The interaction between stimulus and reinforcer control on remembering.

In a symbolic matching-to-sample task, 6 pigeons obtained food by pecking a red side key when the brighter of two white lights had been presented on the center key and by pecking a green side key when the dimmer of two white lights had been presented on the center key. Across Part 1 and Parts 6 to 10, the delay between sample-stimulus presentation and the availability of the choice keys was varied between 0 s and 25 s. Across Parts 1 to 5, the delay between the emission of a correct choice and the delivery of a reinforcer was varied between 0 s and 30 s. Although increasing both types of delay decreased stimulus discriminability, lengthening the stimulus-choice delay produced a greater decrement in choice accuracy than did lengthening the choice-reinforcer delay. Additionally, the relative reinforcer rate for correct choice was varied across both types of delay. The sensitivity of behavior to the distribution of reinforcers decreased as discriminability decreased under both procedures. These data are consistent with the view, based on the generalized matching law, that sample stimuli and reinforcers interact in their control over remembering.     

Decomposing the encoding of action events: A dual conception

Two experiments are reported in which we tested the hypothesis that encoding of verbal features of subject-performed tasks or SPTs (e.g., bounce the ball, lift the spoon) is attention-demanding and effortful, whereas physical features of this memory task (e.g., color, weight) are acquired with little effort, and without deliberate encoding strategies. In Experiment 1, subjects were asked to perform a series of SPTs and were examined on recall of verbal instructions and colors of objects involved under conditions of focused or divided attention. In Experiment 2, performance of a series of SPTs was followed by recall of verbal instructions and recall of weights of objects involved. Results of both experiments indicated that recall of the verbal task component was negatively affected by requirements of dual-task performance, whereas recall of both physical task features was equally good in both encoding conditions. The obtained pattern of outcome is interpreted as supportive of the dual conception hypothesis of the nature of the encoding of action events.     

The cognitive interview: Its origins,empirical support,evaluation and practical implications

This paper provides a background to current research on the cognitive interview (CI), which is a set of cognitive retrieval techniques designed to facilitate memory search (for example, via reinstatement of contextual cues). One of the principal aims of this research is to identify and develop techniques which police investigators can themselves use. A series of studies were conducted at the University of California, Los Angeles, using police officers as interviewers and students, non-students and children as witnesses to realistic crimes. In all studies the CI elicited significantly more correct information with no apparent increase in errors or confabulations. The CI has been tested in a field study involving police officers in Florida. This paper will critically review this research, as well as more recent unpublished work including CI studies conducted in Germany and the UK. Some important modifications of the original CI procedure are described, and there is a theoretical discussion and explanation of the various components of the CI procedure. Finally, we will consider applications of the CI in clinical and organizational settings.     

On the self-perpetuating nature of stereotypes about women and men

An experiment was conducted to investigate an interpersonal process that contributes to the perpetuation of stereotyped beliefs about women and men. Male-female pairs of unacquainted individuals interacted to negotiate a division of labor on a series of work-like tasks (that differed in their sex-role connotations) in a situation that permitted control over the information that male perceivers received about the apparent sex of female targets. The perceivers' beliefs about the sex of their targets initiated a chain of events that resulted in targets providing behavioral confirmation for perceivers' beliefs about their sex. Targets believed by perceivers to be male chose tasks relatively masculine in nature, and targets believed by perceivers to be female chose tasks relatively feminine in nature. Although this behavioral confirmation effect was initially elicited as reactions to overtures made by perceivers, it persevered so that eventually targets came to initiate behaviors “appropriate” to the sex with which they had been labeled by perceivers. The specific roles of perceivers and targets in the behavioral confirmation process are examined. Implications of these findings for the perpetuation of stereotyped beliefs about the sexes are discussed.     

Semantic focus and sentence comprehension.

Reaction time to detect a phoneme target in a sentence was found to be faster when the word in which the target occurred formed part of the semantic focus of the sentence. Focus was determined by asking a question before the sentence; that part of the sentence which comprised the answer to the sentence was assumed to be focussed. This procedure made it possible to vary position of focus within the sentence while holding all acoustic aspects of the sentence itself constant. It is argued that sentence understanding is facilitated by rapid identification of focussed information. Since focussed words are usually accented, it is further argued that the active search for accented words demonstrated in previous research should be interpreted as a search for semantic focus.     

A cusp catastrophe: Hysteresis, bimodality, and inaccessibility in rabbit eyelid conditioning

Three properties of the cusp catastrophe: bimodality, inaccessibility, and hysteresis were evaluated in rabbit eyelid conditioning. Bimodality was evidenced by the fact that responding tended to occur at either very low or very high levels, and inaccessibility by the fact that intermediate levels of responding were rarely encountered. Hysteresis was demonstrated when: (a) levels of responding attained under a continuous schedule of reinforcement were largely maintained by a schedule which was too lean to promote conditioning by itself; and (b) levels of responding attained with a high intensity unconditional stimulus were largely maintained by a lower intensity unconditional stimulus which was too weak to promote conditioning in its own right. These results are consistent with the model of conditioning suggested by P. W. Frey and R. J. Sears (Psychological Review, 1978, 85, 321–340) which postulates response-mapping rules based on the cusp catastrophe.     

Modeling semantic memory: Effects of presenting semantic information in different modalities

How is semantic information from different modalities integrated and stored? If related ideas are encountered in French and English, or in pictures and sentences, is the result a single representation in memory, or two modality-dependent ones? Subjects were presented with items in different modalities, then were asked whether or not subsequently presented items were identical with the former ones. Subjects frequently accepted translations and items semantically consistent with those presented earlier as identical, although not as often as they accepted items actually seen previously. The same pattern of results was found when the items were French and English sentences, and when they were pictures and sentences. The results can be explained by the hypothesis that subjects integrate information across modalities into a single underlying semantic representation. A computer model, embodying this hypothesis, made predictions in close agreement with the data.     

Behavioral inference in young children

Three experiments are reported on behavioral inference in children of 3 to 5 years of age. In each experiment the children learned two separate sequences of behavior which they were required to put together in the final test stage in order to obtain a reward. In the first experiment moderate levels of behavioral inference were obtained, although a relatively high proportion of children failed to respond in the test phase. In the second experiment different instructions were used in the test phase, the number of nonresponders was greatly reduced and a much higher proportion of children showed behavioral inference. The third experiment obtained similar results under conditions which excluded the possibility of mediation during a memory test, which was included in the previous experiments. It was concluded that behavioral inference is found, under suitable conditions, in children as young as 3-years-old, and that reports by other investigators of failure to find such inference up to the age of about 8 were due to problems with apparatus and instructions.     

The processing of fundamental frequency in a dichotic matching task

The temporal characteristics of auditory memory were investigated using a reaction time paradigm. The study attempted to determine whether or not there are functionally distinct left and right hemisphere components of auditory memory with different capacities for the retention of nonlinguistic information, such as fundamental frequency, over the course of several seconds. The results indicated that fundamental frequency information in auditory memory remains substantially unchanged over the course of 2 sec. No evidence was found for the existence of separate left and right hemisphere components of auditory memory with different temporal characteristics. The implications of this finding for the organization of auditory memory in the brain are discussed.     

How a high working memory capacity can increase proactive interference

Previous findings suggested that a high working memory capacity (WMC) is potentially associated with a higher susceptibility to proactive interference (PI) if the latter is measured under high cognitive load. To explain such a finding, we propose to consider susceptibility to PI as a net effect of individual executive processes and the intrinsic potential for PI. With the latter, we refer to the amount of information that is activated at a given time and that has the potential to exert PI subsequently. In two studies deploying generalized linear mixed models, susceptibility to PI was modeled as the decline of performance over trials of a complex span task. The results revealed that a higher WMC was associated with a higher susceptibility to PI. Moreover, the number of stimuli recalled in one trial as a proxy variable for the intrinsic potential for PI negatively affected memory performance in the subsequent trial.