Short Stimulus Onset Research Articles

Asymmetric Morphological Priming Among Inflected and Derived Verbs and Nouns in Greek.

The present study examined differences between inflectional and derivational morphology using Greek nouns and verbs with masked priming (with both short and long stimulus onset asynchrony) and long-lag priming. A lexical decision task to inflected noun and verb targets was used to test whether their processing is differentially facilitated by prior presentation of their stem in words of the same grammatical class (inflectional morphology) or of a different grammatical class (derivational morphology). Differences in semantics, syntactic information, and morphological complexity between inflected and derived word pairs (both nouns and verbs) were minimized by unusually tight control of stimuli as permitted by Greek morphology. Results showed that morphological relations affected processing of morphologically complex Greek words (nouns and verbs) across prime durations (50–250ms) as well as when items intervened between primes and targets. In two of the four experiments (Experiments 1 and 3), inflectionally related primes produced significantly greater effects than derivationally related primes suggesting differences in processing inflectional versus derivational morphological relations, which may disappear when processing is less dependent on semantic effects (Experiment 4). Priming effects differed for verb vs. noun targets with long SOA priming (Experiment 3), consistent with processing differences between complex words of different grammatical class (nouns and verbs) when semantic effects are maximized. Taken together, results demonstrate that inflectional and derivational relations differentially affect processing complex words of different grammatical class (nouns and verbs). This finding indicates that distinctions of morphological relation (inflectional vs. derivational) are not of the same kind as distinctions of grammatical class (nouns vs. verbs). Asymmetric differences among inflected and derived verbs and nouns seem to depend on semantic effects and/or processing demands modulating priming effects very early in lexical processing of morphologically complex written words, consistent with models of lexical processing positing early access to morphological structure and early influence of semantics.

An RT distribution analysis of relatedness proportion effects in lexical decision and semantic categorization reveals different mechanisms.

The magnitude of the semantic priming effect is known to increase as the proportion of related prime-target pairs in an experiment increases. This relatedness proportion (RP) effect was studied in a lexical decision task at a short prime-target stimulus onset asynchrony (240 ms), which is widely assumed to preclude strategic prospective usage of the prime. The analysis of the reaction time (RT) distribution suggested that the observed RP effect reflected a modulation of a retrospective semantic matching process. The pattern of the RP effect on the RT distribution found here is contrasted to that reported in De Wit and Kinoshita's (2014) semantic categorization study, and it is concluded that the RP effect is driven by different underlying mechanisms in lexical decision and semantic categorization.

The contribution of prefixes to morphological processing of Spanish words

Three series of priming experiments were conducted to probe the morphological and phonological contributions to visual word recognition in Spanish. Prefixed, e.g., INCAPAZ (incapable), and pseudoprefixed, e.g., INDUSTRIA (industry) target words were presented for recognition following a prefixed, e.g., infeliz (unhappy), or pseudoprefixed, e.g., insulto (insult), prime starting with the same syllable as the target, at masked short or long stimulus onset asynchronies (SOAs). At long SOAs the recognition of prefixed targets was facilitated by prefixed primes and inhibited by pseudoprefixed ones, whereas both prefixed and pseudoprefixed primes facilitated the recognition at short SOAs. In contrast, the recognition of pseudoprefixed targets was unaffected by the kind of prime presented, even when we used pairs of words overlapping in syllables that cannot be prefixes in Spanish. These results support a special status for morphological elements in access to meaning in reading.

Transdermal nicotine modulates strategy-based attentional semantic processing in non-smokers

Nicotine has been shown to improve various aspects of cognitive processing such as attention and memory, however, its effects on lexical-semantic processing are relatively uncharted. Recent investigations of mnemonic processing in minimally deprived smokers suggest that nicotine might selectively modulate processes concerned with associative memory. This study investigated the effects of nicotine on lexical-semantic processing in non-smokers using a strategy-based lexical-decision priming paradigm. Transdermal nicotine patches (7 mg/24 h) were administered within a double-blind, placebo-controlled, cross-over design. Participants were trained to expect target words to come from a specified semantic category based on the prime word, although in some instances trained expectations were not met. Participants were presented with the stimuli at either a short or long stimulus onset asynchrony (SOA) to target automatic and attentional processing, respectively (n=12 and 17 for the short and long SOAs, respectively). Nicotine was found to selectively affect priming condition reaction times at the long SOA, indicating a nicotinic modulation of attentional mechanisms. Specifically, facilitation effects were dominant under placebo compared to a dominance of inhibition effects under nicotine. These results suggest that nicotine supports inhibitory attentional mechanisms in cognitively demanding semantic processing paradigms.

Emergent perceptual features in the benefit of consistent stimulus-response mappings on dual-task performance

Duncan (1979) examined all combinations of compatible and incompatible stimulus-response mappings for two spatial three-choice tasks in the psychological refractory period paradigm. Performance was better when the mappings for the tasks were consistent than when they were not, even when both mappings were incompatible. He attributed the benefit for the consistent incompatible mapping to an emergent choice between mappings when they are inconsistent that slows performance. Consistent incompatible mappings also may benefit from emergent perceptual features. The present study examined the role of emergent perceptual and mapping-choice features in two experiments that used pairs of two-choice tasks. Results similar to Duncan's were obtained with visual stimuli mapped to keypresses at short (stimulus onset asynchrony) SOAs. However, the benefit of the consistent incompatible mapping condition over the inconsistent mapping conditions was eliminated at an SOA of 1,000 ms. Furthermore, this benefit was not evident when the stimuli were auditory for Task 1 and visual for Task 2. With two-choice tasks, the benefit for consistent mappings apparently is due primarily to an emergent perceptual feature.

Semantic and Cross-Case Identity Priming in Patients With Parkinson's Disease

Semantic and cross-case identity priming were investigated in nondemented patients with Parkinson's disease (PD) and controls using the Lexical Decision Task. Three conditions were administered that consisted of the presentation of prime and target word pairs. In the semantic priming condition the word pairs were semantically related (e.g., table-CHAIR), in the cross-case identity priming condition the word pairs consisted of the same word (e.g., noise-NOISE), and in the unrelated condition the word pairs were not related semantically (e.g., guns-DEEP). A fourth condition was also administered that consisted of the presentation of a prime word and a pronounceable nonword target (e.g., starved-FORVE). Participants were asked to indicate whether the target was a real word or a nonword. The prime and target were separated by either a short or long (250 ms or 1000 ms) stimulus onset asynchrony (SOA). Results indicated that PD patients displayed normal semantic priming (i.e., faster responding to the target in the semantic condition as compared to the unrelated condition) at both the short and long SOA. Similarly, PD patients displayed normal cross-case identity priming (i.e., faster responding to the target in the identity condition relative to the unrelated condition) at the long SOA. At the short SOA, however, PD patients displayed hyper identity priming relative to controls (134 ms vs. 50 ms). These results suggest that semantic processes are normal in nondemented PD patients but that the processes involved in accessing lexical information may be overly activated in these patients.

Measuring lexical-semantic activation over time for an aphasic individual

We were interested in whether we could identify priming effects in a mildly aphasic individual and whether these effects would be consistent over time. The method consisted of repeated semantically primed lexical decision tasks across 24 sessions. To compare automatic and controlled processing, we compared short and long stimulus onset asynchronies, and we used a neutral prime to separate facilitation and inhibition as components of overall priming. The long-term goal is to determine whether we can measure the progress of aphasic patients at automatic and controlled levels of cognitive processing. A particular configuration of prime facilitation led us to begin testing certain hypotheses regarding this configuration during the course of the study. In general, priming effects were identified, but they occurred inconsistently with repeated testing.

The relative time course of semantic and phonological activation in reading Chinese.

The relative time course of semantic and phonological activation was investigated in the context of whether phonology mediates access to lexical representations in reading Chinese. Compound words (Experiment 1) and single-character words (Experiments 2 and 3) were preceded by semantic and phonological primes. Strong semantic priming effects were found at both short (57 ms) and long (200 ms) stimulus onset asynchrony (SOA), but phonological effects were either absent in lexical decision (Experiment 1), were present only at the longer SOA in character decision (Experiment 2) or were equally strong as semantic effects in naming (Experiment 3). Experiment 4 revealed facilitatory or inhibitory effects, depending on SOA, in phonological judgments to character pairs that were not phonologically but semantically related. It was concluded that, in reading Chinese, semantic information in the lexicon is activated at least as early and just as strongly as phonological information.

Differential Effects of Semantic and Identity Priming in Patients with Left and Right Hemisphere Lesions

Abstract Patients with single brain lesions in the anterior or posterior left and right hemispheres and a group of controls were studied in two priming experiments. The first experiment employed associative pairs (DOCTOR-NURSE) and the second employed identical pairs (NURSE-nurse). Short and long prime-target stimulus onset asynchronies (SOAs) (i.e., 250 and 1850 msec) were manipulated within block in both experiments. In the first experiment, patients with left hemisphere injury showed a deficient priming effect while patients with right hemisphere injury and controls showed a normal pattern. In contrast, all groups showed an identity priming effect in the second experiment. These results indicate that while entries in the mental lexicon are available for the groups of patients studied, the spread of activation to related concepts in this lexicon is disrupted in the left hemisphere-damaged group.

Word superiority in signal detection: Barely a glimpse, yet reading nonetheless

In Part 1 data from a number of visual masking studies have been reanalyzed to show that, contrary to the conclusions usually drawn from this data, there is statistical evidence of semantic activation at short target-mask stimulus onset asynchrony levels (SOA) and that for levels of performance close to chance, semantic information extracted from briefly presented targets may be used to detect those targets. In Part 2 this hypothesis is tested directly in three experiments. A word superiority effect is found in a signal detection task, showing unequivocally that (i) high-level activation exists at short SOAs and (ii) such activation can affect levels of target detectability. The results undermine the use of signal detectability as a measure of awareness.