Relative allocation on concurrent schedules can depend on schedule parameters when behavioral parameters are constant

We develop a simple model of switching between the initial links of a concurrent-chain procedure. Behavior is determined by four parameters μ₁, μ₂, q₁, and q₂. The first two are the basic rates of switching from Schedule 1 and Schedule 2, respectively. The second two are the probabilities of leaving Schedule 1 and Schedule 2 after the corresponding terminal link has been completed. We show that for fixed values of these four parameters, the relative allocation on the initial links may change as a result of changes in initial-link schedules. The effect can be quite large if the switching rates are low. An implication is that relative allocation is not necessarily a good measure of behavior.     

Control of responding during stimuli that precede transitions in reinforcement frequency

Pigeons' responses were reinforced on a variant of a mixed variable-interval extinction schedule of reinforcement in which the transition to the higher reinforcement rate was signaled by a trace stimulus projected on the response key prior to the onset of the component correlated with food delivery. In the first of two experiments, the duration of the trace stimulus preceding the component correlated with food delivery was varied from 1.5 to 50.0 s and in the second experiment, the reinforcement frequency in the same component was varied from 10 to 60 reinforcers per hour. Pigeons pecked at the trace stimulus preceding the onset of the component correlated with food delivery even though responding was not reinforced in its presence and only one of the changes in reinforcement rate (i.e., from extinction to reinforcement) was signaled. The rate of pecking during the trace stimulus was a function of its duration but not of the reinforcement frequency in the following component. Higher rates generally occurred at the shorter trace-stimulus durations. Component responding following the offset of the trace stimulus was under discriminative control of the trace stimulus whether or not responding occurred in the presence of the trace stimulus.     

A longitudinal study of the marriage role expectations of college women: 1961–1984

The marriage role expectations of female university students enrolled in an introductory marriage and family course at the University of Kentucky in 1961 (N=72), 1972 (N=58), 1978 (N=115), and 1984 (N=81) were compared. The 1972 group was found to be significantly more egalitarian than the 1961 group in overall marriage role expectations and on all subscales except authority. The 1978 and 1984 groups were significantly more egalitarian than the 1961 group on overall marriage role expectations and on all seven of the subscales: authority, homemaking, child care, personal characteristics, social participation, education, and employment and support. The 1978 group was significantly more egalitarian than the 1972 group only on authority and homemaking, with no significant differences on the other five subscales or on overall role expectation score. The 1984 group was significantly more egalitarian than the 1972 group only on authority, homemaking, and child care, and was slightly (not satistically significant) more traditional on personal characteristics and social participation. There were no significant differences between the 1978 and 1984 groups on overall expectation or on any of the subscales. In fact, the 1984 group was slightly more traditional on homemaking, personal characteristics, social participation, employment and support, and overall expectations. The data from this study showed the greatest gain in egalitarian trends to be between 1961 and 1972, with a continuation of the trends at a somewhat slower rate of change between 1972 and 1978, and a discontinuation of the trend toward more egalitarian expectations between 1978 and 1984.The data were collected in February 1961, January 1972, September 1978, and September 1984. Special acknowledgement and appreciation are expressed to Jessie Ringo (retired), University of Kentucky, for making the 1961 data available for this study.     

Relative effectiveness of three stimulus variables for locating a moving sound source

A study is reported in which it is shown that observers can use at least three types of acoustic variables that indicate reliably when a moving sound source is passing: interaural temporal differences, the Doppler effect, and amplitude change. Each of these variables was presented in isolation and each was successful in indicating when a (stimulated) moving sound source passed an observer. These three variables were put into competition (with each indicating that closest passage occurred at a different time) in an effort to determine their relative importance. It was found that amplitude change dominated interaural temporal differences which, in turn, dominated the Doppler effect stimulus variable. The results are discussed in terms of two interpretations. First, it is possible that subjects based their judgements on the potential discriminability of each stimulus variable. However, because the stimuli used involved easily discriminable changes, subjects may instead have based their judgements on the independence of a stimulus variable from different environmental situation conditions. The dominance ordering obtained supports the second interpretation.     

Remembering left-right orientation of pictures

In a study of recognition memory for pictures, we observed an asymmetry in classifying test items as "same" versus "different" in left-right orientation: Identical copies of previously viewed items were classified more accurately than left-right reversals of those items. Response bias could not explain this asymmetry, and, moreover, correct "same" and "different" classifications were independently manipulable: Whereas repetition of input pictures (one vs. two presentations) affected primarily correct "same" classifications, retention interval (3 hr vs. 1 week) affected primarily correct "different" classifications. In addition, repetition but not retention interval affected judgments that previously seen pictures (both identical and reversed) were "old". These and additional findings supported a dual-process hypothesis that links "same" classifications to high familiarity, and "different" classifications to conscious sampling of images of previously viewed pictures.