Evaluating Assistive Technology in the Education of Persons with Severe Disabilities

This commentary includes a brief discussion of issues raised by the articles and systematic review contained in this special issue addressing technology applications for persons with severe developmental disabilities. Topical areas include a discussion of; (1) a need to compare “high tech” with “low tech” applications, (2) procedural fidelity, (3) collateral effects associated with intervention, (4) the conditional use of newly established behavior, (5) response efficiency and contextual fit, and (6) treatment intensity.     

Eye gaze metrics reflect a shared motor representation for action observation and movement imagery

Action observation (AO) and movement imagery (MI) have been reported to share similar neural networks. This study investigated the congruency between AO and MI using the eye gaze metrics, dwell time and fixation number. A simple reach-grasp-place arm movement was observed and, in a second condition, imagined where the movement was presented from the first person perspective (1PP) and the third person perspective (3PP). Dwell time and number of fixations were calculated for whole scene and regions of interest (ROIs). For whole scene, no significant differences were found in the number of fixations for condition (AO, MI) or perspective. Dwell time, however, was significantly longer in AO than MI. For ROIs, the number of fixations was significantly greater in 1PP than 3PP. The data provide support for congruence between motor simulation states but also indicate some functional differences.     

Intensity and number of alternatives in hue identification: Piéron’s law and choice reaction time

Two experiments investigated the effects of intensity and the number of response alternatives in hue identification. Three questions were addressed. First, what is the relationship between these effects? If intensity and number of alternatives affect different processes in series, these factors would have additive effects on reaction time (RT). Other models predict a multiplicative interaction. These models assume that when a stimulus is presented, evidence accrues over time for each response alternative, and that when the evidence for a particular alternative exceeds its criterion, the response is made. A natural auxiliary assumption is that intensity affects the rate of evidence accrual, while the number of alternatives affects the criterion. The second question addressed is, how does choice RT change as a function of intensity? Piéron used a power function to describe the effect of intensity on simple RT. This paper considers three candidates for intensity’s effect on choice RT: the power, logistic, and Michaelis functions. Each candidate function was tested in an additive model and a multiplicative model. The best account was given by the power function in an additive model. The last question is, does each process produce an output that can be classified as correct or incorrect? Schweickert (1985) proposed that factors that selectively influenced such processes would have additive effects on log percent correct. Instead, an interaction was found. Perhaps the assumption that the process affected by intensity produces a single output is wrong.     

How is linguistic memory accessed? A psychophysiological approach

The role of “subvocalization” during language comprehension, especially reading, is examined. Four arguments against it having a role in accessing memory are erroneous because 1) its latencyis much shorter than is conventionally stated; 2) rate of visual information processing is erroneously estimated by failing to distinguish between reading and scanning; 3) covert speech doesnot disappear in the competent language performer; and 4) the argument that subvocalization is an epiphenomen is irrelevant. Rather, data support the generalization that covert speech is present during all cognitive functioning and that its specific topography is discriminatively related to the class of phoneme being processed. It is thus inferred that during cognition the speech musculature generates a phonetic code that may function to access linguistic memory. However, since there are also numerous other psychophysiologic events associated with covert speech, a multichannel processing system is hypothesized wherein speech, visual, and kinesthetic modalities interact with the brain. Illustrations are given of how this accessing model is compatible with existing holographic and feature analyzer models of memory. Data are presented that illustrate how phonetically encoded neuromuscular events can be directly measured through psychophysiologic methods. It is hypothesized that cognitive processes are generated when cybernetic neuromuscular circuits selectively interact. Consequently,all components of these neuromuscular circuits serve a function during cognition so that a role for “subvocalization” (a muscular component) cannot be ruled out in anapriori manner.     

Is the Medium the Message? A Study of the Effects of Media,Communicator, and Message Characteristics on Attitude Change1

The present study examined the interactive effects of type of media, communicator, and position of message on persuasiveness of the communication. Subjects received a communication over television, radio (audio tape), or written medium, which either agreed with a position they held or strongly disagreed with it. The communicator was either a newscaster or a candidate for political office. The results indicated that subjects felt the newscaster to be more trustworthy than the candidate. In line with previous research, there was no main effect of media on persuasiveness. However, media interacted with the other variables so that when the communication disagreed with the audience, television was the most persuasive medium with the newscaster but the least persuasive with the untrusted candidate. There was no effect for media when the message agreed with the audience. Further, the candidate taking a position congruent with the audience's was rated as more attractive but less trustworthy than a candidate taking the opposite position. It was suggested that television may be the most involving medium and that either a counterargument theory or reactance theory could explain why it was not effective with the candidate.     

A test of the Zucherman heterosexual scales

Summary: Female and male undergraduate students enrolled in the introductory psychology course were administered the Zuckerman heterosexual scale as part of a larger battery of tests. The ordering of items for males was very similar to Zuckerman's with two minor exceptions. Female subjects, on the other hand, reported more sexual experiences of all kinds than did Zuckerman's sample, and two major differences in ordering Were noted. The coefficients of reproducibility for males and females were .928 and .954 respectively which were almost identical to those of Zuckerman. The rank-order correlation between the ranking of the items in the male and female scales was .958.     

What happens between an external stimulus and an overt response?

Peripheral components of feedthrough loops were psychophysiologically measured from the brain, both forelimbs, the tongue and the eyes during simple and choice reaction time tasks using linguistic and non-linguistic stimuli. Closing a microswitch with the little finger was the overt response. Covert electromyographic (EMG) responses were computer identified in the following average temporal order: generally, the earliest covert reactions were in the tongue, brain, eyes, and passive arm-hand region. Next were complex EMG events in the active limb. These covert reactions may function in feedthrough loops to generate and transmit codes during internal information processing. The passive armhand responses occurred significantly earlier than the onset of the covert EMG burst for closing the microswitch; perhaps there is an inhibitory response “commanding” the passive arm not to respond, before the other (active) limb can overtly respond. Mean response patterns to linguistic and non-linguistic stimuli were almost identical. Reaction time to the onset of the EMG burst for switch closing was from 40 to 95 milliseconds earlier than the usual overt reaction time measure (that to switch closing), suggesting that reaction time studies might be improved by using the onset of EMG increase as the more sensitive and precise measure.     

Some developments in multivariate generalizability

This article is concerned with estimation of components of maximum generalizability in multifacet experimental designs involving multiple dependent measures. Within a Type II multivariate analysis of variance framework, components of maximum generalizability are defined as those composites of the dependent measures that maximize universe score variance for persons relative to observed score variance. The coefficient of maximum generalizability, expressed as a function of variance component matrices, is shown to equal the squared canonical correlation between true and observed scores. Emphasis is placed on estimation of variance component matrices, on the distinction between generalizability- and decision-studies, and on extension to multifacet designs involving crossed and nested facets. An example of a two-facet partially nested design is provided.Appreciation is expressed to the Office of Research in Medical Education, University of Texas Medical Branch, for permitting use of their data.