Reinforcement rate and force proportional reinforcement

The research examines the consequences of making two reinforcement contingencies simultaneously available for the same bar-pressing response. Specifically, two experiments are described which concern the effects of reinforcement rate upon force proportional reinforcement (FPR). In Experiment 1, reinforcement rate was constrained by combining differential reinforcement of low rate with a force-proportional reinforcement contingency. The group of rats exposed to this regimen eventually showed a significant increase in response force compared to control groups. Experimental vs control response rates were not significantly different. In Experiment 2, reinforcement rate was affected through the expedient of relating the probability of obtaining a single pellet to the response force. The group for which the probability-force relationship was discontinuous came to exert higher forces than either a group for which the relationship was fairly continuous or an ordinary variable ratio control group. Response rate was significantly higher for the control group.     

Development of visual,name, and conceptual memory codes for pictures

In a recognition memory task, 4-, 8-, and 16-year-olds quickly decided whether or not probe pictures were identical to remembered study pictures. Conceptual and visual, but not acoustic, confusion were evidenced by the longer latencies when probes were visually or conceptually related to study items than when unrelated or rhyming. Visual confusion arose only when seven or fewer pictures intervened between study and probe items, and the kinds of visual similarity that produced confusion changed with age. Conceptual confusion resulted only at longer lags, and the same kinds of conceptual relationships produced confusion at all ages. These findings are discussed in terms of the development of visual and semantic encoding processes.     

Cognitive processes in person perception: Retrieval of personality trait and behavioral information

The processes people use to retrieve information about another person's behavior and personality were investigated. Subjects viewed different lengths of segments from videotaped sequences of actors' behaviors. The subjects' reaction times to questions about the actors' behaviors and about personality traits were both an increasing function of the duration of the segment about which the questions were asked. These data were taken as an indication that people do, in general, carefully examine the contents of their memories in order to respond to questions about another person. In particular, an exhaustive serial search model was supported. Additional data and analyses demonstrated that relatively abstract trait terms usually were answered on the basis of the exhaustive search, while relatively specific trait terms were not. A two-stage process model was proposed to explain the differences in the results for the two types of trait terms.     

Knowledge organization and skill differences in computer programmers

Like experts in other fields, expert computer programmers can recall at a glance far more information relevant to their field than novices can. One explanation for this difference is that experts not only have more information, they have it better organized into meaningful chunks. In this paper, we infer the details of individual programmers' chunks of key programming concepts using the Reitman—Rueter (Cognitive Psychology, 1980, 12(4), 554–581.) technique for inferring tree structures from recall orders. Differences in organizations accompany skill-level differences. Beginner programmers' organizations show a rich variety of common-language associations to these programming concepts; Intermediate programmers show mixtures of programming and common-language associations; and Experts show remarkably similar, but not identical, organizations based clearly on programming knowledge.     

Measurement and interpretation of situational and dispositional attributions

Four problems with the measurement of situational and dispositional causality are reviewed. These are: the assumption that dispositional and situational causality are inversely linked; the diversity of the causes considered within the situational and dispositional categories; the difficulties of differentiating between causes internal and external to the actor; and the low convergent validity of various closed-ended attribution measures. A study reaffirms the lack of convergence among closed-ended measures and between closed and open-ended measures as well. In a second study, subjects' ratings of closed-ended attributions are taken as indicators that a freely chosen to not freely chosen dimension may better represent subjects' attributional thought than the internal/external dimension does. Open-ended data from the convergence study are recoded using this scheme and achieve significantly better convergence with closed-ended data. The implications of this redefinition for solving the various measurement problems are discussed.     

Developmental change in early representational intelligence: Evidence from spatial classification strategies and related verbal expressions

The procedures 1- to 3-year-old children use to group simple sets of objects are analyzed in an investigation of cognitive change in early representational intelligence. Forty children spontaneously manipulated two-class arrays and participated in two experimental probes of object grouping. Children 1 to 2 years of age group classes by looking for one kind of thing at a time. Consistent with this, they verbally mark single classes. Children from $\text{2}\text{1}\text{2}$ to 3 years old employ spatial grouping procedures that require simultaneous consideration of two classes, and they refer to relations between classes. Advances made during the second year are consistent with other initial signs of representational-symbolic intelligence. The advances in the third year are unaccounted for by traditional cognitive-developmental theories, but they are congruent with late-emerging patterns in natural representational systems such as language, suggesting the presence of broad changes in mental organization shortly after the onset of representational intelligence.     

Peer-peer interaction among infants and toddlers with extensive daycare experience

Peer-peer interaction among 10–21- and 24–30-month-olds with extensive daycare experience was studied. Thirteen pairs of familiar agemates were formed, and each dyad was observed in a playpen with toys at their daycare center. Adult preparation and various constraints to peer-peer interaction were minimized. The nine behavioral measures included nonsocial, marginally social, and social play categories. The results revealed equivalent amounts of nonsocial behavior for both age groups, and marginally social behavior was not the dominant play activity at either age. Compared with the younger group, the older children engaged in less marginally social activity, more positive social behavior overall, and more sustained sociable interchanges. Neither age group had high levels of antisocial behavior, but the younger children tended to display more than the older. Support was found for the view that marginally social activity functions as a bridge from nonsocial to social behavior.