The convergence of Kuhn and cognitive psychology

Although psychology has been criticized for adhering to outmoded conceptions of knowledge (e.g. logical positivism), the assertion is made that at least one branch of psychology, namely cognitive psychology, is in the position to corroborate and extend contemporary philosophy of science. Kuhn's “learned perception of similarity” and the related notion of exemplar, which serve to exemplify more adequate conceptions of knowledge within the philosophy of science, are shown to converge with cognitive psychology's schema theory. In this way, the schema theory's empirical offspring provide a validation mechanism for Kuhn's notions and thus provide a richer understanding of the scientific enterprise. This convergence is seen as instantiating an epistemological trend towards understanding of limitations and validity of scientific evidence through an understanding of the limitations and validity of the scientist.     

Trait vs. nontrait conceptualizations of intrinsic/extrinsic motivational orientation

The present study questioned whether intrinsic vs. extrinsic motivation should be conceptualized as a trait among elementary school students. Previous instruments employing question formats that pit an intrinsic orientation against an extrinsic orientation typically result in normal distributions around the midpoint of the scale. Such a pattern could only result from a majority of children endorsing both intrinsic and extrinsic items. In the present study we investigated the hypothesis that such children may be intrinsically motivated in some school subjects but extrinsically motivated in others. Questions designed to assess motivational orientation in each of four academic subjects (math, social studies, English, and science) revealed three types of students: (a) those that were intrinsic in some subjects but extrinsic in others, (b) those that were intrinsic in all school subjects, and (c) those that were extrinsic in all school subjects. It was concluded that for the first group, motivational orientation does not function as a trait, but rather is specific to the academic content. However, for the second and third groups, motivational orientation does appear to be trait-like since children consistently report the same orientation across academic subjects. A similar analysis was applied to consistency vs. change over time where three groups were also identified. Discussion focused on the larger issues involving trait- vs. situation-specific approaches.     

A simulation laboratory for statistics

In this paper, we describe a general purpose data simulator, Datasim, which is useful for anyone conducting computer-based laboratory assignments in statistics. Simulations illustrating sampling distributions, the central limit theorem, Type I and Type II decision errors, the power of a test, the effects of violating assumptions, and the distinction between orthogonal and non-orthogonal contrasts are discussed. Simulations illustrating other statistical concepts—partial correlation, regression to the mean, heteroscedasticity, the partitioning of error terms in splitplot designs, and so on—can be developed easily. Simulations can be assigned as laboratory exercises, or the instructor can execute the simulations during class, integrate the results into an ongoing lecture, and use the results to initiate class discussion of the relevant statistical concepts.     

Spectral restoration of speech: Intelligibility is increased by inserting noise in spectral gaps

In order to function effectively as a means of communication, speech must be intelligible under the noisy conditions encountered in everyday life. Two types of perceptual synthesis have been reported that can reduce or cancel the effects of masking by extraneous sounds: Phonemic restoration can enhance intelligibility when segments are replaced or masked by noise, and contralateral induction can prevent mislateralization by effectively restoring speech masked at one ear when it is heard in the other. The present study reports a third type of perceptual synthesis induced by noise: enhancement of intelligibility produced by adding noise to spectral gaps. In most of the experiments, the speech stimuli consisted of two widely separated narrow bands of speech (center frequencies of 370 and 6000 Hz, each band having high-pass and low-pass slopes of 115 dB/octave meeting at the center frequency). These very narrow bands effectively reduced the available information to frequency-limited patterns of amplitude fluctuation lacking information concerning formant structure and frequency transitions. When stochastic noise was introduced into the gap separating the two speech bands, intelligibility increased for “everyday” sentences, for sentences that varied in the transitional probability of keywords, and for monosyllabic word lists. Effects produced by systematically varying noise amplitude and noise bandwidth are reported, and the implications of some of the novel effects observed are discussed.     

Multicultural Training for Undergraduates: Developing Knowledge and Awareness

The changing demographics of the United States have lead to increased training of multicultural issues in graduate counseling programs. Graduate students report higher levels of multicultural competencies after completing a multicultural counseling course. Similarly, this study indicates increased multicultural awareness and knowledge among undergraduates completing a multicultural course.     

Working memory in chess

Three experiments investigated the role of working memory in various aspects of thinking in chess. Experiment 1 examined the immediate memory for briefly presented chess positions from master games in players from a wide range of abilities, following the imposition of various secondary tasks designed to block separate components of working memory. Suppression of the articulatory loop (by preventing subvocal rehearsal) had no effect on measures of recall, whereas blocking the visuospatial sketchpad (by manipulation of a keypad) and blocking the central executive (by random letter generation) had equivalent disruptive effects, in comparison with a control condition. Experiment 2 investigated the effects of similar secondary tasks on the solution (i.e., move selection) of tactical chess positions, and a similar pattern was found, except that blocking the central executive was much more disruptive than in Experiment 1. Experiment 3 compared performance on two types of primary task, one concerned with solving chess positions as in Experiment 2, and the other a sentence-rearrangement task. The secondary tasks in each case were both designed to block the central executive, but one was verbal (vocal generation of random numbers), while the other was spatial in nature (random generation of keypresses). Performance of the spatial secondary task was affected to a greater extent by the chess primary task than by the verbal primary task, whereas there were no differential effects on these secondary tasks by the verbal primary task. In none of the three experiments were there any differential effects between weak and strong players. These results are interpreted in the context of the workingmemory model and previous theories of the nature of cognition in chess.