Formal reasoning in late adulthood: The role of semantic content and metacognitive strategy

Two experiments explored the availability of deductive or formal reasoning in late adulthood. In Experiment 1, fifty young (M=19.0 years) and 50 elderly adults (M=81.0 years) were assessed using adaptations of Wason's selection task and rated task content for familiarity, affect, and agreement. In Experiment 2, 100 young (M=21.0 years) and 100 elderly adults (M=81.0 years) were similarly assessed, with half of the subjects in each age group receiving a metacognitive strategy to facilitate reasoning. Results from Experiment 1 indicated equivalent reasoning among the groups on problems employed in earlier developmental research. In contrast, problems constructed to entail affect resulted in poorer performance by older adults. In Experiment 2, both young and older adults who used the metacognitive strategy reasoned equally acrossall problems. In both experiments, familiarity and agreement did not play a role in deductive reasoning performance, but affect seemed to be an interfering factor. Results are discussed in terms of competence-procedure and stability-decrement models of adult cognitive development.     

Interval patterning and auditory gap detection

Pattern effects associated with the perception of the temporal microstructure of auditory signals were examined. Temporal changes, or gaps, were introduced into auditory interval patterns produced by a sequence of pulses. Discrimination thresholds for positive, and for negative, gaps were obtained as a function of the surrounding pattern of intervals. Gap thresholds increase with the slope of the surrounding interval pattern. Gap thresholds are smaller when the gap interval represents an extension, rather than a reversal, of the surrounding pattern. The results are in agreement with Heise and Miller’s thresholds of tonal isolation from repeated melodies, and with Mangelsdorf’s visual extrapolation thresholds of point-of-collision. The agreement of results from diverse test situations suggests a non-specifiC., general patterning effect upon discontinuity thresholds.     

Reaction time to different wavelengths at various luminances

The present investigation is concerned with determining whether or not differences in the reaction times exist in a human subject’s responses to 6 different wavelengths equated at 5 levels of luminance. The heterochromatic matching was done by the method of flicker photometry and checked by the method of direct comparison. Simple reaction time, the time interval starting with the presentation of a visual stimulus and terminating in a manual response, was used as the method of determining the latencies for the establishment of equal sensory effects for the different wavelengths. Monocular viewing of the stimuli was used by two subjects and reaction times are determined over a luminance range of 5.2 log units around a central value of I millilambert. The results indicated that simple reaction time is inversely related to stimulus luminance. There were no differences in the reaction times to the different wavelengths at the four highest luminance levels; at the lowest luminance level, the wave-lengths fan out in a manner that is in line with the classical data of vision. In other words, the visual functions obtained with simple reaction time parallel certain well-known visual functions in intensity discrimination, flicker and visual acutty-the results may be accounted for by the Duplicity Theory of vision.     

Statistical power analysis for one-way analysis of variance: A computer program

To facilitate the computation of statistical power for analysis of variance, Cohen developed the index of effect sizef, defined as theSD between groups divided by theSD within groups. A microcomputer program for statistical power allows the user to compute the value off in any of several ways: by specifying the mean andSD for every cell in the ANOVA; by specifying the mean value for the two extreme cells and the pattern of dispersion for the remaining cells; by estimating the proportion of variance in the dependent variable that will be explained by group membership; and/or with reference to conventions for small, medium, and large effects. The program will compute power for any single set of parameters; it will also allow the user to generate tables and graphs showing how power will vary as a function of effect size, sample size, andα.     

Reduced Memory Representations for Music

We address the problem of musical variation (identification of different musical sequences as variations) and its implications for mental representations of music. According to reductionist theories, listeners judge the structural importance of musical events while forming mental representations. These judgments may result from the production of reduced memory representations that retain only the musical gist. In a study of improvised music performance, pianists produced variations on melodies. Analyses of the musical events retained across variations provided support for the reductionist account of structural importance. A neural network trained to produce reduced memory representations for the same melodies represented structurally important events more efficiently than others. Agreement among the musicians' improvisations, the network model, and music-theoretic predictions suggest that perceived constancy across musical variation is a natural result of a reductionist mechanism for producing memory representations.