Does the proportion of associatively related pairs modulate the associative priming effect at very brief stimulus-onset asynchronies?

A number of experiments have shown that the magnitude of the associative priming effect increases substantially when there is a high proportion of associatively related pairs in the list when the stimulus-onset asynchrony (SOA) between prime and target is long (more than 400 ms). In the present series of experiments we manipulated the proportion of associatively related pairs when the SOA was very brief (less than 200 ms). If processing of a target word is facilitated automatically by the prior presentation of a related prime, the occurrence of priming should be unaffected by the proportion of related pairs in the list. Experiment 1 showed a robust relatedness proportion effect obtained in a double lexical decision task. Experiments 2-4 used the masked priming technique at several very short SOAs (66, 116, and 166 ms) in lexical decision and naming. The results showed a reliable associative priming effect in the two tasks, which did not differ as a function of the proportion of related pairs. Finally, Experiment 5 used unmasked primes at an 83-ms SOA in which the primes remained in view after the target presentation. As in Experiments 2-4, the associative effect was not modulated by the proportion of associatively related pairs. The implications of these results are discussed.     

The time course of semantic and associative priming effects is different in an attentional blink task

When two targets are presented using rapid serial visual presentation (RSVP) and the interval between the targets is 200–500 ms, report of the second target is impaired, a phenomena known as the attentional blink (AB). This study examined the time course of semantic-only and associate–semantic priming effects during an AB task. Three RSVP experiments were conducted using targets that shared either a semantic-only or an associative–semantic relationship. The results of the three experiments demonstrated semantic-only priming effects at the shortest stimulus onset asynchronies (SOAs). Associative–semantic priming was evident at shorter and longer SOAs. This suggests that priming in an AB task is driven by conceptual overlap facilitating lexical access at short SOAs and with longer SOAs lexical access benefits from word associations links between targets.     

Direction of association between targets in a RSVP task influences priming at very short but not long SOAs

When two targets are presented using rapid serial visual presentation (RSVP) and the interval between the targets is 200–500 ms, detection or identification of the second target is impaired. This impairment in second target report is known as the attentional blink (AB). This study sought to examine the impact of the direction of target association on priming during an AB task using very short and long SOAs. Two experiments were conducted using dual-stream RSVP tasks and targets that either shared an associative relationship or were unrelated to one another. The direction of association between the targets was also varied so that associatively related targets were presented in the forward (strongest association from target 1 to target 2) or backward directions of association (strongest association from target 2 to target 1). In Experiment 1 very short SOAs between targets (27–213 ms) were used. Priming was evident at the same SOAs for both targets presented in the backward direction of association. However, for targets presented in the forward direction of association, priming occurred for target 1 and target 2 at different SOAs. Experiment 2 used longer SOAs between targets (107 to 535 ms) and it was determined that while direction of association between the targets did not affect priming, there was a larger priming effect for target 2 than for target 1. The results of the two experiments indicate that direction of association between targets influences priming in RSVP tasks that use very short but not long SOAs. The results are discussed in relation to the two-stage response competition model of Potter et al. (J Exp Psychol Hum Percept Perform 28:1149–1162, 2002).     

Summation priming in aphasia: evidence for alterations in semantic integration and activation

The present study used a lexical decision paradigm to study the summation of priming effects in normal and aphasic participants. The amount of priming produced by pairs of definitionally converging associative words was compared to the amount of priming produced by pairs of single associative words and non-words in two experiments in which the ISI between primes and targets varied from 200 ms (Experiment 1) to 600 ms (Experiment 2). Control subjects showed a pattern of additive summation priming at the short ISI and overadditive summation priming at the longer ISI. Broca's aphasics showed overadditive priming at the short ISI and no significant priming at the longer ISI; Wernicke's aphasics showed no significant priming at the short ISI and additive priming at the longer ISI. These results suggest that aphasics differ from normals in their ability to integrate the activation derived from multiple linguistic associations and may provide an account of some of the clinical phenomenology of these patients.     

Lexical processing of ambiguous words: dominance or associative strength?

Four experiments examined the role of meaning frequency (dominance) and associative strength (measured by associative norms) in the processing of ambiguous words in isolation. Participants made lexical decisions to targets words that were associates of the more frequent (dominant) or less frequent (subordinate) meaning of a homograph prime. The first two experiments investigated the role of associative strength at long SOAs (Stimulus Onset Asynchrony) (750 ms.), showing that meaning is facilitated by the targets' associative strength and not by their dominance. The last two experiments traced the role associative strength at short SOAs (250 ms), showing that the manipulation of the associative strength has no effect in the semantic priming. The conclusions are: on the one hand, semantic priming for homographs is due to associative strength manipulations at long SOAs. On the other hand, the manipulation of the associative strength has no effect when automatic processes (short SOAs) are engaged for homographs.     

The relative time course of semantic and phonological activation in reading Chinese

The relative time course of semantic and phonological activation was investigated in the context of whether phonology mediates access to lexical representations in reading Chinese. Compound words (Experiment 1) and single-character words (Experiments 2 and 3) were preceded by semantic and phonological primes. Strong semantic priming effects were found at both short (57 ms) and long (200 ms) stimulus onset asynchrony (SOA), but phonological effects were either absent in lexical decision (Experiment 1), were present only at the longer SOA in character decision (Experiment 2) or were equally strong as semantic effects in naming (Experiment 3). Experiment 4 revealed facilitatory or inhibitory effects, depending on SOA, in phonological judgments to character pairs that were not phonologically but semantically related. It was concluded that, in reading Chinese, semantic information in the lexicon is activated at least as early and just as strongly as phonological information.     

Phonological access of the lexicon: evidence from associative priming with pseudohomophones.

Pseudohomophones were used in a primed naming task. In Experiments 1 and 2, target pseudowords that sounded like real words (e.g., CHARE) were preceded either by context words that related associatively to the word with which the target was homophonic (TABLE-CHARE) or by context words that were not associatively related (NOVEL-CHARE). Control pairs were TABLE-THARE and NOVEL-THARE (Experiment 1) and TABLE-CHARK and NOVEL-CHARK (Experiment 2). In relation to NOVEL, TABLE benefited the naming of CHARE but not the naming of THARE or CHARK. TAYBLE-CHAIR pairs were used in Experiment 3. If the prime TAYBLE activated/table/,then/chair/would be activated associatively and the target CHAIR would be named faster than if TARBLE was the prime. Experiment 4 extended the design of Experiment 3 to include TABLE-CHAIR pairs and a comparison of a short (280 ms) and a long (500 ms) delay between context and target onsets. The priming due to associated pseudohomophones was unaffected by onset asynchrony and equal in magnitude to that due to associated words. Results suggest that lexical representations are coded and accessed phonologically.     

When bees hamper the production of honey: lexical interference from associates in speech production

In this article, the authors explore semantic context effects in speaking. In particular, the authors investigate a marked discrepancy between categorically and associatively induced effects; only categorical relationships have been reported to cause interference in object naming. In Experiments 1 and 2, a variant of the semantic blocking paradigm was used to induce two different types of semantic context effects. Pictures were either named in the context of categorically related objects (e.g., animals: bee, cow, fish) or in the context of associatively related objects from different semantic categories (e.g., apiary: bee, honey, bee keeper). Semantic interference effects were observed in both conditions, relative to an unrelated context. Experiment 3 replicated the classic effects of categorical interference and associative facilitation in a picture-word interference paradigm with the material used in Experiment 2. These findings suggest that associates are active lexical competitors and that the microstructure of lexicalization is highly flexible and adjustable to the semantic context in which the utterance takes place.     

Semantic priming and repetition priming from masked words: evidence for a center-surround attentional mechanism in perceptual recognition

Two lexical decision experiments compared semantic and repetition priming by masked words. Experiment 1 established prime-mask stimulus onset asynchronies (SOAs) with presence-absence detection judgments. Primes presented at detection-threshold SOAs produced equal facilitation for repeated and semantically related targets: 26 ms and 24 ms. Experiment 2 established SOAs with semantic judgments. Primes presented at 70% of the semantic-threshold SOA to mimic the exposure conditions of Experiment 1 produced slightly greater facilitation for repeated targets but a tendency toward inhibition for semantically related targets: 38 ms and -6 ms. These results confirm Dagenbach, Carr, and Wilhelmsen's (1989) report that strategies induced by threshold-setting tasks can influence masked priming. In addition, Experiment 2 suggests a mechanism for retrieving weakly activated semantic codes into consciousness that relies on the center-surround principle to enhance activation of sought-for codes and to inhibit related codes stored nearby in the semantic network.     

Strategic effects in associative priming with words,homophones, and pseudohomophones

G. Lukatela and M. T. Turvey (1994a) showed that at a 57-ms prime-presentation duration, the naming of a visually presented target word (frog) is primed not only by an associate word (toad) but also by a homophone (towed) and a pseudohomophone (tode) of the associate. At a 250-ms prime presentation, priming with the homophone was no longer observed. In Experiment 1, the authors replicated these priming effects in the Dutch language. Next, the authors extended the priming paradigm to a word/legal-nonword lexical decision task (Experiments 2 and 3) and a word/pseudohomophone decision task (Experiment 4). Phonologically mediated associative priming was observed in all conditions with pseudohomophonic primes but not with homophonic primes. The latter did not prime at a 250-ms prime-presentation time and at 57 ms in the word/pseudohomophone task.     

Automatic and attentional priming in young and older adults: reevaluation of the two-process model.

Three experiments addressed the distinction between automatic and attentional mechanisms underlying semantic priming effects by factorially crossing prime-target relatedness, expectancy, and SOA in a task (pronunciation) that minimized postlexical checking processes. Also, possible age-related (young vs. older adults) differences in the automatic and attentional mechanisms were addressed. Across all experiments there was evidence of a Relatedness x Expectancy x SOA interaction, which is inconsistent with the notion of independent automatic and attentional mechanisms in semantic priming and the notion of a self-encapsulated modular lexicon. The results also indicated age-related differences in the build-up of the expectancy effect across SOAs when the prime was visually available for only 200 ms, independently of the prime-target SOA (Experiments 1 and 3), but not when the prime was visually available throughout the SOA (Experiment 2).     

On the interaction between linguistic and pictorial systems in the absence of semantic mediation: Evidence from a priming paradigm

Use of the letter search task in the context of the priming paradigm has proved to be an invaluable tool for the investigation of the strategic control of processes involved in word recognition. In particular, previous findings that letter search on a prime word interferes with the priming of semantically/associatively related targets, but not with the priming of either identical or morphologically related targets, suggests that letter search may selectively interfere with semantic processing, leaving other levels of processing intact. In the present experiments, this investigation was extended by exploring the priming of pictures following letter search of either a same-concept word (repetition priming) or a semantically/associatively related word (semantic priming). There was significant repetition priming of picture categorization following both silent reading and letter search of the prime word (Experiments 1 and 2). In contrast, semantic priming of pictures was found only following silent reading of the prime; there was no semantic priming following letter search of the prime (Experiment 2). This pattern of results suggests that focusing attention at the letter level during prime processing selectively attenuates activation of the semantic system by the prime. It does not prevent the spread of activation between the lexical and pictogen levels of representation of a given concept.     

Discriminating Semantic from Episodic Relatedness in Young and Older Adults

ABSTRACT

The ability of young (aged 18–30) and older (aged 60–80) adults to discriminate pre-experimental (semantic) from experimental (episodic) associations was examined. Participants studied a list containing semantically related and unrelated word pairs and then made either associative recognition (Experiments 1a and b) or semantic relatedness (Experiment 2) judgments at various response deadlines. For associative recognition judgments, both young and older adults benefited from semantic relatedness, leading to more hits for related than unrelated pairs, and at the long response deadline, older adults' performance on those pairs matched that of young participants. Also, both young and older adults demonstrated superior discrimination for unrelated lures whose members had originally been studied in related pairs – evidence for recall-to-reject processing in both age groups. In making semantic relatedness judgments, both young and older adults showed an episodic priming effect. When older adults can rely on long-standing associations, their performance resembles that of young adults – both in associative recognition and in episodic priming.     

Associative and phonological priming effects after letter search on the prime

Responses to target words typically are faster and more accurate after associatively related primes (e.g., "orange-juice") than after unrelated primes (e.g., "glue-juice"). This priming effect has been used as an index of semantic activation, and its elimination often is cited as evidence against semantic access. When participants are asked to perform a letter search on the prime, associative priming typically is eliminated, but repetition and morphological priming remain. It is possible that priming survives letter search when it arises from activity in codes that are represented before semantics. This experiment examined associative and phonological priming to determine whether priming from phonologically related rhymes would remain after letter search (e.g., "moose-juice"; rhyming items were orthographically dissimilar). When participants read the primes, equivalent associative and phonological priming effects were obtained; both effects were eliminated after letter search. The impact of letter search on semantic and phonological access and implications for the structural arrangement of lexical and semantic memory are discussed.     

Associative priming in a masked perceptual identification task: Evidence for automatic processes

Two experiments investigated the influence of automatic and strategic processes on associative priming effects in a perceptual identification task in which prime-target pairs are briefly presented and masked. In this paradigm, priming is defined as a higher percentage of correctly identified targets for related pairs than for unrelated pairs. In Experiment 1, priming was obtained for mediated word pairs. This mediated priming effect was affected neither by the presence of direct associations nor by the presentation time of the primes, indicating that automatic priming effects play a role in perceptual identification. Experiment 2 showed that the priming effect was not affected by the proportion (.90 vs. .10) of related pairs if primes were presented briefly to prevent their identification. However, a large proportion effect was found when primes were presented for 1000 ms so that they were clearly visible. These results indicate that priming in a masked perceptual identification task is the result of automatic processes and is not affected by strategies. The present paradigm provides a valuable alternative to more commonly used tasks such as lexical decision.     

Event-related potentials indicate different processes to mediate categorical and associative priming in person recognition

Whether representations of people are stored in associative networks based on co-occurrence or are stored in terms of more abstract semantic categories is a controversial question. In the present study, participants performed fame decisions to unfamiliar or famous target faces (Experiment 1) or names (Experiment 2), which were primed, either by highly associated celebrity names or by names from the same occupational category, or were unprimed. Reaction times and event-related potentials (ERPs) were recorded. Reaction times yielded significant priming effects for both associated and same category conditions. ERPs to targets in the associated condition were significantly more positive than were ERPs in all other conditions over central and parietal areas (300-600 ms; N400 priming effect). By contrast, a more posterior effect was found for categorical priming. These findings held for both cross-domain (Experiment 1) and within-domain conditions (Experiment 2). Results (a) demonstrate behavioral and ERP evidence for categorical priming in person recognition, consistent with the assumption that shared semantic information units can mediate semantic priming, and (b) suggest that associative and categorical priming are based on mechanisms that are at least partially different.     

Persistence of negative priming: II. Evidence for episodic trace retrieval.

Responses to recently ignored stimuli may be slower or less accurate than to new stimuli. This negative priming effect decays over time when delay is randomized within subjects, but not when delay varies between subjects. In Experiment 1, response-stimulus intervals (RSI) of 500 and 4,000 ms were randomized within subjects in a target localization task. Negative priming of ignored locations diminished with longer delay. However, no significant decay was obtained when RSI and the preceding RSI were equal. Similar results were obtained when RSI and preceding RSI were deliberately confounded by blocking (Experiment 2). Negative priming appears to depend on temporal discriminability of the priming episode.     

Dissociated backward priming effects in lexical decision and pronunciation tasks

Backward priming was examined at 150- and 500-msec prime-target stimulus onset asynchronies (SOAs) using visually presented primes and targets in lexical decision and pronunciation tasks. Two kinds of backward relations were used: compound items for which targets and primes formed a word in the backward direction (e.g., prime: HOP; target: bell), and noncompound items for which targets and primes did not form a word but were associatively related in the backward but not the forward direction (e.g., prime: BABY; target: stork). Results showed that backward priming effects were equivalent for compounds and noncompounds. However, for lexical decisions, backward priming occurred at both SOAs, whereas for pronunciation, it occurred only at the 150-msec SOA. We discuss how this SOA-dissociated backward priming effect in lexical decision and pronunciation tasks poses a serious challenge for all theories of semantic priming.     

Semantic activation and letter search: Blocking or suppression?

Two experiments investigated associative priming with a letter-search prime task where either the prime and letter probe were presented simultaneously, or the letter probe appeared 200 ms (Experiment 1) or 300 ms (Experiment 2) after the prime. Weak associative priming was observed in both experiments, but unlike Stolz and Besner (1996) we found no evidence that priming was increased when the probe was delayed. However, strong associative priming was observed when a semantic decision had to be made on the prime (Experiment 3). Our results are consistent with an account where semantic activation of the prime occurs but its action on the target is suppressed by the prime task. The persistence of weak priming effects with the letter search task is explained in terms of the low-frequency items used.     

Processing phonological and semantic ambiguity: evidence from semantic priming at different SOAs.

Disambiguation of heterophonic and homophonic homographs was investigated in Hebrew using semantic priming. Ambiguous primes were followed by unambiguous targets at 100 ms, 250 ms, and 750 ms stimulus onset asynchrony (SOA). Lexical decision for targets related to the dominant phonological alternatives of heterophonic homographs were facilitated at all SOAs. Targets related to subordinate alternatives were facilitated only at SOAs of 250 ms or longer. When the primes were homophonic homographs, semantic relationship facilitated lexical decision of targets at all SOAs regardless of the dominance of the meaning to which the targets were related. These data can be accounted for by assuming multiple lexical entries for heterophonic homographs, single lexical entries for homophonic homographs, and phonological mediation of accessing meanings. Language-specific factors probably account for the long-lasting activation of subordinate meanings.