Process-dissociation procedure: a testable model for considering assumptions about the stochastic relation between consciously controlled and automatic processes

Multinomial Processing Tree Models

Multinomial processing tree (MPT) models have become popular in cognitive psychology in the past two decades. In contrast to general-purpose data analysis techniques, such as log-linear models or other generalized linear models, MPT models are substantively motivated stochastic models for categorical data. They are best described as tools (a) for measuring the cognitive processes that underlie human behavior in various tasks and (b) for testing the psychological assumptions on which these models are based. The present article provides a review of MPT models and their applications in psychology, focusing on recent trends and developments in the past 10 years. Our review is nontechnical in nature and primarily aims at informing readers about the scope and utility of MPT models in different branches of cognitive psychology.

Automatic retrieval in directed forgetting

In two experiments, we investigated the role of automatic retrieval in directed forgetting, using a stem completion test. In each experiment, we compared the performance of an implicit group, a process dissociation procedure (PDP) group, and a group given a speeded response task. The response times of the speeded response group on the stem completion task replicated earlier data in suggesting that this group adopted a purely automatic retrieval strategy. Experiment 1 revealed a directed-forgetting effect on automatic retrieval with the item method, but Experiment 2 revealed no directed-forgetting effect on automatic retrieval with the list method, consistent with the lack of implicit effects with the list method throughout the literature. Both experiments showed lower automatic estimates for the PDP group than for the implicit and speeded response groups, which did not differ. The data are consistent with either a selective rehearsal or an inhibition account of directed forgetting with the list method. The comparison of methods for assessing automatic retrieval is consistent with earlier evidence suggesting that subjects may adopt a generate/recognize strategy when given direct retrieval instructions.

Measuring automatic retrieval: a comparison of implicit memory, process dissociation, and speeded response procedures

Using the stem completion task, we compared estimates of automatic retrieval from an implicit memory task, the process dissociation procedure, and the speeded response procedure. Two standard manipulations were employed. In Experiment 1, a depth of processing effect was found on automatic retrieval using the speeded response procedure although this effect was substantially reduced in Experiment 2 when lexical processing was required of all words. In Experiment 3, the speeded response procedure showed an advantage of full versus divided attention at study on automatic retrieval. An implicit condition showed parallel effects in each study, suggesting that implicit stem completion may normally provide a good estimate of automatic retrieval. Also, we replicated earlier findings from the process dissociation procedure, but estimates of automatic retrieval from this procedure were consistently lower than those from the speeded response procedure, except when conscious retrieval was relatively low. We discuss several factors that may contribute to the conflicting outcomes, including the evidence for theoretical assumptions and criterial task differences between implicit and explicit tests.

A dissociation between implicit and explicit verbal memory in left temporal lobe epilepsy

PURPOSE

Temporal lobe epilepsy patients are well known to present deficits on explicit verbal memory procedures (e.g., recall, recognition). The integrity of implicit memory procedures in these patients is not established. Previous studies in this area used implicit memory measures contaminated by the effects of explicit memory.

METHODS

We examined the integrity of verbal implicit and explicit memory in left temporal lobe epilepsy (LTLE) patients and hypothesized that a clear dissociation in performance would be found with a relative preservation of implicit memory. TLE patients (n = 15) and age- and education-matched healthy normal patients (n = 15) were shown a 40-word study list, followed by a test phase requiring completion of word stems based on the study words or new/unseen words. Experimental conditions involved instructions to provide either the old (study) words or novel/nonlist words when completing the stem. Measures of automaticity and recollection provided uncontaminated indices of implicit and explicit memory, respectively.

RESULTS

The data showed a significant difference (p < 0.001) between the patients (Recollection, 0.12; SD, 0.18) and controls (0.50, SD, 0.15) on the measure of explicit memory. In contrast, the patients (Automaticity, 0.51; SD, 0.11) and controls (0.45, SD, 0.18) performed similarly on the implicit memory measure, with patient scores clearly at normative levels based on other Process Dissociation Procedure data.

CONCLUSIONS

The data demonstrate the integrity of implicit memory in LTLE patients. Finding a dissociation between the two forms of verbal memory in LTLE patients provides evidence that they rely on different neuroanatomic systems.

Die Wortstammlänge beeinflusst kontrollierte, nicht aber automatische Gedächtnisprozesse im Wortstammergänzungsparadigma

Zusammenfassung. Manche Methoden zur Erfassung verschiedener Gedächtnisprozesse setzen voraus, dass sich die Stärke der an Rekognitionsaufgaben beteiligten bewussten Erinnerungsprozesse nicht von den an Reproduktionsaufgaben beteiligten unterscheidet. Diese Kommensurabilitätsannahme scheint zwar zweifelhaft, ist bis jetzt aber empirisch nicht überprüft worden (vgl. Clark, 1999 ). Die Autoren zeigen, dass die Verlängerung von Wortstämmen in der Wortstammergänzungsaufgabe neben Rateprozessen auch bewusste Erinnerungsprozesse fördert, während automatische Gedächtnisprozesse unbeeinflusst bleiben. Dieser Befund spricht gegen die Gültigkeit der Kommensurabilitätsannahme. Die Konsequenzen des Befunds für Theorien des Gedächtnisses werden diskutiert.

On Raising the International Dissemination of German Research

Abstract. It has been proposed that German basic psychology journals should change publication language to English in order to facilitate access to research from German-speaking countries. However, to truly increase the dissemination of German research, it seems crucial to progress towards an internationalization of authors and readers. We applied bibliometric analysis to investigate the impact of the transition to English on the rate of foreign authors publishing in Zeitschrift für Experimentelle Psychologie/Experimental Psychology, as well as possible associated changes in citation patterns. There was an increase in the rate of articles published by foreign authors from 14.6 and 8.7 per cent, respectively, for the last biannual periods as German-language journal, to 52.7 per cent in the first biannual period as English-language journal. Regarding citations patterns, the clearest changes emerged for domestic authors. The results illustrate possible consequences of a transition to English as publication language, and reveal that Experimental Psychology has successfully established certain prerequisites for an increase of the international dissemination of German psychology research.

Stem-completion tasks (indirect, direct inclusion and exclusion) are differently affected by equipotent doses of lorazepam and flunitrazepam

This study was designed to explore the effects on performance in stem-completion tasks of two benzodiazepines (BZ) in equipotent doses: lorazepam, a drug that atypically disrupts perceptual priming, and flunitrazepam, a compound with standard BZ effects. The study followed a placebo-controlled, double-blind, parallel-group design. Thirty-six young and healthy subjects carried out three completion tasks at theoretical peak-plasma concentrations of drugs: (a) indirect tasks, in which the subjects were instructed to complete stems with the first word that came to mind; (b) direct inclusion tasks/cued recall, in which the participants had to try to use words seen at study as completions; and (c) direct exclusion tasks, in which words seen at study were to be avoided. The PDP was applied to the results in the inclusion and exclusion tasks, to obtain indices of explicit/controlled (C) and implicit/automatic (A) memory. The C index was lowered by both BZs and A was equivalent in all treatments, confirming the general amnestic action of BZs. However, lorazepam led to decreases in completions in the indirect and inclusion tasks, while flunitrazepam impaired performance in the exclusion task. The qualitative differences between the drugs in their effects on performance suggest that these BZs may lead to differences in response bias.

Prozessdissoziationsprozedur: Quo Vadis?

Zusammenfassung. Die Prozessdissoziationsprozedur (PDP) ist ein häufig benutztes Instrument zur Erfassung kontrollierter (“bewusster“) und automatischer (“unbewusster“) Gedächtnisprozesse. Die Forschung der letzten zehn Jahre hat jedoch eine Reihe von Problemen im von L. L. Jacoby (1991) vorgeschlagenen Zwei-Prozess-Messmodell aufgezeigt. Dies hat zur Entwicklung von alternativen Modellen geführt, die in dieser Arbeit vorgestellt, systematisiert und bewertet werden. Die Modelle unterscheiden sich auf drei Dimensionen: 1) Modelle mit diskreten vs. kontinuierlichen Prozessvariablen, 2) Modelle mit prüfbaren vs. unprüfbaren Annahmen über die Beziehungen zwischen den Prozessen und 3) Zwei-Prozess-Modelle versus Quellengedächtnismodelle. Für die Zukunft der PDP besonders bedeutsam dürfte sein, dass einige Befunde, die mit Zwei-Prozess-Modellen nur schwer vereinbar sind, plausibel erscheinen, wenn man dieselben Daten im Rahmen von Quellengedächtnismodellen analysiert.