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Jonathan Grainger

Publications and source records attributed to Jonathan Grainger.

At least 19 recordsLinked to original sources
PubMed2006

Exogenous spatial cueing modulates subliminal masked priming.

An experiment combined exogenous spatial cueing with masked repetition priming. The task consisted of an alphabetic decision task (letter/pseudo-letter classification) with central targets and peripheral primes that were preceded by a valid or invalid spatial cue in the form of an exogenous abrupt onset. In an analysis including only participants who were not aware of prime stimuli, exogenous location cueing was found to reliably modulate the size of unconscious priming effects. These findings suggest that in early vision the exogenous cue boosts the signal at the location of the cue resulting in a higher gain for the subliminal prime. Our findings therefore suggest that exogenous cueing can affect the first feedforward sweep of information through the brain, a processing stream which is considered to be automatic and unconscious.

Adult↗
PubMed2006

Attentional modulation of masked repetition and categorical priming in young and older adults.

Three experiments examined the effects of temporal attention and aging on masked repetition and categorical priming for numbers and words. Participants' temporal attention was manipulated by varying the stimulus onset asynchrony (i.e., constant or variable SOA). In Experiment 1, participants performed a parity judgment task and a lexical decision task in which categorical priming and repetition priming were, respectively, tested. Experiment 2 used a semantic categorization task testing categorical priming. In Experiment 3, repetition and categorical priming were tested in the same semantic categorization task with the same stimuli. The results of the three experiments showed that masked repetition priming is insensitive to manipulations of temporal attention whereas categorical priming is. Furthermore, no differences were found between young and older adults in repetition priming effects, again contrasting with the categorical priming results for which older adults were more sensitive to attentional manipulations than young adults.

Adolescent↗
PubMed2006

Syllable frequency effects in French visual word recognition: an ERP study.

This study examined event-related potentials (ERPs) associated with differences in the frequency of the initial syllable of target words whose syllabic structure provided either a match or mismatch with the /CV/ and /CVC/ syllables under analysis. Results showed ERP effects that were consistent with syllabic activation between 300 and 600 ms, with high frequency syllables producing more positive potentials than those of low frequency. The syllabic locus of these effects was verified by their presence only in the matched syllabic condition, showing that frequency effects respected known syllable boundaries. Syllable frequency effects were also noted in an earlier time window, between 150 and 300 ms. However, these effects were only seen when manipulating /CVC/ frequency, not /CV/, and were common to both the matched and unmatched conditions. These results suggest that phoneme representations are directly activated following presentation of a printed word, and syllable representations are only activated following phoneme activation.

Adolescent↗
PubMed2006

Letter position information and printed word perception: the relative-position priming constraint.

Six experiments apply the masked priming paradigm to investigate how letter position information is computed during printed word perception. Primes formed by a subset of the target's letters facilitated target recognition as long as the relative position of letters was respected across prime and target (e.g., "arict" vs. "acirt" as primes for the target "apricot"). Priming effects were not influenced by whether or not absolute, length-dependent position was respected (e.g., "a-ric-t" vs. "arict"/"ar-i-ct"). Position of overlap of relative-position primes (e.g., apric-apricot; ricot-apricot; arict-apricot) was found to have little influence on the size of priming effects, particularly in conditions (i.e., 33 ms prime durations) where there was no evidence for phonological priming. The results constrain possible schemes for letter position coding.

Attention↗
PubMed2006

A study of relative-position priming with superset primes.

Four lexical decision experiments are reported that use the masked priming paradigm to study the role of letter position information in orthographic processing. In Experiments 1 and 2, superset primes, formed by repetition of 1 or 2 letters of the target (e.g., jusstice-JUSTICE) or by insertion of 1 or 2 unrelated letters (e.g., juastice-JUSTICE), generated significant priming compared with unrelated primes and did not differ significantly from an identity priming condition. In Experiment 3, identity primes generated significantly faster responses than subset primes formed by removal of 2 letters from the target (e.g., jutie-JUSTICE), and subset primes generated faster responses than substitution primes formed by substitution of 2 letters of the target with unrelated letters (e.g., jumlice-JUSTICE). In Experiment 4, insertion of 3 unrelated letters continued to generate facilitation relative to unrelated primes but significantly less so than the identity prime condition. The authors discuss the implications of these results for letter-position coding schemes.

Analysis of Variance↗
PubMed2006

The time course of orthographic and phonological code activation.

The present study used event-related potentials (ERPs) to examine the time course of orthographic and phonological priming in the masked priming paradigm. Participants monitored visual target words for occasional animal names, and ERPs to nonanimal critical items were recorded. These critical items were preceded by different types of primes: Orthographic priming was examined using transposed-letter (TL) primes (e.g., barin-BRAIN) and their controls (e.g., bosin-BRAIN); phonological priming was examined using pseudohomophone primes (e.g., brane-BRAIN) and their controls (e.g., brant-BRAIN). Both manipulations modulated the N250 ERP component, which is hypothesized to reflect sublexical processing during visual word recognition. Orthographic (TL) priming and phonological (pseudohomophone) priming were found to have distinct topographical distributions and different timing, with orthographic effects arising earlier than phonological effects.

Adult↗
PubMed2006

On the time course of visual word recognition: an event-related potential investigation using masked repetition priming.

The present study used event-related potentials (ERPs) to examine the time course of visual word recognition using a masked repetition priming paradigm. Participants monitored target words for occasional animal names, and ERPs were recorded to nonanimal critical items that were full repetitions, partial repetitions, or unrelated to the immediately preceding masked prime word. The results showed a strong modulation of the N400 and three earlier ERP components (P150, N250, and the P325) that we propose reflect sequential overlapping steps in the processing of printed words.

Adult↗
PubMed2006

On the time course of letter perception: a masked priming ERP investigation.

In an experiment measuring event-related brain potentials (ERPs), single-letter targets were preceded by briefly presented masked letter primes. Name and case consistency were manipulated across primes and targets so that the prime was either the same letter as the target (or not), and was presented in the same case as the target (or not). Separate analyses were performed for letters whose upper- and lowercase forms had similar features (or not). The results revealed an effect of prime-target visual similarity between 120 and 180 msec, an effect of case-specific letter identity between 180 and 220 msec, and an effect of case-independent letter identity between 220 and 300 msec. We argue that these ERP results reflect processing in a hierarchical system for letter recognition that involves both case-specific and case-independent representations of alphabetic stimuli.

Adult↗
PubMed2005

An investigation of semantic priming in schizophrenia using a new priming paradigm.

In the present study, twenty schizophrenic patients and twenty healthy controls were tested in a new priming paradigm that allows a clear distinction to be made between automatic, perceptual priming effects and effects related to decision bias. Participants had to identify briefly presented masked target words preceded by clearly visible primes that were semantically related to the target or not. Target presentation duration corresponded to a pre-determined perceptual threshold for each participant, and a two-alternative forced-choice methodology was used. Equivalent amounts of semantic priming were found in schizophrenic patients compared with healthy controls. However, for the schizophrenic patients, a positive correlation was found between the size of automatic perceptual priming effects and formal thought disorders, as measured by Andreasen's Thought, Language and Communication (TLC) scale. The new paradigm tested in the present study overcomes some of the limitations of prior research on semantic priming in schizophrenia, and provides further evidence suggesting that an increased spreading of activation in the semantic network could partly underlie formal thought disorders in schizophrenia.

Cognition Disorders↗
PubMed2005

The effects of prime visibility on ERP measures of masked priming.

In two experiments, the effect of the duration (40, 80 and 120 ms) of pattern masked prime words on subsequent target word processing was measured using event-related potentials. In Experiment 1, target words were either repetitions of the prior masked prime (car-CAR) or were another unrelated word (job-CAR). In Experiment 2, primes and targets were either semantically related (cap-HAT) or were unrelated (car-HAT). Unrelated target words produced larger N400s than did repeated (Exp 1) or semantically related (Exp 2) words across the different prime durations and these N400 priming effects tended to be smaller overall for semantic than repetition priming. Moreover, there was only a modest decline in the size of N400 repetition priming at the shortest prime durations, and there was no relationship between this N400 effect and a measure of prime categorization performance. However, the size of semantic priming at the shortest durations was relatively smaller than at longer durations and was correlated with prime categorization performance. The findings are discussed in the context of the functional significance of the N400 as well as a model that argues for different mechanisms during masked repetition and semantic priming.

Adult↗
PubMed2005

Effects of phonological and orthographic neighbourhood density interact in visual word recognition.

The present study investigated the role of phonological and orthographic neighbourhood density in visual word recognition. Three mechanisms were identified that predict distinct facilitatory or inhibitory effects of each variable. The lexical competition account predicts overall inhibitory effects of neighbourhood density. The global activation (familiarity) account predicts overall facilitatory effects of neighbourhood density. Finally, the cross-code consistency account predicts an interaction, with inhibition of phonological neighbours in sparse orthographic regions and facilitation of phonological neighbours in dense orthographic regions. In Experiment 1 (lexical decision), a cross-over interaction was indeed found, supporting the prediction of the cross-code consistency account. In Experiment 2, this cross-over interaction was exaggerated by adding pseudohomo-phone stimuli (e.g., brane) among the nonword targets. Finally, in Experiment 3 (progressive demasking), we tried to shift the balance between inhibitory and facilitatory mechanisms by using a perceptual identification task. As predicted, the inhibitory effects of phonological neighbourhood were amplified, whereas the facilitatory effects disappeared. We conclude that the level of compatibility across co-activated orthographic and phonological representations is a major causal factor underlying this pattern of effects.

Humans↗
PubMed2005

Sequential effects of phonological priming in visual word recognition.

Two masked priming experiments were conducted to examine phonological priming of bisyllabic words in French, and in particular, whether it operates sequentially or in parallel. Bisyllabic target words were primed by pseudowords that shared either the first or the second phonological syllable of the target. Overlap of the first syllable only-not the second-produced facilitation in both the lexical decision and the naming tasks. These findings suggest that, for polysyllabic words, phonological codes are computed sequentially during silent reading and reading aloud.

Acoustic Stimulation↗
PubMed2005

An electrophysiological study of cross-modal repetition priming.

Few studies have focused on language processing across modalities. Two experiments examined between-modality interactions across three prime-target intervals (0, 200, and 800 ms) in a cross-modal repetition priming paradigm. Event-related potentials were recorded to auditory targets following visual primes (Experiment 1) or visual targets following auditory primes (Experiment 2). In Experiment 1 robust repetition effects were found for auditory targets as early as 100 ms, and continued through the N400 epoch. Moreover, these visual-auditory repetition effects were large across all three prime-target intervals although they onset 200 ms later at the shortest interval. In Experiment 2 repetition effects to visual targets started later (at 200 ms), but also offset relatively later (approximately 1000 ms). These auditory-visual repetition effects were both smaller overall and absent for the two shortest prime-target intervals during the typical N400 window.

Adolescent↗
PubMed2004

Blocking by word frequency and neighborhood density in visual word recognition: a task-specific response criteria account.

Effects of blocking words by frequency class (high vs. low) and neighborhood density (high vs. low) were examined in two experiments using progressive demasking and lexical decision tasks. The aim was to examine the predictions of a task-specific response criteria account of list-blocking effects. Distinct patterns of blocking effects were obtained in the two tasks. In the progressive demasking task, a pure-list disadvantage was obtained to low frequency-high density words, whereas high frequency-low density produced a trend toward a pure-list advantage. In lexical decision, high-frequency words showed a pure-list advantage that was strongest in high-density words, whereas low frequency-low density words produced a trend toward a pure-list disadvantage. A simulation study implementing task-specific response criteria within the framework of the multiple read-out model provided an accurate description of the blocking effects obtained in the experiments. It is argued that adjustments of task-specific response criteria determine changes in list-blocking effects across different tasks.

Adult↗
PubMed2003

Accessing word meaning in two languages: an event-related brain potential study of beginning bilinguals.

Twenty-eight native-English speakers enrolled in beginning and intermediate university Spanish courses participated in a mixed language semantic categorization task in which critical words were presented in English (L1) and Spanish (L2) and repetitions of these words (within- and between-languages) were presented on subsequent trials (i.e., immediate repetition). Event-related potentials were recorded to all items allowing for comparisons of the N400 component to repetitions within- and between-languages as well as to words presented for the first time. Three important findings were observed in this sample of participants during relatively early stages of acquiring a second language. First, in the typical N400 window (300-500ms), between-language repetition (translation) produced a smaller reduction in N400 amplitude than did within-language repetition. Second, the time-course of between-language repetition effects tended to be more extended in time and differed as a function of language with L2-L1 repetitions producing larger priming effects early (during the typical N400 window) and L1-L2 repetitions producing larger priming effects later (during windows after the typical N400). Third, a greater negativity in the ERP waveforms was observed when the word on the directly preceding trial was from the other language. Within the time frame of the N400, this language switch effect arose only when the target word was Spanish and the preceding word English (i.e., L1-L2). The results are discussed within the framework of current models of bilingual lexical processing.

Adolescent↗
PubMed2003

Word superiority, pseudoword superiority, and learning to read: a comparison of dyslexic and normal readers.

Identification of letters embedded in briefly presented words (e.g., TABLE), pseudowords (e.g., TOBLE), and illegal nonwords (e.g., TPBFE) was measured using the Reicher-Wheeler paradigm. Children diagnosed as dyslexic and showing a clear disadvantage in recognizing and reading aloud words and pseudowords (compared to chronological age-matched controls) showed a pattern of results that was qualitatively identical to both reading age and chronological age control children. In all three groups a small nonsignificant advantage was obtained for letter identification in words compared to pseudowords, and a massive advantage for letter identification in pseudowords compared to illegal nonwords. A group of adult participants tested with the same materials showed the classic word superiority effect as well as a pseudoword advantage over illegal nonwords. These results suggest that the pseudoword superiority effect is subtended by regularities operating at the level of sublexical orthographic representations (orthotactic constraints). This phenomenon could provide a useful tool for future investigations of the development of orthotactic constraints during reading acquisition.

Child↗
PubMed2003

Masked repetition and phonological priming within and across modalities.

Lexical decision latencies to word targets presented either visually or auditorily were faster when directly preceded by a briefly presented (53-ms) pattern-masked visual prime that was the same word as the target (repetition primes), compared with different word primes. Primes that were pseudohomophones of target words did not significantly influence target processing compared with unrelated primes (Experiments 1-2) but did produce robust priming effects with slightly longer prime exposures (67 ms) in Experiment 3. Like repetition priming, these pseudohomophone priming effects did not interact with target modality. Experiments 4 and 5 replicated this general pattern of effects while introducing a different measure of prime visibility and an orthographic priming condition. Results are interpreted within the framework of a bimodal interactive activation model.

Decision Making↗