Comparison of selected gait parameters of trainable mentally retarded and nonretarded males

Although there were no significant differences in the single support phase of gait for 6 trainable mentally retarded boys (Mean age 9.6 yr.) and 6 nonretarded boys (Mean age 9.5 yr.), total gait time and time in double support were significantly different for the two groups, supporting previous research which showed gait was was deficient in trainable mentally retarded individuals.     

Developmental study of short-term memory characteristics for kinesthetic movement information

The present experiment was designed to examine age-related characteristics of short-term retention of kinesthetic movement information. 20 children from each age group (6, 8, 10 yr.) were tested for recall of kinesthetic end-location. The results indicate that 6- and 8-yr.-old children became less accurate and more variable in recall performance following a delay interval. However, 10-yr.-old children were capable of maintaining performance accuracy during a delay interval.     

The EPPI family therapy outcome study

Information was evaluated from 1014 families seen in an eight-year period by therapists connected with the Department of Family Psychiatry at Eastern Pennsylvania Psychiatric Institute in Philadelphia. Statistical analysis revealed several factors that had some predictive value in relation to outcome of therapy; these were race, past psychiatric hospitalization, type of presenting family problem, and number of sessions held. There was a rather good chance of improvement being noted by the therapist if the family stayed in treatment for eight or more sessions. About 90% of the cases were seen for less than 20 interviews. Only about 3% were seen for longer than 35 interviews. The vast majority of EPPI cases were short-term. Black families tended to present different problems from white, and therapy was terminated with blacks sooner than for whites. About 35% of families terminated after one to two interviews, and another 30% after three to seven sessions. Since families tended to benefit most after eight or more sessions, the need for better methods or techniques to engage families is highlighted.The research was supported in part by a Career Development Award from the University of California, San Francisco, to the first author.     

The relation between proximity and brightness similarity in dot patterns

The Gestalt studies demonstrated the tendency to visually organize dots on the basis of similarity, proximity, and global properties such as closure, good continuation, and symmetry. The particular organization imposed on a collection of dots is thus determined by many factors, some local, some global. We discuss computational reasons for expecting the initial stages of grouping to be achieved by processes with purely local support. In the case of dot patterns, the expectation is that neighboring dots are grouped as a function of proximity and similarity of contrast, by processes that are independent of the overall organization and the various global factors. We describe experiments that suggest a purely local relationship between proximity and brightness similarity in perceptual grouping.     

Development of clinical tests of vision: Initial data on two hyperacuity paradigms

Many basic psychophysical functions offer promise as clinical tests of vision. Here, we discuss problems that one encounters in the clinical setting, how one identifies a psychophysical test for potential clinical development, and an orderly approach to development of suitable test paradigms. Parameters are selected which are relatively insensitive to variables encountered in the field (clinic) in a normal population, but which are sensitive to changes in the response system being studied. Initial data on two hyperacuity tests are presented. These tests are adaptations of hyperacuity paradigms (Westheimer, 1979) to a clinical environment. This particular test set offers promise because it exhibits a unique threshold which is dependent upon neural data processing and is relatively independent of retinal image degradation.     

Perceptual objects and the cost of filtering

The latency of reading a single word is increased by 20 to 40 msec if another object is present in the display. The delay is affected by the spatial organization of the display: a colored frame causes less delay when it surrounds the word than when it is shown on the opposite side of fixation. A small gap in the frame is also more efficiently detected as a secondary task when the frame is around the word than when the two are spatially separate. The advantage of integrated over separate presentation suggests that a “filtering cost” is incurred when two distinct perceptual objects compete for attention. Attention in filtering tasks operates on perceptually distinct objects rather than on nodes in a semantic network.     

Factor semantics forn-valued logics

In this note we prove that some familiar systems of finitely many-valued logics havefactor semantics, and establish necessary conditions for a system of many-valued logic having semantics of this kind.