A simple method to record arm positioning movements in man with an Apple computer

This paper describes a simple method to record arm positioning movements in humans, via the game paddle entry of an Apple computer. A machine language subroutine reads the successive positions of a rotating potentiometer, with an angular accuracy of .5 deg and a time interval between two measures of 2.5 msec, and stores them sequentially in RAM memory. These measures can be retrieved for further computations of movement parameters.     

Isolating Unconscious Influences: The Neutral Parameter Procedure

Earlier demonstrations of unconscious learning have been regularly challenged. In this paper, we suggest that earlier demonstrations were not compelling due to certain properties of the experimental situations, and notably that conscious exploitation of explicit knowledge, if present, would coincide or conflict with the results of unconscious processing. We designed a method consisting of inducing a neutral behavioural change in the way subjects drew geometric figures. Two experiments showed that important and long-lasting modifications of drawing behaviour were obtained following specially devised practice, although these modifications could not be expected from deliberate adaptive strategies. In addition, we showed that subjects were unaware of the manipulation to which they had been exposed. The study provides striking evidence for unconscious learning and offers insights for the design of suitable new tools to investigate unconscious cognition.     

Expressing Coreference in French: Cognitive Constraints and Development of Narrative Skills

This study looks at how coreference is expressed under various oral production conditions and at various stages of development. Seven- to 11-year-old children and adults told silent comic strip stories involving two characters to a same-age peer. The stories varied as to: (1) the frame presentation mode, (2) the links between events across frames, and (3) thematic continuity. The results showed that, (1) in general, all speakers marked increasing referent givenness (the 7-year-olds and adults less so than the 11-year-olds), (2) arbitrarily placed picture sequences led to a greater number of markers of increasing referent givenness than ordered sequences (which made it easier to put the information into story format), and (3) speakers were more inclined to tell the story when the frames were shown all at once (on the same page) than when they were presented in booklet format (one frame per page). The manipulation of the production conditions turned out to be an effective way of revealing speaker competence. In step-by-step encoding where the pictures were discovered one at a time, 7-year-old children exhibited a greater tendency to describe each frame as an independent entity, 11-year-old children always marked increasing referent givenness, and adults maintained coreference in a more flexible manner by varying the markers used to express referent givenness. The viewing of all frames at once before encoding provided support for the expression of emerging narrative skills. This condition enabled the 7-year-olds to no longer describe the pictures independently, promoted the marking of increasing referent givenness between the ages of 7 and 9, and pointed out the age (9 years) when the speakers began to mark coreference as a function of how the story ended.     

Cognitive effort during note taking

Note taking is a complex activity that requires comprehension and selection of information and written production processes. Here we review the functions, abbreviation procedures, strategies, and working memory constraints of note taking with the aim of improving theoretical and practical understanding of the activity. The time urgency of selecting key points and recording them while comprehending new information at the same time places significant demands on the central executive and other components of working memory. Dual‐ and triple‐task procedures allow the measurement of the momentary cognitive effort or executive attention allocated to note taking. Comparative data show that note taking demands more effort than reading or learning. However, it requires less effort than the creative written composition of an original text. Copyright © 2004 John Wiley & Sons, Ltd.     

Suppressing visual feedback in written composition: Effects on processing demands and coordination of the writing processes

The goal of this experiment was to investigate the role of visual feedback during written composition. Effects of suppression of visual feedback were analyzed both on processing demands and on on‐line coordination of low‐level execution processes and of high‐level conceptual and linguistic processes. Writers composed a text and copied it either with or without visual feedback. Processing demands of the writing processes were evaluated with reaction times to secondary auditory probes, which were analyzed according to whether participants were handwriting (in a composing and a copying task) or engaged in high‐level processes (when pausing in a composing task). Suppression of visual feedback increased reaction time interference (secondary reaction time minus baseline reaction time) during handwriting in the copying task and not during pauses in the composing task. This suggests that suppression of visual feedback only affected processing demands of execution processes and not those of high‐level conceptual and linguistic processes. This is confirmed by analysis of the quality of the texts produced by participants, which were little, if at all, affected by the suppression of visual feedback. Results also indicate that the increase in processing demands of execution related to suppression of visual feedback affected on‐line coordination of the writing processes. Indeed, when visual feedback was suppressed, reaction time interferences associated with handwriting were not reliably different in the copying task or the composing task but were significantly different when visual feedback was not suppressed: They were lower in the copying task than in the composition task. When visual feedback was suppressed, writers activated step‐by‐step execution processes and high‐level writing processes, whereas they concurrently activated these writing processes when composing with visual feedback.     

Lateral foot-movement times in sitting and standing postures

This study examined the effects of foot-side, sex, movement amplitude, and target width on lateral and nonvisually controlled foot-movement time with a reciprocal foot-tapping task in sitting and standing postures. 9 male and 9 female right-foot dominant undergraduates (ages 20 to 25 years) with no reported physical and health problems with their lower limbs voluntarily participated. Analysis indicated foot-movement time in a standing posture was much faster than that in a sitting posture. Target width and movement amplitude had significant effects on foot-movement time, while the effects of foot-side and sex were not significant. Multiple regression models with inclusion of the significant factors were examined which should be useful in predicting foot-movement time required for different tasks in sitting and standing postures. Possible applications of the results may be made to the design of work and foot controls in terms of the related task factors for person-machine interfaces with two or more pedals.