Bradley W. Frankland

Subtypes of aggression in children with attention deficit hyperactivity disorder: medication effects and comparison with typical children.

We examined aggressive behavior in 6- to 12-year-old children, including 20 children with attention deficit hyperactivity disorder (ADHD) on stimulant medication, 19 children with ADHD on placebo (n = 19), and 32 controls. Children completed a laboratory provocation task designed to measure hostile, instrumental, reactive, and proactive aggression. Children in the ADHD-placebo group exhibited increased proactive and reactive aggression following high levels of provocation compared to controls. On the last trials, instrumental aggression dissipated for controls and hostile aggression dissipated for children in the ADHD-placebo group. Both instrumental and hostile aggression dissipated for children in the ADHD-medication group.

Using the Krumhansl and Schmuckler Key-Finding Algorithm to Quantify the Effects of Tonality in the Interpolated-Tone Pitch-Comparison Task

We examined two models that quantified the effects of tonality on accuracy and reaction time in an intervening-tone pitch-comparison task. In each of 16 task conditions (standard tone-interpolated sequence-test tone, abbreviated as S-seq-T), the S and T tones, C₄ and/or C#₄, were separated by a three-tone sequence that was a random arrangement of one of the four triads, \( {\rm{C}}_{{\rm{4Major}}} ,{\rm{C}}_{{\rm{4Minor}}} ,{\rm{C\# }}_{\rm{4}} _{{\rm{Major}}} \) or \( {\rm{C\# }}_{{\rm{4Minor}}} \) . Both models were based on the tonal hierarchy (Krumhansl, 1990a; Krumhansl & Shepard, 1979) and the key-finding algorithm (Krumhansl & Schmuckler, cited in Krumhansl, 1990a); the key- finding algorithm was used to determine the best-fitting key for the first four notes of the condition (i.e., the S-seq combination). Model 1 (S-Tone Stability) determined the stability of the S tone given that key. Model 2 (T-Tone Expectancy) determined the expectancy for the T tone given that key. Over the 16 conditions, for three groups of 12 subjects, differing by level of training, mean proportion correct discrimination ranged from .53 to .95 and increased significantly across levels of musical experience. For the musically trained subjects, both models predicted performance well but neither model was dramatically more effective than the other; the combination of both models did produce an increase in predictability. For untrained subjects, tonality, as assessed by the key-finding algorithm in either model, was not significantly correlated with performance.

Effects of tone sets and serial orders on melodic tracking: Dependence or independence?

Forty listeners, differing in level of musical experience, indicated the serial order of eight tones in 32 sequences representing all combinations of four tone sets or scales (major, minor, chromatic, and three‐semitone spacing) and eight serial orders. Responses were produced with a mouse, which controlled the vertical height (representing pitch height) of a series of eight sliders (representing the eight temporal positions in the sequence) on a computer screen. Response accuracy was higher for tone sets with wider frequency ranges, for serial orders with simpler contours, for sequences in which the tone set did not vary from trial to trial and for listeners with musical training. An interaction between tone set and serial order indicated their interdependent contributions to melodic tracking performance. This interaction was previously observed using a less refined technique [Cohen and Frankland, Canadian Acoustics (submitted)] and the results are here extended to more rapid sequences, to complementary ...

Expectancies generated by tonal contour

Expectancies generated by tonal contour were examined in a two‐part study. Listeners (N = 61) were presented with eight‐note sequences followed by a probe tone. Subjects rated the fit of the probe to the sequence in a two‐level (good or poor), forced‐choice decision. For each probe, the proportion of good‐fit replies provided a rating of its expectancy. In part 1, ascending and descending scales provided a key‐defining context [Krumhansl and Kessler, Psychol. Rev. 89, 334–368 (1982)]. Cluster analyses on individual probe‐tone profiles for all 13×2 contexts classified subjects into 12 groups: 5 were clearly identified as triadic (–n = 11), diatonic (n = 17, n = 3), or proximity (n = 3, n = 3). In part 2, 12 sequences representing degrees of higher‐order sequential expectations provided eight‐note contexts for the probe‐tone task. For the triadic and the large diatonic groups, profiles from the 12 melodies when compared against the baseline profiles indicated effects of hierarchical contour. Thus sensitivity to higher‐order contour structure influences expectations for particular tones. [Work supported by NSERC.]