Memory without organization: Properties of a model with random storage and undirected retrieval

A very simple spatial model of memory storage and retrieval is described, analyzed, and discussed. The postulated memory is without organization in the sense that neither the place of storage nor the order of search during retrieval is influenced by the nature of the information being stored or retrieved. The memory consists of a three-dimensional space containing a large number of homogeneously distributed loci at which data may be stored. Data received near each other in time are stored at nearby locations. Access is by an undirected expanding-sphere search. The model exhibits a wide variety of quantitatively and qualitatively humanlike behavior with respect to both standard learning and forgetting paradigms and with respect to frequency effects and other phenomena in word processing.     

The effect of Pavlovian stimuli on the acquisition of a new response

Three experiments explored the effects of response dependent stimuli which have had different types of contingent relationships with positive reinforcement. Results showed consistent differences in the effects of response dependent appetitive Pavlovian CS + s, CS ? s, and truly random control (TRC) stimuli on the acquisition of a new response. These differences were shown in both a free operant and a discrete-trial learning situation. Appetitive Pavlovian CS?s consistently produced lower levels of responding than did TRC stimuli, even in an experimental situation free of possible contrast effects. The results of these experiments extended a contingency analysis of acquired associations to appetitive conditioning and provided a clear demonstration of a conditioned reinforcement effect against a variety of control procedures.     

An analysis of behavior in the hobbits-orcs problem

Young adults solved a problem in which hobbits and orcs had to be transported across a river. In Expt I, a Part-Whole group of subjects solved the problem starting at a different state in the middle and then were given the entire problem. Comparison with a Control group indicated that the initial practice of the Part-Whole group did not facilitate their later performance on the same problem segment, but did facilitate performance in a different portion of the problem. In Expt II, some subjects were given feedback halfway through the problem that they were on the right track. Results gave some support to the notion that a possible difficulty in the problem is the subject's belief that he must have entered a blind alley in the search space. However, other difficulties were also involved. Inferences from several different dependent performance variables, the transfer results, and subjects' comments consistently suggested that subjects solving this problem needed to undergo a number of cognitive changes (3–4) that was smaller than the minimum number of external moves required to solve the problem (11).     

Quasireinforcement: Control of behavior by second-order interval schedules

Pigeons were trained on a variable-interval 66-sec schedule of reinforcement that was segmented into either fixed- or variable-interval 10-sec components. Three-second access to food followed some components according to the overall VI 66-sec schedule, but 3-sec periods of nonreinforcement followed the other components. With both FI 10-sec and VI 10-sec segments, overall response rates were generally higher when the completion of unreinforced segments was signaled by a red key (never paired with food) than when it was unsignaled. Response rates during the red-key periods dropped to zero. Brief presentations of the red key engendered the distinctive (FI or VI) patterns of responding which would be expected if each segment were followed by food. These data demonstrate behavioral control by brief stimuli which are not paired with primary reinforcement and show that such control may develop even when the sequences of behavior required to produce food or brief stimuli are variable in duration.     

Comparison of two oddity tasks with pigeons

Two oddity tasks were compared: one in which the odd stimulus could appear on any of the three stimulus positions (true oddity); the other in which the odd stimulus could only appear on the left or right but not the center (oddity-from-sample). A stimulus-configuration theory predicts faster oddity-from-sample learning, whereas a theory, based on shifts in observing over trials, predicts faster learning of true oddity. Pigeons learned the oddity-from-sample task faster, thus supporting configuration theory. Performance on the oddity-from-sample task but not the true oddity task was facilitated by increasing the number of responses required to terminate a trial. When the oddity-from-sample pigeons were shifted to the true oddity task, no evidence of positive transfer was found, suggesting that a configuration theory alone is insufficient to explain differences in acquisition. Only when a correction procedure was introduced did the true oddity pigeons perform above 50%.     

The effect of instructions to organize for good and poor learners

Two studies are reported which investigate the possibility that instructing individuals to organize their recall will differentially facilitate the performance of “fast” and “slow” learners (defined in terms of performance on a pretest). Experiment I utilized alphabetic organization in the free-recall learning of a list of unrelated words; Experiment II used a categorized word list under similar conditions. In each study, half of the individuals in each ability group received instructions, prior to the first of six learning trials, that contained information about the respective nature of organization present in the list and encouragement to use this type of organization in learning the list. In Experiment I, instructions to use alphabetic organization facilitated the performance of both ability groups to about the same extent. In Experiment II, instructions to use categorical organization in learning resulted in a substantial facilitation of performance for “slow” learners and a slight decrement in performance for “fast” learners. The results from the two studies are discussed in terms of sources of individual differences in learning.     

The role of control processes and structural constraints in models of memory and social judgment

Six experiments examining a recent model of memory and social judgment are reported. In particular, the theoretical concept of a Work Space is examined in terms of both its structural properties and a variety of control processes that govern its operation. In Experiment 1, subjects were given information about a stimulus person and told that they would later be asked to recall it as well as possible. The length of the actual delay before recall and the length of the anticipated delay were factorially varied. Under short delay conditions, subjects anticipating a short delay recalled more of the information than those anticipating a long delay. The reverse was true under actual long delay conditions. Other results suggest that the anticipated length of the delay has an effect on processes related to both encoding and storage/retrieval. Experiments 2 and 3 demonstrate that, relative to no delay conditions, a long actual delay or a long anticipated delay produces polarization in social judgments. Both of these results are predicted by the model. Experiments 4–6 examine the effect of interpolated cognitive activity on memory and social judgment. As predicted by the model, relatively complicated cognitive activity leads to lower levels of recall and a greater polarization of judgments than less complicated intervening cognitive activity. It is argued that all of these results can be accounted for by the concept of a Work Space as a temporary repository devoted to the current information processing activities of the subject. It is thought that such a concept must be kept theoretically distinct from long-term memory. Implications of the results for models of memory and social judgment are discussed.     

A typology of mid-life career changers

This study examines the motivations for and the outcomes of mid-life career change among a sample of 73 men who had left professional and managerial careers between the ages of 34 and 54. Measures of personal desire for change and external pressure to leave were dichotomized to produce a typology of career changers: Drift-outs, Opt-outs, Force-outs, and Bow-outs. The four types of changers were found to differ on a number of variables, including: amount of education completed, additional schooling undertaken to change careers, time taken to make the change, radicalness of change, and the importance of personal values in deciding to leave their former careers. Overall, respondents were found to be highly satisfied with their career redirection.     

Kindergartners' reasoning in simple problems

Three experiments assessed kindergartners' performance on simple conceptlike problems in which the correct solution could be selected from a specified set of possible solutions by using the information provided by a single positive or negative stimulus. For both positive and negative instances, performance was accurate when all stimulus attributes were logically informative, but performance was impaired when stimuli included an additional, logically uninformative, attribute. This impairment could not be attributed simply to increased information processing load. Children seemed to realize that uninformative attributes provided no basis for choosing among possible solutions, but did not seem to understand how to interpret this fact in order to make appropriate inferences. It was suggested that children's inferential deficit may result from a failure to understand how the relationships that exist between two sets of information are coordinated with the relationships that exist among the parts of each set. Implications were discussed for kindergartners' performance on more complex concept problems.