Facilitator influence in facilitated communication

The use of facilitated communication with individuals with autism has generated considerable controversy over the past several years. Only recently has research begun appearing which examines the procedure using reasonable scientific controls to establish the validity of this form of communication. The present study assessed the validity of facilitated communication and evaluated the effects of facilitator influence with seven individuals with autism and mental retardation. Three individuals showed clear evidence of facilitator influence, another three showed no such influence, and one subject performed at chance levels. A follow-up session with the three subjects who showed no facilitator influence demonstrated that they also showed no unexpected language competence compared to their measured IQ and to assessment under standard conditions. Results are discussed in terms of significance for facilitated communication in general and in terms of the utility of the methodology as a means of demonstrating language competence or facilitator influence.     

Feeling good and feeling close: Affective influences on the perception of intimate relationships

Two experiments investigated the role of short-term affective states on the way people perceive various aspects of their personal relationships. Using an unobtrusive mood induction in a field setting, Experiment 1 found significant mood congruency in evaluative judgments about well-established intimate relationships. Experiment 2 used a controlled laboratory procedure and found that evaluations of the relationship and the partner, as well as preferred styles of conflict resolution were all significantly affected by the respondents' transient mood state. Increasing relationship longevity did not reduce affective influences on judgments in either study. The results arc discussed in terms of the role of affective states in cognition and judgments, and the influence of affect on everyday judgments about personal relationships is considered.     

Teaching the Rescorla-Wagner model using STELLA-II

Although the Rescorla-Wagner model is widely taught in learning courses, most textbooks present a simplified version that does not contain all of its parameters. On the basis of Rescorla and Wagner 1972) and the Turbo PASCAL program by Lachnit, Schneider, Lipp, and Kimme! (1988), we created a simulation using STELLA-II, an icon-based program by High Performance Systems, Inc. We argue that this simulation facilitates teaching the complete Rescorla-Wagner model. Using trans-switching (Kimmel & Ray, 1978; Lachnit, 1986; Murrin & Kimmel, 1986) as an example, we demonstrate the effectiveness of the STELLA-II version of the Rescorla-Wagner model as a heuristic tool.     

Hinton diagrams: Viewing connection strengths in neural networks

A graphical analysis similar to that used by Hinton and Shallice (1991) was applied to the hair cells of a simulated auditory transducer. The graphical analysis made it apparent that there were hair cells that responded to a narrow range of frequencies, as would be predicted by the tonotopic organization of the real physiology. In short, this study demonstrates the efficacy of using graphic techniques to examine the nature of the autopoetic organization of the hidden layer of back-propagation networks.     

Sensorimotor synchronization: Motor responses to pseudoregular auditory patterns

Musically trained and untrained subjects (N=30) were asked to synchronize their finger tapping with stimuli in auditory patterns. Each pattern comprised six successive tonal stimuli of the same duration, the first of which was accented by a different frequency. The duration of interstimulus onset intervals (ISIs) gradually increased or decreased in constant steps toward the end of the patterns. Four values of such steps were used in different trials: 20, 30, 45, and 60 msec. Various time-control mechanisms are hypothesized as being simultaneously responsible for subjects’ incorrect reproduction of the internal temporal ratios of the stimulus patterns. The mechanism of assimilation (of a central tendency) led subjects to enforce a regular (isochronous) structure on the patterns. The influence of other time-control mechanisms (distinction, subjective expression of an accent, sequential transfer) was expressed mainly in differences between intertap onset intervals (ITIs) and the corresponding ISIs at the beginning of the patterns. The duration of the first two ITIs was in the majority of the trials in an inverse ratio to the ratio of the respective ISIs. The distortions resulting from the timing mechanisms concerned were more pronounced in the performance of nonmusicians than in that of musicians.     

Human sensitivity to temporal proximity: The role of spatial and temporal speed gradients

Estimates of temporal proximity (sometimes called time-to-collision) from random-dot flow patterns are shown to be based upon retinal speed, rather than upon changes in dot density. Neither the spatial nor the temporal gradient of motion is essential to the task, but estimates can be made from either alone. Performance is unaffected by the addition of rotational motion, suggesting that observers axe capable of extracting the radial component of motion, which contains all the relevant information, from complex stimuli.