Semantic processing is affected in inhibition of return: evidence from an event-related potentials study

Dividing attention influences contextual facilitation and revision during language comprehension

Although we often seem to successfully comprehend language in the face of distraction, few studies have examined the role of sustained attention in critical components of sentence processing, such as integrating information over a sentence and revising predictions when unexpected information is encountered. The current study investigated the impact of attention on sentence processing using a novel dual-task paradigm. Participants read weakly and strongly constraining sentences with expected or unexpected endings while also tracking the motion of dots in the background, and their EEG was recorded. Under full attention, the amplitude of the N400 component of the ERP, a measure of semantic access, was reduced (facilitated) in a graded fashion by contextual strength and fit. This context-based facilitation was attenuated when attention was divided, suggesting that sustained attention is important for building up message-level representations. In contrast, the post-N400 frontal positivity that has been observed to prediction violations and associated with revision processes was unaffected by dividing attention. However, under divided attention, participants also elicited posteriorly-distributed effects to these violations. Thus, predictive processes seem to be engaged even when attention is divided, but additional resources may then be required to process unexpected information.

Inhibition of Return Is Modulated by Negative Stimuli: Evidence from Subliminal Perception

Inhibition of return (IOR) is considered as a “blindness mechanism” that emotional stimuli have no impact on it. Most previous studies suggested that IOR was not modulated by emotional cues. However, one key question they ignored was that only supraliminal presentation of emotional stimuli was used in their experiments. The present experiment is aimed at exploring the possible interaction between the IOR effect and subliminal emotional process. We manipulated three different kinds of valence strength of negative stimuli (high negative, HN; moderate negative, MN; low negative, LN) which were presented under the subliminal perception level and an event-related potentials (ERPs) recording was adopted. The results showed that, compared to MN and HN, the IOR effect triggered by peripheral cues was more significant for LN with aspects of behavioral and electrophysiological data (a reduction P1 effect, more negative on cued trials than on uncued trials for both early posterior Nd and Nd components). This indicated that IOR can be modulated by emotionally relevant stimuli. The automatic processing that was triggered by subliminally negative stimuli of peripheral cues had an influence on the shifting of spatial attention that was triggered by IOR. These two mechanisms may occur in the perceptual stage simultaneously.

Crowded words can be processed semantically: evidence from an ERP study

The term "crowding" refers to impaired peripheral object identification due to the presence of nearby objects. In this study, event-related potentials (ERPs) were used to investigate semantic processing of crowded Chinese words by combining a crowding task with a semantic-priming paradigm. Results showed that the N400 component, an index of semantic processing, was elicited by both crowded and uncrowded words. These results suggest that words were processed semantically despite crowding, and that features of the crowded words were integrated correctly.

Interhemispheric transfer of spatial and semantic information: electrophysiological evidence

The goal of this study was to cast light on the existence of functional callosal channels for the interhemispheric transfer (IHT) of spatial and semantic information. To do so, we recorded event-related potentials in healthy humans while performing a primed odd-even discrimination task. Targets were visually presented numbers preceded by single-letter primes signaling the probable presentation of an odd or an even number. Primes and targets could appear either in the same or in different visual fields, thus requiring an IHT in the latter case. The P1 and N2 components were influenced by IHT of spatial information only, whereas the later N400 was influenced by IHT of both spatial and semantic information. This was not the case for the P3b, which was modulated by semantic validity only. These results provide novel evidence of the existence of a temporally separated interhemispheric exchange of spatial and semantic information.

Efficacy of attention regulation in preschool-age children who stutter: a preliminary investigation

PURPOSE

This preliminary investigation assessed the attentional processes of preschool-age children who do (CWS) and do not stutter (CWNS) during Traditional cueing and Affect cueing tasks.

METHOD

Participants consisted of 12 3- to 5-year-old CWS and the same number of CWNS (all boys). Both talker groups participated in two tasks of shifting and focusing attention: (a) Traditional cueing and (b) Affect cueing. The Affect cueing task was preceded by stress-heightening instructions intended to influence participants' emotionality. In both tasks participants provided non-speech motor responses (i.e., button pressing) to computer-presented target stimuli. Targets were preceded by a visual cue (i.e., highlighted box) occurring in the same (i.e., Valid trials) or opposite (i.e., Invalid trials) location as the target stimuli. Reaction times (RT) were measured (in ms) from the onset of the target stimuli to the onset of the non-speech motor response. Errors were tallied for both experimental conditions and were categorized by type.

RESULTS

Findings of this preliminary investigation indicated that there were no significant between-group differences in RT or frequency of erroneous responses. There were differences in error type that were correlated with RT for both CWS and CWNS when stress-heightening instructions were introduced.

CONCLUSION

Preliminary findings suggest that speed of attentional disengaging, shifting and re-engaging does not differ between preschool-age CWS and CWNS during the experimental paradigm employed in this study and that introducing stress-heightening instructions does affect components of performance for both preschool-age CWS and CWNS. Caveats for the present study include a limited sample size of young preschool-aged children as well as methodological concerns.

LEARNING OUTCOMES

Readers will be able to: (1) Define attention regulation and describe findings that investigate the role of attention regulation in developmental stuttering of preschool-age children; (2) Describe the components of attention regulation employed during a Posner Cueing Task; (3) Describe the findings of the present study in relation to other studies investigating attention regulation and developmental stuttering in preschool-age children.

Differential Modulation of Word Recognition by Semantic and Spatial Orienting of Attention

In the present study, we investigated the ability to orient attention to abstract associative features of complex stimuli, more specifically, to the semantic categories of visual word stimuli. We compared the behavioral and electrophysiological effects of semantic orienting with those elicited by spatial orienting to word stimuli. Two parallel, cued lexical-decision tasks, with semantic- or spatial-orienting cues, were used. Results showed that both semantic and spatial orienting facilitated behavioral performance. The event-related potential analysis revealed different and non-overlapping patterns of modulation of word processing by semantic and spatial orienting. Modulation by semantic orienting started later, affecting only the potentials linked to conceptual or semantic processing (N300 and N400). The pattern of N300/N400 modulation in the semantic-orienting condition was similar to that observed in semantic-priming tasks, and was compatible with the operation of controlled semantic processes. Spatial orienting significantly enhanced the amplitude of the early visual potential P1 as well as the language-related N400 potential. These findings showed that the similar end-result of behavioral facilitation by semantic and spatial orienting is achieved through largely distinct mechanisms acting upon separate levels of stimulus analysis.