Implicit memory and depression: An analysis of perceptual and conceptual processes

A small number of studies have reported impaired explicit memory and intact implicit memory performance in participants classified as depressed. In the present study we examined this finding taking account of the distinction between datadriven and conceptually driven processing. The performance of participants diagnosed with depression was examined on implicit and explicit memory tasks which were designed to tap either predominantly perceptual or conceptual processes. Depressed participants demonstrated performance deficits on both the implicit and explicit conceptual tasks (category association and free recall, respectively) but showed intact performance in the implicit perceptual task (word-fragment completion). These results suggest that people with severe depression show deficits in conceptual processing and that this deficit occurs under both explicit and implicit task instructions.     

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.     

Implicit memory and depression: preserved conceptual priming in subclinical depression

Depression impairs explicit memory but research on implicit memory is equivocal. Initial studies indicated preserved implicit memory, implying a depressive deficit in intentional but not unintentional forms of memory. Subsequent research indicated that conceptual priming is reduced in depression, implying a deficit in conceptual memory processes be they implicit or explicit. However, the findings with conceptual priming may be compromised by explicit contamination. The present study compared subclinically depressed and non-depressed participants on matched conceptual tests of explicit memory (category-cued recall) and implicit memory (category production). The implicit test was followed by a post-test questionnaire used to categorise participants as test-aware or test-unaware. On the explicit test, the subclinically depressed participants recalled less than the non-depressed participants. The results on the implicit test depended on test-awareness. Among test-unaware participants, conceptual priming was equivalent across the two groups, whereas for the test-aware, non-depressed participants produced significantly more priming than the subclinically depressed. This indicates that when explicit contamination is controlled, depression does not impair conceptual priming. The depressive dissociation between implicit and explicit memory is better accounted for by the difference between intentional and unintentional forms of memory rather than by the difference between conceptual and perceptual memory processes.     

Dissociating perceptual and conceptual implicit memory in multiple sclerosis patients

Previous studies indicate that Multiple Sclerosis (MS) patients exhibit deficits in tests of explicit memory such as free recall, but show normal priming on implicit tests of memory such as word stem completion. However, the memory performance of patients with different MS disease subtypes has not been fully examined. In the current study, memory was assessed in Primary Progressive (PPMS), Relapsing Remitting (RRMS), and Secondary Progressive (SPMS) MS subgroups. Explicit memory as well as perceptual and conceptual implicit memory were examined using free recall, word fragment completion, and exemplar generation tests, respectively. All three groups of MS patients exhibited free recall deficits and normal priming on the exemplar generation test. However, the PPMS group exhibited a deficit in word fragment completion priming, whereas the RRMS and SPMS groups exhibited normal levels of priming on this task. Lesion load was assessed using magnetic resonance imaging and was negatively correlated with explicit memory performance, but it did not account for the observed deficits in perceptual implicit memory. The results indicate that PPMS patients exhibit a pattern of memory impairment that is distinct from that of the RRMS and SPMS groups. Moreover, the results indicate that perceptual implicit memory can be neurologically dissociated from conceptual implicit memory.     

Proofreading familiar text: Allocating resources to perceptual and conceptual processes

Levy (1983) demonstrated that more spelling errors were detected, within a limited time period, when familiar passages were proofread than when unfamiliar passages were proofread. In the present series, Experiment 1 eliminated a possible confound in the Levy (1983) studies and showed that errors were detected both faster and more accurately in familiar texts. Experiment 2 demonstrated higher order involvement in the proofreading transfer effect, suggesting that a strictly word-level account was insufficient. Experiment 3 explored the proofreader’s sensitivity to the semantic properties of the proofreading passage, showing that the familiarity effect resulted from more efficient processing, not from lack of either visual or semantic analyses. The results are more consistent with a resource-allocation explanation than with either a visual-scanning or a skilled-visual-processing account.     

Effects of color on perceptual and conceptual tests of implicit memory

Two experiments are reported that explore why recent investigations of implicit memory failed to find any effects of color information on test performance. In the first experiment, participants studied colored pictures as well as words printed in colored ink without any memory instructions. During the test phase, a verbal and a pictorial version of a color-choice task (a conceptual priming test) were compared to two perceptual tests (word-stem completion and picture-fragment identification). Similar and significant amounts of priming to color occurred in both color-choice tasks. The perceptual tests were found to be sensitive to changes in the stimulus-presentation mode from study to test, but stimuli remaining the same color and those changed to black-and-white did not differ in the priming scores. In the second experiment, a mild division of attention was introduced in the study phase. Once again, priming to color was observed only in the verbal version of a color-choice test and not in the word-stem completion test. Dividing attention did not decrease performance on both implicit tests, whereas an explicit test of color recall for studied pictures suffered from dividing attention at encoding. It is concluded that a perceptual attribute such as color may be represented and coded by conceptual processing. Furthermore, automatic (or not attention-demanding) encoding processes may suffice for later conceptual tests of implicit memory. Previous failures to find any effects of color information on implicit performance are attributed to the use of perceptual priming tests. Received: 30 June 1997 / Accepted: 20 April 1998     

Unconscious phantasy: Some historical and conceptual dimensions

This paper seeks firstly to grasp both conceptually and historically the different phenomenologies that are captured by the term ‘Unconscious Phantasy’. The term is shown to refer to a number of distinct though overlapping conceptual domains. These include: phantasy as scene, phantasy as representation of drive, phantasy as representation of wish as its fulfilment, phantasy as split off activity of the mind functioning under the aegis of the pleasure principle; phantasy as representation of the minds own activities (which Wollheim calls’ the way “the mind represents its own activities to itself’’). Lastly unconscious phantasy is understood as being the basic foundation of all mental life, including drives, impulses, all anxiety situations and defences. Having mapped out this territory through following the development of the concept in the work of Freud and Klein, the author draws on the work of the philosopher Richard Wollheim who, the author contends, has made a fundamental contribution to our conceptual understanding of unconscious phantasy. In the last section of the paper, the author draws a distinction between what he terms ‘objects’ (namely psychic objects) and what he terms ‘facts’. It is suggested that this distinction, though implicit in much of our work, benefits from being made explicit and that in so doing an important dimension of analytic work is illuminated. We aim to help the patient to discover what he is like, to understand the ways in which he conceives and misconceives himself, to unravel the fact‐ness of himself and his world from its ‘object qualities’, to differentiate between unconscious phantasy and reality.     

The representational bias of acquired memory processes

The notion that some memory processes are acquired has been around for at least two thousand years. However, acquired memory processes have been made the object of scientific investigation in only the past two decades. Traditionally, psychologists have assumed that acquired memory processes are equally effective across the entire range of memory tasks. This article reviews research that has investigated whether these processes are equally effective across tasks or are more effective for just certain tasks. The review indicates that most, if not all, acquired memory processes are biased to deal effectively just certain kinds of mental representation. The article proposes that these processes are representationally biased because (1) they activate basic memory processes (e.g. imagery, rehearsal) which themselves are biased to process certain representational attributes and because (2) their use of basic processes follows a sequence required by particular memory tasks. Increased understanding of the representational bias of acquired processes may be seen to enable better control of memory performance and to foster more powerful investigations of memory phenomena.     

Priming on verbal perceptual tests: Roles of lexical,surface, and conceptual processes

According to a lexical-access hypothesis, priming on verbal-completion tests requires previous access to higher-order nodes such as morphemes or words. In two experiments, subjects studied words presented in printed color, either by reading the words or by naming the printed colors. In Experiment 2, some of the words were to be ignored in both study conditions. The words presented in Experiment 2 were either conceptually related or unrelated to each other. And the cues in the test phase for repeated targets were either printed in the studied color or in a different color. In both experiments, the word stems of nouns studied and of new targets were presented with word-completion instructions (implicit test of memory). Consistent with the hypothesis, the amount of priming obtained was greater in the reading than in the color-naming condition. The least amount of priming was observed for targets that were to be ignored at study. In addition, Experiment 2 showed considerable effects of surface similarity (i.e., stronger priming effects with cues whose color was not changed from the study to the test phase) and some effects of conceptual processing, as was indicated by different amounts of priming for unrelated and for related nouns. Because these two effects were observed with both types of study task, it is concluded that perceptual and conceptual processes may make independent contributions to priming effects in verbal perceptual tests. This conclusion modifies and extends the original hypothesis, according to which previous lexical access is required in order to obtain effects of perceptual or conceptual processes on the priming scores.     

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.     

Unconscious phantasy and its conceptualizations: An attempt at conceptual integration

That there is a lack of consensus as to how to decide between competing, at times even contradictory theories, and about how to integrate divergent concepts and theories is well known. In view of this situation, the IPA Committee on Conceptual Integration (2009–2013) developed a method for comparing the different versions of any given concept, together with the underlying theories and fundamental assumptions on which they are based. Only when situated in the same frame of reference do similarities and differences begin to appear in a methodically comprehensible and reproducible form. After having studied the concept of enactment followed by the publication of a paper in this Journal in 2013, we proceeded to analyze the concept of unconscious phantasy while at the same time continuing to improve our method. Unconscious phantasy counts among the central concepts in psychoanalysis. We identified a wide range of definitions along with their various theoretical backgrounds. Our primary concern in the present paper addresses the dimensional analysis of the semantic space occupied by the various conceptualizations. By way of deconstructing the concepts we endeavoured to establish the extent to which the integration of the different conceptualizations of unconscious phantasy might be achieved.     

Selection from perceptual and conceptual representations

The lateral prefrontal cortex has been implicated in a wide variety of functions that guide our behavior, and one such candidate function is selection. Selection mechanisms have been described in several domains spanning different stages of processing, from visual attention to response execution. Here, we consider two such mechanisms: selecting relevant information from the perceptual world (e.g., visual selective attention) and selecting relevant information from conceptual representations (e.g., selecting a specific attribute about an object from long-term memory). Although the mechanisms involved in visual selective attention have been well characterized, much less is known about the latter case of selection. In this article, we review the relevant literature from the attention domain as a springboard to understanding the mechanisms involved in conceptual selection.     

Autobiographical memory processes and the course of depression.

The authors report a 6-month follow-up study of clinically depressed patients. At baseline, 2 indexes of autobiographical memory functioning were assessed: the presence of spontaneous intrusive memories of stressful life events and performance on the Autobiographical Memory Test (J. M. G. Williams & K. Broadbent, 1986), which measures overgeneral memory. The index of overgeneral memory was associated with greater levels of spontaneous intrusion of stressful memories. Overgeneral memory did not predict outcome, but depression at follow-up was predicted by the amount of intrusion and avoidance of stressful memories, even after controlling for initial severity of psychiatric symptoms.     

The indirect effect of attention bias on memory via interpretation bias: Evidence for the combined cognitive bias hypothesis in subclinical depression

Little research has investigated functional relations among attention, interpretation, and memory biases in depressed samples. The present study tested the indirect effect of attention bias on memory through interpretation bias as an intervening variable in a mixed sample of non-depressed and subclinically depressed individuals. Subclinically depressed and non-depressed individuals completed a spatial cueing task (to measure attention bias), followed by a scrambled sentences test (to measure interpretation bias), and an incidental free recall task (to measure memory bias). Bias-corrected bootstrapping yielded evidence for the hypothesised indirect effect model, in that an emotional bias in attention is related to a congruent bias in interpretative choices which are in turn reflected in memory. These findings extend previous research and provide further support for the combined cognitive bias hypothesis in depression. Theoretical and clinical implications of our findings are discussed.     

Haptic modality takes its time: Dynamic of activations of sensory modalities in perceptual and memory processes

Based on claims resulting from grounded cognition theory that perceptual and memory processes are using the same distributed systems, the present study investigated the temporal aspect of access to memory traces through haptic and auditory modalities. Unlike in the case of visual or auditory components, the perception of a vibrotactile component is more sequential in nature and therefore cannot be fully processed before the end of the signal. The present study explores the dynamic of components activation in a situation of audio‐vibrotactile asynchrony. We used a short‐term priming paradigm consisting of an association phase (between a vibration and sound) and a test phase testing priming effect of a vibrotactile stimulation on the processing of a target sound. Results showed an interference with a simultaneous processing and a facilitation with a sequential processing. The temporality process of perceptual components is also important at a memory level.     

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.