C. Michael Levy

The stability of the sigma sleep spindle

The present study closely examined the distribution of sigma sleep spindle activity or six normal human males who slept undisturbed for approximately 8 h/night for 3 consecutive nights. Sigma spindle activity was monitored by an automatic spindle detector system which performed at 92.5% accuracy when judged against established visual criteria. Individuals differed markedly in total sigma spindle production across nights, but the failure to detect significant differences among nights and the large intra-class correlation suggests noteworthy inter-night stability of the sigma spindle.

The structure of writing processes as revealed by secondary task demands

This study investigates how working memory capacity may account for why better writers are able to coordinate mutliple subprocesses more easily than poor writers. Writing, while distracted by secondary task demands, offers one way to explore the importance of working memory to the structure inherent in the writing subprocesses. For the study, the author chose experiments based on the finding that good writers manage the simultaneous demands of writing subprocesses better than poor writers(Levy & Ransdell, 1995, pp. 767–779). Students composed essays while distracted by concurrent loads on working memory. The author found that when relatively minor demands were made on working memory, i.e., unattended and attended background speech, these variables caused a decrease in fluency, but had no effect on quality. Attended, but not unattended, speech reliably reduced average sentence length. A concurrent task of remembering six digits reduced fluency by nearly 50% also reliably decreased quality and sentence length. Resources which are relatively stable in the face of dual-task demands were allocated for the regulation of writing quality, sentence length, pause duration and location. The author found that better writers write longer sentences, pause for shorter durations and at clause boundaries more often than poorer writers. Competing tasks first disrupt the timing of writing and only impact quality when larger secondary task demands in working memory are required.

Ultradian rhythms in the perception of the spiral aftereffect

Young adults were tested on the spiral aftereffect (SAE) for 8-h periods during the day and night. Using time series analyses, prominent cyclicity components in the perception of the illusion were revealed, with periodicities of the SAE the same order of magnitude as the REM-nonREM cycle. It appeared that the duration of the SAE could be used as a sensitive behavioral index of the basic rest-activity cycle.

Writing with Concurrent Memory Loads

This chapter presents a theoretical context that can guide readers in the development of memoryloading tasks useful for studying written language production. The guidelines for and specific examples of these tasks illustrate how systematic testing can be conducted to evaluate the predictions of a modern theory of writing whose structure and functioning depend upon the involvement of working memory.

The “r” that psychology forgot: Research on writing processes

Development of theory and methodology related to the psychology of reading and mathematical problem solving has far outpaced progress in the realm of the psychology of writing. However, recently published theories may serve to link written language production research with mainstream psychology, and new computer-based methodologies may help to make conducting research in writing more tractable. This paper describes several new initiatives for studying writing within a framework based on recent theories of working memory.

Hemispheric Asymmetry of Reaction Time in a Dichotic Discrimination Task

Summary An experiment was reported in which the manual reaction times (RT) to a verbal target stimulus, embedded in a series of dichotically presented digits, was measured in 40 dextral Ss. The major finding was an asymmetry of RTs: RT to target stimuli occurring in the right ear was 132 msecs. faster than in the left ear. The magnitude of the asymmetry was almost 2.5 times faster for this complex discrimination task than that found previously in studies involving simple stimulus detection, suggesting that differential processing time is an important function of task complexity and mediational demands.

Order of report and ear asymmetry in dichotic listening

This study is an attempt to reduce some confusion over reports of an ear asymmetry effect in the dichotic listening paradigm and to assess the criticism that the effect is artifactual. A within-S design was used in which six pairs of digits per trial were presented at 2 pair/sec. When order of report was controlled, a dramatic ear asymmetry and a clear ear order effect was evident The orthogonality of these effects implies that the asymmetry is not an artifact of order of reporting.

Paired associate learning during eeg-defined sleep: A preliminary study

18 male Ss were given 2 adaptation nights and 5 nights of training on Russian-English paired associates during sleep stages 2 or 1-REM and 4. Recall scores were nil, but recognition scores across all nights of training were significantly higher than chance, and generally increased over training, suggesting a learning to learn effect.

Real Time Studies in Writing Research: Progress and Prospects

The last half of the 20th century provided an opportunity for the explosive growth and development of research on writing. From a product-oriented to a process-oriented approach, new theoretical models of writing emerged. Following this shift in conceptual frameworks, new methods of investigations were applied in research. However, in the context of this development, careful analyses of the literature demonstrate clearly that systematic, theoretically-driven empirical research focused on writing has been barely measurable compared with research on speech production and language comprehension. Methods presented in this book illustrate how the study of writing processes is becoming ever more tractable with the use of real time methods that take advantage of their unobtrusive recordings of the writing process.

MOSAIC AND THE INFORMATION SUPERHIGHWAY: A VIRTUAL TIGER IN YOUR TANK

The World-Wide Web (WWW) is a wide-area hypermedia information-retrieval initiative that aims to give access to a large universe of documents. Through software such as Mosaic, the WWW provides a simple, consistent means to access a variety of information stored as text, graphics, video, and sound files. This paper details the requirements for using this software, illustrates some current and planned hypermedia databases, and addresses issues that could affect the greatest possible utilization of the system.