Sensitivity to shifts of a point stimulus: An instance of tactile hyperacuity

The sensitivity of the tactile sense to shifts in the position of a point stimulus was determined at four body loci: the index finger, forehead, belly, and back. Water-jet stimulation was used, a method which allows frictionless travel of a point stimulus over the skin. Three subjects were tested by means of the method of forced choice, with the task being to say whether the stimulus moved to the right or to the left. The shift threshold was defined as that shift excursion which gave rise to 75% correct responding. The basic finding was that shift thresholds were on the order of 10 to 30 times smaller than the corresponding two-point limens obtained by Weinstein (1968) for the same body loci. These unexpectedly small shift thresholds indicate an exquisite sensitivity of the cutaneous sense to rapid changes in position of a point stimulus. A physiological model is presented which accounts for the difference between localization and spatial resolution. nt]mis|This research was supported by Department of Health~ Education, and Welfare Grant 14-P-SS282/9 from the Social and Rehabilitation Services, NIH Research Grant R01-EY-00686 from the National Eye Institute, and the Smith-Kettlewell Eye Research Foundation.     

Behavioral training for myopia: long term maintenance of improved acuity

Two female myopic students participated in a behavioral training program designed to improve uncorrected visual acuity. Following a 3-day baseline, each subject underwent 12 days of training involving stimulus fading and feedback. Acuity measures were taken daily during baseline and training phases and weekly for more than 2 months following the termination of training. Both subjects showed improved acuity as a function of the training program and this improvement was maintained throughout the follow-up period. The results are discussed with respect to the growing body of research evaluating behavioral training for myopia.     

A nonobtrusive heart rate telemetry system for rats

A harness for recording heart rate (HR) from unrestrained rats and an inexpensive FM transmitter for broadcasting high-resolution EKGs are described. The harness, which employs surface electrodes rather than skin pins or implanted electrodes, is especially valuable for recording HR over extended periods of time. Because it is comparatively free of noise generated by the animal’s activity, the system is applicable to a wide range of experimental conditions. Sample HRs obtained from three strains of rats while engaging in different behavioral categories are presented.     

Value Congruence and the Vocational Self Concept of School Counselors

A model based on self concept theory has been presented for the consideration of the vocational values of school counselors. A study of the hierarchy and congruence of their values is interpreted as demonstrating a high degree of self-awareness, a foundation for movement toward the ideal self, and a measure of strong satisfaction with their career identification.     

Effects of Cross-Age Peer Tutoring Networks Among Students with Autism and General Education Students

In this investigation peer networks were formed consisting of students with autism and fourth grade peers. They were trained to tutor first grade students in sight word recognition. The purpose of the study was to determine if the target students could be trained effectively as tutors, to determine outcomes for the first graders, and to determine effects on social integration of network students. Effects were measured for implementation of tutoring steps, increases in sight words learned on a weekly basis for the tutees, and social interactions among network students during free time activities. Using a reversal design, with a multiple baseline component, results demonstrated higher gains on weekly pre- and posttests for first graders than control students who received classroom instruction only, successful implementation of peer tutoring steps by the network participants, and increased duration of social interaction time for the target students with autism and network companions. These findings were replicated in the following year. The peer network system for students with autism, thus not only increased their time and social engagement with typical peers but also provided a productive, socially acceptable activity for increasing academic performance for first graders exhibiting delays.     

Social Support Provision to HIV-Infected Gay Men1

The study examined associations between attitudes toward homosexuality, fear of AIDS, blame of persons infected with the HIV-virus, and social support provision to these individuals. A sample of HIV-infected gay men reported on the support they receive from specific members of their social networks. These network members then completed questionnaires assessing the predictor variables. Homophobia, homosexual preference, and the interaction of these two variables were positively associated with blame. Blame, together with fear of AIDS and low levels of psychological well-being, were negatively associated with provision of emotional support. Fear of AIDS was also related to negative changes in the quality of recipients' and providers' relationships. Finally, emotional support was strongly related to adjustment to illness among support recipients. Results suggest important points for intervention to promote adjustment to HIV infection among gay men.     

Child and Adolescent Mental Health: Building a System of Care

According to recent studies, large numbers of children and adolescents with serious emotional or behavioral disorders receive either no mental health treatment or treatment inappropriate to their needs. In this article the authors examine the problem of unnecessary hospitalization and the inadequacy of community-based systems. They discuss the barriers that impede improved mental health service systems for children and their families and present the Child and Adolescent Service System Program (CASSP) “system of care” model as an alternative. Last, counseling and development's role in promoting and fostering positive changes in the mental health system serving children and adolescents is discussed.     

The shape of the vibrotactile loudness function: The effect of stimulus repetition and skin-contactor coupling

In the psychophysical literature describing the relationships between physical and psychological magnitudes, as physical intensity increases, perceived intensity often grows much faster near threshold than at higher levels. In this laboratory, however, the loudness curve for sinusoidal vibrotactile stimuli was best fit by a single-limbed function rather than by the expected two-limbed function. In the present study, we measured the growth of vibrotactile loudness of 250-Hz sinusoidal stimuli by the method of absolute magnitude estimation to explore the source of the one- versus two-limbed discrepancy. The number of times that the stimulus was presented was varied, as well as whether the stimulator contacted the skin with constant force or constant penetration. Neither of these manipulations affected the shape of the loudness function consistently. Number of repetitions influenced the shapes of the magnitude estimation functions, but only for a few individuals. Skin-contactor coupling did not affect the shapes of the functions, although the absolute level (vibrotactile loudness) was consistently greater for constant indentation.