Hong Li

Responsibility modulates neural mechanisms of outcome processing: an ERP study.

The role of personal responsibility in decision-making and its influence on the outcome evaluation process have been investigated relatively rarely in cognitive neuroscience. The present event-related brain potential (ERP) study manipulated the subjective sense of responsibility by modifying outcome controllability in a gambling task. Participants reported a higher sense of responsibility and produced a larger fERN when they were told that the game was controllable compared with when they were told that the game was uncontrollable. In addition, fERN amplitude was correlated with individual self-reports of personal responsibility over the outcomes. These results indicate that self-attribution of responsibility associated with different degrees of controllability affects the outcome evaluation process and fERN amplitude.

The neural mechanisms of semantic and response conflicts: An fMRI study of practice-related effects in the Stroop task

Previous studies have demonstrated that there are separate neural mechanisms underlying semantic and response conflicts in the Stroop task. However, the practice effects of these conflicts need to be elucidated and the possible involvements of common neural mechanisms are yet to be established. We employed functional magnetic resonance imaging (fMRI) in a 4-2 mapping practice-related Stroop task to determine the neural substrates under these conflicts. Results showed that different patterns of brain activations are associated with practice in the attentional networks (e.g., dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and posterior parietal cortex (PPC)) for both conflicts, response control regions (e.g., inferior frontal junction (IFJ), inferior frontal gyrus (IFG)/insula, and pre-supplementary motor areas (pre-SMA)) for semantic conflict, and posterior cortex for response conflict. We also found areas of common activation in the left hemisphere within the attentional networks, for the early practice stage in semantic conflict and the late stage in pure response conflict using conjunction analysis. The different practice effects indicate that there are distinct mechanisms underlying these two conflict types: semantic conflict practice effects are attributable to the automation of stimulus processing, conflict and response control; response conflict practice effects are attributable to the proportional increase of conflict-related cognitive resources. In addition, the areas of common activation suggest that the semantic conflict effect may contain a partial response conflict effect, particularly at the beginning of the task. These findings indicate that there are two kinds of response conflicts contained in the key-pressing Stroop task: the vocal-level (mainly in the early stage) and key-pressing (mainly in the late stage) response conflicts; thus, the use of the subtraction method for the exploration of semantic and response conflicts may need to be further examined.

The value of emotion: how does episodic prospection modulate delay discounting?

Background Humans often show impatience when making intertemporal choice for monetary rewards, preferring small rewards delivered immediately to larger rewards delivered after a delay, which reflects a fundamental psychological principle: delay discounting. However, we propose that episodic prospection humans can vividly envisage exerts a strong and broad influence on individuals delay discounting. Specifically, episodic prospection may affect individuals intertemporal choice by the negative or positive emotion of prospection. Methodology/Principal Findings The present study explored how episodic prospection modulated delay discounting by emotion. Study 1 showed that participants were more inclined to choose the delayed but larger rewards when they imaged positive future events than when they did not image events; Study 2 showed that participants were more inclined to choose the immediate but smaller rewards when they imaged negative future events than when they did not image events; In contrast, study 3 showed that choice preferences of participants when they imaged neutral future events were the same as when they did not image events. Conclusions/Significance By manipulating the emotion valence of episodic prospection, our findings suggested that positive emotion made individuals tend to choose delayed rewards, while negative emotion made individuals tend to choose immediate rewards. Only imaging events with neutral emotion did not affect individuals choice preference. Thus, the valence of imaged future events emotion might play an important role in individuals intertemporal choice. It is possible that the valence of emotion may affect the changed direction (promote or inhibit) of individuals delay discounting, while the ability to image future events affects the changed degree of individuals delay discounting.

Emotion perception and executive control interact in the salience network during emotionally charged working memory processing.

Processing of emotional stimuli can either hinder or facilitate ongoing working memory (WM); however, the neural basis of these effects remains largely unknown. Here we examined the neural mechanisms of these paradoxical effects by implementing a novel emotional WM task in an fMRI study. Twenty‐five young healthy participants performed an N‐back task with fearful and neutral faces as stimuli. Participants made more errors when performing 0‐back task with fearful versus neutral faces, whereas they made fewer errors when performing 2‐back task with fearful versus neutral faces. These emotional impairment and enhancement on behavioral performance paralleled significant interactions in distributed regions in the salience network including anterior insula (AI) and dorsal cingulate cortex (dACC), as well as in emotion perception network including amygdala and temporal‐occipital association cortex (TOC). The dorsal AI (dAI) and dACC were more activated when comparing fearful with neutral faces in 0‐back task. Contrarily, dAI showed reduced activation, while TOC and amygdala showed stronger responses to fearful as compared to neutral faces in the 2‐back task. These findings provide direct neural evidence to the emerging dual competition model suggesting that the salience network plays a critical role in mediating interaction between emotion perception and executive control when facing ever‐changing behavioral demands. Hum Brain Mapp 35:5606–5616, 2014.

This ought to be good: Brain activity accompanying positive and negative expectations and outcomes

The current study employed a modified gambling task, in which probabilistic cues were provided to elicit positive or negative expectations. Event-related potentials (ERPs) to final outcome and probabilistic cues were analyzed. Difference waves between the negative condition and the corresponding positive condition were examined. The results confirm that feedback related negativity (FRN) amplitude is modulated by the interaction of outcome valence and expectancy by showing larger FRN difference waves for unexpected than expected outcomes. More interestingly, the difference wave between ERPs elicited by positive and negative expectations showed a negative deflection, with a frontal midline source density around 280 ms after onset of the predictive cue. Negative expectations were associated with larger FRN amplitudes than positive expectations. This suggests that FRN is elicited by probabilistic cues to pending outcomes.

Changes in functional connectivity dynamics associated with vigilance network in taxi drivers

An increasing number of neuroimaging studies have suggested that the fluctuations of low-frequency resting-state functional connectivity (FC) are not noise but are instead linked to the shift between distinct cognitive states. However, there is very limited knowledge about whether and how the fluctuations of FC at rest are influenced by long-term training and experience. Here, we investigated how the dynamics of resting-state FC are linked to driving behavior by comparing 20 licensed taxi drivers with 20 healthy non-drivers using a sliding window approach. We found that the driving experience could be effectively decoded with 90% (p<0.001) accuracy by the amplitude of low-frequency fluctuations in some specific connections, based on a multivariate pattern analysis technique. Interestingly, the majority of these connections fell within a set of distributed regions named the vigilance network. Moreover, the decreased amplitude of the FC fluctuations within the vigilance network in the drivers was negatively correlated with the number of years that they had driven a taxi. Furthermore, temporally quasi-stable functional connectivity segmentation revealed significant differences between the drivers and non-drivers in the dwell time of specific vigilance-related transient brain states, although the brains repertoire of functional states was preserved. Overall, these results suggested a significant link between the changes in the time-dependent aspects of resting-state FC within the vigilance network and long-term driving experiences. The results not only improve our understanding of how the brain supports driving behavior but also shed new light on the relationship between the dynamics of functional brain networks and individual behaviors.

Neural correlates of inefficient filtering of emotionally neutral distractors from working memory in trait anxiety

Research has indicated that highly trait-anxious (HTA) individuals exhibit a specific deficit in filtering threat-related distractors from visual–spatial working memory (WM). Prior demonstrations of impaired inhibition control in HTA individuals have mainly focused on tasks that required the inhibition of prepotent response tendencies. Studies on the suppression of emotionally neutral distractors from WM in trait anxiety have also been minimal. In this article, we present a study on the manifestation of general inefficient filtering of neutral distractors during visual–spatial WM maintenance stages in HTA individuals. Female participants performed a visual–spatial WM task while event-related potentials were recorded. They were made to remember the orientations of red rectangles within half of the screen and to ignore all salient green rectangles. As predicted, no significant main effect of group and no interaction between group and condition were found in the N2pc component, suggesting that group differences did not manifest in the initial process of object individuation. During the subsequent WM maintenance phase, HTA individuals were highly inefficient at filtering the irrelevant items from WM, as reflected not only by parallel late contralateral delay activity (CDA; 450 to 900xa0ms) amplitudes for the distractor condition and the four red items, but also by a smaller filtering efficiency score in the HTA group than in the low-trait-anxiety group. Extending previous studies, our findings verify a general filtering impairment in HTA individuals for task-irrelevant salient distractors during a WM maintenance phase.

The Neural Dynamics of Conflict Adaptation within a Look-to-Do Transition

Background For optimal performance in conflict situations, conflict adaptation (conflict detection and adjustment) is necessary. However, the neural dynamics of conflict adaptation is still unclear. Methods In the present study, behavioral and electroencephalography (EEG) data were recorded from seventeen healthy participants during performance of a color-word Stroop task with a novel look-to-do transition. Within this transition, participants looked at the Stroop stimuli but no responses were required in the ‘look’ trials; or made manual responses to the Stroop stimuli in the ‘do’ trials. Results In the ‘look’ trials, the amplitude modulation of N450 occurred exclusively in the right-frontal region. Subsequently, the amplitude modulation of sustained potential (SP) emerged in the posterior parietal and right-frontal regions. A significantly positive correlation between the modulation of reconfiguration in the ‘look’ trials and the behavioral conflict adaptation in the ‘do’ trials was observed. Specially, a stronger information flow from right-frontal region to posterior parietal region in the beta band was observed for incongruent condition than for congruent condition. In the ‘do’ trials, the conflict of ‘look’ trials enhanced the amplitude modulations of N450 in the right-frontal and posterior parietal regions, but decreased the amplitude modulations of SP in these regions. Uniquely, a stronger information flow from centro-parietal region to right-frontal region in the theta band was observed for iI condition than for cI condition. Conclusion All these findings showed that top-down conflict adaptation is implemented by: (1) enhancing the sensitivity to conflict detection and the adaptation to conflict resolution; (2) modulating the effective connectivity between parietal region and right-frontal region.

Notation-dependent processing of numerical magnitude: electrophysiological evidence from Chinese numerals.

To investigate whether the semantic processing of numbers is notation-dependent or notation-independent, three notation stimuli-Arabic digits, Chinese numerals written in simple form (Ch-S), and Chinese numerals written in complex form (Ch-C)-were presented to participants. The participants were asked to judge which target numeral (numerical values 1-4 and 6-9) was smaller or larger than 5 while event-related potentials (ERPs) were recorded. Electrophysiological results revealed that the voltage activity associated with numerical semantic processing was largest across temporo-occipital-parietal electrode sites, regardless of input formats. However, the time windows for the semantic processing of numerals did not overlap across notations. Furthermore, the main effects of notation and notation/distance interaction were still observed at the stage of numerical magnitude processing, suggesting that notation might affect the semantic processing of numbers. In addition, a right-lateralized N1 for both Arabic digits and Ch-C numbers, and a bilateral N1 for Ch-S numbers, were observed; these data imply that number processing in Chinese speakers may be different from that in Western speakers.

How race and age experiences shape young children's face processing abilities.

Despite recent advances in research on race and age biases, the question of how race and age experiences combine to affect young childrens face perception remains unexplored. To fill this gap, the current study tested two ethnicities of 3-year-old children using a combined cross-race/cross-age design. Caucasian children with and without older siblings and Mainland Chinese children without older siblings were tested for their ability to discriminate adult and child Caucasian faces as well as adult and child Asian faces in both upright and inverted orientations. Children of both ethnicities manifested an own-race bias, which was confined to adult faces, and an adult face bias, which was confined to own-race faces. Likewise, sibling experience affected Caucasian childrens processing of own-race child faces, but this effect did not generalize to other-race faces. Results suggest that race and age information are represented at the same hierarchical level in young childrens memory.