N > 800) ranging in age from 40 to 70 years at the 1st measurement occasion were assessed with measures of memory, spatial abilities, and speed on 4 occasions. All cognitive abilities showed decline associated with increased age and improvement across the 4 measurement occasions. The age-related effects were similar across variables, but the practice effects were largest for memory and smallest for speed. When retest effects were not included in the models, the age-related effects were underestimated, with the magnitude of bias depending on the size of the ignored retest effects. It is suggested that both age and retest should be modeled simultaneously when analyzing longitudinal data because part of the change across occasions may be attributable to practice or reactive effects.     

The role of optimism in the process of schema-focused cognitive therapy of personality problems

The aim of this study was to examine the determinants and effects of optimism in the process of schema-focused cognitive therapy of personality problems. The sample consisted of 35 patients with panic disorder and/or agoraphobia and DSM-IV Cluster C personality traits who participated in an 11-week residential program with one symptom-focused and one personality-focused phase. This study examines the role played by optimism during the individual sessions of the second phase, using a time series approach. Decreased patient's belief in his/her primary Early Maladaptive Schema and increased patient-experienced empathy from the therapist in a session predicted increased patient-rated optimism before the subsequent session. Increased patient-rated optimism in turn predicted decreased schema belief and distress and increased insight, empathy, and therapist-rated optimism. The slope of optimism across sessions was related to change in most of the overall outcome measures. There appears to be a positive feedback in the process of schema-focused cognitive therapy between decreased schema belief and increased optimism. In addition, optimism appears to mediate the effects of schema belief and therapist empathy on overall improvement, and to serve as an antecedent to decreased distress and to increased empathy, insight, and therapist's optimism.     

Volatile visual representations: failing to detect changes in recently processed information

Research documenting people’s inability to detect large changes in visual scenes suggests that visual representations may be sparse and volatile, providing no cumulative record of the attended items in a scene. However, these studies have failed to control for attention. Thus, the visual system may construct a cumulative record of all attended stimuli and still miss such changes, because they involve items that were never attended to. In two experiments, subjects saw 12-digit arrays and identified either the highest digit in the array (Experiment 1) or the lowest digit not in the array (Experiment 2). Subsequent change-detection tasks revealed that subjects often failed to detect changes that involved the same digits they had previously identified to perform the digit tasks successfully. This provides additional evidence that our usable visual representations are relatively impoverished and volatile.     

A least squares solution for successive intervals assuming unequal standard deviations

A least squares solution has been presented for the Law of Categorical Judgment and the Method of Successive Intervals, which is formally equivalent to Horst's solution for the matrix of incomplete data. A simplified approximation which is recommended for use with any matrix of complete data is also given. A procedure, analogous to that originally devised by Thurstone and presented by Saffir, is outlined for the typical experimental matrix of incomplete data. It is essentially a point and slope method of fitting a straight line which comes rather directly from the least squares solution.This study was supported in part by Office of Naval Research Contract N6onr 270-20 with Princeton University.The author wishes to acknowledge helpful suggestions and comments received in discussions of this problem with Max Woodbury, Frederic Lord, Frederick Mosteller, Warren Torgerson, Robert Abelson, and Bert F. Green, Jr. Thanks are due to Mrs. Gertrude Diederich and Irving Abrams for work on the computing necessary for the illustrative applications.     

Diagnostic implications of the electroencephalogram for behavior problem children

The purpose of this department is to present alternative points of view on controversial topics related to the practice of psychology in the schools. An author will state his position on some particular issue. This is followed by the reaction of another psychologist, who will discuss points of agreement or disagreement based upon his research and experience.     

Prospect relativity: how choice options influence decision under risk

In many theories of decision under risk (e.g., expected utility theory, rank-dependent utility theory, and prospect theory), the utility of a prospect is independent of other options in the choice set. The experiments presented here show a large effect of the available options, suggesting instead that prospects are valued relative to one another. The judged certainty equivalent for a prospect is strongly influenced by the options available. Similarly, the selection of a preferred prospect is strongly influenced by the prospects available. Alternative theories of decision under risk (e.g., the stochastic difference model, multialternative decision field theory, and range frequency theory), where prospects are valued relative to one another, can provide an account of these context effects.