Interhemispheric communication is via direct connections

Two priming experiments, using normal university students as subjects, independently projected low imagery primes and concrete target words to the left or right visual fields (LVF or RVF) to examine the merits of three spreading activation models of interhemispheric communication: (i) callosal relay of a semantically encoded prime; (ii) transfer of products activated as a result of the spread of activation; and (iii) direct connections between the hemispheres. The first experiment temporally separated pairs by a stimulus onset asynchrony (SOA) of 250 ms and obtained strong support for the direct connections model. Priming effects were obtained only when the prime was projected to the RVF and the target to the LVF. The pattern of priming effects suggested that low imagery words projected to the left hemisphere can activate concrete associates in the right hemisphere via direct callosal connections between the two. In the second experiment, the SOA was increased to 450 ms. This time, RVF-RVF priming was obtained along with RVF-LVF priming. The findings are interpreted within a modification of Bleasdale's (1987) framework, where abstract/low imagery words and concrete/high imagery words are represented in separate subsystems in the left hemisphere lexicon. Support was also found for the view that the left hemisphere is comprised of a complex network of abstract and concrete words, while the right hemisphere operates as a subsidiary word processor, subserving linguistic processing with a limited, special purpose lexicon comprised of associative connections between concrete, imageable words (e.g., Zaidel, 1983a; Bradshaw, 1980). Interhemispheric communication in the priming procedure appears to occur at the semantic level, via direct connections between the hemispheres.     

Semantic Priming of Different Affective Categories.

The authors investigated affective semantic priming using a lexical decision task with 4 affective categories of related word pairs: neutral, happy, fearful, and sad. Results demonstrated a striking and reliable effect of affective category on semantic priming. Neutral and happy prime-targets yielded significant semantic priming. Fearful pairs showed no or modest priming facilitation, and sad primes slowed reactions to sad targets. A further experiment established that affective primes do not have generalized facilitatory-inhibitory effects. The results are interpreted as showing that the associative mechanisms that support semantic priming for neutral words are also shared by happy valence words but not for negative valence words. This may reflect increased vigilance necessary in adverse contexts or suggest that the associative mechanisms that bind negative valence words are distinct. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanisms of unconscious priming: I. Response competition, not spreading activation.

Four experiments were conducted to replicate and expand upon A. G. Greenwald, S. C. Draine, and R. L. Abram's (1996) demonstration that unconsciously perceived priming words can influence judgments of other words. The present experiments manipulated 2 types of relationships between priming and target stimuli: (a) whether priming and target stimuli possess a preexisting semantic relationship (an affective relationship in Experiments 1, 2, and 4; an associative relationship in Experiment 3; and an animacy relationship in Experiment 4) and (b) whether the primes and targets produce the same response. Large priming effects were found only when the primes and targets possessed response compatibility. No residual effects for affective, animacy, or semantic relatedness were observed. Although these results strongly support the conclusion that word meaning can be unconsciously activated, they do not support the claim that the unconscious perception effects obtained in Greenwald et al.'s (1996) paradigm are caused by automatic spreading activation of word meaning. Instead, the results reported here are consistent with a claim that unconsciously perceived words automatically trigger response tendencies that facilitate or interfere with target responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nicotine effects on general semantic priming in Parkinson's disease.

In young healthy nonsmokers, effects of nicotine on semantic processing have been observed under strategy-based priming procedures but not under more general priming procedures (Holmes, Chenery, & Copland, 2008; Holmes, Chenery, & Copland, 2010). Effects of nicotine under general priming procedures, however, may be mediated by baseline priming levels that are below optimum such as when compromised by disease. Nicotinic mechanisms may be involved in the cognitive sequalae of Parkinson's disease (PD). Evidence suggests that semantic processing may be compromised in PD but the potential benefit of nicotinic stimulation is unknown. This study investigated the effects of nicotine on semantic processing in nonsmokers with PD (n = 12) and nonsmoking matched controls (n = 17) using general priming procedures. Specifically, an automatic priming task (0.15 relatedness proportion, RP, and 200 ms stimulus onset asynchrony, SOA) and a controlled priming task (0.8 RP and 1000 ms SOA) were used. Prime-target category relation (category related, noncategory related) was also manipulated. Transdermal nicotine patches (7 mg/24 h) were administered in a double-blind, placebo-controlled, crossover design. For the automatic task, nicotine did not influence priming effects for PD. Unexpectedly, compromised automatic priming for controls was ameliorated. For the controlled task, nicotine influenced priming effects for PD but not controls. The patterns of priming and nicotine effects across the tasks suggest an age-related slowing of the rate of semantic activation for controls, which may be exacerbated in PD. Overall, the findings indicate that nicotine can improve compromised semantic processing in PD, and also influence semantic processing in healthy older individuals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Unconscious priming of association judgments.

Participants judged whether pairs of target words were associated or not-associated in meaning (association judgment task). Target pairs were preceded by a brief (200 ms) related or unrelated (prime) word presented to the nondominant eye. Each participant performed 2 blocks of association judgment task trials: 1 with primes that were legible, and 1 with primes that were masked by a pattern simultaneously presented to the dominant eye. Across 2 experiments, significantly larger masked priming effects were observed for participants who could not detect priming words (low-d′ participants) than for participants who could partially see priming words (high-d′ participants). This result suggests that undetectable masked primes can activate word meaning and that conscious attempts to process masked primes may inhibit unconscious activation. Additionally, evidence is presented that supports claims that spreading activation is the crucial mechanism responsible for unconscious priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

L'Amor?age affectif: Données empiriques et modèles théoriques.

The automaticity of evaluative processing is one of the most important issues in cognitive psychology of emotions. The affective priming paradigm has been created specifically in order to provide some evidence regarding this issue. For 20 years, this paradigm has resulted in a significant number of studies. Originally focused on the automaticity of evaluation, investigation rapidly moved to the underlying mechanisms and it has led to a theoretical dichotomy. Some studies suggest that a spreading activation mechanism underlies affective priming effects, whereas other studies suggest that this priming effect is determined by a response competition mechanism similar to that found in compatibility tasks such as the Stroop task. The clarification of the theoretical models of affective priming therefore appears to be necessary in order to improve the understanding of the effect, possibly leading to its justified use as an indirect measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contrast effects in spontaneous evaluations: A psychophysical account.

In the affective-priming paradigm, target stimuli are preceded by evaluatively polarized prime stimuli and then are to be classified as either good or bad as fast as possible. The typical and robust finding is assimilation: Primes facilitate the processing of evaluatively consistent targets relative to evaluatively inconsistent targets. Nevertheless, contrast effects have repeatedly been observed. The authors propose a new psychophysical account of normal (assimilative) and reversed (contrastive) priming effects and test new predictions derived from it in 5 studies: In Studies 1 and 2, the authors' account is shown to provide a better explanation of contrastive effects in a priming paradigm with two primes than the traditional attentional account does. Furthermore, as predicted by the new account, contrast effects emerge at an intermediate stimulus-onset asynchrony (SOA, Study 3) and even with short SOAs when target onset takes participants by surprise (Study 4). Finally, the use of extremely valenced primes triggers corrective efforts (Study 5) as predicted. Implications for priming measures of evaluative associations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Syllabic priming in lexical decision and naming tasks: The syllable congruency effect re-examined in French.

This study investigated the role of the syllable in visual recognition of French words. The syllable congruency procedure was combined with masked priming in the lexical-decision task (Experiments 1 and 3) and the naming task (Experiment 2). Target words were preceded by a nonword prime sharing the first three letters that either corresponded to the syllable (congruent condition), or not (incongruent condition). When primes were displayed for 67 ms, similar results were found in both the lexical decision and the naming tasks. Consonant-vowel targets such as BA.LANCE were recognised more rapidly in the congruent condition than in the incongruent and control conditions, while consonant-vowel-consonant targets such as BAL.CON were recognised more rapidly in the congruent and incongruent conditions than in the control condition. When a 43-ms SOA was used in the lexical-decision task, no significant priming effect was obtained. The results are discussed in an interactive-activation model incorporating syllable units. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual lexical access is initially phonological: 2. Evidence from phonological priming by homophones and pseudohomophones.

Seven experiments were conducted that examined phonological and orthographic priming of naming using three- and four-field masking procedures with prolonged targets. Experiments 1–3 found significant phonological priming by homophones (TOWED–toad) that was independent of prime identifiability and prime-target stimulus onset asynchrony (SOA; 30, 60, or 250 ms). Subsequent experiments found significant phonological priming by pseudohomophones (TODE–toad) that was similarly independent of prime identifiability and SOA. Collectively, the limited effects of orthographic control primes (TOLD–toad, TODS–toad) and the pronounced and orthographically independent effects of phonological primes suggest (a) a leading role in visual word perception for a fast-acting, automatic, assembled phonology, and (b) a phonological basis, rather than an abstract graphemic basis, for the processing equivalency of letter variations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rhyme priming of pictures and words: A lexical activation account.

Orthographically/phonologically related primes have typically been found to facilitate processing of target words. This phenomenon is usually explained in terms of spreading activation between nodes for orthographically/phonologically similar words in lexical memory. The phenomenon was explored in a series of studies involving the manipulations of prime and target type (word or picture) and prime and target task (naming or categorization). Generally, the results support the lexical activation explanation. Named primes, which activate lexical memory, facilitate processing in all target tasks involving lexical access (word and picture naming and word categorization), independent of prime type. Categorized primes show the expected Prime Type?×?Relatedness interaction with word primes, which activate lexical memory, producing much more facilitation than picture primes. Finally, unlike in semantic priming studies, increased depth of processing of a word prime decreased the size of the priming effects. Apparently, initial activation levels in lexical memory are not maintained when semantic processing of the prime is required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aberrant semantic and affective processing in people at risk for psychosis.

Semantic and affective processing were examined in people at risk for psychosis. The participants were 3 groups of college students: 41 people with elevated Perceptual Aberration and Magical Ideation (PerMag) scores, 18 people with elevated Social Anhedonia (SocAnh) scores, and 100 control participants. Participants completed a single-word, continuous presentation pronunciation task that included semantically related words, affectively valenced words, and semantically unrelated and affectively neutral words. PerMag participants exhibited increased semantic priming and increased sensitivity to affectively valenced primes. SocAnh participants had increased sensitivity to affectively valenced targets. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

List-context effects in evaluative priming.

Evaluative priming effects are often found in the evaluative decision task, in which persons judge the affective connotation (positive vs. negative) of a target word. The present experiments examined list-context effects to test whether evaluative and semantic priming follow the same laws. In Experiment 1, evaluative priming was found at prime-target stimulus onset asynchronies (SOAs) of 0 ms and 100 ms, but not at SOAs of -100, 200, 600, and 1,200 ms. Experiment 2 manipulated SOA (0, 200, and 1,200 ms) and the proportion (25%, 50%, and 75%) of the prime-target pairs that were evaluatively related. Contrary to the typical finding that increases in the proportion of related prime-target pairs lead to increased priming at long but not short SOAs, an effect of consistency proportion was found at SOAs of 0 ms (for reaction times) and 200 ms (in the accuracy data), but not at the 1,200-ms SOA. The pattern of results is discussed in relation to possible explanatory mechanisms of evaluative priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic and strategic processes in picture naming.

Prior presentation of related priming stimuli can facilitate responding to subsequent targets. However, recent research has demonstrated that inhibition effects can be produced by related primes when some of the primes in the testing sequence directly name their targets. This study used a picture-naming task, manipulating strength of relation between the prime word and the target picture, and the presence of identical primes in the testing sequence. Related primes facilitated naming when identical primes were absent, but not when they were present, whereas the strength effect did not vary as a function of identical-prime presence. A second experiment replicated the strength effect and showed that it was not affected by the presence or absence of primary associates in the testing sequence. A comparison-strategy explanation of the inhibition effect is proposed, in which the strategy is superimposed on an automatic activation of related information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual and developmental differences in semantic priming: Empirical and computational support for a single-mechanism account of lexical processing.

Existing accounts of single-word semantic priming phenomena incorporate multiple mechanisms, such as spreading activation, expectancy-based processes, and postlexical semantic matching. The authors provide empirical and computational support for a single-mechanism distributed network account. Previous studies have found greater semantic priming for low- than for high-frequency target words as well as inhibition following unrelated primes only at long stimulus-onset asynchronies (SOAs). A series of experiments examined the modulation of these effects by individual differences in age or perceptual ability. Third-grade, 6th-grade, and college students performed a lexical-decision task on high- and low-frequency target words preceded by related, unrelated, and nonword primes. Greater priming for low-frequency targets was exhibited only by participants with high perceptual ability. Moreover, unlike the college students, the children showed no inhibition even at the long SOA. The authors provide an account of these results in terms of the properties of distributed network models and support this account with an explicit computational simulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition priming and associative priming of face recognition: Evidence from event-related potentials.

Face recognition can be facilitated by previous presentation both of the same face and of an associated person's face. In Experiment 1, the effects of face repetition and associative priming on event-related potentials (ERPs) were compared. Repetition decreased reaction times (RTs) and modulated both early (180–290 ms) and late ERPs beyond 310 ms. Associative priming caused a topographically equivalent late ERP modulation, although RTs and early ERPs were unaffected. The results suggest that repetition acted on an early processing locus, presumably the activation of face representations. Both repetition and associative priming affected a relatively late locus, probably the activation of person-related semantic information. In Experiment 2, face repetitions were omitted and associative priming effects were observed both in ERPs and RTs. This indicates that ERPs may reflect automatic aspects of associative priming more directly than do RTs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

G. Lukatela and M. T. Turvey (1994x) 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/legalnon-word 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit memory and test awareness.

In three experiments we examined whether normal subjects can perform an implicit test without becoming aware that the test items were previously encountered in the study phase of the experiment. Experiment 1 assessed single word priming with the stem completion task, and subjects who reported awareness/unawareness that the test items were previously encoded in the study task showed equivalent priming. Experiments 2a–c and 3 assessed associative priming with the stem completion task, and in this case, only subjects who were aware that the test items were previously encountered showed associative priming effects. These findings suggest that single word priming and associative priming reflect different memory processes because the former and not the latter effect can be observed in unaware subjects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic adaptation to history of trial difficulty explains the effect of congruency proportion on masked priming.

In reaction time research, there has been an increasing appreciation that response-initiation processes are sensitive to recent experience and, in particular, the difficulty of previous trials. From this perspective, the authors propose an explanation for a perplexing property of masked priming: Although primes are not consciously identified, facilitation of target processing by a related prime is magnified in a block containing a high proportion of related primes and a low proportion of unrelated primes relative to a block containing the opposite mix (Bodner & Masson, 2001). In the present study, this phenomenon is explored with a parity (even/odd) decision task in which a prime (e.g., 2) precedes a target that can be either congruent (e.g., 4) or incongruent (e.g., 3). It is shown that the effect of congruence proportion with masked primes cannot be explained in terms of the blockwise prime–target contingency. Specifically, with masked primes, there is no congruency disadvantage in a block containing a high proportion of incongruent primes, but there is a congruency advantage when the block contains an equal proportion of congruent and incongruent primes. In qualitative contrast, visible primes are sensitive to the blockwise prime–target contingency. The authors explain the relatedness proportion effect found with masked primes in terms of a model according to which response-initiation processes adapt to the statistical structure of the environment, specifically the difficulty of recent trials. This account is supported with an analysis at the level of individual trials using the linear mixed effects model. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effets de la nature des relations sémantiques sur les processus d'activation entre amorces et cibles associativement liées.

Classical models of knowledge organization assume a structural and functional independence between lexical and semantic information. This independence is warranted by the fact that conceptual activation processes are assumed to be strategic, unlike intra-lexical processes which are automatic. Nevertheless, some experiments seem to show the existence of automatic processes for conceptually but not associatively linked pairs of words. The present experiments reverse the procedure usually used by testing the effect of the kind of conceptual relations in a lexical decision task on targets associatively linked to primes. The results show the existence of effects dependent on the nature of the semantic relations when only the associative strength was assumed to have an influence on priming. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between stroop interference and facilitation effects: Statistical artifacts, baselines, and a reassessment.

The relationship between interference and facilitation effects in the Stroop task is poorly understood yet central to its implications. At question is the modal view that they arise from a single mechanism—the congruency of color and word. Two developments have challenged that view: (a) the belief that facilitation effects are fractionally small compared with interference effects, or nonexistent altogether; and (b) the finding that interference and facilitation effects are inversely correlated. Statistical simulations, reanalysis of past data, and two new experiments indicate that facilitation is robust and substantial when congruency is deconfounded from lexicality, and that the inverse correlations are mostly spurious. Instead, interference and facilitation are uncorrelated, or at most weakly but inversely related. Resolution of response conflict and lexical convergence can explain either finding. Modeling and interpretation of the Stroop task must distinguish between nonspecific lexicality-based effects and specific color-word congruency effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)