Judging similarity among strings described by hierarchical trees

The paper compares the tree-theoretical model of similarity judgement (in which the similarity between two objects is a function of the distance between them in a conceptual tree) with an averaging model of similarity judgement that is drawn jointly from information integration theory and from current research indicating the prevalence of anchoring and adjustment mechanisms in judgement. Results of an experiment are presented that suggest that even when subjects organize conceptual material as a hierarchical tree, judgments of similarity among the objects are better accounted for by an averaging mechanism than by distances in the tree. These data are discussed in terms of the differences between the representation in which knowledge is encoded and the processes that operate on the represented information.     

Asymmetry of perceived key movement in chorale sequences: Converging evidence from a probe-tone analysis

Summary In a probe-tone experiment, two groups of listeners — one trained, the other untrained, in traditional music theory — rated the goodness of fit of each of the 12 notes of the chromatic scale to four-voice harmonic sequences. Sequences were 12 simplified excerpts from Bach chorales, 4 nonmodulating, and 8 modulating. Modulations occurred either one or two steps in either the clockwise or the counterclockwise direction on the cycle of fifths. A consistent pattern of probe-tone ratings was obtained for each sequence, with no significant differences between listener groups. Two methods of analysis (Fourier analysis and regression analysis) revealed a directional asymmetry in the perceived key movement conveyed by modulating sequences. For a given modulation distance, modulations in the counterclockwise direction effected a clearer shift in tonal organization toward the final key than did clockwise modulations. The nature of the directional asymmetry was consistent with results reported for identification and rating of key change in the sequences (Thompson & Cuddy, 1989 a). Further, according to the multiple-regression analysis, probe-tone ratings did not merely reflect the distribution of tones in the sequence. Rather, ratings were sensitive to the temporal structure of the tonal organization in the sequence.     

Responsiveness of Western adults to pitch-distributional information in melodic sequences

Responsiveness of musically trained and untrained adults to pitch-distributional information in melodic contexts was assessed. In Experiment 1, melodic contexts were pure-tone sequences, generated from either a diatonic or one of four nondiatonic tonesets, in which pitch-distributional information was manipulated by variation of the relative frequency of occurrence of tones from the toneset. Both the assignment of relative frequency of occurrence to tones and the construction of the (fixed) temporal order of tones within the sequences contravened the conventions of western tonal music. A probe-tone technique was employed. Each presentation of a sequence was followed by a probe tone, one of the 12 chromatic notes within the octave. Listeners rated the goodness of musical fit of the probe tone to the sequence. Probe-tone ratings were significantly related to frequency of occurrence of the probe tone in the sequence for both trained and untrained listeners. In addition, probe-tone ratings decreased as the pitch distance between the probe tone and the final tone of the sequence increased. For musically trained listeners, probe-tone ratings for diatonic sequences tended also to reflect the influence of an internalized tonal schema. Experiment 2 demonstrated that the temporal location of tones in the sequences could not alone account for the effect of frequency of occurrence in Experiment 1. Experiment 3 tested musically untrained listeners under the conditions of Experiment 1, with the exception that the temporal order of tones in each sequence was randomized across trials. The effect of frequency of occurrence found in Experiment 1 was replicated and strengthened.     

Recognition memory for pitch of fixed and roving stimulus tones

The method of delayed comparison was used to measure pitch memory under two conditions of presentation, either the same standard tone on every trial (fixed S) or one of four equally likely standard tones (roving S), six durations of interference interval ranging from 0.0 to 4.0 sec, and two types of interference interval, either blank or filled with a pure tone. Listeners were instructed not to rehearse the S tone during the interference interval. For both fixed-S and roving-S conditions, accuracy of performance, as measured by area under the ROC curve, declined as interval duration increased and declined more rapidly following an interference-filled than following a blank interval. In general, forgetting proceeded at a slower rate under fixed-S conditions than under roving-S conditions. A second experiment showed that very little forgetting is obtained over 4 sec for roving-S conditions if instructions permit rehearsal of the S tone and suggests that the conclusions from the first experiment be restricted to nonrehearsal instructional conditions.     

Recognition of transposed melodic sequences

Accuracy of recognition for short (three-note) transposed melodic sequences was measured and compared with accuracy predicted by three models of recognition each of which described a different degree of abstraction and synthesis of the musical intervals contained in the sequence. For subjects with musical training, recognition was best described by a model that assumed abstraction and synthesis of the musical intervals between both adjacent and non-adjacent tones of the sequence. For subjects without musical training, recognition was much less accurate but there was some evidence that intervals between adjacent tones were abstracted. Of major theoretical interest, however, was the finding that none of the models provided a comprehensive account of the data. Not merely the size of the intervals contained in a sequence determines accuracy of recognition of the sequence, but also the order or configuration of the intervals. It is suggested that particular interval configurations facilitate the abstraction of tonal structure.     

An assessment of teratology training provided by masters level genetic counseling programs

The increasing demand in the clinical genetics setting for information about teratogen exposures has created a need for genetic counselors to have the capabilities to appropriately address patient concerns. In order to assess how training in teratogen counseling is currently being conducted, the GLaRGG Teratogen Subcommittee surveyed all 17 genetic counseling training programs in North America in September 1993. Information was obtained from training programs about coursework, resources, and clinical training. In addition, each training program was asked to provide information about how their teratogen training needs could better be met. While all programs responded that some information in their coursework applicable to teratogen counseling was provided, there was wide variation in the amount of time devoted to this topic. The programs also greatly differed in the provision of clinical training in teratogen counseling. For both coursework and clinical work, genetic counselors were the main trainers in teratogen counseling. In spite of this, fewer than 25% of training programs have a defined teratogen clinical rotation. Data from the survey are discussed and recommendations presented.     

Do conjunction errors in auditory recognition imply feature migration?

It has recently been proposed that the feature values (e.g., pitch, duration, etc.) of tones are processed in separate perceptual channels and are later reintegrated to form the experience of a unitary percept. Patterns of errors in recognizing combinations of auditory features have been taken as failures of, and thus evidence for, an auditory feature-integration process. We outline an alternative interpretation of these effects based on similarity structure of the stimuli.