The depth and selectivity of suppression in binocular rivalry

Binocular rivalry occurs when the two eyes are presented with incompatible stimuli and the perceived image alternates between the two stimuli. The aim of this study was to find out whether the periodic perceptual loss of a monocular stimulus during binocular rivalry is mirrored by a comparable loss of contrast sensitivity. We presented brief test stimuli to one eye while its conditioning stimulus was dominant or suppressed. The test stimuli were varied widely across four stimulus domains--namely, the relative stimulation of medium- and long-wavelength-sensitive cones, duration, spatial frequency, and grating orientation. The result in each case was the same. Suppression depended slightly or not at all on the type of test stimulus, and contrast sensitivity during suppression was around 64% of that during dominance. The effect of suppression on sensitivity is therefore very weak, relative to its effect on the perceived image. Furthermore, suppression was largely independent of the similarity between the conditioning and the test stimuli, indicating that our results are better explained by eye suppression than by stimulus suppression. A model is presented to account for the small, monocular sensitivity loss during suppression: It assumes that test detection precedes conditioning stimulus perception in the visual pathway.     

Relationship of numbing to alexithymia, apathy, and depression

The present study assessed the relationship between numbing and three associated conditions of alexithymia, apathy, and depression, utilizing data collected on 353 Vietnam combat veterans diagnosed with Posttraumatic Stress Disorder from in- and out-patient settings and an outreach center at various Department of Veterans Affairs Medical centers. All subjects completed four self-report measures: the Glover Numbing Scale, the Beck Depression Inventory, the Apathy Evaluation Scale, and the Toronto Alexithymia Scale-20. The correlation matrix indicated that scores on the four measures were moderately to highly correlated. Principal components analysis with a varimax rotation indicated a five-factor solution that provided evidence for the factorial validity of each of the constructs assessed. Results of the factor analysis of items from the four measures were consistent with numbing being a separate and distinct construct from alexithymia, apathy, and depression. In general, results indicated that all constructs measured were separate and distinct from one another.     

Spiritual well-being and personality

The hypothesis that High and Low Spiritual Well-being groups have different personality profiles was tested with 319 psychology undergraduates (132 men and 187 women who completed the Revised NEO Personality Inventory and the Spiritual Well-being Scale for partial course credit. Univariate analyses of variance indicated that the High Spiritual Well-being group scored lower on Neuroticism and higher or Extraversion, Agreeableness. and Conscientiousness than the Low Spiritual Well-being group. Multivariate analysis of variance indicated that the two groups had significantly different personality profiles, supporting the hypothesis.     

Quality of life before and after lung transplantation in patients with emphysema versus other indications

Whether lung transplantation improves Health-related Quality of Life in patients with emphysema and other end-stage lung diseases before and after lung transplantation was examined. Between 1992 and 1999, 23 patients with emphysema and 19 patients with other indications completed self-administered questionnaires before lung transplantation, and at 4, 7, 13, and 25 mo. after transplantation. The questionnaire included the Nottingham Health Profile, the State-Trait Anxiety Inventory, the Self-rating Depression Scale, the Index of Well-being, the self-report Karnofsky Index, and four respiratory-specific questions. Neither before nor after transplantation were significant differences found on most dimensions of Health-related Quality of Life between patients with emphysema and other indications. Before transplantation, both groups report major restrictions on the dimensions Energy and Mobility of the Nottingham Health Profile, low experienced well-being, depressive symptoms, and high dyspnea. About 4 mo. after transplantation, most Health-related Quality of Life measures improved significantly in both groups. These improvements were maintained in the following 21 mo.     

Men and women at promise for scientific excellence: similarity not dissimilarity

U.S. math-science graduate students possessing world-class talent (368 males, 346 females) were assessed on psychological attributes and personal experiences in order to examine how their talents emerged and developed. Comparisons were made, using similar assessments, with mathematically talented students (528 males, 228 females) identified around age 13 and tracked into adulthood by the Study of Mathematically Precocious Youth (SMPY). Well before college, both samples were academically distinguished; however, the graduate students could be identified during adolescence as a subset of mathematically talented youths based on their nonintellectual attributes. Their profiles corresponded to what earlier psychological studies found to characterize distinguished (and exclusively male) scientists: exceptional quantitative reasoning abilities, relatively stronger quantitative than verbal reasoning ability, salient scientific interests and values, and, finally, persistence in seeking out opportunities to study scientific topics and develop scientific skills. On these attributes, sex differences were minimal for the graduate students (but not for the SMPY comparison groups). Developing exceptional scientific expertise apparently requires special educational experiences, but these necessary experiences are similar for the two sexes.     

The effects of lesions to the rat hippocampus or rhinal cortex on olfactory and spatial memory: retrograde and anterograde findings

The role of the hippocampal system in retrograde and anterograde amnesia was investigated by using a novel olfactory-guided paradigm and a traditional test of spatial learning. In the retrograde study, rats were trained on a sequence of two-choice olfactory discriminations in the weeks prior to receiving neurotoxic lesions of the hippocampus or aspiration lesions of the perirhinal-entorhinal cortex. Memory tests for preoperatively learned discriminations revealed no statistical impairment for subjects with damage to the hippocampus on a problem learned remote in time from surgery (i.e., 4 weeks +) or on the two recently learned discriminations (i.e., 1–3 weeks prior to surgery). The performance of subjects with perirhinal-entorhinal damage provided an important comparison for subjects with specific hippocampal lesions. Despite showing intact memory for the remotely learned problem, perirhinalentorhinal damage resulted in numerically (although not significantly) weaker performance on postoperative tests of retention for the discriminations learned in the 3 weeks prior to surgery. In the anterograde portion of the study, long-term memory for newly acquired discriminations was spared in subjects with damage to the hippocampus, whereas subjects in the perirhinal-entorhinal lesion group again showed the weakest memory performance on these tests of 5-day retention. Postoperative water maze learning was uniformly impaired in subjects with damage to the hippocampus and perirhinalentorhinal cortex, thus confirming the effect of these lesions and supporting the involvement of these brain areas in spatial processes. These findings further dissociate the specific involvement of the hippocampus in tasks of a spatial-relational nature versus nonrelational tasks, such as discrimination learning and recognition memory (e.g., Duva et al., 1997; Eichenbaum, 1997; Eichenbaum, Schoenbaum, Young, & Bunsey, 1996). Moreover, the results suggest that damage to the hippocampus itself does not contribute to retrograde or anterograde memory impairments for all types of information, whereas the data suggest a more important role for the perirhinal-entorhinal cortex in recognition memory, irrespective of modality.     

Object-oriented millisecond timers for the PC

Object-oriented programming provides a useful structure for designing reusable code. Accurate millisecond timing is essential for many areas of research. With this in mind, this paper provides a Turbo Pascal unit containing an object-oriented millisecond timer. This approach allows for multiple timers to be running independently. The timers may also be set at different levels of temporal precision, such as 10⁻³ (milliseconds) or 10⁻⁵ sec. The object also is able to store the time of a flagged event for later examination without interrupting the ongoing timing operation.     

Negative life events, cognitive emotion regulation and emotional problems

A new questionnaire, named the Cognitive Emotion Regulation Questionnaire, has been constructed, measuring nine cognitive coping strategies people tend to use after having experienced negative life events. A test–retest design was used to study the psychometric properties and relationships with measures of depression and anxiety among 547 high school youngsters. Principal component analyses supported the allocation of items to subscales, while alphas of most subscales exceeded 0.80. Cognitive coping strategies were found to play an important role in the relationship between the experience of negative life events and the reporting of symptoms of depression and anxiety. The results suggest that cognitive coping strategies may be a valuable context of prevention and intervention