In line with musical "common sense" (but contrary to the century-old tradition of musical psychophysics), we show that harmony is an inherently three-tone phenomenon. Previous attempts at explaining the affective response to major/minor chords and resolved/unresolved chords on the basis of the summation of interval dissonance have been notably unsuccessful, but consideration of the relative size of the intervals contained in triads leads directly to solutions to these historical problems. At the heart of our model is Leonard Meyer's idea from 1956 concerning "intervallic equidistance" -i.e., the perception of "tension" inherent to any three-tone combination that has two intervals of equivalent size (e.g., the augmented chord). By including the effects of the upper partials, a psychophysical explanation of the perceived sonority of the triads (major>minor>diminished>augmented) and the affective valence of major and minor chords is easily achieved. We conclude that the perceptual regularities of traditional diatonic harmony are neither due to the summation of interval effects nor simply arbitrary, learned cultural artifacts, but rather that harmony has a psychophysical basis dependent on three-tone combinations.

We studied intermanual motor transfer for right-to-left or left-to-right direction of transfer between either proximal or distal upper extremity muscle groups. The influence of previously acquired motor engrams (original learning, OL) on learning efficiency of the contralateral side (transfer learning, TL) was examined in 26 right-handed healthy subjects. The task consisted of the drawing of meaningless figures. During TL, OL figures had to be reproduced as vertical mirror reversals. Data revealed a benefit for right-to-left but not left-to-right direction of transfer for time to complete a figure as well as a left-to-right transfer benefit for spatial motor precision. Furthermore, a benefit for intermanual transfer of training between proximal but not distal muscle groups was found when movement time to complete a figure was evaluated. Of special interest was the observation of a disadvantage due to prior contralateral learning for performance at right distal effectors. The asymmetrical transfer benefits with respect to side are in line with previous findings and support the proficiency model and the cross-activation model. Results further showed that intermanual transfer of training might differ with respect to muscle group involvement and suggest that, although primarily facilitating, previous opposite hand training may lead to inhibitory influences on subsequent contralateral reproduction.

It has been proposed that temporal perception and performance depend on a biological source of temporal information. A model for a temporal oscillator put forward by Treisman, Faulkner, Naish, and Brogan (1990) predicted that if intense sensory pulses (such as auditory clicks) were presented to subjects at suitable rates they would perturb the frequency at which the resulting pattern of interference between sensory pulse rates and time judgments would depend on the frequency of the temporal oscillator and so might allow the frequency to be estimated. Such interference patterns were found using auditory clicks and visual flicker (Treisman & Brogan, 1992; Treisman et al., 1990). The present study examines time estimation together with the simultaneously recorded electroencephalogram to examine whether evidence of such an interference pattern can be found in the EEG. Alternative models for the organization of a temporal system consisting of an oscillator or multiple oscillators are considered and predictions derived from them relating to the EEG. An experiment was run in which time intervals were presented for estimation, auditory clicks being given during those intervals, and the EEG was recorded concurrently. Analyses of the EEG revealed interactions between auditory click rates and certain EEG components which parallel the interference patterns previously found. The overall pattern of EEG results is interpreted as favouring a model for the organization of the temporal system in which sets of click-sensitive oscillators spaced at intervals of about 12.8 Hz contribute to the EEG spectrum. These are taken to represent a series of harmonically spaced distributions of oscillators involved in time-keeping.

The conclusions concerning hemispheric specializations based on neural network simulations, which were previously reported by Kosslyn, Chabris, Marsolek, and Koenig (1992), are shown not to be valid. Differences in network performance on tasks said to be "categorical" and "coordinate spatial" in nature were due to imbalances in the input stimuli and cannot, in principle, be related to differences in performance on such tasks in human subjects. The use of truth tables and correlation coefficients in the design of neural networks is discussed.

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