Effects of divided attention on perceptual and conceptual memory tests: An analysis using a process-dissociation approach

In two experiments, the nature of the relation between attention available at learning and subsequent automatic and controlled influences of memory was explored. Participants studied word lists in full and divided encoding conditions. Memory for the word lists was then tested with a perceptually driven task (stem completion) in Experiment 1 and with a conceptually driven task (category association) in Experiment 2. For recall cued with word stems, automatic influences of memory derived using the process-dissociation procedure remained invariant across a manipulation of attention that substantially reduced conscious recollection for the learning episode. In contrast, for recall cued with category names, dividing attention at learning significantly reduced the parameter estimates representing both controlled and automatic memory processes. These findings were similar to those obtained using indirect test instructions. The results suggest that, in contrast to perceptual priming, conceptual priming may be enhanced by semantic processing, and this effect is not an artifact of contamination from conscious retrieval processes.     

Divided attention and indirect memory tests

Attentional state during acquisition is an important determinant of performance on direct memory tests. In two experiments we investigated the effects of dividing attention during acquisition on conceptually driven and data-driven indirect memory tests. Subjects read a list of words with or without distraction. Memory for the words was later tested with an indirect memory test or a direct memory test that differed only in task instructions. In Experiment 1, the indirect test was categoryexemplar production (a conceptually driven task) and the direct test was category-cued recall. In Experiment 2, the indirect test was word-fragment completion (a data-driven task) and the direct test was word-fragment cued recall. Dividing attention at encoding decreased performance on both direct memory tests. Of the indirect tests, category-exemplar production but not word-fragment completion was affected. The results indicate that conceptually driven indirect memory tests, like direct memory tests, are affected by divided attention, whereas data-driven indirect tests are not. These results are interpreted within the transfer-appropriate processing framework.     

The picture-superiority effect in category-association tests

In two experiments we examined the picture-superiority effect in the framework of the transfer-appropriate processing approach recently advocated by Roediger, Weldon, and Challis (1989). For the first time conceptual implicit-memory task is used, i.e., category association. In Experiment 1, subjects study a mixed list of pictures and words and then receive either a category-association test or a category-cued recall test, followed by a recognition test. The results show that performance on category-cued recall, recognition, and category-association tests are better when the material is studied in picture format. In Experiment 2, we show that producing a sentence with the material studied (picture or word) eliminates the picture-superiority effect in the implicit test, but does not eliminate picture superiority in the category-cued recall test. These results suggest that conceptually driven processing plays a critical role in category association and explicit tests of memory. The results are discussed in the framework of the transfer-appropriate processing approach to memory.     

Negative Cueing Effects with Weak and Strong Intralist Cues

In three experiments, we studied cueing effects of relational and itemspecific information after enacted and non-enacted encoding of short sentences (e.g. lift the pen, fold the paper). In Experiment 1, all subjects were instructed at encoding to remember only the nouns of these sentences; half of the subjects were informed about the categorical nature of the nouns, whereas the other half were not. At retrieval, all subjects were given a free recall test and a cued recall test with the verb of each sentence as the cue. In Experiment 2, all subjects were instructed at encoding to remember the whole sentence; as in Experiment 1, half of the subjects were informed about the categorical nature of the nouns and half were not. At test, all subjects were given two cued recall tests, one categorical cue for each noun in the first test and one verb cue and one categorical cue for each noun in the second test. In Experiment 3, at encoding, all subjects were informed about the categorical nature of nouns and were instructed to remember the whole sentence. In this experiment, the actions were performed with imaginary objects; free recall and cued recall tests were given to different subjects. In all three experiments, there was a negative effect of intralist cueing with verbs. This finding is at odds with the Encoding Specificity Principle, which assumes facilitation of cueing at retrieval if the cues were encoded together with the to-be-remembered information at encoding. Also, the effect of intralist cueing was different after encoding with enactment than after encoding without enactment; this difference holds true for enactment with real objects but not for enactment with imaginary objects. Enactment increased both the relational and the item-specific cueing efficiency. The results are discussed in terms of encoding interference between cues and targets and between item-specific processing and relational processing. Enacted encoding is conceived as integrating episodic information both with respect to item specificity and relational aspects of the information.     

Implicit and explicit memory in pregnant women: An analysis of data-driven and conceptually driven processes

A study by Brindle, Brown, Brown, Griffith, and Turner (1991), reported that pregnant women showed impaired implicit memory (as measured by a stem completion task) in the presence of intact explicit memory. The present study was an attempt to replicate and extend this finding by employing a read/generate encoding manipulation across data-driven (word fragment completion and graphemic cued recall) and conceptually driven (semantic cued recall and category generation) tests. A total of 64 women (32 pregnant) were tested on both data-driven and conceptually driven tasks either directly or indirectly. No differences emerged between pregnant subjects and non-pregnant controls across tasks. Subjects experiencing their first pregnancy did report their memory in the previous 2 weeks as being considerably worse than normal.     

Lexical,conceptual and motor information in memory for action phrases: a multi-system account

According to the multi-system account [J. Engelkamp, H.D. Zimmer, The Human Memory: A Multi-Modal Approach, Hogrefe & Huber, Seattle, 1994], the enactment effect in free recall of action phrases (e.g. break the stick) is independent of inter- and intra-phrase associations because it emerges from the nonverbal encoding processes under enactment. Two experiments have been reported which tested these and further assumptions of the multi-system account of the enactment effect. In both experiments, inter- and intra-phrase (verb-object) associations were varied simultaneously in addition to enactment. In Experiment 1, the memory test was free recall, and in Experiment 2, it was cued recall. Independent effects of all three factors were observed in free recall. Enacted phrases were recalled better than phrases learned only verbally. Phrases with high-associated objects and verbs were better recalled than phrases with low-associated objects and verbs, and categorically related phrases were better recalled than unrelated phrases. In cued recall, there was no effect of categorical list structure. The effects of intra-phrase structure and enactment corresponded to those in free recall. All interactions were nonsignificant. The findings were interpreted as support for the multi-system account.     

Limits of the processing view in accounting for dissociations among memory measures in a clinical population

In three experiments, we examined the performance of patients with schizophrenia on implicit and explicit memory tests that have been shown to involve predominantly data-driven or predominantly conceptually driven processes. In Experiment 1, we compared the implicit tests of category production (conceptually driven)and word identification (data driven) and found that schizophrenic patients’ performance on these tests did not differ from that of normal subjects. In Experiment 2, a comparison of the category-production and explicit cued-recall tests, both of which involve conceptual processes, showed that schizophrenic patients were impaired on the cued-recall test but not on the category-production test. In Experiment 3, a comparison of the word-identification and explicit graphemic cued-recall tests, both of which involve data-driven processes, showed that patients were impaired on the cued-recall test but not on the word-identification test. The results of both Experiments 2 and 3 revealed a dissociation between implicit and explicit test performance under conditions in which the two tests involve similar- types of processes. These results support theoretical views that distinguish implicit from explicit modes of retrieval.     

Dissociations among memory measures in memory-impaired subjects: Evidence for a processing account of memory

Deficits in conceptual transfer on both implicit and explicit memory tests were obtained for memory-impaired temporal lobe epileptic (TLE) subjects in three studies. In Experiment 1, in which a generate-read paradigm was employed, memory-impaired TLEs failed to show normal generation effects on conceptually driven tests of semantic cued recall and general knowledge questions, although their data-driven memory as measured by word-fragment completion and graphemic cued recall tasks was normal. In Experiment 2, memory-impaired patients having left temporal lobe seizure foci were tested on these four tasks and compared with nonimpaired TLEs having right temporal foci. The left TLEs showed deficits on conceptually driven tasks and normal memory for data-driven tests. These findings were extended in Experiment 3, in which left TLE patients failed to show any benefit from blocked study, as compared with random study, on category production and semantic cued-recall tests, although right TLEs and normal controls showed blocking effects on both tasks. These findings may be accommodated by a processing framework of memory in which memory-impaired patients are characterized as having deficits in conceptual, but not in data-driven, processing capabilities.     

Implicit memory bias,explicit memory bias,and anxiety

Abstract

Normals high, medium, and low in trait anxiety performed two encoding tasks (one predominantly data-driven and the other conceptually driven) on threat-related and neutral words, followed by tests of word completion, cued recall, and free recall. Memory performance indicated the existence of negative memory biases in the high trait-anxious group, but it was generally not possible to decide whether the biases were associated with trait anxiety rather than with depression. The biases were obtained mainly when there was a match between the processes at encoding and those at the time of test, whether the matching processes were predominantly data-driven or conceptually driven. Implications of these findings for implicit and explicit memory biases associated with high trait anxiety are discussed.     

Ageing affects conceptual but not perceptual memory processes

Whereas age effects commonly occur in tests of explicit memory, tests of implicit memory often show age invariance. In two experiments, the traditional confound between test type (implicit vs explicit) and retrieval process (conceptually driven vs perceptually driven) was removed by using conceptually driven and perceptually driven tests of both implicit and explicit memory. Experiment 1 revealed a significant age effect for conceptually driven retrieval and no age effect for perceptually driven retrieval, regardless of the type of memory being measured. Experiment 2 highlighted a difference between the two age groups in their ability to utilise semantic encoding in a nominally perceptually driven explicit memory test. The paper concludes that although perceptually driven processing is stable over age, particular care must be taken to minimise contamination from conceptually driven retrieval processes in such investigations.     

Ageing affects conceptual but not perceptual memory processes

Whereas age effects commonly occur in tests of explicit memory, tests of implicit memory often show age invariance. In two experiments, the traditional confound between test type (implicit vs explicit) and retrieval process (conceptually driven vs perceptually driven) was removed by using conceptually driven and perceptually driven tests of both implicit and explicit memory. Experiment 1 revealed a significant age effect for conceptually driven retrieval and no age effect for perceptually driven retrieval, regardless of the type of memory being measured. Experiment 2 highlighted a difference between the two age groups in their ability to utilise semantic encoding in a nominally perceptually driven explicit memory test. The paper concludes that although perceptually driven processing is stable over age, particular care must be taken to minimise contamination from conceptually driven retrieval processes in such investigations.     

Encoding variability and organization in free recall

Measures of category clustering and subjective organization are well-established predictors of performance in free recall tasks. The present studies demonstrate that a measure of encoding variability affords equally powerful and independent prediction of free recall performance. They also illustrate an interaction between encoding processes and organizational activity. In Experiments 1 and 2, the independent contributions of organization and encoding variability are demonstrated in categorizable and uncategorizable lists and in subjects whose recall is expected to increase (adults) or decrease (children) as a function of more varied encodings across trials. In Experiment 3, a category labeling procedure is used to demonstrate that the negative relationship between encoding variability and recall can be reversed by inducing adult-like organizational activity in children.     

Encoding tasks dissociate the effects of divided attention on category-cued recall and category-exemplar generation

The combined effects of encoding tasks and divided attention upon category-exemplar generation and category-cued recall were examined. Participants were presented with pairs of words each comprising a category name and potential example of that category. They were then asked to indicate either (i) their liking for both of the words or (ii) if the exemplar was a member of the category. It was found that divided attention reduced performance on the category-cued recall task under both encoding conditions. However, performance on the category-exemplar generation task remained invariant across the attention manipulation following the category judgment task. This provides further evidence that the processes underlying performance on conceptual explicit and implicit memory tasks can be dissociated, and that the intentional formation of category-exemplar associations attenuates the effects of divided attention on category-exemplar generation.     

The effect of retrieval enactment on recall of subject-performed tasks and verbal tasks

The effect of retrieval enactment on memory for nouns (objects) or verbal phrases describing simple actions (e.g., “lift the box”) was addressed in two experiments. In Experiment 1, the type of object involved in the actions was manipulated, with three different types of object being used (body parts, laboratory-related objects, and external objects). In Experiment 2, the integration between the verb-noun pairs was manipulated (well-integrated vs. poorly integrated). Results from both experiments showed that whereas encoding enactment (motor encoding and verbal test) substantially improved the memory performance compared with a verbal condition (verbal encoding and verbal test), retrieval enactment (verbal encoding and motor test) had no major impact on the number of recalled nouns or phrases. Moreover, there was no additional effect of dual enactment (motor encoding and motor test). The overall pattern of the results suggests that there is a fundamental difference between motor processing at encoding and motor processing at retrieval, and the lack of encoding specificity advantage for the motor modality contradicts the view that encoding enactment of verbal commands results in storage of motor representations.     

Automatic processing influences free recall: converging evidence from the process dissociation procedure and remember-know judgments

Dual-process theories of retrieval suggest that controlled and automatic processing contribute to memory performance. Free recall tests are often considered pure measures of recollection, assessing only the controlled process. We report two experiments demonstrating that automatic processes also influence free recall. Experiment 1 used inclusion and exclusion tasks to estimate recollection and automaticity in free recall, adopting a new variant of the process dissociation procedure. Dividing attention during study selectively reduced the recollection estimate but did not affect the automatic component. In Experiment 2, we replicated the results of Experiment 1, and subjects additionally reported remember–know–guess judgments during recall in the inclusion condition. In the latter task, dividing attention during study reduced remember judgments for studied items, but know responses were unaffected. Results from both methods indicated that free recall is partly driven by automatic processes. Thus, we conclude that retrieval in free recall tests is not driven solely by conscious recollection (or remembering) but also by automatic influences of the same sort believed to drive priming on implicit memory tests. Sometimes items come to mind without volition in free recall.     

Limits on the role of retrieval cues in memory for actions: Enactment effects in the absence of object cues in the environment

Verb-object phrases (open the umbrella, knock on the table) are usually remembered better if they have been enacted during study (also called subject-performed tasks) than if they have merely been learned verbally (verbal tasks). This enactment effect is particularly pronounced for phrases for which the objects (table) are present as cues in the study and test contexts. In previous studies with retrieval cues for some phrases, the enactment effect in free recall for the other phrases has been surprisingly small or even nonexistent. The present study tested whether the often replicated enactment effect in free recall can be found if none of the phrases contains context cues. In Experiment 1, we tested, and corroborated, the suppression hypothesis: The enactment effect for a given type of phrase (marker phrases) is modified by the presence or absence of cues for the other phrases in the list (experimental phrases). Experiments 2 and 3 replicated the enactment effect for phrases without cues. Experiment 2 also showed that the presence of cues either at study or at test is sufficient for obtaining a suppression effect, and Experiment 3 showed that the enactment effect may disappear altogether if retrieval cues are very salient.     

Hypermnesia occurs in recall but not in recognition

Two experiments investigated the effect of encoding conditions and type of test (recall vs. recognition) on the phenomenon of hypermnesia (improved performance across repeated tests). Subjects in Experiment 1 studied a list of words using either imaginal or semantic elaboration strategies and then received three successive tests. Different groups of subjects received either free recall, four-alternative forced-choice recognition, or yes/no recognition tests. Reliable hypermnesia was found only in the recall conditions, with the recognition conditions showing either no change in performance levels across tests (forced-choice tests) or significant forgetting (yes/no tests). In Experiment 2, subjects studied a list of words, and encoding was manipulated using three orienting tasks. Once again, hypermnesia was found with the recall tests but not with the forced choice recognition tests. Finding hypermnesia in recall but not in recognition indicates that retrieval processes in recall play a major role in producing hypermnesia. Also, the finding that the magnitude of the recall hypermnesias increased with an increase in total cumulative recall levels across study conditions suggests that cumulative recall levels are an important factor in determining the presence or absence of recall hypermnesia.     

Cue utilization following different forms of encoding in mildly, moderately, and severely demented patients with Alzheimer's disease

The ability of patients with Alzheimer's disease (AD) to utilize semantic category cues in order to improve memory performance was examined. Categorizable lists of words or objects were presented under five different encoding conditions: (a) nouns, (b) objects, (c) objects with a semantic orienting question, (d) objects with self-generated motoric acts, and (e) objects with experimenter-instructed motoric acts. Subjects were asked to memorize the items for a free recall test, and were subsequently provided with the category names in a cued recall test. Mildly, moderately, and severely demented AD patients, and a group of normal older adults participated in the study. Results showed that normal older adults and mildly demented AD subjects were able to utilize cues to improve memory performance in all conditions. Moderately demented patients utilized cues in all conditions except in the verbal condition (condition [a]), whereas severely demented patients utilized cues only in the motoric condition (condition [e]). These results suggest that the ability to utilize category cues following a motoric encoding is preserved later in AD than the ability to utilize cues after a semantic encoding.     

Bilingualism and reading difficulties: an exploration in episodic and semantic memory

This study was designed to investigate the effect of bilingualism and reading difficulties (RD) on episodic and semantic memory. The subjects included 190 children (aged 9–12 years): 45 Iranian-Swedish bilinguals and 59 Swedish monolinguals with typically developed reading, along with 41 bilinguals and 45 monolinguals with RD. To measure episodic memory, subject-performed and verbal tasks were used for encoding, and both free and cued recall were used for retrieval. Letter and category fluency tasks were used to test semantic memory. In action memory, bilingual children with RD benefited less from enactment encoding form compared to children with typically developed reading. Additionally, bilingual with RD had lower rates of recollection in category fluency compared to their monolingual counterparts. However, in letter fluency, there was not found a difference between performances of bilinguals and monolinguals with RD. We discuss the involvement of long-term memory in both bilingualism and reading.     

Structuring the Acquisition and Retrieval Environment to Facilitate Learning in Individuals with Dementia of the Alzheimer Type

Three experiments using variations of the Subject Performed Task (SPT) paradigm examined whether structuring the learning and retrieval environment would improve learning in individuals with mild to moderate dementia of the Alzheimer type (DAT). Experiment 1 examined the role of enactment at encoding and retrieval, and found that with appropriate retrieval support DAT volunteers do benefit from enactment at encoding. Experiment 2 showed that recall was further enhanced when the list of SPTs formed a cohesive, goal-directed sequence of actions. In Experiment 3, DAT subjects acquired a more complex action-based sequence and maintained it accurately over a short period of time. It is concluded that the provision of contextual support at encoding and at retrieval can enhance residual memory in individuals with DAT.