The role of categorization in visual search for orientation.

Visual search for 1 target orientation is fast and virtually independent of set size if all of the distractors are of a single, different orientation. However, in the presence of distractors of several orientations, search can become inefficient and strongly dependent on set size (Exp. 1). Search can be inefficient even if only 2 distractor orientations are used and even if those orientations are quite remote from the target orientation (e.g. 20 degrees or even 40 degrees away, Exp. 2). Search for 1 orientation among heterogeneous distractor orientations becomes more efficient if the target orientation is the only item possessing a categorical attribute such as steep, shallow (Exp. 3), tilted left or tilted right (Exp. 4), or simply tilted (Exps. 5 and 6). Orientation categories appear to be 1 of several strategies used in visual search for orientation. These serve as a compromise between the limits on parallel visual processing and the demands of a complex visual world.     

Raids upon the random in family therapy training: Discovering what becomes significant

How do you provide family therapy training in a primarily rural state with limited resources? A model for training therapists and supervisors that well may offer guidance to other states that face such a challenge is described here. A meta supervision approach over long distance was used in the three-year project that is described in this paper. Self-reports from the 31 participants who completed the program reveal some interesting positive reactions.     

Application of chaos theory to a model biological system: Evidence of self-organization in the intrinsic cardiac nervous system

The neural organization that determines the specific beat-to-beat pattern of cardiac behavior is expected to be demonstrated in the independent regulation of the RR intervals (chronotropy) and the corresponding QT subintervals (inotropy), as the former defines the rate of contraction and the latter has a linear negative correlation with the peak pressure inside the contracting ventricular muscles. The neurons of the isolated cardiac nervous system, many of which are located in the fat-pads of the heart, exhibit the same types of mechanical and chemical receptors and the same types of cholinergic and noradrenergic effectors as those found in the neural superstructure. In the surgically isolated and perfused rabbit heart we studied the responses of the QT and RR intervals evoked by block of coronary blood flow. We found that if we separated each RR cycle into QT and RR-QT components, then the dynamics of variation for each subinterval series often had the same fractional number of degrees of freedom (i.e., chaotic dimensions), a finding which suggests they are both regulated by the same underlying system. The ischemia/anoxia evoked transient dimensional increases and separations between the two subinterval series that, after the temporary divergence, reconverged to having the same lower value. The dimensional fluctuations occurred repeatedly and preceded or coincided with alterations in the magnitude and sign of the slope of QT vs RR-QT. We interpret the dimensional fluctuations of the two subinterval series as correlates of adaptation-dependent self-organization and reorganization in the underlying intrinsic cardiac nervous system during accumulating ischemia/anoxia. Such attempts at functional reorganization in this simple neurocardiac system may explain the transient dimensional changes in the RR intervals that precedes by 24 hrs the occurrences of fatal ventricular fibrillation in high-risk cardiac patients.     

Reviews of current books

Pastoral Psychology -     

Cognitive specificity and positive-negative affectivity: complementary or contradictory views on anxiety and depression?

A principal factor analysis, conducted on a mixed psychiatric outpatient sample (N = 470), identified both common and specific dimensions underlying anxiety and depression. Although an initial single-factor extraction accounted for a significant proportion of variance in cognitive and symptom measures of anxiety and depression, a two-factor solution, in which anxiety and depression formed separate dimensions, proved to be the better solution. MANOVAS performed on pure depressed, pure anxious, and mixed anxious/depressed subgroups provided evidence of a specific cognitive profile for anxiety and depression. The mixed subsample evidenced greater severity, a mixed cognitive and symptom profile, and character traits that may indicate increased vulnerability to psychological disturbance. Results are discussed in terms of Beck's (1976) cognitive content-specificity hypothesis and the positive-negative affect model (Watson & Tellegen, 1985).     

Limitations on the parallel guidance of visual search: color x color and orientation x orientation conjunctions

In visual search for a conjunction it is much more difficult to search for the conjunction of 2 colors or 2 orientations than for Color x Orientation or Color x Shape conjunctions. The result is not limited to particular colors or shapes. Two colors cannot occupy the same spatial location in Color x Color searches. However, Experiments 6 and 7 show that Color x Shape searches remain efficient even if the color and shape are spatially separated. Our guided search model suggests that in searches for Color x Shape, a parallel color module can guide attention toward the correct color, whereas the shape module guides attention toward the correct shape. Together these 2 sources of guidance lead attention to the target. However, if a target is red and green among red-blue and green-blue distractors, it is not possible to guide search independently toward red items and green items or away from all blue items.     

The effects of family disruption on adolescent males and females

Given the rapidly increasing rate of marital dissolution, a staggering number of children are experiencing family disruption. The purpose of this study was to ascertain the possible effects of separation and divorce on the formation of adolescents' self-image. Additionally, this study sought to determine if adolescents from disrupted homes differed from those from intact homes with regard to anxiety levels, locus of control, and perception of their family. A total of 217 subjects participated in the study by completing a battery of questionnaires. Results indicated that males from disrupted homes had better self-concepts and better perceptions of their family environment than those from intact homes. The opposite results were found among females, emphasizing the difference between the sexes in adjusting to family disruption.