Jiehui Hu

Oxytocin, the peptide that bonds the sexes also divides them

Significance To interpret and respond appropriately to social cues is a fundamental aspect of human nature that becomes impaired in many mental disorders. The past decade has witnessed unprecedented excitement across neuroscience, psychology, and psychiatry regarding the role of oxytocin in human social cognition and its potential therapeutic use. There is also a considerable long-established public interest in behavioral sex differences and the molecular and brain mechanisms responsible. The current findings provide the first mechanistic explanation, to our knowledge, for how this key social molecule has evolved sex-dependent actions on amygdala function to influence the salience and attractiveness of positive social attributes in women but negative ones in men. Facilitation of social attraction and bonding by the evolutionarily conserved neuropeptide oxytocin is well-established in female mammals. However, accumulating behavioral evidence suggests that oxytocin may have evolved sex-specific functional roles in the domain of human social cognition. A critical question is how oxytocin differentially modulates neural processing of social information in men and women, leading to divergent behavioral responses. Here we show that intranasal oxytocin treatment produces sex- and valence-dependent increases in amygdala activation when women view individuals identified as praising others but in men those who criticize them. Women subsequently show increased liking for the faces of these individuals, whereas in men it is reduced. Thus, oxytocin may act differentially via the amygdala to enhance the salience of positive social attributes in women but negative ones in men. We hypothesize that oxytocin may have evolved different but complementary roles to help ensure successful reproduction by encouraging mothers to promote a prosocial rearing environment for offspring and fathers to protect against antisocial influences.

Multimodal Functional Network Connectivity: An EEG-fMRI Fusion in Network Space

EEG and fMRI recordings measure the functional activity of multiple coherent networks distributed in the cerebral cortex. Identifying network interaction from the complementary neuroelectric and hemodynamic signals may help to explain the complex relationships between different brain regions. In this paper, multimodal functional network connectivity (mFNC) is proposed for the fusion of EEG and fMRI in network space. First, functional networks (FNs) are extracted using spatial independent component analysis (ICA) in each modality separately. Then the interactions among FNs in each modality are explored by Granger causality analysis (GCA). Finally, fMRI FNs are matched to EEG FNs in the spatial domain using network-based source imaging (NESOI). Investigations of both synthetic and real data demonstrate that mFNC has the potential to reveal the underlying neural networks of each modality separately and in their combination. With mFNC, comprehensive relationships among FNs might be unveiled for the deep exploration of neural activities and metabolic responses in a specific task or neurological state.

Oxytocin selectively facilitates learning with social feedback and increases activity and functional connectivity in emotional memory and reward processing regions.

In male Caucasian subjects, learning is facilitated by receipt of social compared with non‐social feedback, and the neuropeptide oxytocin (OXT) facilitates this effect. In this study, we have first shown a cultural difference in that male Chinese subjects actually perform significantly worse in the same reinforcement associated learning task with social (emotional faces) compared with non‐social feedback. Nevertheless, in two independent double‐blind placebo (PLC) controlled between‐subject design experiments we found OXT still selectively facilitated learning with social feedback. Similar to Caucasian subjects this OXT effect was strongest with feedback using female rather than male faces. One experiment performed in conjunction with functional magnetic resonance imaging showed that during the response, but not feedback phase of the task, OXT selectively increased activity in the amygdala, hippocampus, parahippocampal gyrus and putamen during the social feedback condition, and functional connectivity between the amygdala and insula and caudate. Therefore, OXT may be increasing the salience and reward value of anticipated social feedback. In the PLC group, response times and state anxiety scores during social feedback were associated with signal changes in these same regions but not in the OXT group. OXT may therefore have also facilitated learning by reducing anxiety in the social feedback condition. Overall our results provide the first evidence for cultural differences in social facilitation of learning per se, but a similar selective enhancement of learning with social feedback under OXT. This effect of OXT may be associated with enhanced responses and functional connectivity in emotional memory and reward processing regions. Hum Brain Mapp 36:2132–2146, 2015.

Sex-dependent neural effect of oxytocin during subliminal processing of negative emotion faces

&NA; In line with animal models indicating sexually dimorphic effects of oxytocin (OXT) on social‐emotional processing, a growing number of OXT‐administration studies in humans have also reported sex‐dependent effects during social information processing. To explore whether sex‐dependent effects already occur during early, subliminal, processing stages the present pharmacological fMRI‐study combined the intranasal‐application of either OXT or placebo (n = 86–43 males) with a backward‐masking emotional face paradigm. Results showed that while OXT suppressed inferior frontal gyrus, dorsal anterior cingulate and anterior insula responses to threatening face stimuli in men it increased them in women. In women increased anterior cingulate reactivity during subliminal threat processing was also positively associated with trait anxiety. On the network level, sex‐dependent effects were observed on amygdala, anterior cingulate and inferior frontal gyrus functional connectivity that were mainly driven by reduced coupling in women following OXT. Our findings demonstrate that OXT produces sex‐dependent effects even at the early stages of social‐emotional processing, and suggest that while it attenuates neural responses to threatening social stimuli in men it increases them in women. Thus in a therapeutic context OXT may potentially produce different effects on anxiety disorders in men and women. HighlightsOxytocin (OXT) induced sex‐dependent effect on BOLD level and functional connectivity.OXT decreased neural responses to negative faces in men but increased them in women.Increased ACC activity after OXT was positively linked with trait anxiety in women.OXT decreased functional connectivity in women.Sex might be an important factor moderating the putative anxiolytic effects of OXT.

Dissociation of tone and vowel processing in Mandarin idioms.

Using event-related potentials, this study measured the access of suprasegmental (tone) and segmental (vowel) information in spoken word recognition with Mandarin idioms. Participants performed a delayed-response acceptability task, in which they judged the correctness of the last word of each idiom, which might deviate from the correct word in either tone or vowel. Results showed that, compared with the correct idioms, a larger early negativity appeared only for vowel violation. Additionally, a larger N400 effect was observed for vowel mismatch than tone mismatch. A control experiment revealed that these differences were not due to low-level physical differences across conditions; instead, they represented the greater constraining power of vowels than tones in the lexical selection and semantic integration of the spoken words. Furthermore, tone violation elicited a more robust late positive component than vowel violation, suggesting different reanalyses of the two types of information. In summary, the current results support a functional dissociation of tone and vowel processing in spoken word recognition.

Bilingual cognitive control in language switching: an fMRI study of English-Chinese late bilinguals.

The present study explored the bilingual cognitive control mechanism by comparing Chinese-English bilinguals’ language switching in a blocked picture naming paradigm against three baseline conditions, namely the control condition (a fixation cross, low-level baseline), single L1 production (Chinese naming, high-level baseline), and single L2 production (English naming, high-level baseline). Different activation patterns were observed for language switching against different baseline conditions. These results indicate that different script bilingual language control involves a fronto-parietal-subcortical network that extends to the precentral gyrus, the Supplementary Motor Area, the Supra Marginal Gyrus, and the fusiform. The different neural correlates identified across different comparisons supported that bilingual language switching involves high-level cognitive processes that are not specific to language processing. Future studies adopting a network approach are crucial in identifying the functional connectivity among regions subserving language control.

Partial information can be transmitted in an auditory channel: Inferences from lateralized readiness potentials

With the two-choice go/no-go paradigm, we investigated whether timbre attribute can be transmitted as partial information from the stimulus identification stage to the response preparation stage in auditory tone processing. We manipulated two attributes of the stimulus: timbre (piano vs. violin) and acoustic intensity (soft vs. loud) to ensure an earlier processing of timbre than intensity. We associated the timbre attribute more with go trials. Results showed that lateralized readiness potentials (LRPs) were consistently elicited in no-go trials. This showed that the timbre attribute had been transmitted to the response preparation stage before the intensity attribute was processed in the stimuli identification stage. Such a result provides evidence for the continuous model and asynchronous discrete coding (ADC) model in information processing. We suggest that partial information can be transmitted in an auditory channel.

Incorporating fMRI Functional Networks in EEG Source Imaging: A Bayesian Model Comparison Approach

Brain functional networks extracted from fMRI can improve the accuracy of EEG source localization. However, the coupling between EEG and fMRI remains poorly understood, i.e., whether fMRI networks provide information about the magnitude of neural activity, and whether neural sources demonstrate temporal correlations within each network. In this paper, we present an improved version of the NEtwork-based SOurce Imaging method (iNESOI) through Bayesian model comparison. Different models correspond to various matching between EEG and fMRI, and the appropriate one is selected by data with the model evidence. Synthetic and real data tests show that iNESOI has potential to select the appropriate fMRI priors to reach a better source reconstruction than some other typical approaches.

The flexibility of partial information transmission in the auditory channel: The role of perceptual discriminability

A stimulus contains multiple attributes. Under certain circumstances, some information can be transmitted to the next cognitive stage before the processing of other information. An examination of partial information transmission is essential in improving our understanding of the mechanism of information processing. By manipulating two attributes, namely, pitch and intensity, this study examined whether the transmission speed of an attribute could be influenced by its perceptual discriminability. Using a choice go/no-go paradigm, this study presented adults with two pieces of pure tones and measured their LRPs. Results showed that pitch and intensity were transmitted earlier as partial information in the high pitch- and intensity-discriminability conditions, respectively. Thus, this study demonstrated that the transmission speed of a certain attribute could be modulated by its perceptual discriminability.

Integration of consonant and pitch processing as revealed by the absence of additivity in mismatch negativity.

Consonants, unlike vowels, are thought to be speech specific and therefore no interactions would be expected between consonants and pitch, a basic element for musical tones. The present study used an electrophysiological approach to investigate whether, contrary to this view, there is integrative processing of consonants and pitch by measuring additivity of changes in the mismatch negativity (MMN) of evoked potentials. The MMN is elicited by discriminable variations occurring in a sequence of repetitive, homogeneous sounds. In the experiment, event-related potentials (ERPs) were recorded while participants heard frequently sung consonant-vowel syllables and rare stimuli deviating in either consonant identity only, pitch only, or in both dimensions. Every type of deviation elicited a reliable MMN. As expected, the two single-deviant MMNs had similar amplitudes, but that of the double-deviant MMN was also not significantly different from them. This absence of additivity in the double-deviant MMN suggests that consonant and pitch variations are processed, at least at a pre-attentive level, in an integrated rather than independent way. Domain-specificity of consonants may depend on higher-level processes in the hierarchy of speech perception.