An Event-Related Brain Potential Analysis of Visual Word Priming Effects (original) (raw)
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Brain research. Cognitive brain research, 2000
There has been conflicting evidence to date regarding the existence of non-strategic semantic priming based on semantic similarity, and in particular on visual-perceptual semantic features (e.g., button-coin: words refer to objects with the same global shape). Both event-related potential (ERP) and reaction time (RT) measures were employed to investigate visual-perceptual semantic priming in a word-pair lexical decision task designed to minimise the contribution of conscious strategic processing. While no RT priming effect was observed, a robust priming effect was obtained on the N400 component of the ERP. This result shows that semantic priming, as indexed by the N400 component, can be supported by nonassociative visual-perceptual semantic relations. The data are consistent with perceptual form information being accessed during the processing of concrete words, and provide support for models of semantic representation which incorporate semantic features and form information.
The anatomy and time course of semantic priming investigated by fMRI and ERPs
Neuropsychologia, 2003
We combined complementary non-invasive brain imaging techniques with behavioural measures to investigate the anatomy and time course of brain activity associated with semantic priming in a lexical-decision task. Participants viewed pairs of stimuli, and decided whether the second item was a real word or not. There were two variables, the semantic relationship between the prime and the target (related or unrelated) and the interval between the onset of prime and target (200 or 1000 ms), to vary the degree of semantic expectancy that was possible during task performance. Behavioural results replicated the well-established finding that identification of the target is facilitated by a preceding semantically related prime. Event-related functional magnetic resonance imaging (efMRI) identified two brain areas involved in the semantic-priming effect. Activity in the anterior medial temporal cortex was diminished when target words were primed by semantically related words, suggesting involv...
Separable effects of priming and imageability on word processing: an ERP study
Cognitive Brain Research, 2002
Concrete, highly imageable words (e.g. banana) are easier to understand than abstract words for which it is difficult to generate an image (e.g. justice). This effect of concreteness or imageability has been taken by some as evidence for the existence of separable verbaland image-based semantic systems. Instead, however, effects of concreteness may result from better associations to relevant contextual representations for concrete than for abstract words within a single semantic system. In this study, target words of high and low imageability were preceded by supportive (related) or non-supportive (unrelated) context words. The influence of contextual support on the imageability effect was measured by recording event-related brain potentials (ERPs) to the high and low imageable target words in both context conditions. The topographic distributions of the ERPs elicited by the high versus low imageable target words were found to be different, and this effect was independent of contextual support. These data are consistent with the idea that distinct verbal-and image-based semantic codes exist for word representations, and that as a result, concrete words that are highly imageable can be understood more easily.
Journal of Memory and Language, 2000
Mediated priming (e.g., from LION to STRIPES via TIGER) is predicted by spreading activation models but only by some integration models. The goal of the present research was to localize mediated priming by assessing two-step priming effects on N400 and reaction times (RT). We propose that the N400 priming effect mainly reflects integration processes but, in contrast with RT, does not reflect spreading activation. The results show that RT and N400 effects can dissociate. In a standard lexical decision task, we found mediated priming for N400 but not for RT. When a lexical decision to both the prime and the target was required, mediated priming was observed for both measures, but the RT effect was not influenced by list composition, whereas the N400 effect was. We conclude that two qualitatively different processes underlie the two types of mediated priming. A process of "global integration" yields an N400 effect, whereas an RT effect is evoked by spreading activation.
Event-related brain potentials as indices of information extraction and response priming
Electroencephalography and Clinical Neurophysiology, 1990
Measures of overt response and of the event-related brain potential (ERP) were used to investigate the processing of a priming stimulus varying in its information content. Subjects were shown sequences of 2 letters that served as a priming and an imperative stimulus. In 3 randomly interspersed conditions the imperative stimulus had a 0.80, 0.50, or 0.20 probability of physically matching the priming letter. The different probability conditions were signaled by the position of a dot flanking the priming letter. Reaction time and accuracy data indicated that the subjects primed their responses as a function of the information conveyed by the priming stimulus. The amplitude and latency of the P300 to the priming stimulus were sensitive to the amount of information conveyed by the priming stimulus and the duration of the processing required. The readiness potential in the foreperiod was lateralized as a function of the priming stimulus. Furthermore, the larger the amplitude of the P300 to the priming stimulus, the larger the lateralization of the readiness potential, indicating that information extraction, indexed by the P300, was related to response priming, indexed by the readiness potential. The results indicate that ERP measures make manifest covert aspects of the priming process occurring in the foreperiod.
Journal of Neurolinguistics, 2004
We investigated individual differences in second language (L2) proficiency by looking at the efficiency or automaticity of semantic priming using behavioural and event-related brain potential (ERP) measures. In Experiment 1, 37 first language (L1) English speakers varying in second language (L2, French) proficiency made living/non-living judgments to English and French nouns in lists blocked by language. Sixty critical words were each presented twice, once primed by a semantic associate in the preceding trial (e.g. ADULT, CHILD) and once unprimed (e.g. RABBIT, CHILD). Measures of response time (RT) and intra-individual variability in response time (coefficient of variation, CV) were obtained. The CV provided an index of processing efficiency that has been related to automaticity. Participants performed faster and with lower CVs (i.e. with greater efficiency) in L1 than L2, and the more highly proficient bilinguals had lower CVs than the less proficient bilinguals. Experiment 2 replicated these results with 29 participants and provided an electrical brain activity measure of processing efficiency using the N400 ERP. The similar pattern of results obtained between the behavioural and N400 ERP CV measures supported the idea that the CV measure of electrical brain activity can provide useful information about the automaticity or efficiency of cognitive processing. q
High density ERP indices of conscious and unconscious semantic priming
2003
The existence of differential brain mechanisms of conscious and unconscious processing is a matter of debate nowadays. The present experiment explores whether conscious and unconscious semantic priming in a lexical decision task at a long prime-target stimulus onset asynchrony (SOA) correlate with overlapping or different event related potential (ERP) effects. Results show that the N400 effect, which appeared when words were consciously perceived, completely disappeared when primes were masked at a level where the ability of participants to detect the prime was near chance. Instead, a rather different set of ERP effects was found to index unconscious semantic priming. This suggests that the processes at the basis of conscious and unconscious semantic analyses can under some circumstances be rather different. Moreover, our results support the notion that conscious and unconscious processes are at least partially separable in the brain.
Research with the evaluative priming paradigm has shown that affective evaluation processes reliably influence cognition and behavior, even when triggered outside awareness. However, the precise mechanisms underlying such subliminal evaluative priming effects, response activation vs semantic processing, are matter of a debate. In this study, we determined the relative contribution of semantic processing and response activation to masked evaluative priming with pictures and words. To this end, we investigated the modulation of masked pictorial vs verbal priming by previously activated perceptual vs semantic task sets and assessed the electrophysiological correlates of priming using event-related potential (ERP) recordings. Behavioral and electrophysiological effects showed a differential modulation of pictorial and verbal subliminal priming by previously activated task sets: Pictorial priming was only observed during the perceptual but not during the semantic task set. Verbal priming, in contrast, was found when either task set was activated. Furthermore, only verbal priming was associated with a modulation of the N400 ERP component, an index of semantic processing, whereas a priming-related modulation of earlier ERPs, indexing visuo-motor S-R activation, was found for both picture and words. The results thus demonstrate that different neuro-cognitive processes contribute to unconscious evaluative priming depending on the stimulus format.
Attentional control and the relatedness proportion effect in semantic priming
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2007
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.