Semantic, repetition and rime priming between spoken words: behavioral and electrophysiological evidence

Semantic, phonological and repetition priming for auditorily presented words were examined, using both behavioral reaction times (RTs) and electrophysiological event-related potentials (ERPs) measures. On critical trials, a word prime was followed by a word target that was semantically or phonologically related (rime) or not related (control) to the prime. Pairs of word-pseudoword items served as fillers. Participants were asked to respond to word targets in the RT experiment and to pseudowords in the ERP experiment. In each experiment stimuli were presented once and then repeated in the very same way. RTs were found to be fastest for semantic, intermediate for rime and slowest for control targets; large repetition effects occurred for all targets. ERPs results showed that both semantic and phonological priming influenced the same component, namely the N400, whose amplitude was smallest to semantic, intermediate to rime and largest to control targets; repetition effects were only found for semantic trials.     

Word repetition within- and across-visual fields: an event-related potential study

A divided visual field (DVF) procedure was used to investigate the scalp distribution of the event-related potential (ERP) repetition effect. ERPs were recorded from 27 scalp sites whilst subjects (n = 20) discriminated between words and non-words presented to either the left (LVF) or the right (RVF) visual field. A proportion of the words were repeated on the trial immediately following their first presentation. In two within-field repetition conditions the two encounters with a word occurred in the same visual field (LVF or RVF). In two across-field repetition conditions, the two encounters with a word occurred in different visual fields. For both words and non-words, task performance was better for RVF presentations than for LVF presentations. In each repetition condition there was a positive-going shift in the ERP elicited by repeated words compared to that elicited by words on their first presentation. This ERP repetition effect was equivalent in magnitude and lateralised to the right hemisphere to an equivalent degree in all four repetition conditions. It is suggested that the ERP effects largely reflect the processing of visual form thought to occur predominately in the right hemisphere.     

Semantic processing and memory for attended and unattended words in dichotic listening: Behavioral and electrophysiological evidence.

Thirty-two Ss studied words presented to 1 ear, while ignoring a concurrent word list presented to the opposite ear. The N400 component of the event-related potentials elicited by attended words was modulated by semantic priming between successive words. The N400 elicited by unattended words was insensitive to semantic manipulation. Recognition memory was better for attended than for unattended words. However, the percentage of false positives was elevated equally for lures that were semantically related to "old" words, whether they had been attended or unattended. Words that were initially attended induced similar repetition effects in a lexical decision task as words that were initially unattended. Hence, both attended and unattended words are semantically processed and activate semantic representations. However, attended words form traces that are subsequently more available to conscious recollection than unattended words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repeated events in rapid lists: I. Encoding and representation.

People have difficulty reporting both occurrences of a word presented twice in a rapid list. N. G. Kanwisher (see record 1988-34836-001) and others explained this "repetition blindness" through a type-token account, which assumes that encoding a repeated occurrence is inhibited if it occurs soon after the first. Contrary to that account, the authors observed in this article that performance on trials containing a repetition was predictable from nonrepeated trials and that reporting the repeated occurrence of a word was independent of reporting the first. It was concluded that each occurrence of a repeated word is processed in the same way as a nonrepeated word, that they are encoded separately but nondistinctively, and that they contribute independently to recall. The authors concluded that an inhibitory mechanism is unnecessary to explain "repetition blindness." Instead, they suggest that people fail to report both occurrences because they cannot recall distinctive information about the separate events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit memory during balanced anaesthesia. Lack of evidence

The effect of the number of presentations on implicit memory for words was studied in anaesthetised patients. During standardised, balanced anaesthesia, 81 surgical patients were presented with less common specimens of familiar word categories. For each of three word categories the number of word presentations varied between the patients (0 (control), 5, or 30 presentations). Postoperatively, repetition priming was tested by asking patients to generate exemplars for each of the word categories. No implicit memory for the words presented during anaesthesia was found and consequently no effect of number of word presentations could be demonstrated. It is suggested that this finding, which contradicts previous results, may be caused by the relatively low familiarity of the words used.     

On the nonautomaticity of visual word processing: Electrophysiological evidence that word processing requires central attention.

The present study used event-related potentials (ERPs) to determine the degree to which people can process words while devoting central attention to another task. Experiments 1-4 measured the N400 effect, which is sensitive to the degree of mismatch between a word and the current semantic context. Experiment 5 measured the P3 difference between low- and high-frequency words. Because these effects can occur only if a word has been identified, both ERP components index word processing. The authors found that the N400 effect (Experiments 1, 3, and 4) and the P3 difference (Experiment 5) were strongly attenuated for Task 2 words presented nearly simultaneously with Task 1. No such attenuation was found when the Task 1 stimulus was presented but required no response (Experiment 2). Strong attenuation was also evident when the Task 2 word was presented before the Task 1 stimulus (Experiment 4), suggesting that central resources are not allocated to stimuli first-come, first-served but rather are strategically locked to Task 1. The authors conclude that visual word processing is not fully automatic but rather requires access to limited central attentional resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The time course of repetition effects for words and unfamiliar faces.

The repetition effect on reaction time to words and unfamiliar faces was examined at lags of 0, 4, and 15 items between 1st and 2nd presentations. For words, Ss made either a lexical decision or a decision based on the stimulus's structural attributes. In the lexical decision task, a significant repetition effect was found at all 3 lags for words, whereas for nonwords the effect was significant only at Lag 0. In the structural decision task, the repeated decision was facilitated for both words and nonwords only at Lag 0, despite a word superiority effect at all lags. Target faces were presented either 0, 1, or 5 times before testing. Ss made either structural discriminations (face/nonface) or recognition judgments. In the structural discrimination task, the effect of repetition was significant only at Lag 0 (regardless of the number of pretest presentations). In the recognition task, the repetition effect was longer lasting, and its magnitude increased with the number of presentations which, presumably, determined the strength of the episodic memory trace. These results are taken as showing that repetition effects, like other measures of memory, are influenced by the type of stimulus, its preexperimental history, the level to which it is processed, and the lag between the initial presentation and the test. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word Learning and Individual Differences in Word Learning Reflected in Event-Related Potentials.

Adults learned the meanings of rare words (e.g., gloaming) and then made meaning judgments on pairs of words. The 1st word was a trained rare word, an untrained rare word, or an untrained familiar word. Event-related potentials distinguished trained rare words from both untrained rare and familiar words, first at 140 ms and again at 400-600 ms after onset of the 1st word. These results may point to an episodic memory effect. The 2nd word produced an N400 that distinguished trained and familiar word pairs that were related in meaning from unrelated word pairs. Skilled comprehenders learned more words than less skilled comprehenders and showed a stronger episodic memory effect at 400-600 ms on the 1st word and a stronger N400 effect on the 2nd word. These results suggest that superior word learning among skilled comprehenders may arise from a stronger episodic trace that includes orthographic and meaning information and illustrate, how an episodic theory of word identification can explain reading skill. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of immediate stimulus repetition on reaction time and event-related potentials in tasks of different complexity.

Examined the effect of immediate stimulus repetition in lexical decision, face recognition, letter search, face/nonface discrimination, and word/number discrimination tasks using reaction time (RT), accuracy, and event-related brain potential (ERP) measures. Repetition facilitated performance in all tasks and for all stimulus types. However, ERPs were strongly affected by repetition only in lexical decision, face recognition, and letter search, when relatively long stimulus analysis and decision making processes were required. The ERP repetition effect consisted of a significant increase in P300 amplitude and a shortening of its latency. Repetition also resulted in the attenuation of a negative component that was tentatively identified as N400. These results suggest that immediate repetition facilitates stimulus identification and eliminates the need for stimulus analysis processes including access to semantic memory while making categorical decisions. While both factors affected RT, ERPs were modulated primarily by the elimination of the need to access to semantic memory and by the consequent speeding of categorical decision processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-related potential indicators of text integration across sentence boundaries.

An event-related potentials (ERPs) study examined word-to-text integration processes across sentence boundaries. In a two-sentence passage, the accessibility of a referent for the first content word of the second sentence (the target word) was varied by the wording of the first sentence in one of the following ways: lexically (explicitly using a form of the target word); conceptually (using a paraphrase of the target word), and situationally (encouraging an inference concerning the referent of the target word). A baseline condition had no coreference between the two sentences. ERP results on the target word indicated multiple effects related to word identification and word-to-referent mapping processes. Both the explicit and paraphrase conditions, but not the inference condition, showed a reduced N400 relative to the baseline condition, consistent with immediate integration by lexico-semantic processes. A 300-ms effect (P300) was found in the paraphrase condition. The results were consistent with an immediate integration hypothesis and furthermore differentiated a lexical (N200), a conceptual (P300), and a situational (N400) component for this integration. The conceptual basis appears not to extend to predictive inferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of attention and unilateral neglect on auditory stream segregation.

Two pairs of experiments studied the effects of attention and of unilateral neglect on auditory streaming. The first pair showed that the build up of auditory streaming in normal participants is greatly reduced or absent when they attend to a competing task in the contralateral ear. It was concluded that the effective build up of streaming depends on attention. The second pair showed that patients with an attentional deficit toward the left side of space (unilateral neglect) show less stream segregation of tone sequences presented to their left than to their right ears. Streaming in their right ears was similar to that for stimuli presented to either ear of healthy and of brain-damaged controls, who showed no across-ear asymmetry. This result is consistent with an effect of attention on streaming, constrains the neural sites involved, and reveals a qualitative difference between the perception of left- and right-sided sounds by neglect patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gas exchange function of the middle ear in patients with otitis media with effusion

Gas exchange function through the middle ear mucosa was assessed using nitrous oxide (N2O) in patients with otitis media with effusion (OME), as well as in normal ears during elective surgery for unrelated disorders. In all normal ears except one (n = 43), an increase in pressure was observed after N2O inhalation. In 42 of 84 ears with OME, a pressure increase was observed, but not in the remaining 42 ears (50%), indicating that the gas exchange function in these latter ears was impaired. In 21 of the 42 ears showing no middle ear pressure increase following N2O inhalation, the middle ear pressure was again monitored after myringotomy and aspiration of the effusion A pressure increase was found in 16 ears, indicating that the impairment in gas exchange function in ears with OME may be reversible in most cases. Computed tomography of the mastoid was examined preoperatively in 66 ears, with the presence or absence of a middle ear pressure change well correlated in 57 ears with the presence or absence of mastoid aeration.     

Constraints on the additive relationship between semantic priming and word repetition and on the interactive relationship between semantic priming and stimulus clarity.

Describes 2 experiments that manipulated priming condition, repetition, and stimulus clarity. Exp 1 with 87 undergraduates confirmed the additive relationship between semantic priming and word repetition when the time between repetitions was relatively long. Exp 2 with 82 undergraduates limited the number of intervening trials between repetitions (0, 1, 3, 7 trials). Results are interpreted as support for the position that there are 3 components to the repetition effect: sensory, lexical, and episodic. Degradation increased the repetition effect in both experiments without affecting the semantic priming effect. This was interpreted to mean that degradation had its effect late in the information processing sequence. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blinks of the mind: Memory effects of attentional processes.

If 2 words are presented successively within 500 ms, subjects often miss the 2nd word. This attentional blink reflects a limited capacity to attend to incoming information. Memory effects were studied for words that fell within an attentional blink. Unrelated words were presented in a modified rapid serial visual presentation task at varying stimulus-onset asynchronies, and attention was systematically manipulated. Subsequently, recognition, repetition priming, and semantic priming were measured separately in 3 experiments. Unidentified words showed no recognition and no repetition priming. However, blinked (i.e., unidentified) words did produce semantic priming in related words. When, for instance, ring was blinked, it was easier to subsequently identify wedding than apple. In contrast, when the blinked word itself was presented again, it was not easier to identify than an unrelated word. Possible interpretations of this paradoxical finding are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-related potentials of verbal encoding into episodic memory: dissociation between the effects of subsequent memory performance and distinctiveness

Episodic memory encoding and distinctiveness detection were examined using event-related potentials (ERP) in a single-trial word list learning paradigm with free recall following distraction. To manipulate distinctiveness, encoding of high- and very low-frequency words was contrasted. Amplitudes of the N400 and late positive component (LPC) were larger for low- than for high-frequency words, and ERPs were more positive for subsequently recalled than not recalled words. This subsequent memory effect was dissociated from the correlates of distinctiveness by polarity for the N400 and by time course for the LPC and dissociable into two effects. The data suggest that the first subsequent memory effect, which occurred for both word categories, is more directly related to episodic memory formation, whereas the second effect, which occurred for high-frequency words only, is related to processes influencing episodic encoding success indirectly.     

Effects of response and trial repetition on sight-word training for students with learning disabilities

Alternating treatments designs were used to compare the effects of trial repetition (one response within five trials per word) versus response repetition (five response repetitions within one trial per word) on sight-word acquisition for 3 elementary students diagnosed with specific learning disabilities in reading. Although both interventions occasioned the same number of accurate responses per word during training, the trial-repetition condition, which involved complete antecedent-response-feedback sequences, resulted in more words mastered for all 3 students.     

When pseudowords acquire meaning: Effect of semantic associations on pseudoword repetition priming.

In Exp 1, priming increased with additional presentations when the priming task was to generate a potential meaning for each pseudoword but not when the priming task was to read each pseudoword aloud. In Exps 2 and 3, repetition effects were found when Ss attempted to learn definitions assigned to the pseudowords by the experimenter. Equivalent levels of priming were found regardless of whether the definition assigned to a pseudoword changed or remained the same over 3 trials, although recall of the definitions was better for the consistently defined pseudowords. These results are consistent with the hypothesis that the same mechanism underlies both word and pseudoword priming, except that words (and pseudowords that acquire meaning) benefit from the priming of orthographic–semantic associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Masked priming from orthographic neighbors: An ERP investigation.

Two experiments combined masked priming with event-related potential (ERP) recordings to examine effects of primes that are orthographic neighbors of target words. Experiment 1 compared effects of repetition primes with effects of primes that were high-frequency orthographic neighbors of low-frequency targets (e.g., faute-faune [error-wildlife]), and Experiment 2 compared the same word neighbor primes with nonword neighbor primes (e.g., aujel-autel [altar]). Word neighbor primes showed the standard inhibitory priming effect in lexical decision latencies that sharply contrasted with the facilitatory effects of nonword neighbor primes. This contrast was most evident in the ERP signal starting at around 300 ms posttarget onset and continuing through the bulk of the N400 component. In this time window, repetition primes and nonword neighbor primes generated more positive-going waveforms than unrelated primes, whereas word neighbor primes produced null effects. The results are discussed with respect to possible mechanisms of lexical competition during visual word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction between affect and cognition in word perception.

Investigated the hypothesis that the accuracy with which a briefly shown word is perceived depends on both the affective tone of the word and the activation of the corresponding memory code. To increase activation, expectation and word frequency were manipulated. Ss were exposed to a 25-ms flash of a target word. They then chose, from a word pair, the target word. In half the trials, this word pair was given before the flash to create an expectation. Consistent with the hypothesis, when the words were infrequent, accuracy in perception was lower for affective than for neutral words regardless of expectation. When the words were frequent, there was no effect of affective tone in the absence of expectation; in the presence of expectation, accuracy was higher for affective than for neutral words. The valence of the affective words had no effect. Results are interpreted in terms of attentional mechanisms implicated in conscious perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)