Perception of acoustic iterance: Pitch and infrapitch

Detection of acoustic repetition is considered as a continuum extending from .5 through 16,000 Hz. Perceptual characteristics are mapped for the entire range, using repeated randomly derived waveforms (segments from Gaussian noise) as model stimuli. Contributions from temporal domain (neural periodicity) analysis extend from about .5 through 5,000 Hz and from frequency domain (neural place) analysis from roughly 50 through 16,000 Hz. Within the range of overlapping analyses (50 through 5,000 Hz), it is difficult to separate the effects of temporal cues from place cues. However, by using low-frequency acoustic iteration from 1 through 16 Hz, we were able to study temporal analysis in the absence of place cues to repetition. New perceptual phenomena are reported for the “infrapitch” produced by “infratones,” some of which are analogous to phenomena observed for the pitch produced by tones. It appears useful for theory to consider pitch and infrapitch as a single topic: the perception of acoustic iterance.     

A factorization procedure for finite algebras

A procedure is developed for decomposing any finite algebra into a minimal set of maximally independent simple homomorphic images, or factors, of the algebra. The definition of admissible sets of factors is made in relation to the congruence lattice of the algebra, and generalises the notion of an irredundant reduction in a modular lattice. An algorithm for determining all possible sets of factors of a given finite algebra is derived and an index for measuring the degree of independence of factors is defined. Applications of the technique to finite algebraic models within the social psychological domain are presented and include factorizations for certain semigroups of binary relations and for a class of finite semilattices.     

Sex differences in conformity: Instrumental or communal response?

Male and female introductory psychology students (N=88) were asked to read a clinical case history and the opinion consensus of either (a) their peers, (b) advanced psychology students, or (c) Ph.D. clinical psychologists that the patient should be hospitalized for at least 90 days (an extreme treatment). Subjects then indicated on a scale of 10 to 90 days, the length of hospitalization they thought best. In a significant interaction effect (sex of subject × expertise of source) males were least influenced by the opinions of their peers and increasingly influenced as the source became more expert. Females, however, seemed most influenced by their peer group, recommending longest hospitalization terms in that condition. Results are interpreted in terms of sex-role identification and the emergence of an instrumental (task) or communal set.     

Permanence and change in memory II. Reproduction of words in sentences

Abstract.— A retroactive interference paradigm was employed for studying qualitative memory changes. Sentences, containing an ambiguous word that was defined differently by succeeding words, were used as stimulus material. Such retroactive definitions of meaning were found to lead to qualitative changes in reproduction. It is suggested that the issue of permanence and change in memory may be related to the choice of lists of independent items or contextual units as stimulus material. A contextual theory of memory, implying the conception of memory in a stream, is advocated.     

Quantitative judgments of color: The square root rule

Judgments of the appearance of colored papers blended with different proportions of white were obtained using a rotating color mixer. Responses consisted of a mark on a line labeled with the appropriate color name at one end and “white” at the other. Prior context was avoided by obtaining only single judgments. It was found for all six color displays that distance from the colored end of the line was proportional to the square root of the proportion of white present in the mixture. This square root relation is in keeping with the physical correlate theory and with other experiments involving gray papers, point sources, and luminous fields.