Effects of repetition priming on recognition memory: testing a perceptual fluency-disfluency model

Five experiments explored the effects of immediate repetition priming on episodic recognition (the "Jacoby-Whitehouse effect") as measured with forced-choice testing. These experiments confirmed key predictions of a model adapted from D. E. Huber and R. C. O'Reilly's (2003) dynamic neural network of perception. In this model, short prime durations pre-activate primed items, enhancing perceptual fluency and familiarity, whereas long prime durations result in habituation, causing perceptual disfluency and less familiarity. Short duration primes produced a recognition preference for primed words (Experiments 1, 2, and 5), whereas long duration primes produced a preference against primed words (Experiments 3, 4, and 5). Experiment 2 found prime duration effects even when participants accurately identified short duration primes. A cued-recall task included in Experiments 3, 4, and 5 found priming effects only for recognition trials that were followed by cued-recall failure. These results suggest that priming can enhance as well as lower familiarity, without affecting recollection. Experiment 4 provided a manipulation check on this procedure through a delay manipulation that preferentially affected recognition followed by cued-recall success.     

Event-related potential correlates of interference effects on recognition memory

The question of interference (how new learning affects previously acquired knowledge and vice versa) is a central theoretical issue in episodic memory research, but very few human neuroimaging studies have addressed this question. Here, we used event-related potentials (ERPs) to test the predictions of the complementary learning systems (CLS) model regarding how list strength manipulations (strengthening some, but not all, items on a study list) affect recognition memory. Our analysis focused on the FN400 old-new effect, a hypothesized ERP correlate of familiarity-based recognition, and the parietal old-new effect, a hypothesized ERP correlate of recollection-based recognition. As is predicted by the CLS model, increasing list strength selectively reduced the ERP correlate of recollection-based discrimination, leaving the ERP correlate of familiarity-based discrimination intact. In a second experiment, we obtained converging evidence for the CLS model’s predictions, using a remember/know test: Increasing list strength reduced recollection-based discrimination but did not reduce familiarity-based discrimination.     

Effects of similarity and repetition on memory: registration without learning?

We investigated judgments of the frequency of test items (Y) that were highly similar to studied items (X) to test a prediction made by several memory models: that the judged frequency of Y should be proportional to the judged frequency of X. Whether stimuli were pictures or words, judged frequency of Y was bimodally distributed with 1 mode at zero, suggesting that frequency judgments involve a 2-stage process in which a zero judgment is made if there is a mismatch between retrieved information and the test item. Nonzero judgements, taken by themselves, were consistent with the prediction of proportionality. In 2 experiments, the percentage of zero judgments made to Y increased with repetition of X, but in 2 others the percentage did not change beyond frequency = 1. The percentage of "new" judgments in recognition memory followed this same pattern. Because the judged frequency of X increased even as X-Y discrimination showed no improvement, we characterize the result as "registration without learning."     

Evidence for the external validity of a social simulation measure of social skills

Two studies were conducted in order to obtain evidence regarding the external validity of a social simulation measure of social skills. The first study employed a contrasted group design, with the groups consisting of National Guardsmen and psychiatric patients. As predicted, trained judges rated the performances of the National Guardsmen in the simulations as more skillful and appearing less anxious than the psychiatric patients. In the second study, trained judges' ratings of psychiatric patients' performances in the simulations were found to be significantly related to ratings made by interviewers who had conducted a structured social history interview with the patients, nurses' ratings based on their observations of patients after 3 days on the psychiatric unit, a research assistant's ratings based on contact with the patient during the experiment, and finally, the subject's own self-ratings. In discussing the findings, it is hypothesized that one reason why support was found for the external validity of the simulation strategy in this study, in contrast to some previously reported studies, was the use of molar ratings in this study as opposed to the more molecular rating procedures used in those previous studies.These studies were funded in part by a research grant from the Veterans Administration.     

The Application of Latent Curve Analysis to Testing Developmental Theories in Intervention Research

The effectiveness of a prevention or intervention program has traditionally been assessed using time-specific comparisons of mean levels between the treatment and the control groups. However, many times the behavior targeted by the intervention is naturally developing over time, and the goal of the treatment is to alter this natural or normative developmental trajectory. Examining time-specific mean levels can be both limiting and potentially misleading when the behavior of interest is developing systematically over time. It is argued here that there are both theoretical and statistical advantages associated with recasting intervention treatment effects in terms of normative and altered developmental trajectories. The recently developed technique of latent curve (LC) analysis is reviewed and extended to a true experimental design setting in which subjects are randomly assigned to a treatment intervention or a control condition. LC models are applied to both artificially generated and real intervention data sets to evaluate the efficacy of an intervention program. Not only do the LC models provide a more comprehensive understanding of the treatment and control group developmental processes compared to more traditional fixed-effects models, but LC models have greater statistical power to detect a given treatment effect. Finally, the LC models are modified to allow for the computation of specific power estimates under a variety of conditions and assumptions that can provide much needed information for the planning and design of more powerful but cost-efficient intervention programs for the future.     

Use of delayed feedback and reinforcement for reducing inappropriate behaviors with chronically institutionalized mental clients

This study investigated the efficacy of: (a) delayed feedback; (b) delayed feedback and social reinforcement; or (c) delayed feedback, social reinforcement, and tangible reinforcement for reducing the rate of bizarre motoric behaviors for 2 female and 1 male chronically institutionalized mental clients. These treatments were consecutively employed with each subject, utilizing a multiple baseline across subjects experimental design. Results indicated that these subjects were able to retain and understand the feedback on both their problem and alternative behaviors but that reductions in the inappropriate motoric behaviors resulted only when tangible reinforcers were included in the treatment. Implications for further investigations and for the utility and efficiency of delayed feedback and reinforcement with chronically institutionalized adults are discussed.     

The perception of time following stress

To determine whether the relationship between the overestimation of time and anxiety or stress is a function of the anticipation of the stressful event, high and low socially anxious subjects judged a series of eight short (5-second and 7-second) intervals both prior to and following a stressful or nonstressful social interaction. The results indicated that overestimation of fixed intervals occurs following a stressful interaction, thus disconfirming the hypothesis that such overestimation is due to anticipation of the stressful event. These results are discussed with regard to a modified storage size model of time estimation.