Six musicians with relative pitch judged 13 tonal intervals in a magnitude estimation task. Stimuli were spaced in .2-semitone increments over a range of three standard musical categories ifourth, tritone, fifth,). The judged magnitude of the intervals did not increase regularly with stimulus magnitude. Rather, the psychophysical functions showed three discrete steps corresponding to the musically defined intervals. Although all six subjects had identified In-tune intervals with >95% accuracy, all were very poor at differentiating within a musical categorythey could not reliably tell "sharp" from "flat." After the experiment, they judged 63% of the stimuli to be "in tune," but in fact only 23% were musically accurate. In a subsequent labeling task, subjects produced identification functions with sharply defined boundaries between each of the three musical categories. Our results parallel those associated with the identification and scaling of speech sounds, and we interpret them as evidence for categorical perception of music.

No abstract

In the absolute judgment (AJ) paradigm, the retention interval varies from trial to trial. Moreover, the average retention interval is dependent upon the number of items judged, and is thus confounded with stimulus information. In a series of four pitch-judgment studies, the role of memory in AJ was investigated. All 5s in all conditions showed rapid forgetting and it was concluded that the well-known channel capacity results from this poor retention. Both the time and the number of intervening trials between repetitions of a given item covary in AJ, and both factors were found to produce forgetting. When memory demands were minimized in AJ, stimulus discriminability was comparable to that found in relative-judgment tasks. Feedback appeared to influence Ss' decision rule, not their sensitivity to pitch differences.2 Requests for reprints should be sent to William M-I., ,.

--Moderate aerobic exercise alone should not be considered a replacement for pharmacologic therapy in nonobese patients with mild hypertension.

The journal club is an established teaching modality in many house-staff training programs. To determine if a journal club improves house-staff reading habits, knowledge of epidemiology and biostatistics, and critical appraisal skills, we randomized 44 medical interns to receive either a journal club or a control seminar series. A test instrument developed by the Delphi method was administered before and after the interventions (mean, five journal club sessions). By self-report, 86% of the house staff in the journal club group improved their reading habits vs 0% in the control group. Knowledge scores increased more in the journal club group than in the control group, and a trend was found toward more knowledge gained as more sessions were attended. Ability to appraise critically a test article increased slightly in each group, but there was no significant difference between the groups. We conclude that a journal club is a powerful motivator of critical house-staff reading behavior and can help teach epidemiology and biostatistics to physicians-in-training.