The role of the counselor's experience in building an alliance with the clients remains controversial. Recently, the expanding nascent studies on interpersonal brain synchronization (IBS) using functional near-infrared spectroscopy (fNIRS) on human subjects have hinted at the possible neural substrates underlying the relationship qualities between the counselor-client dyads. Our study assessed the clients' selfreport working alliance (WA) as well as simultaneously measured IBS by fNIRS in 14 experienced vs. 16 novice counselor-client dyads during the first integrativeorientation psychological counseling session. We observed that synchronous brain activity patterns were elicited from the right temporo-parietal junction across counselor-client dyads. Furthermore, such IBS, together with alliance quality, was especially evident when counselors had more psychotherapy experience. Time-lagged counselor-client brain synchronization might co-vary with the alliance (goal component) when the client's brain activity preceded that of the counselor. These findings favor the notion that the IBS between counselor-client associated with the WA is an experience-dependent phenomenon, suggesting that a potential adaptive mechanism is embedded in psychological counseling. Public Health Significance Statements: Recent expanding nascent studies on interpersonal brain synchronization (IBS) during the interpersonal communication process using functional near-infrared spectroscopy(fNIRS) have hinted at the possible neural substrates underlying the effective relationship/alliance between the counselor-client dyads. By using fNIRs, our study found that the experienced counselors could build better alliance and stronger IBS of the right temporo-parietal 4 junction (rTPJ) with the clients vs. novice counselors, at least in the first session. This result supports the notion that a counselor's level of experience is important in establishing positive alliance and the increased IBS of the rTPJ in the experienced counselor group vs. the novice counselor group might indicate the neural basis of the better alliance during the psychological counseling process.

Recent neuroimaging research has suggested that unequal cognitive efforts exist between interpreting from language 1 (L1) to language 2 (L2) compared with interpreting from L2 to L1. However, the neural substrates that underlie this directionality effect are not yet well understood. Whether directionality is modulated by interpreting expertise also remains unknown. In this study, we recruited two groups of Mandarin (L1)/English (L2) bilingual speakers with varying levels of interpreting expertise and asked them to perform interpreting and reading tasks. Functional near-infrared spectroscopy (fNIRS) was used to collect cortical brain data for participants during each task, using 68 channels that covered the prefrontal cortex and the bilateral perisylvian regions. The interpreting-related neuroimaging data was normalized by using both L1 and L2 reading tasks, to control the function of reading and vocalization respectively. Our findings revealed the directionality effect in both groups, with forward interpreting (from L1 to L2) produced more pronounced brain activity, when normalized for reading. We also found that directionality was modulated by interpreting expertise in both normalizations. For the group with relatively high expertise, the activated brain regions included the right Broca’s area and the left premotor and supplementary motor cortex; whereas for the group with relatively low expertise, the activated brain areas covered the superior temporal gyrus, the dorsolateral prefrontal cortex (DLPFC), the Broca’s area, and visual area 3 in the right hemisphere. These findings indicated that interpreting expertise modulated brain activation, possibly because of more developed cognitive skills associated with executive functions in experienced interpreters.