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 (Exps 2, 4, and 5) or was less affected than was explicit memory (Exps 1 and 3). Study-to-test changes of speaker's voice had significant effects on priming when white noise masked target items on the identification test (Exps 1 and 2) or the stem-completion test (Exp 5). However, significant voice change effects were observed on priming of completion performance when stems were spoken clearly (Exps 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired priming on the general knowledge task in amnesia.

The status of priming on the general knowledge test was examined in amnesia. Twenty amnesic and 20 control participants studied words (e.g., CHEETAH) under semantic and nonsemantic encoding conditions and attempted to answer general knowledge questions (e.g., "What is the fastest animal on earth"?) under implicit and explicit retrieval instructions. The measure of memory was how many more test questions participants answered correctly using studied than nonstudied words. Amnesic patients showed impaired memory under implicit and explicit retrieval instructions. Control participants showed equal memory under implicit and explicit retrieval instructions, a result indicating that they engaged in explicit retrieval in both instruction conditions. General-knowledge priming appears to involve explicit retrieval that depends on medial-temporal and diencephalic regions damaged in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual specificity of auditory priming: Implicit memory for voice intonation and fundamental frequency.

Five experiments explored the effect of acoustic changes between study and test on implicit and explicit memory for spoken words. Study-test changes in the speaker's voice, intonation, and fundamental frequency produced significant impairments of auditory priming on implicit tests of auditory identification and stem completion but had little or no effect on explicit recall and recognition tests (Exps 1–4). However, study-test changes in overall decibel level had no effect on priming on an auditory stem-completion test or on cued-recall performance (Exp 5). The results are consistent with the idea that fundamental frequency information is represented in a perceptual representation system that plays an important role in auditory priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in amnesia: An analysis of data-driven and conceptually driven processes.

The extent to which data-driven and conceptually driven processing determines amnesic patients' differential performance on implicit and explicit tasks was investigated. In 2 data-driven tasks, words that looked visually similar to target words were used as cues for a graphemic production task (implicit) and a graphemic cued-recall task (explicit). In 2 conceptually driven tasks, words semantically related to the target words were used as cues for both a production task and a cued-recall task. The nature of the task instructions consistently determined amnesic patient performance, regardless of the nature of the processing required. Thus, the distinction between implicit and explicit tasks captured the performance of amnesic patients better than did the distinction between data-driven and conceptually driven processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition memory and familiarity judgments in severe amnesia: No evidence for a contribution of repetition priming.

The amnesic patient E.P. has demonstrated normal levels of repetition priming and at-chance recognition performance (S. B. Hamann & L. R. Squire, 1997), suggesting that the sense of familiarity used to make a recognition memory judgment is not based on the same mechanism responsible for repetition priming. However, the recognition tests previously used may have discouraged the use of familiarity and encouraged reliance on episodic memory. This issue was addressed in 5 experiments with E.P., 3 other amnesic patients with hippocampal damage, and 8 healthy controls. In Experiments 1–3, which were designed to discourage the use of episodic memory, the amnesic patients were impaired and E.P. performed at chance. In Experiments 4 and 5A, a stem-completion priming task was combined with a recognition memory task on each trial. E.P.'s priming was intact, yet his recognition memory performance was at chance. This suggests that although recognition memory judgments may be made on the basis of familiarity, repetition priming is not the source of this feeling of familiarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit priming of alcohol expectancy memory processes and subsequent drinking behavior.

Expectations about the effects of alcohol have been modeled as stored memories. This study tested the memory view for investigating the processes that influence drinking. Strategies taken from recent memory research were used to implicitly prime drinking. Consequent effects on consumption of a commercial nonalcoholic beer were measured. Participants were led to believe this beer contained alcohol. Eighty undergraduate women (n?=?20 per cell) participated in 2, apparently unrelated, studies. A 2?×?2 factorial design simultaneously varied videotaped primes (bar setting or neutral video) with semantic primes (expectancy or neutral words). Women exposed to unobtrusive alcohol primes of either type drank significantly greater amounts (p?     

Implicit memory in posttraumatic stress disorder with amnesia for the traumatic event

The regulators of G-protein signaling (RGS) family members contain a conserved region, the RGS domain, and are GTPase-activating proteins for many members of G-protein alpha-subunits. We report here that the core domain of RGS16 is sufficient for in vitro biochemical functions as assayed by its G-protein binding affinity and its ability to stimulate GTP hydrolysis by G alpha(o) protein. RGS16 also requires, in addition to the RGS domain, the divergent N-terminus for its biological function in the attenuation of pheromone signaling in yeast, whereas its C-terminus region is dispensable. Together with other evidence, these data support the notion that RGS proteins interact with other cellular factors and may serve to link specific G-proteins to different downstream effectors in G-protein-mediated signaling pathways.     

Perceptual thresholds and priming in amnesia.

The widely accepted idea that perceptual priming is intact in amnesia was challenged recently by the suggestion that perceptual identification (PID) thresholds are elevated in amnesia and that this impairment could mask a priming deficit by artificially inflating priming scores. The authors examined the PID thresholds of amnesic patients across a wide range of stimulus conditions and accuracy levels. Baseline thresholds and priming effects were fully intact for all amnesic patients except in a condition using small stimuli (1.1"?×?0.25" of visual angle). In that condition, only the patients with Korsakoff's syndrome were impaired. Accordingly, elevated perceptual thresholds are not a necessary consequence of amnesia, and normal priming in amnesia is not an artifact of threshold differences. The results support the conclusion that priming is independent of the brain structures important for declarative memory that are damaged in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spared priming despite impaired comprehension: Implicit memory in a case of word-meaning deafness.

Previous research has established that direct priming effects on implicit memory tests can be dissociated from explicit remembering. Evidence from studies of college students suggests that priming on various implicit tests can be characterized as a presemantic phenomenon: Priming can occur at full strength following nonsemantic encoding tasks that typically produce low levels of explicit memory. To provide a strong test of this idea, auditory priming in a case of word-meaning deafness was examined. Despite the patient's impaired auditory comprehension abilities, he showed normal priming on auditory identification tests after study-list exposure to spoken words. Results support the idea that priming depends on perceptual systems that operate at a presemantic level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in amnesia: some explanations and predictions by the TraceLink model

After a brief overview of some of the characteristics and neuroanatomy of amnesia, a new model of amnesia is described: the TraceLink model. One novel aspect of the model is that it makes specific and testable predictions regarding semantic dementia, a recently described disorder that is viewed here as being related to amnesia. The TraceLink model consists of: a trace system (roughly the neocortix), a link system (hippocampus and adjacent areas), and a modulatory system (certain basal forebrain nuclei). Different forms of learning in the TraceLink model are explained, followed by a discussion of implicit and explicit memory, prominence (ease of recall) and persistence (resistance to brain damage), consolidation, and Ribot gradients in retrograde amnesia. Patterns of recovery from retrograde amnesia are also discussed, and novel predictions are derived regarding implicit memory and various forms of amnesia.     

Intact and long-lasting repetition priming in amnesia.

In 2 experiments, the ability of amnesic patients to exhibit long-lasting perceptual priming after a single exposure to pictures was evaluated. Ss named pictures as quickly as possible on a single occasion and later named the same pictures mixed with new pictures. In Exp 1, amnesic patients exhibited fully intact priming effects lasting at least 7 days. In Exp 2, the priming effect for both groups was shown to depend on both highly specific visual information and on less visual, more conceptual information. In contrast, recognition memory was severely impaired in the patients, as assessed by both accuracy and response time. The results provide the 1st report of a long-lasting priming effect in amnesic patients, based on a single encounter, which occurs as strongly in the patients as in normal Ss. Together with other recent findings, the results suggest that long-lasting priming and recognition memory depend on separate brain systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing time and memory for pictures.

Postexposure processing of an iconic memory following the presentation of pictures of complex, colored, naturalistic scenes was assessed in 3 experiments which examined the effects of exposure duration and mask delay upon recognition memory. Ss were 50 undergraduates. Exposure durations ranged from 50 to 550 msec and mask delays from 0 to 500 msec. For exposure durations of 300 msec and longer, recognition accuracy was primarily determined by exposure duration, and mask delay had no significant effect. For exposure durations of less than 300 msec, postexposure processing continued for up to 250 msec following the offset of a target picture, and recognition accuracy was a function of total processing time (i.e., the total time separating target and mask onsets.) This reciprocity between exposure duration and mask delay was similar to that previously demonstrated for verbal materials. The processing-time/recognition memory relationship was also shown to be due to differences in initial encoding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit false memory in the DRM paradigm: Effects of amnesia, encoding instructions, and encoding duration.

Recent studies with the Deese/Roediger–McDermott (Deese 1959; Roediger & McDermott, 1995) paradigm have revealed that amnesic patients do not only show impaired veridical memory, but also diminished false memory for semantically related lure words. Due to the typically used explicit retrieval instructions, however, this finding may reflect problems at encoding, at recollection, or both. Therefore, the present experiments examined implicit as well as explicit false memory in patients suffering from Korsakoff’s syndrome and controls. In Experiment 1, encoding instructions either focused on remembering individual list words, or on discovering semantic relationships among the words. In Experiment 2, different presentation durations were used. Results emphasize the distinction between automatic and intentional retrieval: Korsakoff patients’ veridical and false memory scores were diminished when explicit recollection was required, but not when memory was tested implicitly. Encoding manipulations only significantly affected veridical memory: Priming was reduced with thematic encoding, and explicit retrieval was facilitated when given more study time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired priming of new associations in amnesia.

We assessed priming of new associations in amnesic patients and healthy control subjects in a paradigm developed by P. Graf and D. L. Schacter (see record 1986-12203-001). Subjects were presented unrelated word pairs embedded in sentences (e.g., A BELL was hanging over the baby's CRADLE) and were asked to rate how well the sentences related the two words. Subjects were then given a word completion test. They were shown three-letter word stems and were asked to complete the stem with the first word that came to mind. In the same context condition, each word stem was presented together with the word that had appeared in the same sentence during study (e.g., BELL-CRA ). In the different context condition, each stem was presented together with a new word that had never been presented (e.g., APPLE-CRA ). Control subjects completed more words in the same context condition than in the different context condition. In contrast, amnesic patients did not complete any more words in the same context condition than in the different context condition. Indeed, across two experiments none of the amnesic patients exhibited consistent priming of new associations. Thus, although amnesic patients do exhibit entirely normal priming of preexisting memory representations, they do not appear to exhibit priming of new associations in this paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and memory for pictures of faces.

The hypothesis that pictorial aspects of face-recognition memory are lower in old age was tested in 2 studies. Young and elderly Ss viewed 48 face pictures, and then took a test containing identical copies of input faces, pictorially changed versions of input faces, and entirely new faces. Replicating prior findings, Experiment 1 showed that false recognitions of entirely new faces were higher among elderly Ss. However, there were no age differences in distinguishing identical from pictorially changed faces. Using a modified test, Experiment 2 showed that although the elderly Ss had good knowledge that changed faces were changed, they had relatively poor knowledge of how they were changed. There appears to be age differences in analytical matching of pictorial information against information in memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Remembering pictures: Pleasure and arousal in memory.

Assessed incidental memory performance for pictures that varied along the affective dimensions of pleasantness and arousal. For both an immediate and delayed (1 yr later) free-recall task, only the arousal dimension had a stable effect on memory performance: Pictures rated as highly arousing were remembered better than low-arousal stimuli. This effect was corroborated in a speeded recognition test, in which high-arousal materials encoded earlier in the experiment produced faster reaction times (RTs) than their low-arousal counterparts. Pleasantness affected RT decisions only for pictures not encoded earlier. These results suggest that whereas both the dimensions of pleasantness and arousal are processed at initial encoding, long-term memory performance is mainly affected by arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

Conducted 4 experiments investigating the role of priming effects in paired-associate learning. Ss for all 4 experiments were 5 male and 3 female alcoholics (mean age 53.8 yrs; WAIS—R IQs 85–203) with Korsakoff syndrome. Control Ss were 26 male alcoholics (mean age 47.6 yrs). Exp I illustrated the distinction between the memory impairment of amnesic (Korsakoff) Ss and their intact priming ability. In Exp II, amnesic Ss showed good paired-associate learning for related word pairs but controls performed significantly better. Exp II also showed that the forgetting of related word pairs by amnesic Ss followed the same time course as the decay of word priming. Exp III showed that amnesic Ss were as good as controls at learning related word pairs when word-association tests were used. Exp IV showed that amnesic Ss exhibited normal priming when they were asked to free associate to words that were semantically related to previously presented words. Results indicate that both priming effects and paired-associate learning of related words depended on activation, a process that is preserved in amnesia. Activation is a transient phenomenon presumed to operate on and facilitate access to preexisting representations. (67 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory dysfunction and word priming in dementia and amnesia.

Memory performance of patients with the clinical diagnosis of Alzheimer's disease was compared with performance of patients with alcoholic Korsakoff's syndrome and patients with Huntington's disease. Although all patient groups exhibited impairment on tests of verbal memory, only patients with Alzheimer's disease exhibited priming. Priming is an unconscious expression of recently encountered material, and it is intact even in severely amnesic patients. Because mildly demented patients with Alzheimer's disease exhibited impaired priming, damage to brain structures in addition to those damaged in the amnesic syndrome must occur at a relatively early stage of the disease process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional perception and memory in amnesia.

The authors examined whether perception of emotional stimuli is normal in amnesia and whether emotional arousal has the same enhancing effect on memory in amnesic patients as it has in healthy controls. Forty standardized color pictures were presented while participants rated each picture according to emotional intensity (arousal) and pleasantness (valence). An immediate free-recall test was given for the pictures, followed by a yes-no recognition test. Arousal and valence ratings were highly similar among the amnesic patients and controls. Emotional arousal (regardless of valence) enhanced both recall and recognition of the pictures, and this enhancement was proportional for amnesic patients and controls. Results suggest that emotional perception and the enhancing effect of emotional arousal on memory are intact in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)