Specificity of memory representations for spoken words

Many theories of spoken word recognition assume that lexical items are stored in memory as abstract representations. However, recent research (e.g., Goldinger, 1996) has suggested that representations of spoken words in memory are veridical exemplars that encode specific information, such as characteristics of the talker’s voice. If representations are exemplar based, effects of stimulus variation such as that arising from changes in the identity of the talker may have an effect on identification of and memory for spoken words. This prediction was examined for an implicit and explicit task (lexical decision and recognition, respectively). Comparable amounts of repetition priming in lexical decision were found for repeated words, regardless of whether the repetitions were in the same or in different voices. However, reaction times in the recognition task were faster if the repetition was in the same voice. These results suggest a role for both abstract and specific representations in models of spoken word recognition.     

Voice-specificity effects on auditory word priming

This research explores the nature of the memory traces that support spoken word identification. Specifically, do voice-specificity effects in implicit memory depend on information in a perceptual representational system or, alternatively, on the similarity of study and test exemplars? Memory for words and voices was assessed with two perceptual identification tests—the identification of words in noise and the identification of low-pass filtered words—after two encoding conditions (identification of words in noise and of words in the clear). At test, a word was presented in the same voice as at study or in a different voice. The data from the two experiments showed that study-to-test changes in voice reduced priming and that voice-specificity effects were greatest when the type of processing engaged at study overlapped with that required at test. Taken together, the results implicate the goodness of the processing match between encoding and test as the primary determinant of voice-specificity effects on perceptual identification tests and support the hypothesis that both voice and word information is represented within a single episodic memory system.     

Contributions of surface and conceptual information to recognition memory

The present experiments were designed to determine whether memory for the voice in which a word is spoken is retained in a memory system that is separate from episodic memory or, instead, whether episodic memory represents both word and voice information. These two positions were evaluated by assessing the effects of study-to-test changes in voice on recognition memory after a variety of encoding tasks that varied in processing requirements. In three experiments, the subjects studied a list of words produced by six voices. The voice in which the word was spoken during a subsequent explicit recognition test was either the same as or different from the voice used in the study phase. The results showed that word recognition was affected by changes in voice after each encoding condition and that the magnitude of the voice effect was unaffected by the type of encoding task. The results suggest that spoken words are represented in long-term memory as episodic traces that contain talker-specific perceptual information.     

Effect of divided attention on explicit and implicit aspects of recall

If subjects have to form word images before spelling a word from the image, results of a repetition of the spelling test reveal a reliable priming effect: Old words can be spelled faster than comparable control words, reflecting a form of implicit memory. We investigated whether this kind of repetition priming remains stable under conditions of divided attention in the study phase. The subjects had to spell meaningful words, meaningless non-words, and non-words that were meaningful with a backward spelling direction (troper, for example). In the testing stage, recognition judgments as a form of explicit memory were required, too. Divided attention in the study phase had a negative effect on explicit memory, as revealed by performance on the recognition task, but had little effect on implicit memory, as revealed by performance on the repetition of the spelling test. A further dissociation between implicit and explicit memory showed up as meaningful words were recognized much better than non-words, whereas implicit memory was uninfluenced by the meaningfulness variable. The disadvantage of backward spellings was not reduced with non-words (like troper) spelled backwards. Finally, we analyzed the relations between spelling times and recognition judgments and found a pattern of dependency for non-words only. Generally, the results are discussed within processing-oriented approaches to implicit memory with a special emphasis on controversial findings concerning the role of attention in different expressions of memory.     

Implicit and explicit memory for new associations in normal and amnesic subjects

Two experiments examined whether repetition priming effects on a word completion task are influenced by new associations between unrelated word pairs that were established during a single study trial. On the word completion task, subjects were presented with the initial three letters of the response words from the study list pairs and they completed these fragments with the first words that came to mind. The fragments were shown either with the paired words from the study list (same context) or with other words (different context). Both experiments showed a larger priming effect in the same-context condition than in the different-context condition, but only with a study task that required elaborative processing of the word pairs. This effect was observed with college students and amnesic patients, suggesting that word completion performance is mediated by implicit memory for new associations that is independent of explicit recollection.     

The word frequency effect in recognition memory versus repetition priming

The role of word frequency in recognition memory and repetition priming was investigated by using a manipulation of attention. In Experiment 1, the lexical decision task produced greater repetition priming for low-frequency words than for high-frequency words following either the attended or the unattended study condition. The recognition memory test, on the other hand, showed a low-frequency word advantage only following the attended study condition. Furthermore, this advantage was limited to the measure of recognition memory based on conscious recollection of the study episode. In Experiment 2, a speeded recognition memory test replicated the pattern obtained with the unspeeded recognition memory test in Experiment 1. These results argue against the view that the word frequency effects in recognition memory and repetition priming have the same origin. Instead, the results suggest that the word frequency effect in recognition memory has its locus in conscious recollection.     

Effects of hearing words, imaging hearing words, and reading on auditory implicit and explicit memory tests

In four experiments, we examined the degree to which imaging written words as spoken by a familiar talker differs from direct perception (hearing words spoken by that talker) and reading words (without imagery) on implicit and explicit tests. Subjects first performed a surface encoding task on spoken, imagined as spoken, or visually presented words, and then were given either an implicit test (perceptual identification or stem completion) or an explicit test (recognition or cued recall) involving auditorily presented words. Auditory presentation at study produced larger priming effects than did imaging or reading. Imaging and reading yielded priming effects of similar magnitude, whereas imaging produced lower performance than reading on the explicit test of cued recall. Voice changes between study and test weakened priming on the implicit tests, but did not affect performance on the explicit tests. Imagined voice changes affected priming only in the implicit task of stem completion. These findings show that the sensitivity of a memory test to perceptual information, either directly perceived or imagined, is an important dimension for dissociating incidental (implicit) and intentional (explicit) retrieval processes.     

Production and identification repetition priming in amnestic mild cognitive impairment

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

汉语听觉阈下启动效应：来自听觉掩蔽启动范式的证据

使用汉语双字词为实验材料,采用听觉掩蔽启动范式,通过3个实验考察汉语听觉阈下启动效应。结果发现,真词的听觉阈下重复启动效应显著,并且听觉阈下重复启动效应不受启动、目标发音者性别一致性的影响。但真词的阈下语音、语素和语义启动效应及假词的阈下重复和首字启动效应都不显著。这些结果说明,听觉通道阈下呈现的汉语双字词的词汇水平信息可以得到无意识加工。汉语双字词的听觉阈下启动效应可能是基于启动词整词表征的无意识激活。     

Priming and false memories from Deese-Roediger-McDermott lists on a fragment completion test with children

This study examined priming and false memories with children on a word fragment completion task using the Deese-Roediger-McDermott (DRM) paradigm. Forty-five 4th- and 5th-grade children were shown lists of words and instructed to fill in fragments with the first word that came to mind (implicit instructions) or with the words that were presented during study (explicit instructions). Reliable priming to critical lure words was found under implicit retrieval instructions, and false memory to critical lure words was found under explicit retrieval instructions. However, priming under implicit retrieval instructions did not depend on whether the critical lure word was in the study list. In addition, greater false memory was observed under explicit test instructions. The results replicate and extend research on DRM false memory illusion with children to include implicit retrieval and word fragment completion. Explanations of false memory including gist failure (Brainerd, Reyna, & Forrest, 2002) and implicit associative response (Underwood, 1965) are considered.     

Production and Identification Repetition Priming in AmnesticMild Cognitive Impairment

ABSTRACT

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

Perceptual and lexical components of auditory repetition priming in young and older adults

In the present study, we examined whether age modulates the processing of lexical and perceptual information in auditory implicit and explicit memory tests. Young and older adults performed a surface encoding task on spoken and printed words and then either identified degraded words or made explicit recognition judgments. The implicit test of perceptual identification yielded no evidence of age-related declines in the processing of either lexical information or coarse perceptual details (modality of presentation). The same test, however, produced marked age-related declines in the processing of fine-grained perceptual details (voice) when subjects were not familiarized with the talkers' voices prior to the encoding task. Marked age differences were also observed in recognition memory. These findings suggest that although aging preserves the encoding and incidental retrieval of lexical and coarse perceptual information, it affects the encoding of fine-grained perceptual information and deliberate retrieval processes.     

Direct comparison of auditory implicit memory tests

In this experiment, we examined the degree to which four implicit tests and two explicit tests, all involving auditory presentation, were sensitive to the perceptual characteristics of the stimuli presented during study. Presenting stimuli visually decreased priming in all the implicit memory tests, relative to auditory presentation. However, changing voice between study and test decreased priming only in the implicit memory tests requiring identification of words degraded by noise or by low-pass filtering, but not in those tests requiring generation from word portions (stems and fragments). Modality effects without voice effects were observed in cued recall, but the opposite pattern of results (voice effects without modality effects) was obtained in recognition. The primary new finding is the demonstration that auditory memory tests, both explicit and implicit, differ in their sensitivity to the perceptual information encoded during study.     

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.     

The effects of talker familiarity on spoken word identification in younger and older listeners

The present study was designed to examine age differences in the ability to use voice information acquired intentionally (Experiment 1) or incidentally (Experiment 2) as an aid to spoken word identification. Following both implicit and explicit voice learning, participants were asked to identify novel words spoken either by familiar talkers (ones they had been exposed to in the training phase) or by 4 unfamiliar voices. In both experiments, explicit memory for talkers' voices was significantly lower in older than in young listeners. Despite this age-related decline in voice recognition, however, older adults exhibited equivalent, and in some cases greater, benefit than young listeners from having words spoken by familiar talkers. Implications of the findings for age-related changes in explicit versus implicit memory systems are discussed.     

非熟练中—英双语者跨语言长时重复启动效应

采用跨语言长时重复启动研究范式进一步探讨非熟练中－英双语者的记忆表征模型。被试为华南师范大学大一本科生共140名。实验自变量是语言条件（同语言和跨语言）和学习状况（学习过的和未学习过的）,实验因变量是单词判断的反应时和正确率。实验1中被试在学习和测验阶段都完成概念任务,结果表明获得了跨语言长时重复启动效应。实验2中被试在学习和测验阶段完成词汇任务,结果表明没有获得跨语言长时重复启动效应。实验3中被试在学习阶段完成概念任务,在测验阶段完成词汇任务,结果表明没有获得跨语言长时重复启动效应。实验4中在学习阶段的概念任务中呈现汉语单字词,在测验阶段的词汇任务中呈现英语翻译对等词,结果表明没有获得跨语言长时重复启动效应。总的实验结果表明,在基于内隐记忆的跨语言重复启动的范式下,非熟练中－英双语者的记忆表征支持概念表征共享、词汇表征分离的观点。更重要的是,非熟练中－英双语者需要经由汉语翻译对等词的词汇表征,才能通达英语单词的概念表征,支持了词汇连接模型的观点     

IMPLICIT MEMORY IN AMNESIC PATIENTS:

Abstract— Previous observations of spared priming in amnesic patients have been based almost entirely on data from visual implicit memory tests Our research examined perceptual priming.in amnesic patients and control subjects on an auditory identification task in which previously spoken words and new words were presented in white noise We manipulated type of encoding task (semantic vs nonsemantic) and speaker's voice at study and test (same vs different) Priming was little affected.by either manipulation, and amnesic patients exhibited normal priming in all experimental conditions On an explicit test of recognition memory, by contrast, amnesic patients exhibited.severely impaired performance following the semantic study task, all subjects showed poor explicit memory following the nonsemantic study task Results are consistent with the idea that auditory priming depends largely on a presemantic auditory perceptual representation system     

Effects of dividing attention on the memory-block effect

S. M. Smith and D. R. Tindell (1997) reported that prior study of words that are orthographically similar to the solutions of test word fragments (e.g., studying ANALOGY and completing the fragment A_L _ _GY, whose solution is ALLERGY) reduced the fragment completion rate relative to a baseline condition in which unrelated words were studied. They called this effect the memory-block effect. In the present experiment, the authors replicated this effect using a larger set of materials than that used by S. M. Smith and D. R. Tindell. The authors also found that dividing attention at study eliminated the memory-block effect. This pattern mimicked the effect of dividing attention on recognition memory but differed from the effect on repetition priming effects. The authors suggest that the memory-block effect is driven by a mechanism different from that responsible for producing repetition priming effects in an implicit fragment completion test.     

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.     

Acute alcohol effects on repetition priming and word recognition memory with equivalent memory cues

Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words in the study lists. Twenty-two female and male social drinkers (age 21-24 years) completed equivalent versions of the memory tasks in two counterbalanced sessions (alcohol challenge, no-alcohol). Alcohol and the FOC manipulation affected recollection-based memory processing, but not repetition priming. Results supported alcohol's dissociative effects on memory systems.