A psychological pulse train: how young children use this cognitive framework to structure simple rhythms

Summary This paper examines the reproduction of both regular rhythms and irregular sequences by 5- and 7-year-old children, concentrating on the important role played by their organization around a pulse train. It is shown that: (a) the closer rhythms are to a regular beat the easier they are to reproduce and the greater are the improvements with age; (b) memory capacity is limited by the number of pulses around which the rhythm is organized rather than by the number of elements it contains; (c) all the children's productions contain two interval lengths that are in a ratio close to 1:2 and arranged in preferential sequences which we have called stereotypes; (d) arrhythmic sequences can only be reproduced if the intervals undergo a systematic distortion towards regularity. These results are interpreted in relation to a pulse-train hypothesis which states that on hearing a rhythm an internal clock or time base is evoked around which the rhythm is structured.     

Computer simulation with DATASIM

A general purpose program is described for generating, analyzing, and graphing simulated data for experimental, multivariate, and contingency table designs. Applications include simulating actual or hypothetical research studies, conducting Monte Carlo investigations of the consequences of violating assumptions on statistical tests, generating randomized data sets for students to analyze and interpret as homework, and performing simulations demonstrating sampling theory. Data sets may be generated that have normal or nonnormal distributions, independent or correlated observations, and equal or unequal sample sizes. Data-analysis capabilities include one-way, two-way, and three-way ANOVA with any combination of independent- and correlated-groups factors, as well as simple-effects analyses, multiple pairwise comparisons, linear contrasts, and trend analyses.     

Desktop flight simulators: Simulation fidelity and pilot performance

Improvements in the computing power and visual resolution of modern desktop computing systems, as well as advances in software technology for displaying high-speed animations, have encouraged the development of relatively sophisticated real-time flight simulators for the PC and Macintosh. We review some of the factors that determine how well such programs capture the actual experience of flight. The most significant factor limiting the quality of performance in flying a simulated aircraft is the “frame rate” problem: at low altitudes and in highly detailed visual environments, as in approaching a runway threshold during landing, the computational demands of the animation may necessitate a reduction in the number of frames displayed per second on the screen. The delayed sensory feedback that results proves to be very detrimental to sustaining smooth control of the aircraft, especially during the flare to touchdown where such control is needed most. This finding parallels the well-known effects of delayed auditory feedback (Lee, 1950) and delayed visual feedback (Smith, 1962).     

QUANTITATIVE PSYCHOPHYSICAL AND ELECTRO-PHYSIOLOGICAL DATA ON SOME ODOROUS COMPOUNDS

D rake , B., J ohansson , B., von S ydow , E. & D øving , K. B. Quantitative psychophysical and electrophysiological data on some odorous compounds. Scand.J. Psychol ., 1969, 10 , 89–96.—Magnitude estimations of odor intensity, and electrophysiological responses from frog olfactory epithelia, were obtained for dilution series of 8 odorous compounds. Comparing of data with each other and with known vapor phase concentrations showed relations between pooled psychophysical data and vapor phase concentrations, and between electrophysiological data and vapor phase concentrations, describable by power functions (exponents 0.26–0.50 and 0.18—0.39). There were also high correlations between electrophysiological data and individual as well as pooled psychophysical data. The results give an impression about the feasibility of using a biological detector in gas chromatography.     

Presence and television.

Film and a number of emerging entertainment technologies offer media consumers an illusion of nonmediation known as presence. To investigate the possibility that television can evoke presence, 65 undergraduate students were shown brief examples of rapid point‐of‐view movement from commercially available videotapes on a television with either a small screen (12 inches [30.5 cm], measured diagonally) or a large screen (46 inches [116.8 cm]). Participants' responses were measured via a questionnaire and a computer‐based recording of arousal (electrodermal activity). Viewers of both televisions reported an enjoyable sense of physical movement, excitement, involvement, and a sense of participation. Furthermore, as predicted, participants who watched the large screen television thought the movement in the scenes was faster, experienced a greater sense of physical movement, enjoyed the movement to a greater extent, found the viewing experience more exciting, and were more physiologically aroused. Practical and theoretical implications are discussed.     

School climate and ethnic‐racial identity in school: A longitudinal examination of reciprocal associations

The messages youth receive in schools about how they matter as individuals and as members of ethnic‐racial groups are influential in constructing their developing ethnic‐racial identities (ERI). However, the developing ERI students hold also have a role in shaping their experiences at school. The current study examined the longitudinal and reciprocal association between ERI (exploration and resolution) and school climate (support for cultural pluralism and teacher supportiveness) among 491 Black, Latino, and White middle school youth (M_age = 12.03, SD = 1.05, range: 11–17) in the Midwest. Cross‐lagged analyses revealed that greater perceptions of support for cultural pluralism within the school predicted greater exploration and resolution at later time points for all students. Moreover, greater exploration and resolution among White students was predictive of greater perceptions of support for cultural pluralism at the school. Higher quality teacher–student relationships predicted greater engagement in ERI exploration for all youth. The findings highlight the importance of school climate in helping shape ERI among youth attending a culturally diverse school and the role of such youth in shaping the climate at their school.     

Tempo sensitivity in auditory sequences: Evidence for a multiple-look model

Differential thresholds for tempi (with interonset intervals ranging from 100 to 1,500 msec) were measured using an adaptive 2IFC paradigm for several types of auditory sequences. In Experiment 1, the number of intervals in an isochronous sequence was varied to compare the sensitivity for single intervals withthat for sequences of two to six intervals. Mean relative just noticeable differences (JNDs) decreased as the number of intervals increased (single intervals=6%, two intervals=4%, four intervals=3.2%, six intervals=3%) and were optimal at intermediate tempi for both sequences and single intervals (as low as 1.5% in the range between 300 and 800 msec). In Experiment 2, the sensitivity for different types of irregular sequences was studied. Globally, JNDs for irregular sequences were of an intermediate level between that observed for single intervals and that observed for regular sequences. However, the closer a sequence was to regularity, the lower its relative JND. Experiment 3 demonstrated that musicians were more sensitive than nonmusicians to changes in tempo, and this was true for single intervals and for regular and irregular sequences, demonstrating the role of training on these abilities. The results are discussed in terms of possible underlying mechanisms, in particular those providing a mental representation of the mean and dispersion of successive interval durations.