Underwater audiogram of the California sea lion by the conditioned vocalization technique

Conditioning techniques were developed demonstrating that pure tone frequencies under water can exert nearly perfect control over the underwater click vocalizations of the California sea lion (Zalophus californianus). Conditioned vocalizations proved to be a reliable way of obtaining underwater sound detection thresholds in Zalophus at 13 different frequencies, covering a frequency range of 250 to 64,000 Hz. The audiogram generated by these threshold measurements suggests that under water, the range of maximal sensitivity for Zalophus lies between one and 28 kHz with best sensitivity at 16 kHz. Between 28 and 36 kHz there is a loss in sensitivity of 60 dB/octave. However, with relatively intense acoustic signals (> 38 dB re 1 μb underwater), Zalophus will respond to frequencies at least as high as 192 kHz. These results are compared with the underwater hearing of other marine mammals.     

Relation between intelligence and short-term memory

Several prior studies have concluded that the correlation between IQ and STM depends on differences in encoding or rehearsal strategies. Low IQ subjects use less effective strategies than high IQ subjects. One basis for these conclusions is that IQ exerts its greatest influence on the recall of early items in to-be-remembered lists, having little effect on the recall of recency items. The present study measured IQ/STM correlations in children, using probed serial recall of supraspan digit lists. The results showed the predictive power of IQ to range from a maximum in the case of recall for recency items to practically zero in the case of primacy items. Several explanations for the data are discussed, taking account of the possible roles of individual differences in rehearsal, in item persistence, and in the ability to access specified information in a short-term store.     

Associative responding versus analogical reasoning by children

Following upon work which showed that college and high school students' analogy solutions were predictable from ratings of the relatedness of the words comprising the analogy choices, this study extended those results to children's analogy solutions. Achenbach's Children's Associative Responding Test was used as the criterion to determine (1) whether analogy solutions by children were as related to word relatedness ratings as analogy solutions were in previous subject samples, (2) whether individual differences in using associative responding versus analogical reasoning processes could enhance the predictability estimates, and (3) whether associative priming can affect analogy solutions. Two correlational studies were done, one on an American and another on a Nigerian sample. A third study was an experimental manipulation of choices on analogy items on an American sample. The results suggest that the answer to questions (1) and (3) is yes, but the answer to question (2) is no.     

Survey of integrated statistical computer packages

The statistical features and general characteristics of seven integrated packages were surveyed. SPSS, DATA-TEXT, and OSIRIS emerged as the most comprehensive. OSIRIS in particular offered the most extensive multivariate analysis capabilities. The only category of statistical analysis neglected in all of the packages was nonparametric procedures related to ordinal data. Information on availability and user’s manuals is provided.     

Time-Share SKED acquisition of analog data: Blood pressure and heart rate

A computer program records, within the framework of the SKED minicomputer operating system, blood pressure and heart rate data in behavioral experiments. By repetitive (500-Hz) analog-to-digital conversions of a blood pressure waveform, the program finds and stores successive-beat systolic and diastolic pressures, and intersystolic intervals. SKED initiates and terminates blood pressure recording periods, and controls all experimental procedures. The program is currently operational, servicing four independent stations simultaneously, with sufficient computer operating time remaining to service low-priority background programs.     

Early Election Returns and the Voting Behavior of Adolescent Voters1

High school students participated in a field experiment that tested the effects of exposure to early election returns in a nonpartisan referendum. On a pretest of attitudes, students stated their preferences on the issue of the school's grading policy. One week later, just before voting, subjects in the experimental condition received information announcing the probable outcome of the election. There was a significant relationship between class achievement level and (a) likelihood of changing vote, and (b) the direction of change. Students in the brighter classes changed their votes less frequently, but when they changed their preferences they showed a greater bandwagon effect. Students in the classes of lower academic achievement changed their votes more frequently, but when they changed their preferences they showed a greater underdog effect. Differences between the more typical political election in which bandwagon and underdog effects are seldom reported and the experimental election were discussed.     

Sequential decision making: An aggregate scheduling methodology

Recent studies of sequential decision making performance have utilized optimal dynamic programming solutions as the criteria for evaluating the quality of human decisions. The difficulties incumbent in increasing the dimensionality of dynamic programming formulations effectively prohibit their extension beyond the case of a single decision variable. In the following article an alternative optimization formulation for a two-decision-variable case is presented, followed by the development of a corresponding one-decision-variable problem. In addition, related methodological problems limiting the comparability of results among previous studies are presented. It is suggested that the proposed problem formulation and its accompanying interpretation for the decision maker largely eliminate these previous methodological problems. Furthermore, the problem formulation permits quantification of the relative weights that should optimally be placed on future decision periods in the multiple-stage decision problem.