Masked inhibitory priming in english: evidence for lexical inhibition

Predictions derived from the interactive activation (IA) model were tested in 3 experiments using the masked priming technique in the lexical decision task. Experiment 1 showed a strong effect of prime lexicality: Classifications of target words were facilitated by orthographically related nonword primes (relative to unrelated nonword primes) but were inhibited by orthographically related word primes (relative to unrelated word primes). Experiment 2 confirmed IA's prediction that inhibitory priming effects are greater when the prime and target share a neighbor. Experiment 3 showed a minimal effect of target word neighborhood size (N) on inhibitory priming but a trend toward greater inhibition when nonword foils were high-N than when they were low-N. Simulations of 3 different versions of the IA model showed that the best fit to the data is produced when lexical inhibition is selective and when masking leads to reset of letter activities.     

On obtaining episodic priming in a lexical decision task following paired-associate learning

In four experiments, subjects made lexical (word-nonword) decisions to target letter strings after studying paired associates. In this lexical decision test, word targets previously studied as response terms in the paired associates were preceded at a 150-ms and/or 950-ms stimulus onset asynchrony (SOA) by one of various subsets of the following six types of primes: a neutral (XXX or ready) prime, a semantically unrelated word prime episodically related to the target through its having been previously studied in the same pair, a semantically related word prime previously studied in a pair with some other unrelated word, a semantically unrelated word prime previously studied in a pair with some other unrelated word, a nonstudied semantically related word prime, and a nonstudied semantically unrelated word prime. At the 950-ms SOA, facilitation of lexical decisions produced by the episodically related primes was greater in test lists in which there were no 150-ms SOA trials intermixed, no previously studied semantically related primes, and no studied nonword targets. At the 150-ms SOA, facilitation from episodic priming was greater in test lists in which there were no semantically related primes and all studied word targets and no studied nonword targets. Facilitation effects from semantically related primes were small in magnitude and occurred inconsistently. Discussion focused on the implications these results have for the episodic-semantic memory distinction and the automaticity of episodic and semantic priming effects.     

Target letter inclusion in single and multiple word substrings and identification accuracy

In experiment 1, target letter discrimination in quadrigrams containing multiple subwords was found to be no more accurate than target letter discrimination in strings of four unrelated letters. Discrimination in quadrigrams, each including the target letter and a one-word trigram of which the target was not a part, was significantly poorer than discrimination in either of the other two types. In Experiment 2, a possible explanation of the latter result involving capacity limitations was eliminated by presenting the target above or below the other letters, which were presented in the same order as in corresponding strings in Experiment 1. The results are explained with respect to the interactive activation model of context effects in letter perception, with a modification proposed involving inhibitory connections between word nodes.     

Color aftereffect contingent on text

During adaptation, two different letter strings (each five or six letters) were presented to subjects alternately, one in green and the other in magenta. The extent to which these letter strings subsequently elicited a color aftereffect was assessed. In different experiments, the chromatic letter strings consisted of words and nonwords. The results indicated that letter strings that form English words can contingently elicit a color aftereffect. This was the case even when the words were anagrams. There was no evidence that nonword letter strings could contingently elicit such an aftereffect, even when the nonwords conformed to English orthography. The results are relevant to understanding other contingent color aftereffects (McCollough effects), illusory color noted by computer operators who work at monochrome (green or amber) displays, and the processing of text.     

Visually-presented letter strings typically are encoded phonologically: some converging evidence

Three experiments were conducted to show that phonological encoding is typical for visually-presented letter strings, and that an interactive activation model with a phonological route to the mental lexicon accounts adequately for the word-superiority effect. In Experiment 1, pseudohomophones produced a word-superiority effect that was as great as that produced by words. More accurate target discrimination in homophones than in nonhomophones in Experiment 2 was interpreted to mean that excitability of entries in the mental lexicon increases with frequency of access. Target discrimination accuracy was inversely related to the phonological complexity of strings containing targets in Experiment 3, supposedly because lexical access through which target discrimination is enhanced becomes more difficult as phonological complexity increases.     

The use of abstract graphemic information in lexical access

Three experiments investigated the nature of the information required for the lexical access of visual words. A four-field masking procedure was used, in which the presentation of consecutive prime and target letter strings was preceded and followed by presentations of a pattern mask. This procedure prevented subjects from identifying, and thus intentionally using, prime information. Experiment I extablished the existence of a semantic priming effect on target identification, demonstrating the lexical access of primes under these conditions. It also showed a word repetition effect independent of letter case. Experiment II tested whether this repetition effect was due to the activation of graphemic or phonemic information. The graphemic and phonemic similarity of primes and targets was varied. No evidence for phonemic priming was found, although a graphemic priming effect, independent of the physical similarity of the stimuli, was obtained. Finally Experiment III demonstrated that, irrespective of whether the prime was a word or a nonword, graphemic priming was equally effective. In both Experiments II and III, however, the word repetition effect was stronger than the graphemic priming effect. It is argued that facilitation from graphemic priming was due to the prime activating a target representation coded for abstract (non-visual) graphemic features, such as letter identities. The extra facilitation from same identity priming was attributed to semantic as well as graphemic activation. The implications of these results for models of word recognition are discussed.     

Perceptual and response interactions in semantic priming

In two experiments, subjects made pairs of lexical decisions verbally. In Experiment 1, masked stimuli appeared concurrently to the left and right of fixation; in Experiment 2, nonmasked stimuli appeared sequentially at fixation. The left-hand letter strings were judged more accurately in in Experiment 1, and the second letter strings were judged more accurately in Experiment 2. Each string in the pair could be either a word (e.g., fork) or a nonword anagram (e.g., frok). Consequently, the two strings in the pair could be related (e.g., fork-spoon, frok-spoon, etc.) or unrelated (e.g., fork-door, frok-door, etc.), independently of whether neither, either, or both strings were words. Semantically related stimuli induced consistent biases to respond "word," as noted in other studies. These biases were typically stronger for the event reported second. Minimal evidence was found for perceptual priming effects. The asymmetrical effects were consistent with spreading-activation-type mechanisms, but other considerations support a multiple-process view.     

Access to spoken language and the acquisition of orthographic structure: Evidence from deaf readers

Sensitivity to two types of orthographic structure was investigated: linguistically based orthographic regularity and summed single letter positional frequency. Deaf college students were found to make use of positional frequency information no less than hearing college students; however, the extent to which they made use of orthographic regularities in word recognition was related to their speech production skills. In one task, subjects were presented nonword letter strings for short durations, each followed by a masking stimulus and a target letter. They were asked to indicate whether or not the target had been present in the letter string. It was found that the accuracy of deaf subjects with good speech, like that of hearing subjects, was considerably greater for orthographically regular than irregular strings. In contrast, the accuracy of deaf subjects with poor speech was much less related to orthographic regularity. In a second task, in which subjects made judgements about how word-like various letter strings appeared, the judgements of the hearing subjects were more influenced by regularity than those of deaf subjects with poor speech. These results are discussed in terms of how expertise in speech relates to appreciation of orthographic regularity.     

Masked constituent letter priming in an alphabetic decision task

Abstract

The experiments presented here were designed to test whether the prior presentation of a letter in a word, nonword or a string of Xs facilitates the subsequent identification of this letter. Using briefly presented masked primes, clear facilitatory constituent priming effects were obtained in an alphabetic decision task (letter/non-letter classification) when prime letters were flanked by Xs, but the effects disappeared or were greatly reduced when the prime letter formed part of a consonant array (nonword primes). Evidence for word-letter constituent priming was also obtained but almost only for word-initial letten. These facilitatory constituent priming effects were strongest when the target letter was embedded in a string of hash marks and occupied the same relative position in this string as the prime letter in the prime string. The mediating role of letter representations in word recognition and the position-specific coding of character arrays are discussed in the light of these results.     

Does<Emphasis Type="SmallCaps">LGHT</Emphasis> prime<Emphasis Type="SmallCaps">DARK</Emphasis>? Masked associative priming with addition neighbors

We present two masked priming lexical decision experiments in which we examined whether a nonword prime word would activate associative/semantic information from its corresponding addition neighbor (e.g.,lght-DARK via the addition neighborlight), producing associative/semantic priming. The rationale was the following: If a nonword prime with a missing letter produced a semantic/associative priming effect, this would clearly indicate that this nonword was activating the lexical/semantic representations of its base word, thereby reinforcing the models of visual-word recognition in which the orthographic representations produced bylght (orligt) andlight are quite similar (e.g., SOLAR, SERIOL, open-bigram, and overlap models). The results showed that the magnitude of the masked associative priming effect with subset primes was remarkably similar to that of the priming effect with the corresponding word prime. Furthermore, the magnitude of the associative priming effect was similar when the deleted letter was a vowel and when the deleted letter was a consonant.     

The word-superiority effect under conditions that approximate reading

Observers detected a briefly flashed target letter embedded in word, pronounceable nonword, and unpronounceable nonword contexts. The word context facilitated perception under both holistic and analytical processing strategies; the facilitative effect was enhanced when processing was analytical.     

Surface features can deeply affect artificial grammar learning

Three experiments explored the extent to which surface features explain discrimination between grammatical and non-grammatical strings in artificial grammar learning (AGL). Experiment 1 replicated Knowlton and Squire’s (1996) paradigm using either letter strings as in the original study, or an analogous set of color strings to further explore if learning was affected by type of stimuli. Learning arose only with letter strings, but the results were mostly due to the discrimination of non-grammatical strings containing highly salient illegal features. Experiments 2 and 3 tested a new grammar devised to control for those features. Experiment 2 showed reduced grammar learning effects, and again only for letter materials. Experiment 3 explored the effect of additional practice with letter stimuli, and found increased learning only in the spaced practice condition, though additional practice also produced more explicit knowledge. These findings call for further research on the boundary conditions of learning in AGL paradigms.     

Conflicting strategies and hemispheric suppression in a lexical decision task

The research tests the prediction of the inhibitory-interaction hypothesis that experience with a task accentuates the functional imbalance between the hemispheres. Right-handed males who were experienced readers were presented a letter string to the centre visual field for lexical decision. The string was or was not accompanied by a blinking light to the left or right visual field. It was predicted that asymmetry would be greatest for strings that spelled words, less for strings that were orthographically correct (pseudowords) and least for strings that were orthographically incorrect (nonwords) because efficient adult readers have more experience with letter strings that do than do not spell a word, and have more experience with orthographically correct than incorrect letter strings. The analysis of response times supported the prediction. Moreover, in the nonword and in early trials of the pseudoword conditions, response times were faster when one or other hemisphere was distracted than when both were engaged suggesting the hemispheres use strategies that conflict when suppression has not been accentuated by practice. As well, as the trials progressed in the pseudoword condition, asymmetry reversed before increasing suggesting that the hemispheres reduce conflict by competing for and then strengthening suppression.     

The priming of word associations: A levels-of-processing approach

Four experiments are reported in which the magnitude of the associative-priming effect is manipulated by varying both the experimental task and the conditions within a given task. The between-task manipulation involved a comparison of priming effects in length categorization on the one hand and lexical decision on the other. The within-task manipulation involved varying the type of letter strings presented as the nonword stimuli in lexical decisions. Pseudowords and two types of orthographically illegal letter strings—namely, consonant strings and random letter strings—served as nonwords. Finally, the effect of varying the proportion of pseudowords to illegal nonwords across four sets of experimental materials was investigated. On the whole, these within-and between-task manipulations turned out to be very effective ways of affecting the size of the associative-priming effect. Also, the size of the lexicality effect (the difference between the RTs to word and nonword stimuli) varied systematically with these within-and between-task manipulations. The results are discussed in relation to both Shulman and Davison's (1977) parallel-processing model and Balota and Chumbley's (1984) account of lexical decision.     

When orthographic neighbors fail to facilitate

Forward masked word primes that differed from the target in the initial, the final or both the initial and final positions tended to slow target decision latencies and there were no significant differences among prime types. After forward masked nonword primes we observed non significant facilitation when primes differed from the target by one letter in either the initial or final position and significant inhibition when primes differed in both initial and final positions. The patterns did not differ significantly for targets with large and with small neighborhoods. Only in post hoc analyses was there any indication of facilitation after nonword neighbor primes and it appeared only when body neighborhood was small. For slower participants, neighbors tended to facilitate target decision latencies while for relatively fast readers showed neighbors made inhibition that tended to vary with amount of mismatch.     

The word-detection effect: Sophisticated guessing or perceptual enhancement?

Subjects discriminate letters in words better than letters in nonwords. The sophisticated guessing hypothesis attributes this word advantage to a guessing strategy. In words, the possible letters at each letter position are constrained by letters at other positions, whereas letters in nonwords are not restricted in this manner. A critical test of this hypothesis is that if subjects are givenexplicit knowledge of the letters in nonwords before the trial, the word advantage would disappear. We investigated the effect of preknowledge of the alternatives in the word-detection effect. In the word-detection effect, subjects decide which of two character strings contains letters and which contains pseudoletters. In four experiments, subjects were more accurate with words than with nonwords, and subjects were more accurate when they were told the word or nonword before the trial. However, even with foreknowledge of the alternatives, subjects were more accurate with words than with nonwords.     

The interfering effect of word perception on letter identification

Subjects identified a single lowercase letter in a visual display by pressing one of two buttons. Two letters were assigned to each response. Groups received one of three context conditions: word, nonword, or single-letter displays. In words and nonwords, the flanking letters adjacent to the target varied as to whether they were response compatible or incompatible with the target. Single letters produced faster response latencies than either multi-letter condition, and words yielded slower latencies than did nonwords. Items Containing an incompatible-response flanking letter produced longer latencies than items containing a compatible flanking letter. Subgroups of subjects with different characteristic processing patterns were identified with a separate test. These subgroups were differentially affected by the context conditions in the letter-identification task. A greater subgroup difference was found in nonwords than in words.     

Forced serial processing of words and letter strings: A reexamination

Words and nonword strings, three and seven letters long, were displayed serially (i.e., one letter at a time) or simultaneously, with or without a backward mask following display of each letter or string. Recognition of words, and of individual letters within words, was markedly impaired in the masked serial condition relative to the unmasked serial, unmasked simultaneous, and masked simultaneous conditions. Analogous differences were smaller or nonexistent for seven-letter nonwords; however, three-letter nonwords produced relatively “wordlike” data. Implications for the issue of spatially serial vs. parallel processing in word recognition are discussed.     

Whole-word units are used before orthographic knowledge in perceptual development

A visual search task for target letters in multiletter displays was used to investigate information-processing differences between college students and presecond-grade children (mean age = 7 years, 4 months). The stimulus displays consisted of single words, pronounceable pseudowords, and unpronounceable nonwords varying in length from three to five letters. The mean response times for indicating whether or not a target letter occurred in the display increased with the number of display letters for both groups, although there were apparent differences between groups in the rate of search and type of search strategy used. Pre-second-grade children responded faster to word displays than to pseudoword and nonword displays, indicating that familiar letter strings could be processed faster than unfamiliar strings regardless of whether or not the latter were consistent with rules of English orthography. In contrast, college students processed words and pseudowords about equally well, and both resulted in faster responses than nonwords. As reading skills develop, children apparently come to process familiar words differently from other letter strings. Only after a significant sightword vocabulary is established do children seem to recognize the regularities of standard English orthography and make use of this knowledge to facilitate perceptual processes.     

Ignoring 'brutal' will make 'numid' more pleasant but 'uyuvu' more unpleasant: The role of a priori pleasantness of unfamiliar stimuli in affective priming tasks

Based on assumptions borrowed from negative priming research, in two experiments an evaluative decision to a clearly valenced target word that was flanked by a positive or negative distractor (i.e., the “affective priming” technique in the tradition of of Fazio, Sanbonmatsu, Powell, & Kardes, 1986) was followed by a pleasantness rating of an unfamiliar, senseless string of letters. Of main interest was whether an inhibition of the distractor valence affects the rating. Unexpectedly, it was found that the effect depended on subtle differences in the a priori pleasantness of the letter strings. For (relatively) less pleasant sounding strings, the rating was congruent to the prime whereas it was incongruent for (relatively) more pleasant sounding strings. In Experiment 3, the rating of the letter strings was preceded by a masked positive or negative prime only. The same pattern of congruence and incongruence effects emerged. The results are related to a matching account of negative priming.