The relation between response rates and reinforcement rates in a multiple schedule

In a multiple schedule, exteroceptive stimuli change when the reinforcement schedule is changed. Each performance in a multiple schedule may be considered concurrent with other behavior. Accordingly, two variable-interval schedules of reinforcement were arranged in a multiple schedule, and a third, common variable-interval schedule was programmed concurrently with each of the first two. A quantitative statement was derived that relates as a ratio the response rates for the first two (multiple) variable-interval schedules. The value of the ratio depends on the rates of reinforcement provided by those schedules and the reinforcement rate provided by the common variable-interval schedule. The following implications of the expression were evaluated in an experiment with pigeons: (a) if the reinforcement rates for the multiple variable-interval schedules are equal, then the ratio of response rates is unity at all reinforcement rates of the common schedule; (b) if the reinforcement rates for the multiple schedules are unequal, then the ratio of response rates increases as the reinforcement rate provided by the common schedule increases; (c) the limit of the ratio is equal to the ratio of the reinforcement rates. Satisfactory confirmation was obtained for the first two implications, but the third was left in doubt.     

Measuring the Mystique

A sample of 517 freshman women at a large state university was studied in order to learn whether differences might be discerned on the basis of rank on the SVIB Masculinity-Femininity (MF) Scale. This scale divided the sample so that 30 per cent ranked high, 55 per cent average, and 15 per cent low in MF. No differences were found among the three groups in college of enrollment, reason for finishing college, most important factor in choosing an occupation, or parental expectation of educational level. On the California Psychological Inventory scores, subjects in the high MF group scored high in Dominance, Capacity for Status, Sociability, and Femininity. The average MF group, as compared with the low MF group, tested high in Good Impression and Femininity and low in Psychological Mindedness and Responsibility. The high MF group scored higher on the CPI Femininity scale than did the low MF group.     

Two-flash thresholds as a function of flash luminance and area

Two-flash thresholds were obtained from three dark-adapted Ss by means of a two-interval, temporal forced-choice technique involving foveally fixated circular targets varying in luminance and area. The Ss were instructed to report the temporal position of the longer of two pairs of I-msec flashes. a comparison pair with an interflash interval of 1 msec, and a test pair with a varying interflasn interval. The Ss were informed about the accuracy of their responses after each response. For all three Ss the results replicated a previous finding that two-flash thresholds are a negatively accelerated function of flash luminance. but the function was shown to be dependent on area. a greater threshold change occurring at smaller areas. Two-flash thresholds were also found to be a decreasing function of stimulus area. with the greatest threshold change occurring at low luminances.     

Neonates' heart rate,sucking rhythm,and sucking amplitude as a function of the sweet taste

In previous studies of human newborn sucking, the effects of increasing fluid sweetness and/or volume included a decrease in sucking rate within sucking bursts and, paradoxically, an increase in heart rate. To determine whether the heart rate increase can be attributed to increased sucking amplitude for sweeter fluids, sucking and heart rates of 20 full-term infants were studied. Half sucked for three consecutive 2-min periods, first receiving small drops of water for each suck, then no fluid, then 15% sucrose. The other half experienced the reverse order. The results for sucking and heart rate were consistent with previous studies; sucking rates within bursts were slowest for sucrose and fastest for no fluid. Heart rate was higher for sucrose than for the other fluid conditions, however, only in the water-first group. The heart rate increase was significant on statistical tests which controlled for sucking amplitude as well as for several other motor variables. Sucking amplitude itself varied with fluid sweetness in the water-first group only, in which it was highest for water. There were more total sucks, longer sucking bursts, and less time between successive bursts under the sucrose condition. Multivariate statistics helped establish a set of dependent variables—sucking rate within bursts, total number of sucks, and heart rate—which most parsimoniously describes the effects of fluid sweetness. A hedonic explanation of the response of newborns to sweetness is thus reiterated.     

Memorability, word frequency and negative recognition

Brown (1976) has provided an analysis of the effect of the memorability of an item on the confidence with which it is accepted or rejected in a test of recognition or recall. When the subject has no clear recollection of the inclusion of an item in an input list, he is assumed to evaluate its memorability in the context of the experiment before he decides whether to accept or reject it. If the judged memorability is high, the absence of a clear recollection is stronger evidence against the item than if it is low. A specific prediction is that memorable distractors in a recognition test will be more confidently rejected than non-memorable ones. This prediction was tested and confirmed in three experiments in which recognition was tested by 4-category rating. Except in Experiment I, items memorable to individual subjects were identified by administering a questionnaire. For example, in Experiment III forenames of immediate family were assumed to have high memorability. This experiment also included word frequency as a variable. Low-frequency distractors were rejected significantly more firmly than high-frequency distractors: extraction of memorable names enhanced this effect. The relationship of memorability to word frequency is discussed.     

Working with the institutionalized aged and their families: Considerations for clergy

The institutionalization of an aged parent presents unique challenges and strains to the family system. It also provides opportunities for limited intervention and support by empathic clergy. It is often difficult for middle-aged children to understand some of the strong and often sudden emotions they experience regarding their institutionalized parents, particularly as these feelings become confused with their own sense of having reached middle age. Again, opportunities present themselves for clergy to be sensitive to these confusing feelings.     

Visual attention at three months as a predictor of cognitive functioning at two years of age

The purpose of the present study was to examine the predictive power of various cognitive skills at 3 months of age in terms of later cognitive functioning. Habituating to redundant and recovering to novel stimuli at 3 months of age were found to predict later intellectual functioning at 24 months better than 3-month global intelligence or object permanence scores. In terms of information processing skills, recovery predicted later intelligence test scores better than habituation. It is suggested that changes in cognitive functioning may be viewed as a transformation of skills from one age to another rather than as a continuum of the same skills. With regard to the cognitive abilities of the 3-month-old, it is suggested that information processing may be central to cognitive functioning at this age.     

Influences of test expectations on memory-processing strategies

In a series of four experiments, recall and recognition performance were examined following recall and recognition instructions. It was found that recall-instructed subjects produced significantly better performance than recognition-instructed subjects on tests of ordered and free recall of words, particularly on the early part of the list (Experiments 1 and 2). The results of two further experiments suggest that this is mediated by differences occurring at input, and is due to increased rehearsal by subjects expecting a recall test (Experiments 3 and 4).