Phonemic priming with words and pseudowords

Abstract

The bi-alphabetic nature of the Serbo-Croatian writing system allows unequivocal examination of phonemic similarity unconfounded with graphemic similarity. The Roman and Cyrillic alphabets are largely independent but map onto the same sounds. A lower-case context written in one alphabet bears no visual similarity to an uppercase target written in the other alphabet. One naming experiment and one lexical decision experiment investigated phonemic priming of high-frequency words and pseudowords with word and pseudoword contexts. For naming, targets that were phone-mically similar to the preceding context were named significantly faster than were phonemically dissimilar targets. This result was indifferent to the lexicality of the contexts and targets. For lexical decision, in contrast, phonemically similar word-word pairs showed inhibition, whereas phonemically similar pseudoword-word pairs showed facilitation relative to their phonemically dissimilar counterparts. These results were discussed in terms of (1) a model of visual word processing that posits a layer of phoneme units between letter units and word units, and (2) the idea that active word units inhibit one another in proportion to each one's frequency. In this account, phonemic similarity effects in naming are based on the states of the phoneme units, while phonemic similarity effects in lexical decision are based on the states of the word units. These results lend further support to the claim that, for readers of Serbo-Croatian, the visual computation of phonology is automatic and prelexical.     

Encoding specificity revisited: the role of semantics.

Three experiments examined the effects of semantic characteristics of word pairs on memory using the encoding specificity paradigm. The paradigm involved four phases: (a) an encoding phase to relate cues and targets, (b) a phase in which words were generated to new cues, (c) a phase for recognition of generated targets, and (d) a cued-recall phase using the original encoding cues. Encoding pairs were classified a priori as either semantically similar (e.g., alluring-PRETTY), semantically contrasting (e.g., drab-PRETTY), or semantically unrelated (e.g., sore-PRETTY). Generation pairs were classified a priori as either semantically similar (e.g., beautiful-PRETTY) or semantically contrasting (e.g., ugly-PRETTY). For recall, the results showed that both the semantic relations between the encoding cue and target and the reprovision of the encoding cue at retrieval were important factors. In the case of recognition, however, both the semantic congruence between the encoding and generation contexts and the amount of semantic elaboration provided by the encoding context were important factors.     

The effects of intravenous diazepam and hyoscine upon human memory

Diazepam and hyoscine are known to have amnesic effects when administered intravenously. The two drugs are pharmacologically quite different from each other and might be expected to produce qualitatively distinct patterns of impairment in formal memory tasks. Groups of normal volunteers received intravenous administrations of diazepam, hyoscine and saline following a double-blind procedure and were then tested on immediate serial recall. Diazepam and hyoscine produced similar deficits on concrete and abstract words whether scored for ordered recall or item recall. In terms of ordered recall, phonemic similarity produced impaired performance under all three administrations, but semantic similarity did not. In terms of item recall, diazepam and hyoscine produced impaired performance on unrelated words, but the impairment was reduced under conditions of either phonemic or semantic similarity. There were also some interesting differences between diazepam and hyoscine in terms of their effects upon the shape of the serial-position curve and upon the types of intrusion error. The results confirm that both diazepam and hyoscine impair acquisition processes but fail to distinguish the effects of the two drugs upon different categories of encoding operations.     

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.     

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.     

Conceptual similarity effects on working memory in sentence contexts: Testing a theory of anaphora

The degree of semantic similarity between an anaphoric noun phrase (e.g., the bird) and its antecedent (e.g., a robin) is known to affect the anaphor resolution process, but the mechanisms that underlie this effect are not known. One proposal (Almor, 1999) is that semantic similarity triggers interference effects in working memory and makes two crucial assumptions: First, semantic similarity impairs working memory just as phonological similarity does (e.g., Baddeley, 1992), and, second, this impairment interferes with processes of sentence comprehension. We tested these assumptions in two experiments that compared recall accuracy between phonologically similar, semantically similar, and control words in sentence contexts. Our results do not provide support for Almor's claims: Phonological overlap decreased recall accuracy in sentence contexts, but semantic similarity did not. These results shed doubt on the idea that semantic interference in working memory is an underlying mechanism in anaphor resolution.     

The semantic‐similarity effect in children: Influence of long‐term knowledge on verbal short‐term memory

The present research was designed to highlight the relation between children's categorical knowledge and their verbal short‐term memory (STM) performance. To do this, we manipulated the categorical organization of the words composing lists to be memorized by 5‐ and 9‐year‐old children. Three types of word list were drawn up: semantically similar context‐dependent (CD) lists, semantically similar context‐independent (CI) lists, and semantically dissimilar lists. In line with the procedure used by Poirier and Saint‐Aubin (1995) , the dissimilar lists were produced using words from the semantically similar lists. Both 5‐ and 9‐year‐old children showed better recall for the semantically similar CD lists than they did for the unrelated lists. In the semantic similar CI condition, semantic similarity enhanced immediate serial recall only at age 9 but contributed to item information memory both at ages 5 and 9. These results, which indicate a semantic influence of long‐term memory (LTM) on serial recall from age 5, are discussed in the light of current models of STM. Moreover, we suggest that differences between results at 5 and 9 years are compatible with pluralist models of development.     

Semantic distance effects on object and action naming

Graded interference effects were tested in a naming task, in parallel for objects and actions. Participants named either object or action pictures presented in the context of other pictures (blocks) that were either semantically very similar, or somewhat semantically similar or semantically dissimilar. We found that naming latencies for both object and action words were modulated by the semantic similarity between the exemplars in each block, providing evidence in both domains of graded semantic effects.     

Global shape cannot be attended without object identification.

Whether the global shape of objects can be processed without accessing semantic or identity information was tested. Ss judged which of 2 fragmented forms had the same global shape as a reference stimulus. Matching stimuli could be physically identical, semantically related, or unrelated. The reference stimulus and nonmatching (distractor) form could be semantically related or unrelated. Similarity effects in the related condition were unconfounded with matches nameable and nonnameable forms. For nameable forms, related matching forms facilitated performance; a related distractor disrupted performance. Semantic interference was eliminated when nameable distractors were replaced with nonnameable partners; semantic similarity effects on matching were eliminated with a nonnameable reference stimulus and with inverted targets and distractors. Access to information concerning global shape does not normally occur without object identification.     

Semantic Similarity and Immediate Serial Recall: Is There a Detrimental Effect on Order Information?

Four experiments investigated the disruptive effect of semantic similarity on short-term ordered recall. Experiments 1 and 2 contrasted immediate serial recall performance for lists of semantically similar items, drawn from the same semantic category, with performance for lists that contained items from different categories. Experiments 1 and 2 showed the usual similarity advantage for item information recall, but, contrary to expectations, there was no similarity disadvantage for the recall of order information, even when the level of item recall was controlled. Experiments 3 and 4 replicate and extend these findings by using an order reconstruction task or a limited word pool strategy, both of which yield alternate measures of order retention. These findings clearly contradict the widespread belief stating that semantic similarity hinders the short-term recall of order information. Results are discussed in the light of a retrieval-based account where the effects of semantic similarity reflect the processes called upon at recall: It is suggested that long-term knowledge is accessed to support the interpretation of degraded phonological traces.     

Interpreting semantic clustering effects in free recall

The order in which participants choose to recall words from a studied list of randomly selected words provides insights into how memories of the words are represented, organised, and retrieved. One pervasive finding is that when a pair of semantically related words (e.g., "cat" and "dog") is embedded in the studied list, the related words are often recalled successively. This tendency to successively recall semantically related words is termed semantic clustering (Bousfield, 1953; Bousfield & Sedgewick, 1944; Cofer, Bruce, & Reicher, 1966). Measuring semantic clustering effects requires making assumptions about which words participants consider to be similar in meaning. However, it is often difficult to gain insights into individual participants' internal semantic models, and for this reason researchers typically rely on standardised semantic similarity metrics. Here we use simulations to gain insights into the expected magnitudes of semantic clustering effects given systematic differences between participants' internal similarity models and the similarity metric used to quantify the degree of semantic clustering. Our results provide a number of useful insights into the interpretation of semantic clustering effects in free recall.     

Phonemic similarity effects and prelexical phonology

Ten experiments were conducted on visually presented Serbo-Croatian words and pseudowords, comprising phonemically similar and dissimilar context-target sequences. There were five main results. First, phonemic similarity effects in both lexical decision and naming are independent of graphemic similarity. Second, phonemic similarity need not facilitate lexical decision; the direction of its effect depends on lexicality, target frequency, and type of similarity (specifically, the position of the phoneme that distinguishes context and target). Third, phonemic similarity expedites the naming of words and pseudowords, and to the same degree. Fourth, phonemic similarity is negated in naming, but not in lexical decision, when the visually presented context and target are stressed differently. Fifth, the phonemic similarity effect occurs even when the context is a masked pseudoword. These results are discussed in terms of a model in which word-processing units are activated routinely by phoneme-processing units, and in which compositionally similar word units, when activated, inhibit one another in proportion to each's familiarity. In this model, the phonemic similarity effect in naming is based on the states of phoneme units, whereas the phonemic similarity effect in lexical decision is based on the states of word units. Overall, the results comport with an account in which phonology is computed prelexically and automatically.     

Phonological and semantic strategies in immediate serial recall

It has been suggested that certain theoretically important anomalous results in the area of verbal short-term memory could be attributable to differences in strategy. However there are relatively few studies that investigate strategy directly. We describe four experiments, each involving the immediate serial recall of word sequences under baseline control conditions, or preceded by instruction to use a phonological or semantic strategy. Two experiments varied phonological similarity at a presentation rate of one item every 1 or 2 seconds. Both the control and the phonologically instructed group showed clear effects of similarity at both presentation rates, whereas these were largely absent under semantic encoding conditions. Two further experiments manipulated word length at the same two rates. The phonologically instructed groups showed clear effects at both rates, the control group showed a clear effect at the rapid rate which diminished with the slower presentation, while the semantically instructed group showed a relatively weak effect at the rate of one item per second, and a significant reverse effect with slower presentation. The latter finding is interpreted in terms of fortuitous differences in inter-item rated associability between the two otherwise matched word pools, reinforcing our conclusion that the semantically instructed group were indeed encoding semantically. Implications for controlling strategy by instruction are discussed.     

Emotional mood states and memory: elaborative encoding, semantic processing, and cognitive effort

The effects of experimentally induced mood states on recall of target words embedded in sentences or alone were examined in three experiments. All experiments focused on the role of a depressed-mood induction on recall and looked at the effects of elaborative encoding, semantic processing, or cognitive effort. The overall effect of the depressed-mood state was to reduce recall in all three situations; however, the opportunity to process information semantically still led to superior recall in the depressed condition. In contrast, the superiority of recall of high-effort items disappeared in the depressed condition, suggesting that subjects may differentially allocate resources when under a depressed-mood state. The results are briefly discussed within the framework of a resource allocation theory.     

Phonological and semantic strategies in immediate serial recall

It has been suggested that certain theoretically important anomalous results in the area of verbal short-term memory could be attributable to differences in strategy. However there are relatively few studies that investigate strategy directly. We describe four experiments, each involving the immediate serial recall of word sequences under baseline control conditions, or preceded by instruction to use a phonological or semantic strategy. Two experiments varied phonological similarity at a presentation rate of one item every 1 or 2 seconds. Both the control and the phonologically instructed group showed clear effects of similarity at both presentation rates, whereas these were largely absent under semantic encoding conditions. Two further experiments manipulated word length at the same two rates. The phonologically instructed groups showed clear effects at both rates, the control group showed a clear effect at the rapid rate which diminished with the slower presentation, while the semantically instructed group showed a relatively weak effect at the rate of one item per second, and a significant reverse effect with slower presentation. The latter finding is interpreted in terms of fortuitous differences in inter-item rated associability between the two otherwise matched word pools, reinforcing our conclusion that the semantically instructed group were indeed encoding semantically. Implications for controlling strategy by instruction are discussed.     

Integrative and semantic relations equally alleviate age-related associative memory deficits

Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms.     

Semantic similarity and immediate serial recall: Is there an effect on all trials

In immediate serial recall, items are better recalled when they are all drawn from the same semantic category. This is usually accounted for by a two-stage retrieval-based framework, in which, at recall, long-term knowledge is used to reconstruct degraded phonological traces. The category shared by list items would serve as an additional retrieval cue restricting the number of recall candidates. Usually, the long-term search set is not defined, but some authors have suggested an extended search set and others a restricted set that is composed of the most recently presented items. This was tested in an experiment in which participants undertook an immediate serial recall task either alone or under articulatory suppression with either semantically similar or dissimilar lists. A trial-by-trial analysis revealed that, in both quiet and suppression conditions, items from similar lists were better recalled on all the trials, including the first one. In addition, there was no interaction between semantic similarity and trial, indicating that the effect of similarity was of similar size on all the trials. The results are best interpreted within a proposal suggesting an extended long-term search set.     

Differences in semantic encoding as a function of reading comprehension skill

Using a modified Stroop procedure, we examined the extent to which the semantic encoding of a word is governed by the context within which that word appears. Good and poor comprehenders named the color of target words following their reading of either sentences or single words representing the object nouns of the sentences. Target words represented contextually emphasized (appropriate) attributes of the object nouns, nonemphasized (inappropriate) attributes of these nouns, or object attributes not related to these nouns (neutral). For single-word contexts, all subjects exhibited equal semantic interference to appropriate and inappropriate targets, relative to neutral targets. For sentence contexts, however, good comprehenders exhibited semantic interference only to appropriate targets, whereas poor comprehenders again exhibited equal interference to appropriate and inappropriate targets. These findings suggest that differences in comprehension skill may be attributable, at least in part, to fundamental differences in the way in which sentences are semantically encoded.     

Priming effects with phonemically similar words:

Recent studies have demonstrated that two-word lexical decision times may be influenced by the degree of shared phonemic and graphemic similarity between the items. Specifically, graphemically similar rhyming pairs (e.g., BRIBE-TRIBE) are responded to more rapidly than graphemically and phonemically unrelated controls (e.g., BREAK-DITCH), whereas graphemically similar nonrhyming pairs (TOUCH-COUCH) are responded to more slowly. In a series of three experiments, the present study examined the encoding-bias explanation (Meyer, Schvaneveldt, & Ruddy, 1974) of these effects by modifying or eliminating the graphemic information available. Experiment 1 found that rhyming facilitation was not eliminated by presenting the initial pair member auditorily. Experiments 2 and 3 showed the rhyming effect to be independent of graphemic similarity with equivalent facilitation for graphemically similar and dissimilar (EIGHT-MATE) rhymes. These findings were all considered contrary to the predictions of the encoding-bias model. As an alternative, a model by Forster (1976) was employed. In the Forster model, sensory representations of lexical entries are represented as entries in a separate access file organized by physical, rather than semantic, similarity. The rhyming facilitation can then be seen as the result of spreading activation between entries in this file.     

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.