Electrophysiological difference between mental state decoding and mental state reasoning

Recursive structures modulate the electrophysiological correlates of visual perspective taking

An increasing number of studies have focused on the neural basis of complex mental inferences, which requires an understanding of the recursive nature of thought; however, the precise electrophysiological response to a recursive structure remains unclear. The present event-related potential (ERP) study investigated the recursive structure effect on the neural correlates of visual perspective taking by modifying a third-person visual perspective-taking task. Participants were required to determine how many dots in the presented scenes could be seen from the cued perspective, including the perspectives in the self, other, and recursive (one avatar's belief of another avatar) conditions. The ERP results showed that the N100 and P200 components specific to the recursive-perspective condition showed greater attentional allocation; the N200 component increased in the recursive condition and was related to the conflict process; and larger late slow waves were found in the other- and recursive-perspective conditions compared with those in the self-perspective condition, which reflected the decoupling mechanism. The results suggested that high-order perspective taking requires more attentional resources and conflict processing for further decoupling from the self-perspective.

ERP responses to sexual cues among young women attracted to men

Previous event-related potential (ERP) studies reported larger N170, P3, and late positive potential (LPP) amplitudes to sexual than nonsexual stimuli. These ERPs may not be specifically sensitive to processing sexual cues, however, because the sexual stimuli included information beyond sexual cues (e.g., faces, bodies, social interaction) to a greater extent than comparison stimuli. We investigated ERPs to stimuli that focused on sexual and nonsexual body regions, in different states of readiness for activity, to elucidate neural responses involved in processing sexual cues. Forty cisgender, primarily white, undergraduate women who were attracted to men (M_age  = 18.6, SD = 0.9) viewed images that varied by male body part (penis, arm) and activity state (rest, poised for activity). Participants viewed 40 images per category (flaccid penises, erect penises, outstretched arms, bent arms). Electroencephalography (EEG) was recorded using a 128-channel net, time-locked to the onset of each image. Using a whole-head cluster-mass approach, we found that the P3 was sensitive to sexual readiness-P3 amplitudes were larger to erect than flaccid penises, but not to bent than outstretched arms. The N170 and LPP components did not show evidence of similarly specific responses to sexual readiness, revealing potential dissociation of different neural processes commonly elicited in response to more complex sexual stimuli. An additional novel finding was that an anterior N270-400 was sensitive to sexual readiness. Findings clarify the brain's rapid responses to sexual stimuli, setting the stage for future research aimed at better understanding the neurocognitive processes that contribute to the coordination of sexual arousal.

Theory of mind in schizotypy: A behavioral and event-related potential (ERP) study

Background

Schizophrenia is known for their theory of mind (ToM) impairment. However, this impairment in schizotypy (schizotypal traits) lacks investigation.

Aims

The present study investigated: (1) whether ToM ability was impaired in schizotypy; (2) whether the ERP amplitudes in nine brain regions of interest associated with ToM (e.g., frontal region) in schizotypy and healthy controls differed; and (3) whether the relationship between ToM performances and ERP amplitudes in schizotypy differed from that in healthy controls.

Method

Forty eight adolescents and young adults (16 schizotypy) with the mean age of 18 years were tested. The Reading the Mind in the Eyes Test (RMET) was used to assess their ToM during which ERP amplitudes were recorded.

Results

The schizotypy group showed significantly lower ERP amplitudes in all conditions of RMET in frontal, frontal-central, central, occipital and temporal regions when compared to those in healthy controls. Also, schizotypy's ERP amplitudes in the frontal, frontal-central, central, occipital, and temporal regions were different from those in the healthy individuals in responding to different types of ToM stimuli (positive, negative and neutral). In schizotypy group, reaction time responding to emotional stimuli was negatively related to ERP amplitudes in the frontal, central-parietal, parietal, occipital, and occipito-temporal regions during RMET while no significant correlations were found in healthy controls.

Conclusion

The present findings inform us with the knowledge regarding the neural and behavioral abnormality of ToM in schizotypy, suggesting that brain activity can be an alternative to detect ToM impairment in schizotypy.

ERP evidence for asymmetric orthographic transfer between traditional and simplified Chinese

Transferring orthographic processing skills from one language to new languages is important for language learning. However, the specific orthography hypothesis and condition-based transfer hypothesis have debated orthographic transfer. No study has ever examined these debates in a logographic language, and the neural correlates of orthographic transfer in a logographic language remain unknown. Therefore, the present study uses event-related potentials to examine orthographic transfer with Hong Kong (Experiment 1) and mainland China (Experiment 2) participants who only use traditional or simplified Chinese, respectively. The participants sequentially read two of the same (repetition) or different (nonrepetition) traditional or simplified Chinese characters and judged whether they were identical. The results showed that the orthography-related N200 component was smaller in the repetition condition than in the nonrepetition condition. Importantly, for traditional Chinses users, this effect was more salient in traditional Chinese than in simplified Chinese, suggesting limited transfer from traditional to simplified Chinese. For simplified Chinese users, this effect was comparable in traditional and simplified Chinese, suggesting a smooth transfer from simplified to traditional Chinese. The results supported the condition-based transfer hypothesis, and showed asymmetric transfer between simple orthographic rules and complex ones. That is, simple orthographic rules can be transferred to complex ones smoothly, but not vice versa.

The temporal course of vicarious embarrassment: An electrophysiological study

Vicarious embarrassment as a social pain emotion has been studied from cognitive and neuroimaging perspectives. However, the dynamic time course of vicarious embarrassment remains unclear. We conducted an event-related potential (ERP) study to investigate the temporal dynamics of vicarious embarrassment and examine the role of perspective-taking in an emotional judgment task. The ERP results showed that vicarious embarrassment evoked more negative MFN (250-310 ms) and N400 (400-520 ms) components than the neutral condition over the frontal region. The time-frequency analysis results showed that, in the 200-1,600 ms time window, greater alpha power was elicited when participants imagined themselves rather than others in an awkward situation; in the 500-1,900 ms time window, for both groups, vicarious embarrassment involved greater theta oscillations than the neutral condition over the frontal region. These results extend previous findings that vicarious emotion involves mentalizing processes, and demonstrate that people first detect and evaluate the target's misconduct and negative outcomes and then experience the vicarious embarrassment.

Perceived Gaze Direction Differentially Affects Discrimination of Facial Emotion, Attention, and Gender - An ERP Study

The perception of eye-gaze is thought to be a key component of our everyday social interactions. While the neural correlates of direct and averted gaze processing have been investigated, there is little consensus about how these gaze directions may be processed differently as a function of the task being performed. In a within-subject design, we examined how perception of direct and averted gaze affected performance on tasks requiring participants to use directly available facial cues to infer the individuals' emotional state (emotion discrimination), direction of attention (attention discrimination) and gender (gender discrimination). Neural activity was recorded throughout the three tasks using EEG, and ERPs time-locked to face onset were analyzed. Participants were most accurate at discriminating emotions with direct gaze faces, but most accurate at discriminating attention with averted gaze faces, while gender discrimination was not affected by gaze direction. At the neural level, direct and averted gaze elicited different patterns of activation depending on the task over frontal sites, from approximately 220-290 ms. More positive amplitudes were seen for direct than averted gaze in the emotion discrimination task. In contrast, more positive amplitudes were seen for averted gaze than for direct gaze in the gender discrimination task. These findings are among the first direct evidence that perceived gaze direction modulates neural activity differently depending on task demands, and that at the behavioral level, specific gaze directions functionally overlap with emotion and attention discrimination, precursors to more elaborated theory of mind processes.

The neural basis of desire reasoning for self and others: an event-related potential study

Theory of mind refers to the ability to attribute mental states to self and others, and predict actions in terms of mental states. It is still unclear how certain kinds of processing occur in theory of mind operation. The present study compared neural activities elicited by desire reasoning for self and for others under consistent or inconsistent conditions using the event-related potential method. The results showed that the late positive component (LPC) associated with desire reasoning was larger during the 450-550 ms time period in the condition of reasoning for self than that for others when desires were inconsistent. A left hemisphere effect on the scalp distribution was observed for the LPC component. The present study showed that a left frontal LPC component might reflect the subjective categorization process in desire reasoning.

Electrophysiological evidence of separate pathways for the perception of depth and 3D objects

Previous studies have investigated the neural mechanism of 3D perception, but the neural distinction between 3D-objects and depth processing remains unclear. In the present study, participants viewed three types of graphics (planar graphics, perspective drawings, and 3D objects) while event-related potentials (ERP) were recorded. The ERP results revealed the following: (1) 3D objects elicited a larger and delayed N1 component than the other two types of stimuli; (2) during the P2 time window, significant differences between 3D objects and the perspective drawings were found mainly over a group of electrode sites in the left lateral occipital region; and (3) during the N2 complex, differences between planar graphics and perspective drawings were found over a group of electrode sites in the right hemisphere, whereas differences between perspective drawings and 3D objects were observed at another group of electrode sites in the left hemisphere. These findings support the claim that depth processing and object identification might be processed by separate pathways and at different latencies.

Characterizing an ERP correlate of intentions understanding using a sequential comic strips paradigm

Chronometric properties of theory of mind and intentions understanding more specifically are well documented. Notably, it was demonstrated using magnetoencephalography that the brain regions involved were recruited as soon as 200 ms post-stimulus. We used event-related potentials (ERPs) to characterize an electrophysiological marker of attribution of intentions. We also explored the robustness of this ERP signature under two conditions corresponding to either explicit instructions to focus on others' intentions or implicit instructions with no reference to mental states. Two matched groups of 16 healthy volunteers each received either explicit or no instructions about intentions and performed a nonverbal attribution of intentions task based on sequential four-image comic strips depicting either intentional or physical causality. A bilateral posterior positive component, ranging from 250 to 650 ms post-stimulus, showed greater amplitude in intentional than in physical condition (the intention ERP effect). This effect occurs during the third image only, suggesting that it reflects the integration of information depicted in the third image to the contextual cues given by the first two. The intention effect was similar in the two groups of subjects. Overall, our results identify a clear ERP marker of the first hundreds of milliseconds of intentions processing probably related to a contextual integrative mechanism and suggest its robustness by showing its blindness to task demands manipulation.

The use of single-electrode wireless EEG in biobehavioral investigations

The purpose of this chapter is to introduce novice and intermediate EEG researchers to a convenient and user-friendly EEG system from NeuroSky, Inc. In our recent study we were interested in changes in the frontal cortical EEG activity of healthy adults as a function of accommodative stress during performance of a sustained attention task. We used a commercially available low-cost wireless EEG device from NeuroSky (MindSet), which has a single active Fp1 dry electrode capable of recording research-grade EEG coupled with powerful noise-filtering and data software support. The convenience and ease-of-use of MindSet is further enhanced with validated eSense meters of Attention and Meditation. In this chapter we also provide additional data analytic support for EEG power spectrum using SPSS syntax commonly used in many biobehavioral sciences.

Theory of mind deficits in patients with mild symptoms of major depressive disorder

The aim of this study was to investigate theory of mind (ToM) in a sample of depressed patients with mild symptom severity using a measure with varied cognitive processing demands. Patients demonstrated impaired performance on second-order, cognitively demanding ToM scenarios. Reduced ToM ability was associated with poor psychosocial functioning.