Long-term Semantic Priming Research Articles

Unique Mechanisms for the Availability of Declarative Memory Elements and the Strengthening of Cognitive Operations.

The purpose of this study was to investigate the role of memory for prior cognitive operations and availability of declarative memory elements in long-term semantic priming. The impetus for this investigation was the role of working memory (WM) in complex cognitive processing. Empirical estimates of WM are too limited to explain complex cognitive processes. Therefore, contemporary models of WM propose access to long-term memory (LTM) to expand these limits. The priming literature provides one theoretical mechanism for access to LTM: long-term semantic priming. However, explanations for long-term semantic priming include both increased availability of LTM elements and the facilitation of prior cognitive operations. Our goal was to examine if the facilitation of prior cognitive operations is dependent on the availability of previously encountered LTM elements. A task used in previous research proposed to capture the facilitation of cognitive operations coupled with a directed forgetting manipulation was used to examine this relationship. Three experiments were conducted to that end. All experiments resulted in facilitation of the procedure of categorization. Experiments 1 and 2 additionally found relatively poor recognition for items that participants were told to forget despite the fact that categorization was facilitated for related items. Experiment 3 resulted in similarly poor recognition for category names that participants were told to forget. Taken together, the experiments in this investigation demonstrate a clear separation between the cognitive operations and declarative elements of the categorization task. Namely, the continued availability of declarative elements is not necessary for the subsequent facilitation of categorization operations.

Mapping the time course of semantic activation in mediated false memory: Immediate classification, naming, and recognition.

We evaluated the time course of persistent automatic spreading activation from a mediated list of indirect associates (e.g., meow, day, and basement) that all converged upon a non-presented critical item (CI; e.g., black). Mediated lists were related to CIs through non-presented mediators (e.g., cat, night, and bottom). Three speeded tasks were used to evaluate the time course of semantic activation of the CI: a continuous semantic classification task (concrete/abstract decisions), a naming task (reading words aloud), or a recognition test (old/new memory decisions). Test lists were presented immediately following the mediated lists, and CIs were presented in the first, third, or eighth positions. The results revealed that in both the classification and naming tasks, CI priming was greatest in the first test position and declined across the remaining test positions. Importantly, priming was statistically reliable in the late test positions, providing evidence for long-term semantic priming (i.e., across positions on immediate tasks). False recognition, however, was stable across test positions. Collectively, these patterns suggest that spreading-activation processes decline, consistent with implicit spreading activation, and these processes may contribute to long-term false recognition.

Memory processes underlying long-term semantic priming.

Two decades of research in semantic priming has provided substantial evidence for a distinction between short- and long-term semantic priming effects. Early models of cognition suggested a single mechanism to explain priming at short and long lags. Later models refuted this explanation and proposed that different mechanisms are necessary to account for different durations of priming effects. Two alternative explanations of long-term semantic priming effects have been proposed in the extant literature. The first explanation is that long-term semantic priming effects rely upon the incremental strengthening of abstract semantic memory representations. The second explanation is that long-term priming is the result of memory for prior cognitive operations. In two experiments, we used different semantic content - word meaning versus category membership - to investigate the mechanisms accountable for long-term semantic priming. Evidence from the two experiments suggests that long-term semantic priming effects are due to different memory processes for different semantic content. Long-term semantic priming of word meanings was dependent on strengthening abstract semantic memory representations and persistent priming of category membership was dependent on memory for prior cognitive operations.

Long-term semantic priming of propositions representing general knowledge

Abstract Six experiments investigated semantic priming of individual propositions that reflect common knowledge. Participants performed a sentence-completion task in which each sentence expressed a single proposition, and the same or similar proposition was expressed in prime-target sentence pairs that shared no words. The primary goal was to evaluate the degree to which long-lasting facilitation in primed target sentences reflected memory for abstract proposition meaning versus memory for the operations used to construct proposition meaning and select a response. Priming effects persisted over delays exceeding 15 min, were not attributable to explicit memory processes, did not depend on either repeated syntactic structure or response decision, and were greater than facilitation attributable to priming individual word meanings. In total, the evidence provides initial support for operation-independent, long-term semantic priming of propositions outside the context of connected discourse. This extends the empirical evidence for long-lasting facilitation that theories of semantic priming must explain.

Efficient cognitive operations predict skill acquisition

The present study examined the relationship between performance on the ALTM task and improvement in Stroop task performance across trials. Prior research indicated that the ALTM task may be capturing individual differences in facilitation of procedural memory but has often been confounded with long-term semantic priming due to the nature of the task. The Stroop task was chosen because related semantic information is largely irrelevant to performance. Path analysis revealed that ALTM task performance accounted for 11.3% of the variance in improvement in color–word Stroop improvement over two sessions. No other hypothesized relationships were significant in the path model. Results are discussed in light of the apparent relationship between ALTM task performance and an individual's ability to acquire new procedural memory traces. Implications of these findings are discussed and future directions for continued research are proposed.

Common Representations between Working Memory and Long-term Memory: Evidence from Event-Related Potentials

Human memory can be characterized as an elaborate network of stored representations. Researchers propose that both working memory (WM) and long-term memory (LTM) utilize same representations, and the representations they activate are in diverse patterns. So the similarity and coherence between WM and LTM are emphasized in the activation-based model, and the priming effect of LTM on WM and vice versa should be both found. By simultaneously recording event-related potentials (ERPs), the present study aimed to investigate two long-term semantic priming effects to illustrate the common representations involved in WM and LTM. Fifteen college students (mean age=20.33±1.91; 7 male) participated in the experiment. The participants were all right-hand, had normal or corrected-to-normal vision and had no neurological or psychological disorders. Each participant signed a consent form prior to experiment and was paid after experiment. We combined a WM component (short-term verbal encoding) and a LTM component (category comparison) into one task, so that WM and LTM processing could be concurrently investigated. LTM priming on WM was manipulated by asking participants to learn before short-term verbal encoding, and the priming effect of WM on related LTM should be found in category comparison. Results revealed two long-term semantic priming effects in behavior data and ERPs. The first effect was found in short-term encoding phase, which was reflected as the priming of LTM on WM. Compared with new targets in WM, the reaction time of studied targets was shorter. They elicitedearlier N2 and P3, and they also decreased N2 amplitude. These may index the so-called neural priming (or repetition suppression) of scalp potentials. However, there was no difference between new and studied distractors in WM. Furthermore, the neural priming of WM on LTM also exhibited in category comparison. Specific contents, which were formerly concerned or ignored in short-term encoding phase, led relevant representations of LTM to diverse activation patterns. N400 elicited by target category (items in which were the same category as the targets in short-term encoding phase)was more positive than that of unprimed category, which also index the neural priming of scalp potentials. But this neural priming was modulated by repetation, that is, when target category was relevant to studied targets rather than new ones, the N400 would be more negative. Results indicate that common representations are used both in WM and in LTM, supporting the activation-based model. Furthermore, these results point to the key role of attention as a modulator in the linkage between WM and LTM.

Word-frequency effects in long-term semantic priming and false memory

Several studies have used the lexical decision task (LDT) with the Deese-Roediger-McDermott (DRM) false-memory paradigm to investigate whether long-term semantic priming (LTSP) occurs following presentation of lists of items (e.g., bed, dream, snore) for related non-presented lure words (e.g., sleep). However, results have been mixed, with some studies observing priming, whilst others have not. The present study had four goals: (i) to investigate the existence of LTSP in the LDT; (ii) to investigate effects of LTSP on standard effects of word frequency on LDT performance; (iii) to investigate the effect, if any, of word frequency on true and false recall; and (iv) to compare LDT performance with performance on a subsequent free-recall task. The findings showed (i) a significant effect of LTSP on LDT performance; (ii) no effect of LTSP on standard effects of word frequency on LDT performance; (iii) no effect of word frequency on either true or false free recall; and (iv) a significant relationship between LDT and free-recall performance. Implications of these findings for understanding LTSP and false memories are discussed.

The persistence of content-specific memory operations: Priming effects following a 24-h delay

The duration of long-term semantic priming is typically described in minutes. Woltz and Was (2007) found that priming effects following processing in working memory were relatively long-lasting, reporting there was no decrease in priming effects following 32 intervening Stroop-like trials. These findings were interpreted as an increased availability of long-term memory elements, in part due to memory for prior operations, and as not being solely explicable by spreading-of-activation accounts of priming. The present study was designed to test the persistence of these effects following a 24-h delay. In the present study, priming effects were found to be present following a minimum of a 24-h delay between processing of information in working memory and measures of increased availability of long-term memory elements. The results are discussed, in the context of long-term semantic priming, as being the result of persistent memory for prior cognitive operations.

Long-term semantic priming of word meaning.

Three experiments investigated facilitation in synonym decisions as a function of prior synonym decision trials that were either identical or semantically related. Experiment 1 demonstrated that semantically related prime trials produced less facilitation than identical prime trials, but facilitation from both persisted over 14 intervening trials. Experiments 2 and 3 demonstrated that word meaning retrieval without meaning comparison in prime trials was sufficient for persistent facilitation in semantically related targets, and meaning comparison was necessary for repetition priming to show greater facilitation than semantic priming. Results suggest that semantic priming in this task may solely reflect strength changes in abstract semantic representations, whereas repetition priming may reflect additional nondeclarative memory for operations performed in prime events.

Semantic and repetition priming effects for Deese/Roediger—McDermott (DRM) critical items and associates produced by DRM and unrelated study lists

Two lexical decision experiments investigated priming for a critical item (CI, sleep) and its related yoked associate (YA, blanket) when one had been studied in a related Deese/Roediger-McDermott (DRM) list (Experiments 1 & 2) or a list of totally unrelated words (Experiment 2) and the other had been nonstudied. Semantic priming from the related DRM list occurred for nonstudied CIs (but not YAs) regardless of whether the CI received within-test priming from its studied related YA during the lexical decision task, though the effect in the absence of within-test priming averaged across experiments was only significant by a one-tailed test. Also averaged across experiments, repetition priming occurred for both studied CIs and YAs when they had been studied in related DRM lists whether or not there was also within-test priming from a nonstudied related yoked pairmate, though individual effects within the two experiments were sometimes not significant. Repetition priming boosted semantic priming from related DRM lists less for CIs than for YAs, similar to the finding that memory discriminability is poorer for CIs than for YAs in episodic recognition. This smaller repetition priming boost for CIs than for YAs occurred to the same degree when the CIs or YAs were studied in an unrelated list. When nonstudied CIs and YAs were totally unrelated to all previously studied items and separated by 3-7 items in the lexical decision task, aYA produced a small 16 msec priming effect for its CI, averaged across both experiments. The implications of these results for the activation account of the DRM false-memory effect and for single-prime versus multiple-prime long-term semantic priming effects are discussed. The online addendum may be downloaded from www.psychonomic.org/archive.

Availability of related long-term memory during and after attention focus in working memory

In a series of four experiments, we investigated the magnitude and pattern of indirect, semantically mediated priming that emanates from various working memory (WM) processes. When such priming effects are taken to reflect temporary increases in the availability of long-term memory (ALTM), results suggest a close link between the amount and type of attention-driven processing in WM and the resulting accessibility of semantically related memory structures. Patterns of priming were equivalent when attention demands were prior to, versus concurrent with, the priming measures, suggesting that ALTM processes either require no additional cognitive resources or require resources that are independent of those underlying effortful WM processes. The results are discussed with respect to emerging evidence for long-term semantic priming and models of WM that incorporate active but unattended information as part of a limited capacity cognitive workspace.

False memories and lexical decision: even twelve primes do not cause long-term semantic priming

Semantic priming effects are usually obtained only if the prime is presented shortly before the target stimulus. Recent evidence obtained with the so-called false memory paradigm suggests, however, that in both explicit and implicit memory tasks semantic relations between words can result in long-lasting effects when multiple `primes' are presented. The aim of the present study was to investigate whether these effects would generalize to lexical decision. In four experiments we showed that even as many as 12 primes do not cause long-term semantic priming. In all experiments, however, a repetition priming effect was obtained. The present results are consistent with a number of other results showing that semantic information plays a minimal role in long-term priming in visual word recognition.

Adult age differences in long-term semantic priming

Young and older adults were first asked to decide if a list of individually presented words were “living” (e.g., “tree”) or “nonliving” (e.g., “store”). This was termed the “orienting task.” Next, subjects performed a pronunciation task. Semantic priming for young and older adults was indexed by determining if semantic congruence between words in the orienting task and words in the pronunciation task improved performance on the pronunciation task relative to pronounced words from semantic categories not primed in the orienting task. The present data, from two different experiments, revealed that subjects pronounced high-dominance exemplars of the “living” words primed in the orienting task faster than words not primed in the orienting task. These data indicated that semantic priming for relatively long prime-target stimulus onset asynchronies can occur, and that such priming is at least as robust for older adults as for young adults. The results are discussed in terms of four current models of semantic priming.

Long-term semantic priming: A computational account and empirical evidence.

Semantic priming is traditionally viewed as an effect that rapidly decays. A new view of long-term word priming in attractor neural networks is proposed. The model predicts long-term semantic priming under certain conditions. That is, the task must engage semantic-level processing to a sufficient degree. The predictions were confirmed in computer simulations and in 3 experiments. Experiment 1 showed that when target words are each preceded by multiple semantically related primes, there is long-lag priming on a semantic-decision task but not on a lexical-decision task. Experiment 2 replicated the long-term semantic priming effect for semantic decisions with only one prime per target. Experiment 3 demonstrated semantic priming with much longer word lists at lags of 0, 4, and 8 items. These are the first experiments to demonstrate a semantic priming effect spanning many intervening items and lasting much longer than a few seconds.

The long and short of semantic priming effects in lexical decision.

Unlike other forms of priming, semantic priming appears only to occur at short lags. In apparent contrast to this, S. Becker, M. Moscovitch, M. Behrmann, and S. Joordens (1997) described a theory of priming that predicts long-term effects for all forms of relatedness. This prediction is reconciled with previous failures to observe long-term semantic priming on the basis of 2 claims: (a) that previously used pairs share few semantic features and (b) that tasks typically used to study priming are not especially sensitive to semantic influences. The present experiments provide further support for these claims by demonstrating long-term semantic priming in the lexical-decision task when the stimuli and task are modified in a way that increases semantic involvement. However, the findings' suggest that in addition to the mechanism advocated by Becker et al., a second mechanism is necessary to provide a complete account of semantic priming effects.

Long-term semantic priming: A computational account and empirical evidence.

Long-term semantic priming: A computational account and empirical evidence.

The long and short of semantic priming effects in lexical decision.

Unlike other forms of priming, semantic priming appears only to occur at short lags. In apparent contrast to this, S. Becker, M. Moscovitch, M. Behrmann, and S. Joordens (1997) described a theory of priming that predicts long-term effects for all forms of relatedness. This prediction is reconciled with previous failures to observe long-term semantic priming on the basis of 2 claims: (a) that previously used pairs share few semantic features and (b) that tasks typically used to study priming are not especially sensitive to semantic influences. The present experiments provide further support for these claims by demonstrating long-term semantic priming in the lexical-decision task when the stimuli and task are modified in a way that increases semantic involvement. However, the findings' suggest that in addition to the mechanism advocated by Becker et al., a second mechanism is necessary to provide a complete account of semantic priming effects.