Inefficient integration during multiple facial processing in pre-morbid and early phases of psychosis

Abnormal Scanning Patterns Based on Eye Movement Entropy in Early Psychosis

BACKGROUND

Restricted scan path mode is hypothesized to explain abnormal scanning patterns in patients with schizophrenia. Here, we calculated entropy scores (drawing on gaze data to measure the statistical randomness of eye movements) to quantify how strategical and random participants were when processing image stimuli.

METHODS

Eighty-six patients with first-episode schizophrenia (FES), 124 individuals at clinical high risk (CHR) for psychosis, and 115 healthy control participants (HCs) completed an eye-tracking examination while freely viewing 35 static images (each presented for 10 seconds) and cognitive assessments. We compared group differences in the overall entropy score, as well as entropy scores under various conditions. We also investigated the correlations between entropy scores and symptoms and cognitive function.

RESULTS

Increased overall entropy scores were noted in the FES and CHR groups compared with the HC group, and these differences were already apparent within 0 to 2.5 seconds. In addition, the CHR group exhibited higher entropy than the HC group when viewing low-meaning images. Moreover, the entropy within 0 to 2.5 seconds showed significant correlations with negative symptoms in the FES group, attention/vigilance scores in the CHR group, and speed of processing and attention/vigilance scores across all 3 groups.

CONCLUSIONS

The results indicate that individuals with FES and those at CHR scanned pictures more randomly and less strategically than HCs. These patterns also correlated with clinical symptoms and neurocognition. The current study highlights the potential of the eye movement entropy measure as a neurophysiological marker for early psychosis.

Implicit induction of expressive suppression in regulation of happy crowd emotions

Implicit emotion regulation provides an effective means of controlling emotions triggered by a single face without conscious awareness and effort. Crowd emotion has been proposed to be perceived as more intense than it actually is, but it is still unclear how to regulate it implicitly. In this study, participants viewed sets of faces of varying emotionality (e.g. happy to angry) and estimated the mean emotion of each set after being primed with an expressive suppression goal, a cognitive reappraisal goal, or a neutral goal. Faster discrimination for happy than angry crowds was observed. After induction of the expressive suppression goal instead of the cognitive reappraisal goal, augmented N170 and early posterior negativity (EPN) amplitudes, as well as attenuated late positive potential (LPP) amplitudes, were observed in response to happy crowds compared to the neutral goal. Differential processing of angry crowds was not observed after the induction of both regulatory goals compared to the neutral goal. Our findings thus reveal the happy-superiority effect and that implicit induction of expressive suppression improves happy crowd emotion recognition, promotes selective coding, and successfully downregulates the neural response to happy crowds.

Eye Movement Characteristics for Predicting a Transition to Psychosis: Longitudinal Changes and Implications

BACKGROUND AND HYPOTHESIS

Substantive inquiry into the predictive power of eye movement (EM) features for clinical high-risk (CHR) conversion and their longitudinal trajectories is currently sparse. This study aimed to investigate the efficiency of machine learning predictive models relying on EM indices and examine the longitudinal alterations of these indices across the temporal continuum.

STUDY DESIGN

EM assessments (fixation stability, free-viewing, and smooth pursuit tasks) were performed on 140 CHR and 98 healthy control participants at baseline, followed by a 1-year longitudinal observational study. We adopted Cox regression analysis and constructed random forest prediction models. We also employed linear mixed-effects models (LMMs) to analyze longitudinal changes of indices while stratifying by group and time.

STUDY RESULTS

Of the 123 CHR participants who underwent a 1-year clinical follow-up, 25 progressed to full-blown psychosis, while 98 remained non-converters. Compared with the non-converters, the converters exhibited prolonged fixation durations, decreased saccade amplitudes during the free-viewing task; larger saccades, and reduced velocity gain during the smooth pursuit task. Furthermore, based on 4 baseline EM measures, a random forest model classified converters and non-converters with an accuracy of 0.776 (95% CI: 0.633, 0.882). Finally, LMMs demonstrated no significant longitudinal alterations in the aforementioned indices among converters after 1 year.

CONCLUSIONS

Aberrant EMs may precede psychosis onset and remain stable after 1 year, and applying eye-tracking technology combined with a modeling approach could potentially aid in predicting CHRs evolution into overt psychosis.

Attentional biases in facial emotion processing in individuals at clinical high risk for psychosis

Individuals at clinical high risk (CHR) for psychosis exhibit altered facial emotion processing (FEP) and poor social functioning. It is unclear whether FEP deficits result from attentional biases, and further, how these abnormalities are linked to symptomatology (e.g., negative symptoms) and highly comorbid disorders that are also tied to abnormal FEP (e.g., depression). In the present study, we employed an eye-tracking paradigm to assess attentional biases and clinical interviews to examine differences between CHR (N = 34) individuals and healthy controls (HC; N = 46), as well as how such biases relate to symptoms and functioning in CHR individuals. Although no CHR-HC differences emerged in attentional biases, within the CHR group, symptoms and functioning were related to biases. Depressive symptoms were related to some free-view attention switching biases (e.g., to and from fearful faces, r = .50). Negative symptoms were related to more slowly disengaging from happy faces (r = .44), spending less time looking at neutral faces (r =  - .42), and more time looking at no face (Avolition, r = .44). In addition, global social functioning was related to processes that overlapped with both depression and negative symptoms, including time looking at no face (r =  - .68) and free-view attention switching with fearful faces (r =  - .40). These findings are consistent with previous research, indicating that negative symptoms play a prominent role in the CHR syndrome, with distinct mechanisms relative to depression. Furthermore, the results suggest that attentional bias indices from eye-tracking paradigms may be predictive of social functioning.