Behavioral engineering: stuttering as a function of stimulus duration during speech synchronization

Past studies have shown that stuttering is eliminated when speech is synchronized with a metronomic beat, but the speech sounds artificial. The present study investigated the effect of increasing the duration of these individual stimulus beats with the stimulus-off period constant at 1 sec. When subjects were instructed to speak during the stimulus-on period, stuttering was an inverse function of stimulus duration, indicating that the known metronome effect on stuttering is one point on a continuum of effective rhythm procedures. The "naturalness" of speech increased as the stimulus duration increased up to durations of about 2 sec, and then decreased. At optimal values, stuttering was greatly reduced and naturalness and rapidity of speech were retained. These optimal values effectively controlled stuttering in a field test that used two types of specially designed portable instruments, one of which produced a tactual stimulus and the other an auditory stimulus.     

Factor analysis by minimizing residuals (minres)

This paper is addressed to the classical problem of estimating factor loadings under the condition that the sum of squares of off-diagonal residuals be minimized. Communalities consistent with this criterion are produced as a by-product. The experimental work included several alternative algorithms before a highly efficient method was developed. The final procedure is illustrated with a numerical example. Some relationships of minres to principal-factor analysis and maximum-likelihood factor estimates are discussed, and several unresolved problems are pointed out.The authors wish to thank the Factor Analysis Work Group (supported, in part, by ONR) for valuable criticisms and suggestions made in the course of a discussion of the present work in April, 1965.     

Disruption of proofreading by irrelevant speech: Effects of attention,arousal or memory?

A series of five experiments examined the effects of irrelevant speech on proofreading and memory. Four of the experiments used a proofreading task and showed that the deleterious effects of irrelevant speech: (1) depend on the speech being meaningful, (2) are only present when the burden on short-term memory is low and (3) are manifested in a lower detection rate for non-contextual as opposed to contextual errors. Neither the spatial location of the speech (either in terms of spatial dispersion of sources or spatial movement of a single source) nor the intensity of the speech (in a range bounded by 50 dB(A) and 70 dB(A)) had any effect on proofreading. Late selection models of attention are favoured by the results in preference to models having arousal, short-term memory or early selection in attention as their basis. A final experiment showed serial recall for visual lists to be impaired by the presence of any speech-like sound (including reversed speech and speech in an unfamiliar language) which suggests a set of phenomena qualitatively different from those associated with proofreading. Throughout the article the practical consequences of the findings are emphasized.     

Safety locus of control and employees' accidents

This study further established the criterion-related validity of the Safety Locus of Control Scale. The safety scale was designed to predict employment applicants' propensity for on-the-job accidents. In this study, 283 hospital employees with moreexternal safety locus of control orientations reported significantly more occupational accidents, as well as more severe and costly injuries, than workers with moreinternal safety attitudes (p<.05 in all cases). Implications of these results are discussed.Research study presented at the 1988 Annual Conference of the Association of Human Resources Management and Organizational Behavior, Long Beach, California, October 26–29.     

Reducing adverse reaction to stress in the workplace. Psychology's expanding role

This section draws attention to occupational stress and suggests ways in which psychologists can apply their knowledge of research methods and treatment to this issue. In this article, the past and present role of psychologists in occupational stress is examined and ways in which psychologists might play a more central role are proposed. Although industrial/organizational and health psychology are most obviously applicable to the study of workplace wellness, more focused attention and wider application of knowledge from other subspecialities are also examined. The need for increased attention to work and family; race, class, and gender; and training and public policy issues are also discussed.