In defense of functional independence: Violations of assumptions underlying the process-dissociation procedure?

T. Curran and D. L. Hintzman (see record 1995-42725-001) claim to have shown that the independence assumption underlying the process-dissociation procedure (L. L. Jacoby, see record 1992-07943-001) is not justified. They argued that correlations between processes at the level of items can result in an underestimation of automatic processes large enough to produce artifactual dissociations between process estimates. In contrast, the authors show that the effects of extremely high correlations at the level of items are likely to be trivial, and not differential across conditions. Curran and Hintzman's dissociations probably reflect violations of boundary conditions for use of the process-dissociation procedure, rather than violations of independence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ordinal Process Dissociation and the Measurement of Automatic and Controlled Processes.

The process-dissociation equations (L. Jacoby, 1991) have been applied to results from inclusion and exclusion tasks to derive quantitative estimates of the influence of controlled and automatic processes on memory. This research has provoked controversies (e.g., T. Curran & D. Hintzman, 1995) regarding the validity of specific assumptions underlying the process-dissociation equations. In this article, the author explores the conclusions one can draw about the ordinal relations between automatic and controlled processes across experimental conditions from results in the inclusion and exclusion tasks. Given relatively neutral assumptions, this article presents and proves 6 theorems that allow investigators to draw conclusions about the ordinal relations between automatic and/or controlled processes across experimental conditions. An illustrative example is presented, and the current approach is compared with the original process-dissociation framework. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

More than one way to violate independence: Reply to Jacoby and Shrout (1997).

T. Curran and D. L. Hintzman's (see record 84-21403) analysis of nonindependence in process dissociation did not confound aggregation bias with process dependence, as L. L. Jacoby and P. E. Shrout (see record 84-21425) claimed. This reply shows that the numerical example presented as undermining Curran and Hintzman's arguments is entirely consistent with their equations and reinforces their analysis of the effect of subject–item variance in inducing aggregation bias. Process dependence and aggregation bias can be understood as distinct sources of nonindependence in data. However, process-dissociation estimates are affected by both. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling the Effects of Repetitions, Similarity, and Normative Word Frequency on Old-New Recognition and Judgments of Frequency.

Judgments of frequency for targets (old items) and foils (similar; dissimilar) steadily increase as the number of times a target is studied increases, but discrimination of targets from similar foils does not steadily improve, a phenomenon termed registration without learning (D. L. Hintzman & T. Curran, 1995; D. L. Hintzman, T. Curran, & B. Oppy, 1992). The present experiment explores this phenomenon with words of differing normative word frequency. The retrieving-effectively-from-memory model (REM; R. M. Shifrrin & M. Steyvers, 1997, 1998) predicts that low-frequency words will be better recognized than high-frequency words because low-frequency words have more distinctive memory representations. A corollary of this assumption predicts that the typical recognition word-frequency effect will be disrupted when similar foils are tested. These predictions were confirmed, but to fit both the recognition and the judgment-of-frequency data, the authors used a "dual-process" extension of the REM model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the logic of testing the independence assumption in the process-dissociation procedure

The process-dissociation procedure is designed to provide quantitative estimates of the influence of explicit and implicit memory in a variety of tasks. The procedure relies on the assumption that these two forms of memory produce independent influences on performance. Prior investigators have attempted to test this assumption by determining whether the parameter representing the influence of implicit memory (denoted A) is constant across experimental conditions. I argue that the constancy of A cannot provide an appropriate test of the independence assumption, because (1) the prediction of constancy can be generated without the assumption of independence, obviating the need to posit independence; and (2) the constancy of A does not necessarily imply independence, even if one assumes that a dependency hypothesis, supplemented by ancillary assumptions (Curran & Hintzman, 1995), predicts differences in A. I close by emphasizing that we can test the independence assumption by using standard procedures that compare the fit of a model that assumes independence with the fit of a model that assumes dependence.     

Consequences and causes of correlations in process dissociation.

In T. Curran and D. L. Hintzman's (see record 1995-42725-001) article, the authors explained how violations of the independence assumption could affect the process-dissociation procedure and presented evidence that was consistent with the hypothesized effects of independence violations. L. L. Jacoby, I. M. Begg, and J. R Toth (see record 84-21424) argued that independence violations could not account for Curran and Hintzman's results. In this reply, the current authors demonstrate that even moderate correlations between recollective and automatic word-stem completion can cause paradoxical dissociations like those the authors previously reported, and they explain how Jacoby et al came to their contrary conclusion. Second, the authors argue that discussion by Jacoby et al of process-dissociation "boundary conditions" is consistent with Curran and Hintzman's original claims. Finally, the authors discuss problems with the evidence for independence that Jacoby et al presented in their Table 1, including their questionable criteria for excluding experiments from the table and the fact that they did not consider statistical power. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forgetting rates are comparable in conscious and automatic memory: A process-dissociation study.

The forgetting functions for conscious and automatic components of memory were evaluated in 2 stem completion experiments with retention delays ranging from 1 to 70 min. L. L. Jacoby's (1991) process-dissociation equations were used to estimate conscious and unconscious memory. Two guessing-elaborated multinomial models of process dissociation as well as a generate-source model were also evaluated. Different levels of processing produced differing levels of initial availability. However, the form and rate of forgetting did not differ for conscious and automatic memory estimates under any model. The results are consistent qualitatively and quantitatively with findings (D. M. McBride & B. A. Dosher, 1997) on forgetting in implicit stem completion and explicit stem-cued recall. Either conscious and automatic memory reflect different systems with very similar forgetting characteristics, or they reflect different types of information in a common memory store. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for a generate–recognize model of episodic influences on word-stem completion.

Application of the process-dissociation procedure has shown that conceptual encoding episodes do not lead to automatic influences of memory on purportedly data-driven indirect tests of memory. Using 2 variants of the process-dissociation procedure with the word-stem completion task, the procedure is shown to underestimate automatic influences of memory when prior encoding includes a conceptual component. The underestimation is attributed to an awareness of past occurrence that is particularly likely with conceptually encoded items. This effect occurs even in the absence of the signature of a generate-recognize strategy and suggests that prior conceptual encoding may contribute to automatic influences of memory in stem completion. A multinomial generate-recognize model is presented that fits these results and previous results typically taken as support for the assumption that controlled and automatic influences of memory are independent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A meta-analytic investigation of the structure of posttraumatic stress disorder symptoms.

Converging lines of evidence have called into question the validity of conceptualizations of posttraumatic stress disorder (PTSD) based on the Diagnostic and Statistical Manual of Mental Disorders (DSM; American Psychiatric Association, 2000) and suggested alternative structural models of PTSD symptomatology. We conducted a meta-analysis of 40 PTSD studies (N = 14,827 participants across studies) that used a DSM-based measure to assess PTSD severity. We aggregated correlation matrices across studies and then applied confirmatory factor analysis to the aggregated matrices to test the fit of competing models of PTSD symptomatology that have gained support in the literature. Results indicated that both prominent 4-factor models of PTSD symptomatology yielded good model fit across subsamples of studies; however, the model comprising Intrusions, Avoidance, Hyperarousal, and Dysphoria factors appeared to fit better across studies. Results also indicated that the best fitting models were not moderated by measure or sample type. Results are discussed in the context of structural models of PTSD and implications for the diagnostic nosology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in controlled and automatic memory processing.

The memory performance of groups of younger, middle-aged, and older participants was tested on indirect and direct tests of word stem completion and on a process-dissociation task. As expected, on the direct tests of stem completion, older participants had lower scores than the younger and middle-aged groups. Age effects were also found on the indirect word completion test. The process-dissociation task allowed memory performance to be divided into controlled and automatic processing components. Estimates of automatic processing were comparable for the three groups, but there was an age effect for controlled processing, with the middle-aged and older groups differing from the younger group. These results confirm the findings of J. M. Jennings and L. L. Jacoby (1993) and suggest that the decline in conscious processing efficiency begins in middle age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Separating conscious and unconscious influences of memory: Measuring recollection.

How can conscious and unconscious influences of memory be measured? In this article, a process-dissociation procedure (L. L. Jacoby, 1991) was used to separate automatic (unconscious) and consciously controlled influences within a task. For recall cued with word stems, automatic influences of memory (1) remained invariant across manipulations of attention that substantially reduced conscious recollection and (2) were highly dependent on perceptual similarity from study to test. Comparisons with results obtained through an indirect test show the advantages of the process-dissociation procedure as a means of measuring unconscious influences. The measure of recollection derived from this procedure is superior to measures gained from classic test theory and signal-detection theory. The process-dissociation procedure combines assumptions from these 2 traditional approaches to measuring memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Not evidence for separable controlled and automatic influences in artificial grammar learning: Comment on Higham, Vokey, and Pritchard (2000).

P. A. Higham, J. R. Vokey, and J. L. Pritchard (see record 2000-16324-006) claimed to provide evidence for separable controlled and automatic processes in artificial grammar learning. It is argued that their results are compatible with a single controlled influence: Participants might mistakenly identify more grammatical items than nongrammmatical items as belonging to the other grammar, because the grammars are very similar to each other, and the nongrammatical items are relatively highly dissimilar. Participants' knowledge may be ambiguous, rather than automatic. It is further argued that even if Higham et al's data do support automatic effects, opposition logic, in this case, cannot be said to have succeeded where dissociation logic has failed, because it is used to address the issue of whether participants have conscious control over the knowledge they acquire, rather than whether they possess conscious awareness of that knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An opposition procedure for detecting age-related deficits in recollection: Telling effects of repetition.

In 2 experiments, the advantages of placing automatic and consciously controlled memory processes in opposition to study age-related declines in memory performance were examined. Drawing on the common memory failure of mistakenly repeating oneself, a task was designed in which participants had to rely on conscious memory (recollection) to avoid repetition errors. Recollection proved to be severely affected by aging; older adults showed significantly more repetition errors than did younger adults, even at very short retention intervals. These results contrast sharply with the small age differences found with a standard recognition test. Moreover, L. L. Jacoby's (1991) process-dissociation procedure (Experiment 2) showed that automatic memory processes were unaffected with age and could support recognition performance in older adults. The advantages of the opposition procedure for studying memory in older adults relative to other measures are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of divided attention and time course on automatic and controlled components of memory in older adults.

The relation between attention available at encoding and automatic and consciously controlled aspects of memory was investigated within a single task using the process-dissociation procedure (L. L. Jacoby, 1991). Sixty-four older adults and 64 young adults studied a word list in either a full or a divided attention condition. Recall cued with word stems was tested immediately and at 20-minute and 60-minute delays. In contrast to consciously controlled influences of memory, automatic influences of memory (a) showed generally no reliable age differences, (b) remained invariant across the manipulation of attention, and (c) remained relatively invariant across the 60-minute time course. Furthermore, age did not interact with the attentional manipulation or the time course factor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring automatic retrieval.

A variety of procedures have been used to assess automatic retrieval effects on memory, including implicit memory tests and the process dissociation approach. Theoretical concerns with each are summarized prior to describing a procedure for evaluating automatic retrieval that is based on retrieval speed. Specifically, in a speeded implicit task, participants were encouraged to complete word stems using strictly automatic retrieval by presenting several practice test trials that did not allow responding based on previously studied items, and by encouraging speed of responding. This speeded implicit task was compared with a condition in which conscious retrieval of studied information was not possible and a condition in which conscious retrieval was required, providing converging evidence to support the hypothesis that the speeded implicit procedure can yield pure estimates of automatic retrieval. Furthermore, evidence from a standard implicit memory task yielded comparable data that suggests that participants engaged automatic retrieval processes on this task also. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Invariance in automatic influences of memory: Toward a user's guide for the process-dissociation procedure.

Three experiments investigated assumptions of the process-dissociation procedure for separating consciously controlled and automatic influences of memory. Conditions that encouraged direct retrieval revealed process dissociations. Manipulating attention during study or manipulating study time affected recollection but left automatic influences of memory relatively invariant. However, paradoxical dissociations were found when conditions encouraged use of a generate-recognize strategy, violating assumptions underlying the estimation procedure. Use of subjective reports to gain estimates produced parallel results. Easily observed correlations are shown to be not useful for testing assumptions underlying the process-dissociation procedure. A multinomial model produced results that agree with those from the process-dissociation approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Separating habit and recollection: Memory slips, process dissociations, and probability matching.

Memory slips are errors in performance that result when an automatic basis for responding (e.g., habit) opposes the intention to perform a specific behavior. Prior research has focused on factors that influence the probability of a memory slip while neglecting factors that facilitate performance. Using L. L. Jacoby's (1991) process-dissociation procedure to examine performance in both a memory-slip and a facilitation condition, the authors separated the contribution of habit and recollection (intentional memory) in a cued-recall task. The authors found that manipulating the strength of habit affected its contribution to performance in a manner that produced probability matching, but recollection was unchanged. In contrast, manipulations of presentation rate and response time influenced recollection but did not affect habit. Such dissociations support a model of memory in which automatic and intentional influences make independent contributions to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health effects of occupational diseases diagnosed in Poland during the years 1990 and 1994]

Three experiments investigated assumptions of the process-dissociation procedure for separating consciously controlled and automatic influences of memory. Conditions that encouraged direct retrieval revealed process dissociations. Manipulating attention during study or manipulating study time affected recollection but left automatic influences of memory relatively invariant. However, paradoxical dissociations were found when conditions encouraged use of a generate-recognize strategy, violating assumptions underlying the estimation procedure. Use of subjective reports to gain estimates produced parallel results. Easily observed correlations are shown to be not useful for testing assumptions underlying the process-dissociation procedure. A multinomial model produced results that agree with those from the process-dissociation approach.