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 stimulus onset asynchrony (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?×?Expectancy?×?SOA interaction, which is inconsistent with the notion of independent automatic and attentional mechanisms in semantic priming and the notion of a self-incapsulated 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 msec, independently of the prime–target SOA (Exp 1 and 3), but not when the prime was visually available throughout the SOA (Exp 2). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of semantic context by patients with Alzheimer's disease.

Used semantic-priming procedures to examine limitations in the use of semantic context by 18 patients (mean age 68.9 yrs) with Alzheimer's disease (AD) and to determine whether any such contextual effects were mediated solely through automatic processes or whether attentional processes were also involved. Three tasks were applied to examine the effect of semantic context on the performance of 18 normal elderly Ss (mean age 67.2 yrs), 18 normal young Ss (mean age 24.1 yrs), and the AD Ss. When normal and AD Ss were asked to decide whether a given item was a member of a certain category, their response times were equally affected by the item's dominance in the category. The time that AD Ss took to recognize a word was actually affected more by the semantic context provided by a priming sentence than was that of normal Ss. When asked to generate the final word of an incomplete sentence, AD Ss performed very poorly unless potential responses were highly constrained by sentence context. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming in young and older adults: Evidence for age constancy in automatic and attentional processes.

Automatic and attentional components of semantic priming and the relation of each to episodic memory were evaluated in young and older adults. Category names served as prime words, and the relatedness of the prime to a subsequent lexical decision target was varied orthogonally with whether the target category was expected or unexpected. At a prime-target stimulus-onset asynchrony (SOA) of 410 ms, target words in the same category had faster lexical decision latencies than did different category targets. This effect was not significant at a 1,550-ms SOA and was attributed to automatic processes. Expected category targets had faster latencies than unexpected category targets at the 410-ms SOA, and the magnitude of the effect increased at the 1,550-ms SOA. This effect was attributed to attentional processes. These patterns of priming were obtained for both age groups, but in a surprise memory test older adults had poorer recall of primes and targets. We discuss the implications of these results for the hypothesis that older adults suffer deficits in selective attention and for the related hypothesis that attentional deficits impair semantic processing, which causes memory decrements in old age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional sensitization of unconscious cognition: Task sets modulate subsequent masked semantic priming.

According to classical theories, automatic processes are autonomous and independent of higher level cognitive influence. In contrast, the authors propose that automatic processing depends on attentional sensitization of task-congruent processing pathways. In 3 experiments, the authors tested this hypothesis with a modified masked semantic priming paradigm during a lexical decision task by measuring event-related potentials (ERPs): Before masked prime presentation, participants attended an induction task either to semantic or perceptual stimulus features designed to activate a semantic or perceptual task set, respectively. Semantic priming effects on the N400 ERP component, an electrophysiological index of semantic processing, were obtained when a semantic task set was induced immediately before subliminal prime presentation, whereas a previously induced perceptual task set attenuated N400 priming. Across experiments, comparable results were obtained regardless of the difficulty level and the verbal or nonverbal nature of the induction tasks. In line with the proposed attentional sensitization model, unconscious semantic processing is enhanced by a semantic and attenuated by a perceptual task set. Hence, automatic processing of unconscious stimuli is susceptible to top-down control for optimizing goal-related information processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional control and the relatedness proportion effect in semantic priming.

In 2 experiments, participants completed both an attentional control battery (OSPAN, antisaccade, and Stroop tasks) and a modified semantic priming task. The priming task measured relatedness proportion (RP) effects within subjects, with the color of the prime indicating the probability that the to-be-named target would be related. In Experiment 2, participants were cued before each trial with the probability of a related target. Stimulus onset asynchronies traditionally thought to tap automatic processing (267 ms) versus controlled processing (1,240 ms) were used. Across experiments, principal component analysis on the battery revealed a general attentional control component. Moreover, the RP effect increased linearly with attentional control in both experiments. It is concluded that RP effects produced in this paradigm depend purely upon the effortful process of expectancy generation, which renders them sensitive to individual differences in attentional control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of divided attention on automatic and controlled components of memory after severe closed-head injury.

The relation between attention available at encoding and automatic and consciously controlled aspects of memory was investigated using the process-dissociation procedure. Twenty-four severely closed-head injured (CHI) participants (> 1 year postinjury) and 24 matched controls studied word lists in full- and divided-attention conditions. Recall cued with word stems was tested. In contrast to consciously controlled memory, the CHI group did not perform more poorly than the controls in estimates of automatic memory. Furthermore, for both groups, the divided-attention manipulation reduced the controlled estimates of memory, whereas automatic influences remained invariant. These results suggest that automatic memory processes may remain partially immune to the deleterious effects of severe CHI or show recovery by 1 year postinjury. They also indicate that automatic memory processes do not require additional attentional resources following severe CHI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming in major depressive state

We studied semantic priming in 20 major depressive subjects. The methodology used was a visual lexical decision task. Semantic priming is the facilitation of target word recognition (shortening of response time) by the prior presentation of a semantically related context (a prime word). It relies on semantic processing of words and context, facilitating early cognitive stages of response. Varying the temporal interval between prime and target words onset allows us to distinguish between two priming mechanisms, relying on more automatic (test 1) or more controlled (i.e. attention dependent) (test 2) information processing. We observe a significant retardation for words and pseudo-words in depressives (in relation to controls) in both tests. In spite of a general retardation and increase of response times in depressives, semantic priming is evident in both groups and both tests, and does not differ significantly between depressive and control groups in either automatic or controlled conditions. Theses results confirm that semantic processing is not impaired in depression, and are discussed with regard to the hypothesis of an effortful processing impairment in depression, and to depressive retardation.     

Role of set in visual word recognition: Activation and activation blocking as nonautomatic processes.

The semantic priming effect in lexical decision is widely assumed to reflect automatic processes when the prime is merely read. In contrast, semantic priming is typically eliminated when the prime is subjected to a letter search. The present experiments demonstrate that semantic priming (a) occurs following letter search given a short stimulus onset asynchrony between prime and probe and (b) is reinstated in the standard, simultaneous letter search condition when such trials are mixed with delayed probe trials. These results are discussed in terms of the role of set in the context of an interactive activation framework. Activation and activation blocking are seen as nonautomatic processes controlled by set so as to balance bottom-up and top-down influences. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Automatic semantic priming: Effect of category exemplar level and word association level.

Evaluated semantic priming when the prime was masked below naming threshold and the target was named in 4 experiments with 263 undergraduates. Exp I showed that when word primes were masked and word targets were named, prior knowledge of the related pairs did not alter semantic priming. Semantic priming within categories occurred only when the prime stimulus was the 1st category exemplar. Findings of Exp II indicate that when masked pictures were used as primes, semantic priming for word targets was sensitive to the category exemplar level of the prime but not to the category exemplar level of the target. Word association norms collected in Exp III did not support the hypothesis that the effect of category exemplar level was mediated by the strength of word association. Exp IV revealed significant semantic priming for masked picture primes and within-category word targets, regardless of the level of word association between prime and target. Exp IV also demonstrated semantic priming for high word association targets that were not members of the same semantic category. For all experiments, Ss with the longest average reaction times (RTs) also showed the largest semantic priming effect for naming word targets. It is suggested that viewing one of the highest ranking category exemplars activates the memory representation of the category, perhaps because such prototypic exemplars are contained within the category concept itself. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual word recognition: Effort after meaning but not (necessarily) meaning after effort.

A robust semantic priming effect typically occurs in visual word recognition if the prime is read prior to a response to the target. M. C. Smith, D. Besner, and H. Miyoshi (1994) reported that this semantic priming effect is markedly reduced for short-duration primes randomly intermixed with longer duration primes, and they offered a signal-detection account of their results. This general finding is replicated and extended in 3 experiments, which demonstrate the importance of list context for this prime duration effect and suggest that a center-surround attentional mechanism provides a better account of the results to date. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

With great expectations, can two "wrongs" prime a "right"?

The proportion of related prime-target pairs (relatedness proportion, RP) and prime-target stimulus onset asynchrony (SOA) was varied to determine the involvement of strategic priming mechanisms in the reduction in semantic priming that occurs when a target follows an unmasked prime that itself receives immediate repetition priming from a masked prime. At 300-ms and 1,200-ms SOAs, (a) strategic semantic priming was operating, in that priming from a nonrepeated prime increased as RP increased from .25 to .75, and (b) for both RPs, prime repetition reduced semantic priming. At a 167-ms SOA, (a) priming from a nonrepeated prime was unaffected by RP, suggesting that strategic priming was not operating, and (b) for both RPs, prime repetition did not reduce semantic priming. Because prime repetition did not reduce priming at the 167-ms SOA (when only spreading activation should have been mediating semantic priming), the reduction in semantic priming produced by prime repetition is not evidence against spreading activation automaticity. Possible mechanisms through which prime repetition reduces semantic priming are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibitory mechanisms of attentional networks: Spatial and semantic inhibitory processing.

Four experiments assessed the relationships between the orienting and the executive networks of visual attention. Experiment 1 showed spatial inhibition of return (IOR) with target words. Experiment 2 showed a type of semantic inhibition that mimicked spatial IOR. Reaction times to targets preceded by 2 consecutively presented words, the prime and the intervening stimulus, were longer when the target and prime were related than when they were unrelated. Experiment 3 combined spatial and semantic inhibition in a lexical-decision task. Spatial IOR was observed with both related and unrelated targets, but semantic inhibition was observed only when target words were presented in uncued locations. A similar interaction between IOR and positive semantic priming was observed when the intervening stimulus was not presented (Experiment 4). Implications for the relationships between the 2 attentional networks are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast priming during eye fixations in reading.

Near-threshold primes were "flashed" in a target location prior to the onset of a target word while Ss read. The type and duration of the prime were manipulated. In Exp 1, identical, related, and unrelated primes were presented for 60, 45, or 30 msec from onset of an eye fixation. The prime was then replaced with the target word, which remained in place while Ss finished reading the sentence. Fixation time on the target word was measured. Exp 2 replicated Exp 1, with 2 exceptions: A random letter string replaced the identical prime condition, and prime durations of 39, 30, or 21 msec were used. In both experiments, significant priming effects (related vs unrelated) were obtained when the prime was presented for 30 msec. Results are discussed with regard to subliminal priming effects. Applications to the study of word recognition processes are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric dissociations in controlled lexical–semantic processing.

Cognitive mechanisms of semantic priming in individuals with intact cerebral hemispheres were studied using the visual half-field method and lexical-decision tasks. In Experiment 1, unidirectionally associated word pairs were presented in a forward direction (e.g., BEAVER–TAIL) to isolate priming attributable to automatic activation or expectancy-based processing. Forward priming was restricted to the right visual field-left hemisphere, and it occurred only when expectancy-based processing was encouraged in the instructions. Experiments 2 and 3 found backward priming (e.g., TAIL–BEAVER) only in the left visual field, indicating that the right hemisphere contributes to retrospective semantic matching of the target back to the prime. The results suggest that the 2 hemispheres have different roles in controlled processing of semantic relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word-based grouping affects the prime-task effect on semantic priming.

Semantic priming between words is reduced or eliminated if a low-level task such as letter search is performed on the prime word (the prime task effect), a finding used to question the automaticity of semantic processing of words. This idea is critically examined in 3 experiments with a new design that allows the search target to occur both inside and outside the prime word. The new design produces the prime task effect (Experiment 1) but shows semantic negative priming when the target letter occurs outside the prime word (Experiments 2 and 3). It is proposed that semantic activation and priming are dissociable and that inhibition and word-based grouping are responsible for reduction of semantic priming in the prime task effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative priming without overt prime selection.

Investigated whether negative priming occurs in the absence of overt prime selection in 3 Exps using 16 college students with normal or corrected-to-normal vision as Ss. In Exp 1, Ss responded to a target item in the probe display only, instead of the usual procedure that requires Ss to also respond to 1 of the items in the prime display. In Exp 2, Ss were asked to choose the less bright of 2 probes displayed in the same color. The same procedure was used for Exp 3 except the distractor was removed from the probe display. The authors conclude that overt selection against a prime distractor in favor of a probe target is not necessary to observe negative priming. This result demonstrates a fundamental misunderstanding concerning the procedure required to measure negative priming and presents an experimental procedure that is of considerable utility in evaluating theoretical accounts of negative priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic priming and Stroop-like interference in word-naming tasks.

Three studies with 72 undergraduates examined why a semantic relation between relevant and irrelevant stimulus components facilitates performance in priming tasks but seems to inhibit performance in Stroop-like tasks. In a series of word-naming tasks, the effect of number of semantic domains (varied concomitantly with number of response alternatives) was examined by presenting to Ss an identical set of stimuli either blocked or mixed. Exp I showed that blocked presentation yielded Stroop-like interference, whereas mixed presentation yielded semantic facilitation. Exps II and III showed that the word–word variant of the Stroop task and the word-naming variant of the semantic priming task belonged to 1 family of tasks. Both tasks showed a facilitation effect when the prime was related to the target and an interference effect when the prime was a member of the response set. In the Stroop task, response competition outweighed facilitation; in the priming task, semantic facilitation outweighed response competition. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased semantic and repetition priming in schizophrenic patients.

Positive and negative priming (PP and NP) in schizophrenia were studied with a lexical-decision task. Probe words, presented 800 ms after the response to the prime (containing a word and a nonword), were either identical to, semantically related to, or unrelated to the prime target word (PP) or to the prime distractor word (NP). Schizophrenic patients displayed stronger semantic and repetition PP than controls after controlling for their slower responses. Significant NP was observed in both groups for word repetition only. The PP findings contrast with results from studies with similar prime-probe intervals but without prime responses. It is proposed that schizophrenic patients, because of impaired (controlled) processes of response selection, strongly benefit from (or rely on) the automatic retrieval of processing episodes containing response information. Related findings indicating automatic response facilitation in schizophrenia are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive penetrability of syntactic priming in Broca's aphasia.

Agrammatic Broca's aphasia has been explained as an impairment of automatic syntactic processes. The present study investigated whether controlled processes play a role in agrammatics' handling of syntactic information. Agrammatic patients and normal controls performed a cross-modal priming task with sentence fragments and visual targets forming either grammatical or ungrammatical pairs. In Exp 1, Ss of both groups were instructed to ignore the auditory prime. The grammaticality effect observed in a previous study disappeared for the aphasic Ss but not for normal controls. Exp 2 demonstrated that for normal controls, the grammaticality effect was present even with a larger prime-target interval. These findings indicate that although automatic parsing routines in normal Ss are impervious to strategic effects, agrammatic Broca patients appear to use syntactic information in a controlled fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased priming interference at a long SOA with brief masked targets.

Tests prediction of a model of priming proposed by B. E. McLeod and R. E. Walley (1989) in which interference (ITF) is caused by inhibitory processes between nodes in semantic memory. This model predicts that ITF normally found in a high cue validity condition at long stimulus onset asynchrony (SOA) will be considerably increased when a brief target is masked. 80 male and female, native English-speaking Ss participated; within S variables were prime type, prime relatedness, and target condition. 192 trials were given in 2 blocks of 96 trials; 25% were nonword trials. The task was a primed lexical decision with an SOA of 800 ms. Cue validity was high or low; targets were brief, masked in either block 1 or block 2 of trials. In the high cue validity condition, both reaction time (RT) and error data show increased ITF when the brief target was masked. Results confirm that target node activation is considerably reduced. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)