Children's choice: Sensitivity to changes in reinforcer density

Two experiments were carried out in which children's sensitivity to changes in reinforcer density (number of reinforcers per session) was measured in a choice paradigm. In Experiment 1, 24 girls (ages 6, 9, and 12 years) performed on concurrent-chain schedules of reinforcement. The initial links were variable-interval 10-s schedules. One terminal link always gave three tokens after 30 s, but the parameters associated with the other were varied. Independent manipulations of reinforcer size (two tokens or four tokens) and prereinforcement delay (25 s or 65 s) led to equal changes in the relative density of tokens that could be earned on the schedules. Subjects at all ages were sensitive to changes in reinforcer density brought about by changes in reinforcer size, whereas only 3 12-year-olds showed sensitivity to the changes brought about by manipulation of prereinforcer delay. In Experiment 2, titration procedures were used to test the extent of this insensitivity to delay in 32 6- and 12-year-old children. In these procedures, a repeated choice of the large reinforcer increased the delay to its delivery, and a repeated choice of the small reinforcer reduced the delay to the delivery of the large reinforcer. Whereas 6-year-old boys and girls tended to maintain a strong preference for the large reinforcer, so increasing the delay to its delivery, 12-year-olds tended to distribute their responses to both alternatives, thus producing a stable level of delay to the large reinforcer. The results from the two experiments support the idea of two stages in the development of adaptive intertemporal choice.     

Algorithmic shaping and misbehavior in the acquisition of token deposit by rats

In two experiments, rats were trained to deposit ball bearings down a hole in the floor, using an algorithmic version of shaping. The experimenter coded responses expected to be precursors of the target response, ball bearing deposit; a computer program reinforced these responses, or not, according to an algorithm that mimicked the processes thought to occur in conventional shaping. In the first experiment, 8 of 10 rats were successfully shaped; in the second, 5 of 5 were successfully shaped, and the median number of sessions required was the same as for a control group trained using conventional shaping. In both experiments, “misbehavior,” that is, excessive handling and chewing of the ball bearings, was observed, and when the algorithmic shaping procedure was used, misbehavior could be shown to occur in spite of reduced reinforcement for the responses involved.     

Visually guided catching and tracking skills in pigeons: A preliminary analysis

Research on reaching, tracking, and catching in the pigeon has been hampered by limitations of technology. A new system was developed in which the target was a small rectangle presented on a video display terminal and the pecking response was detected with touch technology. The target moved up and down vertically with sinusoidal velocity. A coincidence between the location of the pigeon's beak and the cursor produced reinforcement. The pigeon pecked ahead and behind the target, but most pecks occurred behind the target so the dominant tracking strategy was lagging. The pigeon was adept at “catching” the target at many locations throughout the trajectory. Transfer of motor learning was tested on probe trials during which the trajectory changed from vertical to horizontal. On transfer trials the pigeons' dominant pattern of pecking immediately shifted from vertical to horizontal. The motor skill displayed by the pigeons was flexible and adaptive, suggesting that the pigeons had learned to track the cursor.     

Connectionist models of conditioning: A tutorial

Models containing networks of neuron-like units have become increasingly prominent in the study of both cognitive psychology and artificial intelligence. This article describes the basic features of connectionist models and provides an illustrative application to compound-stimulus effects in respondent conditioning. Connectionist models designed specifically for operant conditioning are not yet widely available, but some current learning algorithms for machine learning indicate that such models are feasible. Conversely, designers for machine learning appear to have recognized the value of behavioral principles in producing adaptive behavior in their creations.     

Inferring Emotions From Multiple Cues: Revealing Age-Related Differences in "How" Without Differences in "Can"

This study examined differences in children's use of social cues to make emotional inferences. Children ages 4, 5, and 8 years were presented with stimuli that depicted another child in affectively congruous and affectively incongruous expression/situation combinations. The intensity of positive and negative facial expressions was varied across situations. Subjects judged the target's feelings and selected among the alternative facial expressions or situations the one they had just seen. No significant age-related differences were found in the extent to which children registered and used both the expressive and situational information when making emotional inferences. The main experimental measure asked children to explain their judgments. In explaining their judgments, subjects' rationales indicated that they: (a) used both the situational and expressive cues; and (b) were sensitive to congruous versus incongruous cues, and even to mild versus strong incongruous cues. Children's rationales also reflected a sensitivity to expressive and situational negativity. For each age group, the rationales were more elaborate when the cues were problematic. Characteristic strategies, however, were also found for each age group. These distinct strategies may reflect social-life changes in children's social "theories" of emotion.     

Continuities and Discontinuities in Self-Regulatory and Self-Evaluative Processes: A Developmental Theory Relating Self and Affect

This article presents a developmental theory of the relation between self and affect. Self-discrepancy theory (Higgins, 1987) is used as a framework for considering developmental and individual differences in children's self-concepts, self-regulation, and self-evaluation. Developmental changes in children's representational capacities are described that produce developmental shifts in this self-system. Different modes of caretaker-child interaction are distinguished in terms of how features of the interaction impact psychologically on the child. The implications of these differences for children's self-system and emotional/behavioral vulnerabilities are discussed. The development of self-regulatory and self-evaluative processes are distinguished with respect to developmental continuities and discontinuities. Patterns of sex differences in socialization, conduct, and emotional problems are described to exemplify the need for distinguishing these two processes developmentally. The question is raised whether children can be socialized to maximize the positive conduct valued by society and the positive self-regard valued by individuals.     

Probability of relapse after recovery from an episode of depression

Examined relapse rates in those individuals who have experienced an episode of unipolar depression as a function of the number of previous episodes, gender, age at onset of the episode (less than 40 vs. greater than 40), time since a previous episode, and depression level at time of interview. From of 6,742 participants, 2,046 were interviewed; of these, 1,130 had at least one, 513 reported a second and 173 reported a third episode. The probability for relapse was positively related to number of previous episodes, being female, depression level at time of interview, but not to age at onset (less than 40 vs. greater than 40). Women were also more likely to have more severe episodes. Participants with elevated depression symptoms reported a greater number of previous episodes. Following the first episode, there was a decline in hazard rate for men but not women; following the second episode, there was no change in vulnerability for men; for women, the results were ambiguous.     

A Test of Bipolar and Androgyny Perspectives of Masculinity and Femininity: The Effect of Participation in an Outward Bound Program

ABSTRACT The purposes of the present investigation are to examine theoretical issues in androgyny theory by testing the effect of participation in the Outward Bound program on measures of masculinity (M) and femininity (F) Bipolar conceptualizations of MF posit that an increase in either M or F must lead to a decrease in the other, whereas androgyny theory posits M and F to be independent constructs Consistent with a priori predictions based on the nature of the Outward Bound program, participation substantially enhanced M and had a small positive effect on F The results were reasonably consistent for male and female participants, for single-sex and mixed-sex groups, and across responses to three different MF measures Results support the androgyny interpretation of MF and demonstrate the effectiveness of the Outward Bound program in changing MF The results contradict the bipolar perspective that an increase in M must be accompanied by a decrease in F     

Metamemory, memory performance, and causal attributions in gifted and average children

Fifth and seventh graders who had been teacher-selected as high- or average-achieving were tested on the Kognitiver F?higkeits Test, a standardized test of intellectual abilities for German children. Children who met preestablished criteria as gifted or average were then tested on measures of metacognitive knowledge, attributional beliefs, and performance on a sort recall task. Results indicated ability-related differences in metamemory and sort recall performances. Responses to the attributional questionnaires also varied systematically according to ability: gifted children were more likely to attribute their academic successes to high ability than were average children, who showed a stronger belief in the importance of effort in determining task outcomes. Causal modeling analyses illustrated the strength of metacognitive knowledge as a performance predictor on the memory task, especially for average children. Results are discussed in terms of the value of metacognitive theory in understanding individual performance differences.