Robust Averaging of Faces and Delusion Proneness

This project explores the impact of paranoia and psychosis-proneness on robust averaging of facial expressions, aiming to understand how these factors influence social interactions and outcomes such as loneliness and perceived social support.

Background and Significance:

  1. Understanding Robust Averaging: This research investigates robust averaging, a perceptual mechanism that reduces the influence of extreme values, essential for accurately interpreting facial expressions and social cues.

  2. Impact on Psychosis-Proneness: The study explores how individuals with hallucination-proneness and psychotic-like symptoms exhibit alterations in robust averaging, potentially leading to social isolation and impaired social functioning.

  3. Broader Implications: By addressing the impact of psychosis-proneness on robust averaging, the research aims to provide insights into social dysfunction mechanisms and inform interventions to improve social outcomes for affected individuals.

Specific Aims/Hypotheses:

Aim 1: Test whether individuals demonstrate robust averaging for facial expressions.

  • Hypothesis 1: Robust averaging for facial expressions of emotions will be observed in the general population.

Aim 2: Examine whether paranoia-proneness and psychosis-proneness are associated with alterations in robust averaging for facial expressions.

  • Hypothesis 2: Individuals with high paranoia-proneness and psychosis-proneness will exhibit impaired robust averaging of facial expressions.

Aim 3: Investigate the relationship between altered robust averaging and social outcomes such as loneliness and perceived social support.

  • Hypothesis 3: Altered robust averaging correlates with higher levels of loneliness and lower perceived social support.

Methods

100 Participants will include undergraduates aged 18-29 years, the peak age range for the incidence of psychotic disorders, with normal or corrected-to-normal vision, recruited from college psychology courses and through campus flyers (Kessler et al., 2007).

Measures

Uses various measures to assess robust averaging of facial expressions, paranoia-proneness, delusion proneness, hallucination proneness, loneliness, and perceived social support. Key tools include the Revised Green Paranoid Thoughts Scale, Peters Delusion Inventory, Cardiff Anomalous Perceptions Scale, and Multidimensional Scale of Perceived Social Support.

Procedure:

After obtaining informed consent, participants will complete a robust averaging task using PsychoPy. Evaluate arrays of 8 facial expressions with varying emotional intensities, where mean intensity (high or low) and variance (high or low) are manipulated. Each trial includes a fixation cross (500 ms), a mask (100 ms), the stimulus array (500 ms), and the participant's response (up to 1200 ms). Participants will judge the overall emotional intensity of each array. Following the task, participants will complete the RGPTS, PDI, CAPS, three-item Loneliness Scale, and MSPSS on Qualtrics.

Data Analysis:

Data analysis will be performed in R. Following Larsen et al. (2023), we will estimate the weight each participant gives each element in the 8-face array when making decisions by conducting logistic regressions with the element rank as the predictor (rank 1-8) and decision (“positive” or “negative”) as the outcome, on a trial-by-trial basis. Element weights (i.e., standardized beta values) will be averaged across trials for each participant.

Timeline:

  • August 2024: Submit IRB protocol.

  • September 2024-February 2025: Test participants.

  • January 2025-March 2025: Finalize data analysis code in R.

  • March 2025-April 2025: Conduct and interpret analysis. Write thesis.

Basic