Effects of elaborative processing on implicit and explicit memory for new associations.

Explored the relation between elaborative processing and implicit memory for new associations (i.e., the phenomenon that priming effects on word-completion tests are influenced by newly acquired associations between normatively unrelated words) in 4 experiments, using a total of 240 undergraduates. Results indicate that implicit memory for new associations, like explicit memory, depended on encoding of meaningful relations between paired words in the study list. However, variations in degree and type of associative elaboration had a large effect on explicit memory, as revealed by performance on letter-cued recall and paired-associate tests, but had little effect on implicit memory, as revealed by performance on a word-completion test. Discussion focuses on the theoretical implications of the observed similarities and differences between implicit and explicit memory for new associations. (49 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigating dissociations among memory measures: Support for a transfer-appropriate processing framework.

In three experiments subjects performed one of five tasks after an initial study phase. Results showed that performance on conceptually driven retention tasks (those requiring the processing of meaning) was consistently dissociated from that on data-driven tasks (those relying more on analysis of physical features). Performance on conceptually driven tasks of free recall, semantic cued recall, and a task of answering general knowledge questions was enhanced most when target items had been generated rather than read at study (Experiment 1) and when subjects formed mental images of item referents at study (Experiment 3). Conversely, the data driven tasks of word fragment completion and recall using graphemic cues were performed best when subjects read rather than generated items at input (Experiment 1) and when the physical features of study and test items matched in terms of modality (Experiment 2) and typography (Experiment 3). These findings indicate that dissociations among memory tasks are better explained in terms of the degree of overlap between mental operations at study and test than in terms of various memory systems underlying different tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer-appropriate processing for implicit and explicit memory.

To examine how feature-specific pattern-analyzing processes affect implicit and explicit memory test performance, words were displayed for study and testing in 2 visually distinct formats: upside down vs normal for Exp 1, upside down vs backward for Exp 2, and in Applesoft pudgy vs shadow typeface for Exp 3. Implicit and explicit memory performance were assessed with word identification and recognition tests, respectively. The results showed larger priming effects when the study and test formats were the same rather than different, but only in some experimental conditions. The discussion focuses on how skill and processing strategies contribute to format-specific effects on implicit and explicit memory test performance, and it outlines a theoretical account based on the idea of transfer-appropriate processing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Midazolam amnesia and conceptual processing in implicit memory.

Prominent theories of implicit memory (D. Schacter, B. Church, & J. Treadwell, 1994) emphasize the dominant role of perceptual processing in mediating priming on perceptual implicit memory tests. Examinations of the effects of conceptual processing on perceptual implicit memory tests have produced ambiguous results. Although a number of investigations (e.g., J. Toth & R. Hunt, 1990) have demonstrated that variations in conceptual processing affect priming on perceptual implicit memory tests, these effects may arise because of the contaminating effects of explicit memory. The current experiment examined this controversy using midazolam, a benzodiazepine that produces a dense, albeit temporary, anterograde amnesia when injected prior to study. The experiment examined whether the effects of generation found on the implicit memory test of perceptual identification were affected by a midazolam injection prior to study. Results demonstrated that midazolam substantially diminished generation effects in free and cued recall, as well as overall performance on these tests, but had no detectable effect on the generation effect in perceptual identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural processing and implicit memory for possible and impossible figures

Previous investigations have shown that participants are biased to respond "possible" to studied items when asked to decide whether objects could or could not exist in an object possibility test. The present study clarified and extended the concept of bias in implicit memory research in two ways. First, the authors showed that participants were biased to respond "possible" (rather than "impossible") on the object possibility test because structural processing was facilitated by prior study of possible, but not impossible, portions of objects. Second, the authors demonstrated that bias in this context was a form of, not an alternative to, implicit memory, by showing priming effects in response times when accuracy scores for studied and unstudied items were equated. The authors concluded by comparing proceduralist and memory-systems accounts of implicit memory effects and suggested that the two approaches could be seen as complementary rather than conflicting.     

Depression and implicit memory: A commentary.

Reviews 4 studies in which the issue of whether depression affects priming on implicit memory tests was examined. The authors conclude that a depressive mood does not affect the amount of priming on several implicit memory tests under conditions in which marked effects are shown on conscious recollection (explicit memory). The mood congruity effect (depressives remember depression-related words better than controls; controls remember other types of material better than depressives) also largely disappears on perceptual implicit memory tests. The authors speculate about reasons for discrepancies in the literature, relate the findings to some current theories of individual differences in memory, and suggest some directions for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical depression and implicit memory.

Investigated performance on implicit and explicit memory tasks in Ss diagnosed with major depression and matched controls. Depressed Ss showed impaired performance on both the explicit and implicit tasks in comparison with controls. These findings are in contrast to groups such as amnesic patients and older adults, who show preserved abilities on implicit tasks and deficits on explicit tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unitization and grouping mediate dissociations in memory for new associations.

Previous research has demonstrated performance dissociations between explicit and implicit memory for newly acquired associations between unrelated words. The present article accounts for this finding in terms of two factors: unitization and grouping. Unitization involves representing previously separate items as a single unit, and grouping involves forming associations among separate representations. We propose that grouping facilitates primarily explicit remembering by providing the routes for accessing encoded word pairs via the cues available during testing; in contrast, unitization affects primarily implicit remembering by enabling the reintegration of studied items in response to partial cues. Consistent with this view, the results from two experiments show that by focusing processing on the relation between target word pairs, explicit remembering can be manipulated independently of implicit remembering. Two further experiments reveal that a material manipulation (concreteness of words) affects both implicit and explicit remembering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations in infant memory: Rethinking the development of implicit and explicit memory.

Extending the Jacksonian principle of the hierarchical development and dissolution of function to the development and dissolution of memory, researchers have concluded that implicit (procedural) memory is a primitive system, functional shortly after birth, that processes information automatically, whereas explicit (declarative) memory matures late in the 1st year and mediates the conscious recollection of a prior event. Support for a developmental hierarchy has only been inferred from the memory performance of adults with amnesia on priming and recognition-recall tests in response to manipulations of different independent variables. This article reviews evidence that very young infants exhibit memory dissociations like those exhibited by adults with normal memory on analogous memory tests in response to manipulations of the same independent variables. These data demonstrate that implicit and explicit memory follow the same developmental timetable and challenge the utility of conscious recollection as the defining characteristic of explicit memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding implicit memory: A cognitive neuroscience approach.

Dissociations between implicit and explicit memory have attracted considerable attention in recent memory research. A central issue concerns whether such dissociations require the postulation of separate memory systems or are best understood in terms of different processes operating within a single system. This article presents a cognitive neuroscience approach to implicit memory in general and the systems–processes debate in particular, which draws on evidence from research with brain-damaged patients, neuroimaging techniques, and nonhuman primates. The article illustrates how a cognitive neuroscience orientation can help to supply a basis for postulating memory systems, can provide useful constraints for processing views, and can encourage the use of research strategies that are referred to as cross-domain hypothesis testing and cross-domain hypothesis generation, respectively. The cognitive neuroscience orientation suggests a complementary role for multiple systems and processing approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional disregulation: A benefit for implicit memory.

The authors investigated the effect of age and time of testing on the ability to control attention and addressed the possibility that older adults' susceptibility to distraction may sometimes facilitate performance on a later cognitive task. Using a modification of a G. Rees, C. Russell, C. D. Frith, and J. Driver (1999) procedure, the authors asked the participants to make same or different judgments on line drawings superimposed with task-irrelevant letter strings. Memory for the distractors was subsequently tested with an implicit memory task. Both older and young adults demonstrated greater memory for distractors at nonoptimal times of day than at optimal times of day; however, older adults showed considerably better memory for the distractors than did young adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Separating habit and recollection in young and older adults: Effects of elaborative processing and distinctiveness.

An extension of L. L. Jacoby's (1991) process-dissociation procedure was used to examine the effects of aging on recollection and automatic influences of memory (habit). Experiment 1 showed that older adults were impaired in their ability to engage in recollection but did not differ from young adults in their reliance on habit. Elderly adults were also less able to exploit distinctive contextual information to enhance recollection. Experiments 2 and 3 showed that with more supportive conditions, older adults were able to benefit from distinctive contextual information. Quantitative and qualitative deficits in recollective abilities are interpreted within a dual-process model of memory. The problem of distinguishing between a deficit in recollection and a deficit in inhibitory processes in older adults (e. g., L. Hasher & R. T. Zacks, 1998) and the importance of this distinction for purposes of repairing memory performance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of divided attention on implicit and explicit memory performance following severe closed head injury.

This study investigated the relation between attentional limitations and memory impairments in patients with closed head injuries (CHI). Twenty-seven CHI participants ( > 1 year postinjury) and 27 matched controls rated their liking of target words under conditions of full and divided attention. Participants then completed an implicit test of tachistoscopic identification (TI) and an explicit test of recognition for the target words As expected, the results revealed impaired explicit memory but preserved perceptually driven implicit memory performance following a CHI. Contrary to what was hypothesized, a reduction in attention available at encoding did not disproportionately impair the recognition performance of the CHI patients. Finally, unlike controls, the CHI participants' priming scores on the TI task were significantly affected by dividing attention at encoding. However, this finding interacted with CHI participants perceptual processing rates, suggesting that nonmemory cognitive factors may influence measured performances on implicit memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explicit and implicit memory for rotating objects.

Although both the object and the observer often move in natural environments, the effect of motion on visual object recognition has not been well documented. The authors examined the effect of a reversal in the direction of rotation on both explicit and implicit memory for novel, 3-dimensional objects. Participants viewed a series of continuously rotating objects and later made either an old-new recognition judgment or a symmetric-asymmetric decision. For both tasks, memory for rotating objects was impaired when the direction of rotation was reversed at test. These results demonstrate that dynamic information can play a role in visual object recognition and suggest that object representations can encode spatiotemporal information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term implicit memory for words and nonwords.

A short-term implicit memory effect is reported and interpreted as arising within the word recognition system. In Experiment 1, repetition priming in lexical decision was determined for low-frequency words and pseudowords at lags of 0, 1, 2, 3, 4, 5, 9, and 23 intervening items. For words, a large short-term priming component decayed rapidly but smoothly over the first 3 items (8 s) to a stable long-term value. For nonwords, priming dropped to the long-term value with a single intervening item. This Lag x Lexicality interaction was replicated with a naming task in Experiment 2 and with high-frequency words in Experiment 3. Word frequency affected long-term priming but not the size or decay rate of short-term priming, dissociating the two repetition effects. In Experiment 4, an old-new decision task was used to test explicit memory. Parallel word and nonword decay patterns were found, dissociating short-term priming from explicit working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

TAP, implicit and explicit memory, and adult memory development.

This paper proposes a view of memory based on the notion of transfer appropriate processing (TAP) of Morris, Bransford, and Franks (1977). The author makes three specific assumptions to explain the disassociation between implicit and explicit memory. First, the author distinguishes between two memory organizing processes--integration and elaboration. Second, the author assumes that every kind of study task engages a combination of integrative and elaborative processing, but that some tasks focus primarily on integrative processing, and others focus more heavily on elaborative processing. Third, the author also assumes that every kind of test engages a combination of integrative and elaborative processing, but that implicit memory tests depend primarily on integrative processing, whereas explicit tests focus more heavily on elaborative processing. The long term goal of several on-going experiments is to learn more about the specific stimulus attributes that serve as cues for initialing/guiding integrative versus elaborative processing, and how these cues change across the life-span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proactive interference, accessibility bias, and process dissociations: Valid subject reports of memory.

Proactive interference was assessed with a variant of the process-dissociation procedure, which separates effects of habit (accessibility bias) and recollection (discriminability). In three cued-recall experiments, proactive interference was shown to be an effect of bias rather than an effect on actual remembering. Divided attention, age, and study duration selectively influenced the recollection parameter, whereas training probability selectively influenced the habit parameter. Furthermore, in Experiments 2 and 3, subjective reports of remembering were highly correlated with, and nearly identical to, objective estimates of recollection gained from the process-dissociation procedure. The authors discuss the relevance of the results to theories of proactive interference and argue that older adults' greater susceptibility to interference effects is sometimes caused by an inability to recollect rather than by an inability to inhibit a preponderant response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrophysiologic dissociations in memory encoding of abstract and concrete words

This study examined memory encoding of auditorily presented abstract and concrete nouns. 22 subjects performed various blocks of a free recall memory task in which lists of 22 either abstract or concrete words had to be memorized. Consistent with a large variety of memory studies, recall performance was better for concrete than for abstract words. When the event-related potentials (ERPs) recorded during study were selectively averaged for those words that were subsequently recalled and those subsequently not recalled, the ERPs were more positive going for words that were subsequently recalled. These Dm effects (Difference due to memory) started around 500 ms post-stimulus and differed in timing and scalp topography for both types of words: For abstract words, they were present in an early (i.e., 600 to 1100 ms) time interval at parieto-occipital electrodes only. In contrast, for concrete words, Dm effects were obtained with a broad topographic distribution in the 600 to 1000 ms time range and were also present in a late time interval (1100 to 1600 ms) at fronto-central recording sites. The topographical dissociations of the Dm effects in the early time interval are taken to reflect the larger distinctiveness of concrete words during encoding, whereas the late effects presumably play a functional role in elaborative processing of concrete words. The results do not agree with models of word concreteness that propose separate processing systems for the two types of words, and rather support those models that propose quantitative differences in the processing of abstract and concrete words.     

Direct comparison of four implicit memory tests.

Four verbal implicit memory tests, word identification, word stem completion, word fragment completion, and anagram solution, were directly compared in 1 experiment and were contrasted with free recall. On all implicit tests, priming was greatest from prior visual presentation of words, less (but significant) from auditory presentation, and least from pictorial presentations. Typefont did not affect priming. In free recall, pictures were recalled better than words. The 4 implicit tests all largely index perceptual (lexical) operations in recognizing words, or visual word form representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)