Incidental learning as a function of anticipated task difficulty

Three experiments were conducted to demonstrate the effects of motivational arousal, due to anticipated task difficulty, on retention of familiar and unfamiliar incidental materials. Brehm, Wright, Solomon, Silka, and Greenberg (1983) have provided evidence that motivational arousal in immediate anticipation of a task is a nonmonotonic function of task difficulty, with difficult tasks producing a relatively higher level of motivational arousal than easy or impossible tasks. It was predicted that increased motivational arousal would facilitate retention of incidentally presented familiar materials (presumably more easily retained) and interfere with retention of incidentally presented unfamiliar materials (presumably less easily retained). In Study 1, subjects anticipating either an easy or a difficult task were exposed to familiar and unfamiliar first names. The predicted interaction between task difficulty and familiarity on recall of the first names was reliably supported. In Study 2, an impossible task condition was added. The results indicated that an effective impossible condition had not been created. In a third study designed as a procedural modification of Study 2, the predicted nonmonotonic interaction was found. Theoretical implications are discussed.These experiments were ably conducted by Ralph Young, whose help is gratefuly acknowledged. We would like to express our gratitude to Jack Brehm for invaluable suggestions concerning this research.     

Hierarchical organization as a determinant of sequential learning

Subjects learned a set of permutations of a base sequence of letters. A set of permutations either defined a hierarchical organization for the base sequence or did not. Sets that defined organizations led to more correct responses, and the pattern of interitem sequential dependencies revealed that subjects had learned the organization defined by a response set. Differences in learning could not be explained in terms of the frequency with which items occurred adjacently because that frequency was held constant for both organization-defining and organization-free response sets. The difficulty of learning a particular organization was related to the memory load induced by the organization, and those differences were more consistent with a model of sequential learning proposed by Johnson (1970) than they were with a model proposed by Estes (1972).     

Structural complexity as a determinant of serial pattern learning

A new methodology extends the study of serial pattern learning to nonhuman organisms by constructing patterns using elements that are both familiar and motivationally meaningful to animals. Two experiments examine the ability of rats to anticipate various quantities of food as measured by running times in a runway when the quantities occur in a serial order. In Experiment 1, a serial monotonic pattern (14-7-3-1-0 food pellets) produced more rapid learning and more accurate anticipation of the various quantities (“tracking”) than a serial nonmonotonic pattern (14-1-3-7-0 food pellets), particularly with respect to the final 0-pellet element. In Experiment 2, the same monotonic pattern generated faster learning and more accurate anticipation of pattern elements than a weakly monotonic pattern (14-5-5-1-0 pellets). Associative explanations including simple excitatory or inhibitory effects, temporal anticipation, reinforcement contrast, and the number and discriminability of pairwise associations are not adequate to account for the data. Rather, the formally defined structural complexity of each pattern adequately predicts its relative difficulty.     

Probability learning as a function of momentary reinforcement probability

Pigeons were trained on a probability learning task where the overall reinforcement probability was 0.50 for each response alternative but where the momentary reinforcement probability differed and depended upon the outcome of the preceding trial. In all cases, the maximum reinforcement occurred with a “win-stay, lose-shift” response pattern. When both position and color were relevant cues, the optimal response pattern was learned when the reinforcement probability for repeating the just-reinforced response was 0.80 but not when the probability was 0.65. When only color was relevant, learning occurred much more slowly, and only for subjects trained on large fixed ratio requirements.     

Short-term retention of response outcome as a determinant of serial reversal learning

The correlation between short-term retention of the outcome of the preceding response and overall learning proficiency was investigated for serial reversal learning. Pigeons were trained to asymptote on a serial reversal problem and then were presented a percentage reinforcement schedule where only some correct trials were rewarded. Nonrewarded correct trials were treated exactly as incorrect trials. The difference in error probability following the two types of correct trials was then used as a measure of short-term retention. When intertrial intervals (ITI) were short (6 sec), substantial differences occurred. When the ITI's were increased, the difference in accuracy declined regularly to no difference at an ITI of 60 sec. This demonstration of a short-term retention gradient, coupled with the finding that overall reversal learning was much better with the shorter ITI's, suggests that a primary mechanism of improvement in serial reversal learning is the acquisition of a conditional discrimination based on the outcome of the preceding response.     

Reinforcing value of physical activity as a determinant of child activity level.

This study examined whether the relative reinforcing value of physical activity (RRVPA) measured in the laboratory predicted physical activity measured in the natural environment in 32 6-11-year-old children. RRVPA correlated with physical activity level (r = .42, p < .05), and contributed to the prediction of physical activity level along with child obesity. RRVPA was related to the number of moderate to vigorous physical activity exercise bouts (r = .35, p < .05), not to the duration of those bouts. These results suggest that RRVPA is a determinant of child physical activity level, and that it may be naturally more reinforcing for children to engage in multiple, short exercise bouts than fewer, more extended bouts.     

Frequency of reinforcement as a determinant of extinction-induced aggression during errorless discrimination learning.

Seven pigeons were trained to discriminate without errors between a green keylight and a dark key. The key-pecking response was reinforced in the presence of green, and extinction was in effect in the presence of the dark key. The opportunity to attack a restrained target pigeon was present only during extinction. Both variable-interval 30-sec and fixed-ratio 1 schedules of reinforcement during the positive stimulus induced a higher rate of attack during extinction than a variable-interval 5-min schedule. The highest rate of attack during extinction occurred during the first 20 sec after the positive stimulus terminated. Hence, the withdrawal of the positive condition, rather than the consequences of the pecking response during extinction, appears to be one of the primary factors responsible for attack between pigeons during extinction. Behavioral contrast, defined as a decrease in the rate of responding when the positive stimulus was presented alone, was obtained from the four birds that displayed the lowest overall rates of attack while the three birds with the highest attack rates did not display behavioral contrast. For the birds without contrast, components of the attack response during the positive stimulus presumably competed with and reduced the rate of pecking the key, thereby recluding behavioral contrast.     

Sharing moral values: anticipated ingroup respect as a determinant of adherence to morality-based (but not competence-based) group norms

This research examines how moral values regulate the behavior of individual group members. It argues that group members behave in line with moral group norms because they anticipate receiving ingroup respect when enacting moral values that are shared by ingroup members. Data from two experimental studies offer evidence in support. In Study 1 (N = 82), morality-based (but not competence-based) ingroup norms determined whether members of a low-status group opted for individual versus collective strategies for status improvement. This effect was mediated by anticipated ingroup respect and emerged regardless of whether group norms prescribed collectivistic or individualistic behavior. These effects were replicated in Study 2 (N = 69), where no comparable effect was found as a result of moral norms communicated by a higher status outgroup. This indicates that social identity implications rather than interdependence or more generic concerns about social approval or importance of cooperation drive these effects.