Involuntary aware memory enhances priming on a conceptual implicit memory task

This study investigated the role of involuntary aware memory (phenomenological awareness of the study episode) on a conceptual implicit memory task. Subjects studied words under levels of processing conditions (LOP: nonsemantic vs. semantic) and then received a category exemplar generation priming task. Subjects were either aware or unaware of the study test relationship. Subjects who were study test aware showed more priming for semantic study than subjects who were study test unaware, thus producing an LOP dissociation between them. The findings suggest that involuntary aware memory can enhance performance on conceptual implicit memory tasks, thus having theoretical implications for implicit and explicit memory.     

IMPLICIT MEMORY IN THE TACTILE MODALITY:

Abstract— Research on perceptual priming has previously focused exclusively on priming in the visual and auditory modalities. The present study explored whether perceptual priming also extends to the tactile modality. Tactile priming for Braille words was examined in a group of blind participants, using a Braille analogue of the stem-completion task. The results for tactile priming paralleled previous stem-completion results in other modalities. Manipulating the encoding task at study (semantic vs nonsemantic) dissociated implicit and explicit Braille stem-completion performance, and priming was unaffected by the number of study presentations (one vs three). Finally, Braille stem-completion priming was found in a cross-modal paradigm to have both a specifically tactile component and a cross-modal component. These results demonstrate for the first time that verbal priming can occur in the tactile domain and that tactile priming has basic functional similarities with stem-completion priming in the visual and auditory domains.     

Study-test awareness can enhance priming on an implicit memory task: evidence from a word completion task

The role of study-test awareness in implicit memory tasks has been an open question for some time. This study investigated the possibility that study-test awareness may enhance priming on an implicit memory task. In three experiments, subjects studied words under levels of processing conditions (nonsemantic vs. semantic) and then received a word stem completion priming task. The results of all three experiments showed that study-test awareness had no effect on priming for nonsemantic study but it did on semantic study, significantly enhancing priming for that study condition. The results are interpreted according to an involuntary aware memory framework.     

Auditory priming: implicit and explicit memory for words and voices.

Five experiments explore priming effects on auditory identification and completion tasks as a function of semantic and nonsemantic encoding tasks and whether speaker's voice is same or different at study and test. Auditory priming was either unaffected by the study task manipulation (Experiments 2, 4, and 5) or was less affected than was explicit memory (Experiments 1 and 3). Study-to-test changes of speaker's voice had nonsignificant effects on priming when white noise masked target items on the identification test (Experiments 1 and 2) or the stem-completion test (Experiment 5). However, significant voice change effects were observed on priming of completion performance when stems were spoken clearly (Experiments 3 and 4). Results are consistent with the idea that a presemantic auditory perceptual representation system plays an important role in the observed priming. Alternative explanations of the presence or absence of voice change effects under different task conditions are considered.     

Cross-modal priming and explicit memory in patients with verbal production deficits

Implicit memory is often thought to reflect an influence of past experience on perceptual processes, yet priming effects are found when the perceptual format of stimuli changes between study and test episodes. Such cross-modal priming effects have been hypothesized to depend upon stimulus recoding processes whereby a stimulus presented in one modality is converted to other perceptual formats. The present research examined recoding accounts of cross-modal priming by testing patients with verbal production deficits that presumably impair the conversion of visual words into auditory/phonological forms. The patients showed normal priming in a visual stem completion task following visual study (Experiment 1), but showed impairments following auditory study in both implicit (Experiment 2) and explicit (Experiment 3) stem completion. The results are consistent with the hypothesis that verbal production processes contribute to the recoding of visual stimuli and support cross-modal priming. The results also indicate that shared processes contribute to both explicit memory and cross-modal implicit memory.     

The effect of generation on long-term repetition priming in auditory and visual perceptual identification

Perceptual implicit memory is typically most robust when the perceptual processing at encoding matches the perceptual processing required during retrieval. A consistent exception is the robust priming that semantic generation produces on the perceptual identification test (Masson & MacLeod, 2002), a finding which has been attributed to either (1) conceptual influences in this nominally perceptual task, or (2) covert orthographic processing during generative encoding. The present experiments assess these possibilities using both auditory and visual perceptual identification, tests in which participants identify auditory words in noise or rapidly-presented visual words. During the encoding phase of the experiments, participants generated some words and perceived others in an intermixed study list. The perceptual control condition was visual (reading) or auditory (hearing), and varied across participants. The reading and hearing conditions exhibited the expected modality–specificity, producing robust intra-modal priming and non-significant cross-modal priming. Priming in the generate condition depended on the perceptual control condition. With a read control condition, semantic generation produced robust visual priming but no auditory priming. With a hear control condition, the results were reversed: semantic generation produced robust auditory priming but not visual priming. This set of results is not consistent with a straightforward application of either the conceptual-influence or covert-orthography account, and implies that the nature of encoding in the generate condition is influenced by the broader list context.     

A reevaluation of semantic versus nonsemantic processing in implicit memory

A number of investigations have purported to demonstrate that semantic processing does not produce a memorial advantage over nonsemantic processing on implicit tests, as contrasted with the typical advantage of semantic over nonsemantic processing on explicit tests. A review of 166 outcomes from 38 studies that have manipulated processing on implicit tests reveals that on 131 occasions (79%), priming was greater following semantic than it was following nonsemantic processing. This difference was found in both perceptual and conceptual implicit memory tests, as well as in within- and between-subjects designs. It suggests that implicit tests reflect the involvement of both conceptual and perceptual processes. Although explicit contamination may account for some of the processing difference in implicit tests, the pervasiveness of the phenomenon, especially in perceptual implicit tests, makes it an unlikely account for the entire effect.     

Long-lasting perceptual priming and semantic learning in amnesia: a case experiment.

An investigation of perceptual priming and semantic learning in the severely amnesic subject K.C. is reported. He was taught 64 three-word sentences and tested for his ability to produce the final word of each sentence. Despite a total lack of episodic memory, he exhibited (a) strong perceptual priming effects in word-fragment completion, which were retained essentially in full strength for 12 months, and (b) independent of perceptual priming, learning of new semantic facts, many of which were also retained for 12 months. K.C.'s semantic learning may be at least partly attributable to repeated study trials and minimal interference during learning. The findings suggest that perceptual priming and semantic learning are subserved by two memory systems different from episodic memory and that both systems (perceptual representation and semantic memory) are at least partially preserved in some amnesic subjects.     

额叶参与对新异联系的启动效应——来自脑损伤病人的证据

对新异联系的启动效应是内隐记忆的一种形式,又称联想启动。采用知觉辨认任务,探讨额叶损伤与联想启动的关系。25例额叶损伤病人及18例匹配的正常被试参与实验。结果表明,额叶受损病人辨认旧词对与重组词对的正确率没有明显差别;而且,轻度记忆损伤的额叶病人再认成绩正常,但联想启动值低于对照组,内隐记忆和外显数、坚持性反应数和语词流畅性等有中度相关。这些结果提示,额叶不仅与情节记忆、工作记忆等外显记忆有关,也参与了以非相关词对为材料的联想启动。     

The effects of divided attention on auditory priming

Traditional theorizing stresses the importance of attentional state during encoding for later memory, based primarily on research with explicit memory. Recent research has begun to investigate the role of attention in implicit memory but has focused almost exclusively on priming in the visual modality. The present experiments examined the effect of divided attention on auditory implicit memory, using auditory perceptual identification, word-stem completion and word-fragment completion. Participants heard study words under full attention conditions or while simultaneously carrying out a distractor task (the divided attention condition). In Experiment 1, a distractor task with low response frequency failed to disrupt later auditory priming (but diminished explicit memory as assessed with auditory recognition). In Experiment 2, a distractor task with greater response frequency disrupted priming on all three of the auditory priming tasks as well as the explicit test. These results imply that although auditory priming is less reliant on attention than explicit memory, it is still greatly affected by at least some divided-attention manipulations. These results are consistent with research using visual priming tasks and have relevance for hypotheses regarding attention and auditory priming.     

The effects of generation on auditory implicit memory

The generation manipulation produces the classic functional dissociation between explicit and implicit memory. This dissociation has been explained by the transfer-appropriate processing (TAP) framework, which emphasizes the overlap in cognitive processes operative at encoding and at retrieval. However, the vast majority of implicit memory studies have been conducted in the visual modality; in the auditory modality, the effects of generation have never been investigated. In four experiments, we examined the effects of generating from semantic and nonsemantic cues on auditory implicit tests. Generating from antonyms produced a reversed generation effect on priming in auditory perceptual identification and word stem completion, while producing the traditional positive effect on explicit recognition. Generating from definitions, as well as from rhymes, also produced a reversed generation effect on auditory priming. These results are critical for more fully characterizing auditory priming and are consistent with an extended TAP analysis.     

IMPLICIT MEMORY IN AMNESIC PATIENTS:

Abstract— Amnesic patients generally exhibit spared priming effects on implicit memory tasks despite poor explicit memory In a previous study, we demonstrated normal auditory priming in amnesic patients on an identification-in-noise test in which the magnitude of priming is independent of whether the speaker's voice is the same or different at study and test In the present experiment, we examined auditory priming on a filter identification test in which the magnitude of priming in control subjects is higher when the speaker's voice is the same at study and test than when it is different Amnesic patients, by contrast, failed to exhibit more priming in a same-voice condition than in a different-voice condition Voice-specific priming may depend on a memory system that is impaired in amnesia     

Remembering the levels of information in words

The qualitative nature of the incidental memory trace produced by perceptual and conceptual processing within a speeded inference task was examined. Performance on recall and auditory recognition tests replicated the general finding that semantic processing leads to better retention of words than does nonsemantic processing. This pattern of results was reversed on a visual recognition test designed to measure the amount of perceptual information remembered. These data suggest that different types of processing result in different aspects of the stimulus being encoded, with conceptual processing resulting primarily in the encoding of semantic information and perceptual processing resulting primarily in the encoding of physical information. Thus, the effectiveness of a particular kind of processing for good memory performance depends on the kind of information being tested.     

Levels and speed of processing effects on word analysis

Previous work on semantic priming effects has suggested that priming is contingent upon semantic analysis of the prime stimulus. In the present series of experiments, subjects in Grade 3, Grade 6, and college performed variants of a priming task in which semantic (lexical decision) as well as fast (case judgment) and slow (letter search) nonsemantic levels of processing were required for both prime and target stimuli. Contrary to a levels of processing hypothesis, context effects were not simple functions of the level at which the prime was processed. Priming effects were found with a slow nonsemantic prime task (letter search), but generally not with a fast nonsemantic analysis of the prime (case judgment). The form of the priming effect when the prime was processed semantically by a lexical decision depended on the relationship between prime and target processing: a switch from semantic prime processing to nonsemantic target processing produced Stroop-like interference, with other combinations of prime and target processing producing facilitation. By using a series of discrimination, focusing, and classification tasks in a Garner (1978) paradigm, it was possible to determine how subjects were processing the semantic and nonsemantic dimensions, and these perceptual strategies were compared across educational levels to account for the priming effects. Our results suggest that context effects need to be understood in terms of the speeds of processing of different codes of information inherent in words.     

Paired-associate learning and priming effects in amnesia: a neuropsychological study

Despite severe deficits of recall and recognition, amnesic patients can exhibit normal priming effects. Amnesic patients have also been reported to perform well on tests of paired-associate learning that involve related word pairs (e.g., table-chair). The present study investigated the role of priming effects in paired-associate learning. Experiment 1 illustrated the distinction between the memory impairment of amnesic patients and their intact priming ability. Amnesic patients were markedly deficient in learning unrelated word pairs, despite exhibiting normal priming as measured by a word-completion test involving the same words. In Experiment 2A, amnesic patients showed good paired-associate learning for related word pairs, though control subjects still performed significantly better. In addition, the good performance by amnesic patients was short-lived, and performance fell to baseline after a 2-hr delay. Control subjects performed well above baseline at all delay conditions. Experiment 2B showed that the forgetting of related word pairs by amnesic patients followed the same time course as the decay of word priming. Experiment 3 showed that amnesic patients were as good as control subjects at learning related word pairs when incidental learning and test procedures were used (a word-association test). The advantage of control subjects over amnesic patients in Experiments 2A and 2B could therefore be attributed to the explicit learning instructions that are standard in paired-associate tests. Finally, Experiment 4 showed that amnesic patients exhibited normal priming when they were asked to "free associate" to words (e.g., child) that were semantically related to previously presented words (e.g., baby). The results indicate that both priming effects and paired-associate learning of related word pairs depend on activation, a process that is preserved in amnesia. Activation can account for the findings of good performance by amnesic patients on tests of word priming (Experiments 1 and 2B), related paired associates (Experiments 2A and 2B), and word association (Experiments 3 and 4). Activation is a transient phenomenon presumed to operate on and facilitate access to preexisting representations. Control subjects can establish new associations and can strengthen preexisting associations by engaging processes that are impaired in amnesia. As a result, when explicit learning instructions are used to test paired-associate learning of related word pairs, control subjects can learn better and can remember longer than can amnesic patients (Experiments 2A and 2B).(ABSTRACT TRUNCATED AT 400 WORDS)     

Word priming without awareness: A new approach to circumvent explicit memory contamination

A major methodological limitation arising in the experimental study of implicit memory is that tasks that are characterized as implicit memory tests can be seriously contaminated by the use of covert explicit memory strategies. Given the evidence indicating that brief presentation of words (below the awareness threshold of subjects) can produce semantic priming, we wondered whether rapid visual presentation of primed words might provide an avenue to produce word priming without explicit memory contamination. Normal subjects were tested for word priming on a speeded category membership decision task. Explicit or implicit encoding procedures were used in four different experiments. Results demonstrated that brief presentation of words can indeed offer a means of producing word priming in absence of explicit recognition or recall of the primed words presented during the study phase. They also showed that such priming is equivalent in degree to the priming measured when using either a conventional implicit memory design or an explicit encoding procedure prior to the study of the primes.     

Picture superiority in conceptual memory: Dissociative effects of encoding and retrieval tasks

We examined the role of encoding processes for picture superiority in explicit and conceptual-implicit memory. The nature of encoding instruction (naming or semantic categorization) yielded dissociative effects on picture and word memory on one explicit test, category-cued recall, and two conceptual-implicit tests, category-cued generation and category-cued verification. Category-cued recall was greater for pictures than for words following naming, but it did not differ for pictures and words following semantic categorization. Category-cued generation priming was greater for pictures than for words following naming, but it was greater for words than for pictures following semantic categorization. In contrast, category-cued verification priming did not differ for pictures and words following either naming or semantic categorization. Thus, picture superiority can be eliminated or reversed depending on the type of conceptual encoding task and conceptual-retrieval test.     

Implicit memory for novel conceptual associations in amnesia

In two experiments, we evaluated the status of implicit memory for novel associations in amnesia. Experiment 1 assessed priming in a category exemplar generation task in which contextual information associated with a target could increase the likelihood of target generation. Control participants, but not amnesic patients, showed associative priming. Amnesics’ impairment was not due to the use of explicit memory by control subjects but reflected a genuine impairment in implicit memory for novel conceptual associations. Experiment 2 assessed priming in a relatedness judgment task, in which associative priming was manifest as longer latencies for old than for recombined pairs of unrelated words. Amnesic patients showed intact associative priming in this task. We discuss differences in the status of implicit memory for novel conceptual associations in amnesia, with reference to the nature of the representation that supports priming in the two tasks and the type of processing that is required at test.     

On the locus of the semantic satiation effect: Evidence from event-related brain potentials

The present study sought to determine whether semantic satiation is merely a by-product of adaptation or satiation of upstream, nonsemantic perceptual processes or whether the effect can have a locus in semantic memory. This was done by measuring event-related brain potentials (ERPs) in a semantic word-detection task involving multiple presentations of primes and critical related and unrelated words in three experiments involving visual (Experiment 1) and auditory (Experiments 2A and 2B) stimuli. Primes varied in their type case (Experiment 1) or pitch (Experiment 2B) in order to discourage sensory adaptation. Prime satiation and relatedness of the primes to the critical word had interacting effects on ERP amplitude to critical words, particularly within the time-window of the N400 component. Because numerous studies have indicated a role for the N400 in semantic processing, modulation of the N400 relatedness effect by prime satiation (with little or no contribution from perceptual adaptation) suggests that semantic memory can be directly satiated, rather than the cost to semantic processing necessarily resulting from impoverishment of perceptual inputs.     

Locus of Control and Implicit Memory

Two experiments were conducted to investigate the influence of locus of control on implicit and explicit memory. We hypothesized that internals would rely on semantic processing, externals on perceptual processing. In Experiment 1, 80 college students studied 36 words and completed an implicit memory test in either a consistent or cross-modality condition. The results revealed that externals had higher priming scores than did internals, regardless of modality. In Experiment 2, 80 college students took either an implicit or explicit test. The results again revealed that externals showed higher priming scores than internals. The higher priming scores exhibited by the externals do not necessarily mean that they are more perceptually oriented than the internals are.