Hemiplegic writing in severe aphasia

Three patients with severe aphasia and right hemiplegia are described who could write to dictation with the right arm using a limb prosthesis though agraphic with the "intact" left hand. The phenomenon of "hemiplegic writing" is explained as an access to submerged or preprocessing levels in language and action structure, through the use of older proximal motor systems. This interpretation has implications for our understanding of language and brain function, as well as for approaches to the treatment of patients with severe language disorders.     

Control of CRT intensity via Apple II software

An inexpensive, easy-to-build device for the Apple II microprocessor is described. The modification permits software control of four levels of relative screen intensity (contrast) settings for any video monitor. The relationship of the technology to choice reaction time and perception research is briefly indicated. Principles governing operation of the modification are also discussed. Finally, a set of step-by-step instructions for building the device is provided.     

Feature-positive effect in adults and attention to portion of stimulus array

In three experiments, adult humans were tested in a feature-positive or feature-negative simultaneous symbol task. In Experiment 1, some persons focused on the correct side of the stimulus cards, whereas other persons focused on the not-correct side of the stimulus cards. The feature-positive group learned faster than the feature-negative group did in the correct side condition; the feature-negative group learned faster than the feature-positive group did in the not-correct side condition. In Experiments 2 and 3, all persons focused on both the correct and not-correct sides of the stimulus cards. Under these circumstances, feature-positive and feature-negative performances were comparable. These results indicated that the usual superiority of feature-positive over feature-negative learning results from a tendency to attend to only a portion of the stimulus array.     

A review of the tip-of-the-tongue experience

The tip-of-the-tongue experience (TOT) has intrigued psychologists for nearly a century. R. Brown and McNeil (1966) provided the first systematic exploration of the phenomenon, and the findings since their seminal study suggest that TOTs (a) are a nearly universal experience, (b) occur about once a week, (c) increase with age, (d) are frequently elicited by proper names, (e) often enable access to the target word's first letter, (f) are often accompanied by words related to the target, and (g) are resolved during the experience about half of the time. Important questions remain concerning TOTs: (a) Are emotional reactions necessary, (b) do only low frequency targets elicit TOTs, (c) do TOTs reflect incomplete target word activation or interference from related words, and (d) do spontaneous retrievals really occur? A more precise definition of the TOT experience is needed, as well as greater uniformity in the information gathered during TOTs.     

Reducing the effects of adjacent distractors by narrowing attention.

Three experiments explored the gradual narrowing of visual attention to a letter target when other letters were positioned close by. The method by which attention was narrowed involved presenting a digit target immediately prior to the latter target and in the same location for progressively shorter durations and requiring the subject to identify both the digit target and the letter target before responding. The response time data from the first 2 experiments indicated that shorter durations of the digit reduced the amount of information processed from noise letters positioned on either side of the letter target. In the third experiment, in which separation of letters was increased slightly, the response times indicated that the information from flanking noise letters may have been virtually eliminated.     

Back to basics: Percentage agreement measures are adequate, but there are easier ways

Percentage agreement measures of interobserver agreement or "reliability" have traditionally been used to summarize observer agreement from studies using interval recording, time-sampling, and trial-scoring data collection procedures. Recent articles disagree on whether to continue using these percentage agreement measures, and on which ones to use, and what to do about chance agreements if their use is continued. Much of the disagreement derives from the need to be reasonably certain we do not accept as evidence of true interobserver agreement those agreement levels which are substantially probable as a result of chance observer agreement. The various percentage agreement measures are shown to be adequate to this task, but easier ways are discussed. Tables are given to permit checking to see if obtained disagreements are unlikely due to chance. Particularly important is the discovery of a simple rule that, when met, makes the tables unnecessary. If reliability checks using 50 or more observation occasions produce 10% or fewer disagreements, for behavior rates from 10% through 90%, the agreement achieved is quite improbably the result of chance agreement.     

Conceptual preference for thematic or taxonomic relations: A nonmonotonic age trend from preschool to old age

Two experiments examined the development of conceptual preference for either thematic (functional) or taxonomic relationships in a match-to sample task. In Experiment 1 twenty subjects from each of five age groups—preschool to old age—completed a method of triads preference test where they were forced to choose a thematic or taxonomic match. Young and old individuals preferred the thematic parings while school age and college adults preferred the taxonomic matches. Although the Age × Preference relation was pronounced, the majority of subjects at all ages could provide adequate justification of both the preferred and nonpreferred relationship. In addition, kindergarten subjects in Experiment 2 could readily be trained to respond on the basis of the nonpreferred mode. These data suggest that the pervasive shift in conceptual responding from syntagmatic to paradigmatic, thematic to taxonomic, etc., represents a change in preference rather than a shift to a fundamentally new way of organizing knowledge.