Consecutive repetition effects for affective-distractor pictures in a visual oddball task: Electrophysiological evidence from an ERP study

Lasting Effects of Using Distraction to Manage Responses to Unpleasant Pictures: Electrophysiological Evidence

Distraction is a widely used form of emotion regulation. Most studies have focused on the influence of distraction on the processing of aversive stimuli during distraction regulation, however, few studies investigated the impact on responses to aversive stimuli when they are re-presented later. This study examined whether processing of unpleasant pictures could be modulated by previous distraction and whether this modulation was associated with the intervals between regulation and re-exposure. Participants were presented with unpleasant images and asked to attend to or distract themselves from the images. After a 5- or 30-minute interval, the participants were re-exposed to the same images in an oddball task. Event-related potential measurements revealed that compared with the previous attention condition, the P3 amplitudes were significantly larger in the 30-min interval group, but not in the 5-min interval group under the previous distraction condition, and that the late positive potential amplitudes were significantly larger in the 30-min interval group, but tended to be smaller in the 5-min interval group. These findings suggest that the effects of distraction were diminished or disappeared after a 5-min interval and reversed after a 30-min interval. This pattern suggests that caution should be exercised in the use of distraction strategies to reduce negative emotions, particularly in cases in which unpleasant images may reappear in everyday life.

Effects of Directed Attention on Subsequent Processing of Emotions: Increased Attention to Unpleasant Pictures Occurs in the Late Positive Potential

Directed attention is a fundamental mental resource for voluntarily managing the focus and direction of cognitive resources. The present study investigated how processing of unpleasant and neutral images is affected by emotion and previous directed attention. The results showed that there was enhanced early posterior negativity, anterior N2, and parietal late positive potential (LPP) in response to unpleasant pictures compared to neutral pictures. Furthermore, attention history (i.e., whether stimuli were previously attended to) modulated the amplitudes of the anterior N2 and parietal LPP. Most notably, an interaction between attention history and emotion was found in the LPP: pictures with an 'attended history' evoked larger LPP amplitudes than pictures with an 'unattended history,' but this effect was only significant for unpleasant pictures (not for neutral pictures). These results suggest that directed attention to affective pictures facilitates subsequent neural processing of these pictures, and that this effect was amplified by unpleasant emotions experienced in the LPP. The current findings provide further empirical evidence of a two-stage model of emotion-attention interaction.

Differential Preparation Intervals Modulate Repetition Processes in Task Switching: An ERP Study

In task-switching paradigms, reaction times (RTs) switch cost (SC) and the neural correlates underlying the SC are affected by different preparation intervals. However, little is known about the effect of the preparation interval on the repetition processes in task-switching. To examine this effect we utilized a cued task-switching paradigm with long sequences of repeated trials. Response-stimulus intervals (RSI) and cue-stimulus intervals (CSI) were manipulated in short and long conditions. Electroencephalography (EEG) and behavioral data were recorded. We found that with increasing repetitions, RTs were faster in the short CSI conditions, while P3 amplitudes decreased in the LS (long RSI and short CSI) conditions. Positive correlations between RT benefit and P3 activation decrease (repeat 1 − repeat 5), and between the slope of the RT and P3 regression lines were observed only in the LS condition. Our findings suggest that differential preparation intervals modulate repetition processes in task switching.

Hearing subject's own name induces the late positive component of event-related potential and beta power suppression

The neuronal response to hearing a subject's own name (SON) has been often investigated using event-related potential (ERP) or time-frequency analysis, but seldom by a combination of these methods. Using this combination of approaches would allow the relationship between memory processes engaged by SON and the neuronal responses to be studied in more detail. Thus, the present study used both ERP and time-frequency analysis to investigate memory process for SON by comparing the responses to SON and to unfamiliar names. Specifically, the SON condition was compared with two control conditions: repeated unfamiliar names and singly presented unfamiliar names. This experimental design allowed us to determine the differences in memory processes between hearing one's own name and hearing unrelated but repeatedly heard names. ERP analysis showed that SON elicited a late positive component in parietal areas, while unfamiliar names elicited no positivity. Beta power suppression was observed in response to SON at 0.4-0.6s after stimulus onset at right central sites, but not in response to unfamiliar names. These results are indicative of an involvement of episodic memory processes on hearing SON, which corresponds to the recognition of one's own name. Further, the ERP results suggest the presence of a "new" stimulus recognition process that is activated by singly presented unfamiliar names but not by repeated unfamiliar names.