Precategorical acoustic storage and postcategorical lexical storage

A variety of experimental findings have indicated that a system of precategorical acoustic storage is responsible for the recency effect obtained in the immediate serial recall of sequences of digits, consonants, or syllables. This study investigated whether such findings could be generalized to the recall of sequences of words. Experiment 1 showed that phonemic similarity among a sequence of words failed to reduce the modality effect or the recency effect. Experiment 2 demonstrated that this finding was not attributable to a failure to control the phonemic properties of the stimulus material. Experiment 3 showed that the stimulus suffix effect obtained with sequences of words was not affected by the acoustic similarity between the list items and the stimulus suffix. Finally, Experiment 4 demonstrated that phonemic similarity among a sequence of words failed to reduce the stimulus suffix effect. These results were explained by extending the original model of short-term memory to incorporate a system of postcategorical lexical storage.     

Memory for pictures and words as a function of level of processing: Depth or dual coding?

The experiment was designed to test differential predictions derived from dual-coding and depth-of-processing hypotheses. Subjects under incidental memory instructions free recalled a list of 36 test events, each presented twice. Within the list, an equal number of events were assigned to structural, phonemic, and semantic processing conditions. Separate groups of subjects were tested with a list of pictures, concrete words, or abstract words. Results indicated that retention of concrete words increased as a direct function of the processing-task variable (structural < phonemic 相似文献   

Reconstructive retrieval deficits in Broca's aphasia

Anterior aphasic patients' ability to utilize the phonemic and/or semantic features of verbal material for retention purposes was investigated. In the first experiment, patients were asked to either detect word repetitions, phoneme repetitions, or rhymes in a list of items. The aphasics performed well on word and phoneme repetition detection but below both normals and amnesic Korsakoffs on rhyme detection. In the second experiment the patients were instructed to analyze either the physical, phonemic, or semantic features of words they were later asked to recognize. Aphasics were differentially affected (as were normals) by these instructions: semantic feature analysis resulted in the best performance, followed by phonemic feature analysis. It was concluded that anterior aphasics can analyze, recirculate, and even store the phonemic features of words, but find difficulty in reconstructing the originally presented item from these features.     

Constant capacity in an immediate serial-recall task: a logical sequel to Miller (1956)

We assessed a hypothesis that working memory capacity should include a constant number of separate mental units, or chunks (cf. Miller, 1956). Because of the practical difficulty of measuring chunks, this hypothesis has not been tested previously, despite wide attention to Miller's article. We used a training procedure to manipulate the strength of associations between pairs of words to be included in an immediate serial-recall task. Although the amount of training on associations clearly increased the availability of two-item chunks and therefore the number of items correct in list recall, the number of total chunks recalled (singletons plus two-word chunks) appeared to remain approximately constant across association strengths, supporting a hypothesis of constant capacity.     

Retention of phonemic and semantic features of words

Subjects were asked to detect either repetitions, rhymes, or words from the same category during an auditory or visual list presentation. It was discovered in both cases that the number of intervening words had a differential effect on probability of detection, with phonemic feature detection deteriorating more rapidly than semantic. However, "rate" of presentation did not have a differential effect on the probability of feature detection, since phonemic and semantic feature detection improved equally with increased interword interval time. It was suggested that phonemic feature retention might be more vulnerable than semantic feature retention to interference.     

The effect of stress on the linguistic generalization of bilingual individuals

Spanish-English coordinate bilinguals were subjects in a GSR linguistic conditioning experiment using strong and mild buzzer conditions and spoken stimuli. Each subject was randomly assigned to one of two lists of words and one of two levels of buzzer sounds. A Spanish word from the Spanish list and an English word from the English list functioned as a conditioned word (CS). The lists were Spanish and English words related semantically and phonemically and unrelated to the CS. Generalization was studied under conscious and unconscious conditions. We found that both buzzer conditions resulted in significantly greater GSR responses to semantic and phonemic words than to words unrelated to the CS. Generalization to semantic words was not significantly greater than to phonemic words. There was a tendency toward greater phonemic than semantic generalization in the strong buzzer condition. The opposite was observed regarding the mild buzzer. The results were the same in both lists and languages. Under a conscious and unstressful condition, generalization to semantic words was found to be more prominent than to phonemic words. This suggests that under normal condition semantic generalization is mediated by conscious cognition. We concluded that strong emotion produces an increase in phonemic, as compared to semantic, generalization in both languages. Hence, primitivization of the subjects' cognitive and linguistic functioning is assumed to have occurred. These results are important in understanding the deleterious effect that stressful situations may have on linguistic functioning and cognition in bilinguals.     

Dimensions of lexical coding in Chinese and English

Phonology and orthography are closely related in some languages, such as English, and they are nearly unrelated in others, such as Chinese. The effects of these differences were assessed in a study of the roles of phonemic, graphemic, and semantic information on lexical coding and memory for Chinese logographs and English words. Some of the stimuli in the two languages were selected such that the natural confounding between phonemic and graphemic information in English was matched in the set of Chinese words used. An initial scaling study indicated that this attempt to equate degree of phonemic-graphemic confounding was successful. A second experiment used a recognition memory task for English and Chinese words with separate subject groups of native speakers of the two languages. Subjects were to select one of a pair of test words that was phonemically, graphemically, or semantically similar to a word on a previously studied list. Differences in the dimensions of lexical coding in memory were demonstrated in significant Stimulus Type by Decision Type interactions in the recognition data. Chinese-speaking subjects responded most rapidly and accurately in the graphemic recognition task, whereas performance was generally equivalent in all three tasks for the English-speaking subjects. Alphabetic and logographic writing systems apparently activate different coding and memory mechanisms such that logographic characters produce significantly more visual information in memory, whereas alphabetic words result in a more integrated code involving visual, phonological, and semantic information.     

Orthography,phonology, and meaning: Word features that give rise to feelings of familiarity in recognition

In the present study, it is shown that participants can recognize test cues as resembling studied words even when these cues cannot be used to recall the words that they resemble. After studying a list of words, participants were given a cued recall test for which half of the cues resembled studied words on one particular feature dimension and half resembled nonstudied words on that dimension. In addition to trying to use each cue to recall a study list item, participants rated the degree to which the cue resembled a studied word. For those cues whose targets could not be identified, the mean rating was higher when the cues corresponded to studied items than when they corresponded to nonstudied items. Various types of features can give rise to this phenomenon, which was found when orthographic, phonemic, and semantic cued recall tasks were used. In all of these cases of recognition without recall, analysis of receiver operating characteristics revealed a pattern consistent with that of an equal-variance signal detection process.     

Reading Words and Wirds: Phonology and Lexical Access

Naming latency for printed words is inversely related to their frequency. Four experiments were run to test whether the naming of non-words that are homophones of words (pseudohomophones) is similarly influenced by the frequency of those words. McCann and Besner (1987) failed to find such a frequency effect for pseudohomophones when they were presented in a list of non-words. The present studies show that list structure is critical: A frequency effect occurs for pseudohomophones in a list only of homophones and in a list containing words. The list structure effect was found for three different stimulus lists and suggests that lexical access is strategic. If none of the items in a list has a lexical entry, then pronunciation may be the product of a non-lexical process. If all items have a lexical entry that may be accessed orthographically or phonologically, then pronunciation will be the product of a lexical process.     

The phonological similarity effect in serial recognition

An experiment is reported examining the effect of consistent phonemic similarity among list items on memory retention in a task that is independent of overt speech production, the serial recognition task. Lists of consonant-vowel-consonant (CVC) words and nonwords were constructed such that although phoneme overlap was manipulated (i.e., shared vowel and final consonant [_VC], initial consonant and vowel [CV_], or the two consonants [C_C]), similarity remained constant. The results show that the influence of sub-syllabic mechanisms on STM performance is independent of speech production processes, and similarity in the pattern of results suggests that the same mechanisms subserve the recall of words and nonwords in STM. It is argued that the results are more consistent with psycholinguistic models than nonlinguistic models of STM, and implications for current STM models are discussed.     

The phonological similarity effect in serial recognition

An experiment is reported examining the effect of consistent phonemic similarity among list items on memory retention in a task that is independent of overt speech production, the serial recognition task. Lists of consonant-vowel-consonant (CVC) words and nonwords were constructed such that although phoneme overlap was manipulated (i.e., shared vowel and final consonant [_VC], initial consonant and vowel [CV_], or the two consonants [C_C]), similarity remained constant. The results show that the influence of sub-syllabic mechanisms on STM performance is independent of speech production processes, and similarity in the pattern of results suggests that the same mechanisms subserve the recall of words and nonwords in STM. It is argued that the results are more consistent with psycholinguistic models than nonlinguistic models of STM, and implications for current STM models are discussed.     

Judgments of recency and their relation to recognition memory

Subjects went through a list of 550 high- and low-frequency words (Experiment 1) or concrete and abstract words (Experiment 2) in which individual items were repeated at lags of 5 to 30 other items. They made old versus new recognition decisions on each word and followed each "old" response with a numerical judgment of recency (JOR). Recognition judgments displayed the mirror effect. Conditionalized on recognition, JORs were shorter for low-frequency words than for high-frequency words, and shorter for concrete words than for abstract words. This was true at every lag, suggesting that recognition and JOR may have a common basis. However, recognition confidence ratings obtained in Experiment 3 proved much less sensitive than JOR to test lag. Memory models applicable to multiple judgment tasks will be needed to account for such findings.     

Chunking during serial learning by a pigeon: II. Integrity of a chunk on a new list

Can a group of items that a pigeon chunks on one list function as such on a second list? In Experiment 1, the ordinal position of the chunk was held constant across both lists. Following training on a list of colors and achromatic geometric forms (A----B----C----D'----E'), the integrity of the color chunk [A----B----C] was maintained on a list of five colors (A----B----C----F----G) even though the basis for establishing that chunk was eliminated. The integrity of the chunk [A----B----C] was also maintained on a new list of colors and forms (A----B----C----D*----E*). In Experiment 2, the ordinal position of a chunk established on list1 (A----B----C'----D') was changed on list 2. As shown by positive transfer between lists 1 and 2, the integrity of the chunks [A----B] and [C'----D'] was maintained on lists X'----A----B----Y' and X'----C'----D'----Y', respectively. Conversely, the heterogeneous list X'----B----C'----Y' took longer to learn than the original list.     

Tactile retention: Reading with the skin

In four experiments, subjects were required to identify sequences of random digits, letters, or words drawn on the skin. The passive tactile digit span was determined to be three items when the digits were drawn with an interstimulus interval of 1 sec. Identification was significantly better for words than for random letter sequences. Slower rates of presentation produced better tactile retention. The deficiencies in passive retention were ascribed to two processes, the generation of aftersensations and a difficulty in the generation of a unitary percept. Perceptual activity may normally act to inhibit aftersensations and facilitate the construction of a unitary percept The results supported the notion that the tactile span of immediate memory is labile and may be limited by passivity.     

Lexical viability constraints on speech segmentation by infants

The Possible Word Constraint limits the number of lexical candidates considered in speech recognition by stipulating that input should be parsed into a string of lexically viable chunks. For instance, an isolated single consonant is not a feasible word candidate. Any segmentation containing such a chunk is disfavored. Five experiments using the head-turn preference procedure investigated whether, like adults, 12-month-olds observe this constraint in word recognition. In Experiments 1 and 2, infants were familiarized with target words (e.g., rush), then tested on lists of nonsense items containing these words in "possible" (e.g., "niprush" [nip+rush]) or "impossible" positions (e.g., "prush" [p+rush]). The infants listened significantly longer to targets in "possible" versus "impossible" contexts when targets occurred at the end of nonsense items (rush in "prush"), but not when they occurred at the beginning (tan in "tance"). In Experiments 3 and 4, 12-month-olds were similarly familiarized with target words, but test items were real words in sentential contexts (win in "wind" versus "window"). The infants listened significantly longer to words in the "possible" condition regardless of target location. Experiment 5 with targets at the beginning of isolated real words (e.g., win in "wind") replicated Experiment 2 in showing no evidence of viability effects in beginning position. Taken together, the findings suggest that, in situations in which 12-month-olds are required to rely on their word segmentation abilities, they give evidence of observing lexical viability constraints in the way that they parse fluent speech.     

Subjective memorability and the mirror effect.

The mirror effect refers to the common finding that hit and false alarm rates on a recognition test are inversely related. The present research investigated the generality of the mirror effect (to rare words) and tested whether the effect might be grounded in accurate estimates of word memorability. The first 2 experiments showed that although high- and low-frequency words exhibit a mirror effect, rare words do not. Furthermore, contrary to expectations, Ss consistently (and mistakenly) predicted that memorability was directly correlated with frequency of usage. These findings weight against the idea that the mirror effect arises because of a S's ability to reject low-frequency lures on the grounds that such words would have been remembered had they appeared previously. Instead, the rejection of lures from different frequency categories may be determined by their semantic or phonemic overlap with list targets, and an analysis along these lines may help to explain why rare words constitute an exception to the otherwise ubiquitous mirror effect.     

A recency-based account of the list length effect in free recall

Free recall was examined using the overt rehearsal methodology with lists of 10, 20, and 30 words. The standard list length effects were obtained: As list length increased, there was an increase in the number and a decrease in the proportion of words that were recalled. There were significant primacy and recency effects with all list lengths. However, when the data were replotted in terms of when the words were last rehearsed, recall was characterized by extended recency effects, and the data from the different list lengths were superimposed upon one another. These findings support a recency-based account of episodic memory. The list length effect reflects the facts that unrehearsed words are less recent with longer lists, and that with longer lists, a reduced proportion of primacy and middle items may be rehearsed to later positions.     

Investigating the childhood development of working memory using sentences: New evidence for the growth of chunk capacity

Child development is accompanied by a robust increase in immediate memory. This may be due to either an increase in the number of items (chunks) that can be maintained in working memory or an increase in the size of those chunks. We tested these hypotheses by presenting younger and older children (7 and 12 years of age) and adults with different types of lists of auditory sentences: four short sentences, eight short sentences, four long sentences, and four random word lists, each read with a sentence-like intonation. Young children accessed (recalled words from) fewer clauses than did older children or adults, but no age differences were found in the proportion of words recalled from accessed clauses. We argue that the developmental increase in memory span was due to a growing number of chunks present in working memory with little role of chunk size.     

Creating proactive interference in immediate recall: Building a DOG from a DART, a mop, and a FIG

Phonemic codes are accorded a privileged role in most current models of immediate serial recall, although their effects are apparent in short-term proactive interference (PI) effects as well. The present research looks at how assumptions concerning distributed representation and distributed storage involving both semantic and phonemic codes might be operationalized to produce PI in a short-term cued recall task. The four experiments reported here attempted to generate the phonemic characteristics of a nonrhyming, interfering foil from unrelated filler items in the same list. PI was observed when a rhyme of the foil was studied or when the three phonemes of the foil were distributed across three studied filler items. The results suggest that items in short-term memory are stored in terms of feature bundles and that all items are simultaneously available at retrieval.     

False working memories? Semantic distortion in a mere 4 seconds

False memories are well-established, episodic memory phenomena: Semantically related associates are confidently and erroneously remembered as studied items. We report four experiments yielding similar effects in a working memory paradigm. Four semantically related words were retained over a brief interval. Whether or not the interval was filled with a math verification task, semantically related lures were mistakenly recognized as members of the memory set and took longer to reject than did unrelated negative probes. In a short-term recall task, semantic intrusions exceeded other errors (e.g., phonemic). Our results demonstrate false memory effects for a subspan list when a mere 4 sec was given between study and test. Such rapid semantic errors presumably result from associative processing, may be related to familiarity-based proactive interference in working memory, and are consistent with recent models that integrate short- and long-term memory processes.