Shiwei Jia

Are we sensitive to valence differences in emotionally negative stimuli? Electrophysiological evidence from an ERP study

The present study investigated whether the human brain is sensitive to valence differences in emotionally negative stimuli by recording event-related potentials (ERPs) for extremely negative (EN), moderately negative (MN), and neutral pictures while subjects perform a standard/deviant categorization task, irrespective of the emotional valence of the deviants. Using the same design, we also investigated the sensitivity of the human brain to valence differences in emotionally positive stimuli. Experiment 1 showed that EN stimuli elicited more negative deflections than MN stimuli in the early P2 and N2, later P3, and slow negative wave (SNW) components. In contrast, there were no differences in amplitude or latency in these components during the extremely positive (EP) and moderately positive (MP) conditions of Experiment 2. This suggests that humans are only sensitive to valence differences in negative stimuli, and that these negative valences could be processed differentially throughout the information processing stream even when individuals are highly engaged in a non-emotional task.

The influence of the diffusion of responsibility effect on outcome evaluations: Electrophysiological evidence from an ERP study

Previous studies have revealed that personal responsibility has an influence on outcome evaluation, although the way this influence works is still unclear. This study imitated the phenomenon of responsibility diffusion in a laboratory to examine the influence of the effect of responsibility diffusion on the processing of outcome evaluation using the event-related potential (ERP) technique. Participants of the study were required to perform the gambling task individually in the high-responsibility condition and with others in the low-responsibility scenario. Self-rating results showed that the participants felt more responsible for monetary loss and believed that they had more contributions to the monetary gains in the high-responsibility condition than in the low-responsibility situation. Both the feedback-related negativity (FRN) and the P300 were sensitive to the responsibility level, as evidenced by the enhanced amplitudes in the high-responsibility condition for both components. Further correlation analysis showed a negative correlation between FRN amplitudes and subjective rating scores (i.e., the higher the responsibility level, the larger the FRN amplitude). The results probably indicate that the FRN and P300 reflect personal responsibility processing under the social context of diffusion of responsibility.

Detecting perceptual conflict by the feedback-related negativity in brain potentials.

The feedback-related negativity (FRN) in brain potentials is typically observed for the outcome evaluation concerning ones performance or monetary reward. Using a task in which the participant guesses whether the first stimulus (S1) would have the same color as the subsequently presented second stimulus (S2), this study demonstrates that the FRN to S2, which serves as feedback to the guessing, is also sensitive to the conflict between perceptual representations of S1 and S2 in working memory. The FRN effect for the feedback concerning the correctness of ones performance is modulated by the congruency between perceptual properties of the stimuli. The anterior cingulate cortex, which generates the FRN, is thus a general conflict-monitoring device detecting both response and perceptual conflicts.

ERP correlates of pre-attentive processing of Cantonese lexical tones: The effects of pitch contour and pitch height

The pre-attentive processing of Cantonese tones was studied with an auditory passive oddball paradigm. Event-related potentials to standard and deviant auditory stimuli were recorded as participants watched a silent movie attentively. The standards and deviants differed in either pitch level or pitch contour. Mismatch negativity (MMN) and P3a were elicited by all types of deviant tones, suggesting that lexical tone was processed pre-attentively. In addition, the size and latency of MMN were sensitive to the size of pitch level change, while the latency of P3a captured the presence of pitch contour change. These results indicate that pitch contour and pitch height are two important dimensions in sensory processing of lexical tones.

Feedback-related negativity effects vanished with false or monetary loss choice

Feedback-related negativity (FRN) is sensitive to both monetary loss and evaluation of the correctness of a response. This study used a gambling task that required participants to choose between two cards that were unpredictably associated with monetary gains or losses. Feedback stimuli then indicated gain or loss, and the correctness of the participants choice. Greater FRN amplitudes for loss versus gain conditions were observed when participants guessed correctly, as well as for incorrect versus correct conditions when they made gain choices. Conversely, FRN effects were absent after either false choices or those that led to losses. Therefore, FRN may reflect an interaction between guess correctness and the utilitarian value of feedback.

Attitude toward money modulates outcome processing: An ERP study

Love of money (LOM) is concerned with the attitude toward money, which can be measured by the LOM scale through affective, behavioral, and cognitive dimensions. Research has observed that monetary attitude was tightly related to reward processing and could affect economic behavior. This study examined how monetary attitude modulated risky behavior and the underlying neural mechanisms of reward processing using event-related potential (ERP) technique. We compared both the risk level and brain responses of a high-level LOM (HLOM) group to a low-level LOM (LLOM) group using a simple gambling task. The behavioral results showed that the HLOM group was more risky than the LLOM group, particularly after loss. The feedback-related negativity (FRN) was measured as the difference wave (gain-related ERP was subtracted from loss-related ERP). The FRN difference wave was larger in the HLOM group than that in the LLOM group. The P3 in the HLOM group was more positive than that in the LLOM group. These results suggest that monetary attitude can modulate both the underlying neural mechanisms and behavioral performance in a reward-related task. The HLOM participants are more sensitive to gain/loss than the LLOM participants.

Field dependence–independence modulates the efficiency of filtering out irrelevant information in a visual working memory task

Past research has demonstrated that field dependence-independence (FDI) can affect academic performance, selective attention, and working memory. However, the underlying mechanism of how FDI modulates selective attention and working memory is still unclear. Using event-related potential (ERP) techniques, specifically with the contralateral delay activity (CDA), the present study found that the correct response rates and CDA amplitudes in the 2-item and 2-item-2-distractor conditions were comparable for field independence (FI) participants. Field dependence (FD) participants performed worse, and the CDA amplitude was enhanced when distractors appeared. These results indicated that FI participants can filter out task-irrelevant information more efficiently than FD participants. The main difference between FD and FI individuals is their inhibition function.

Processing Cantonese lexical tones: Evidence from oddball paradigms

Two event-related potential (ERP) experiments were conducted to investigate whether Cantonese lexical tones are processed with general auditory perception mechanisms and/or a special speech module. Two tonal features (f0 direction and f0 height deviation) were manipulated to reflect acoustic processing, and the contrast between syllables and hums was used to reveal the involvement of a speech module. Experiment 1 adopted a passive oddball paradigm to study a relatively early stage of tonal processing. Mismatch negativity (MMN) and novelty P3 (P3a) were modulated by the interaction between tonal feature and stimulus type. Similar interactions were found for N2 and P3 in Experiment 2, where more in-depth tonal processing was examined with an active oddball paradigm. Moreover, detecting tonal deviants of syllables elicited N1 and P2 that were not found in hum detection. Together, these findings suggest that the processing of lexical tone relies on both acoustic and linguistic processes from the early stage. Another noteworthy finding is the absence of brain lateralization in both experiments, which challenges the use of a lateralization pattern as evidence for processing lexical tones through a special speech module.

Right hemisphere advantage in processing Cantonese level and contour tones: evidence from dichotic listening.

The brain lateralization pattern of Cantonese tonal processing was examined with the dichotic listening (DL) paradigm. Three factors were manipulated systematically in the study. First, the processing of level tones was compared with that of contour tones. Second, the influence of a linguistic context in tonal processing was studied by contrasting the patterns of brain lateralization for real syllables, pseudo-syllables, and hums. Finally, the discrimination and the identification tasks were used to test how processing depth might modulate the results obtained. A right hemisphere advantage (RHA) was obtained regardless of tone type, stimulus type, and task. In addition, the performance on level tones was in general better than that on contour tones. These findings suggest that Cantonese speakers are highly sensitive to the acoustic features of lexical tones, which supports the acoustic view about tonal processing.

Object and spatial visualizers have different object-processing patterns: behavioral and ERP evidence.

Both behavioral and neurophysiological evidence shows the advantage of object visualizers in object-related tasks relative to spatial visualizers. It is still unclear, in which stage the advantage appears. In this study, a behavioral experiment revealed that spatial visualizers’ performance decreased evidently from short delay to long delay in a high-load condition, but object visualizers performed stably. In addition, an event-related potential experiment found the slow cortical potentials for the spatial visualizer to be more negative in relation to object visualizers in the 1800–3800 ms stage, although spatial visualizers performed worse than the object visualizers. Therefore, the processing advantage of object visualizers, which is caused by the higher neural efficiency of object visualizers than spatial visualizers in object tasks, seems to be at the retention stage rather than the encoding stage.