Lun Zhao - Academia.edu (original) (raw)

Papers by Lun Zhao

Frontiers in Human Neuroscience

Mismatch negativity (MMN) of event-related potentials (ERPs) is a biomarker reflecting the preatt... more Mismatch negativity (MMN) of event-related potentials (ERPs) is a biomarker reflecting the preattentional change detection under non-attentional conditions. This study was performed to explore whether high self-related information could elicit MMN in the visual channel, indicating the automatic processing of self-related information at the preattentional stage. Thirty-five participants were recruited and asked to list 25 city names including the birthplace. According to the difference of relevance reported from the participants, we divided names of the different cities into high (birthplace as deviants), medium (Xi’an, where participants’ university is located, as deviants), and low (totally unrelated cities as standard stimuli) self-related information. Visual MMN (vMMN) was elicited by high self-related information but not by medium self-related information, with an occipital–temporal scalp distribution, indicating that, under non-attentional condition, high self-related informati...

Scientific Reports

It is unclear whether the face perceptual processing, especially the perceptual computation in ea... more It is unclear whether the face perceptual processing, especially the perceptual computation in early stages of processing faces, impaired in young patients with major depressive disorder (MDD). In this study, the face perception was investigated by analyzing the early ERP components in response to upright and inverted faces versus objects. Across all conditions, both the P1 and the N170 components were similar in MDD patients versus in the controls, regardless of latencies or amplitudes. Faces elicited larger N170 than objects (N170 face effect) and inverted faces elicited higher and delayed N170 (N170 inversion effect); however, none of these effects were modulated by depression. These findings suggest that there is intact perceptual mechanism of processing faces in young MDD patients, relying primarily on global/configural information versus non-face objects.

Frontiers in Psychiatry

The aim of the present study was to investigate the age effect on face perceptual processing in M... more The aim of the present study was to investigate the age effect on face perceptual processing in MDD patients by analyzing the N170 component in response to faces and objects presented in upright and inverted conditions. For controls, although the N170 amplitude, overall, did not differ between young and middle-aged participants, the size of N170 inversion effect was larger for young than for middle-aged controls, but the N170 face effect was not influenced by age. For young participants, MDD patients showed N170 amplitude similar to controls and neither the N170 face effect nor the N170 inversion effect were influenced by depression. For middle-aged participants, MDD patients revealed larger N170 than did controls, and both the size of N170 inversion effect and the N170 face effect were larger for MDD patients than controls. These data indicate that, at least at the early stage of face perception, there is altered face perception in middle-aged but not in young MDD patients. This re...

Journal of Integrative Neuroscience, 2021

Frontiers in Psychiatry, 2020

In this paper, from the perspective of complex network dynamics we investigated the formation of ... more In this paper, from the perspective of complex network dynamics we investigated the formation of the synchronization state of the brain networks. Based on the Lyapunov stability theory of complex networks, a synchronous steady-state model suitable for application to complex dynamic brain networks was proposed. The synchronization stability problem of brain network state equation was transformed into a convex optimization problem with Block Coordinate Descent (BCD) method. By using Random Apollo Network (RAN) method as a node selection rule, the brain network constructs its subnet work dynamically. We also analyzes the change of the synchronous stable state of the subnet work constructed by this method with the increase of the size of the network. Simulation EEG data from alcohol addicts patients and Real experiment EEG data from schizophrenia patients were used to verify the robustness and validity of the proposed model. Differences in the synchronization characteristics of the brai...

This study investigated emoji semantic processing by measuring changes in event-related electroen... more This study investigated emoji semantic processing by measuring changes in event-related electroencephalogram (EEG) power. The last segment of experimental sentences was designed as either words or emojis consistent or inconsistent with the sentential context. The results showed that incongruent emojis led to a conspicuous increase of theta power (4-7Hz), while incongruent words induced a decrease. Furthermore, the theta power increase was observed at midfrontal, occipital and bilateral temporal lobes with emojis. This suggests a higher working memory load for monitoring errors, difficulty of form recognition and concept retrieval in emoji semantic processing. It implies different neuro-cognitive processes involved in the semantic processing of emojis and words.

Frontiers in behavioral neuroscience, 2018

To investigate gender differences in functional connectivity during the unattended processing of ... more To investigate gender differences in functional connectivity during the unattended processing of facial expressions, we recorded visual mismatch negativity (vMMN) in 34 adults using a deviant-standard reverse oddball paradigm. Using wavelet analysis, we calculated the time-frequency (TF) power at each electrode associated with happy-deviant, sad-deviant, happy-standard and sad-standard conditions. We also calculated the phase lag index (PLI) between electrode pairs and analyzed the dynamic network topologies of the functional connectivity for happy and sad vMMNs in the delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13-30 Hz) and gamma (30-45 Hz) bands. The results showed that females induced stronger TF power and PLI values than males in only the alpha band over the whole brain regarding the vMMN. Moreover, females had a higher ratio of the number of connections between long-distance electrode pairs than males. While theoretical analysis of dynamic network topologies indic...

Frontiers in human neuroscience, 2017

The present study aimed to explore the modulation of frequency bands (alpha, beta, theta) underly... more The present study aimed to explore the modulation of frequency bands (alpha, beta, theta) underlying the positive facial expressions classification advantage within different post-stimulus time intervals (100-200 ms, 200-300 ms, 300-400 ms). For this purpose, we recorded electroencephalogram (EEG) activity during an emotion discrimination task for happy, sad and neutral faces. The correlation between the non-phase-locked power of frequency bands and reaction times (RTs) was assessed. The results revealed that beta played a major role in positive classification advantage (PCA) within the 100-200 and 300-400 ms intervals, whereas theta was important within the 200-300 ms interval. We propose that the beta band modulated the neutral and emotional face classification process, and that the theta band modulated for happy and sad face classification.

Neuroreport, Jan 18, 2018

To investigate the emotional face processing in patients with schizophrenia, the preattentive aut... more To investigate the emotional face processing in patients with schizophrenia, the preattentive automatic processing of emotional faces in individuals with schizophrenia was compared with that of age-matched healthy control group as indexed by the expressional mismatch negativity (EMMN) elicited by facial expressions. Compared with neutral faces as standard stimuli, deviant emotional faces elicited posterior EMMN between 150 and 500 ms after stimuli onset, with larger amplitudes for sad than happy deviant faces. Both early and late EMMNs significantly decreased in the schizophrenia group, regardless of sad or happy EMMN, in comparison with the healthy control group. These data suggest the dysfunction of automatic processing of expressional information in patients with schizophrenia.

Frontiers in Psychology, 2017

Frontiers in behavioral neuroscience, 2017

It has been shown that emotionally positive facial expressions are recognized substantially faste... more It has been shown that emotionally positive facial expressions are recognized substantially faster than emotionally negative facial expressions, the positive classification advantage (PCA). In this experiment we explored the involvement of configural computations while processing positive and negative faces in an expression categorization task using artificial faces. Analyzing the reaction times (RTs), we found that happy faces were categorized more quickly than sad faces (PCA) and this effect disappeared for inverted faces. Event-related potentials (ERPs) data showed that the face-sensitive N170 component was larger for sad than for happy faces only at upright condition and that face inversion significantly enhanced N170 amplitudes only for happy faces. Moreover, the happy faces elicited shorter N170 latency than did the sad faces, whereas for inverted condition the N170 latency did not differ between happy and sad faces. Finally, the significant positive correlation between the RT...

Computational and mathematical methods in medicine, 2016

Estimation of human emotions from Electroencephalogram (EEG) signals plays a vital role in affect... more Estimation of human emotions from Electroencephalogram (EEG) signals plays a vital role in affective Brain Computer Interface (BCI). The present study investigated the different event-related synchronization (ERS) and event-related desynchronization (ERD) of typical brain oscillations in processing Facial Expressions under nonattentional condition. The results show that the lower-frequency bands are mainly used to update Facial Expressions and distinguish the deviant stimuli from the standard ones, whereas the higher-frequency bands are relevant to automatically processing different Facial Expressions. Accordingly, we set up the relations between each brain oscillation and processing unattended Facial Expressions by the measures of ERD and ERS. This research first reveals the contributions of each frequency band for comprehension of Facial Expressions in preattentive stage. It also evidences that participants have emotional experience under nonattentional condition. Therefore, the u...

Frontiers in human neuroscience, 2015

The current study investigated the time course of the other-race classification advantage (ORCA) ... more The current study investigated the time course of the other-race classification advantage (ORCA) in the subordinate classification of normally configured faces and distorted faces by race. Slightly distorting the face configuration delayed the categorization of own-race faces and had no conspicuous effects on other-race faces. The N170 was sensitive neither to configural distortions nor to faces' races. The P3 was enhanced for other-race than own-race faces and reduced by configural manipulation only for own-race faces. We suggest that the source of ORCA is the configural analysis applied by default while processing own-race faces.