Feedback Processing as it Relates to Suicidal Ideation and Behavior Using a Time-Frequency Approach

Background. Suicidal ideation (SI) and suicidal behavior (SB) may have different etiological pathways, particularly related to feedback processing. Identifying ERP components related to these suicide states may help researchers localize and understand these differences. Objective. Our primary purpose was to utilize time-frequency decomposition techniques to assess neurophysiological correlates of SI and SB during positive and negative feedback processing. Methods. 271 subjects (55.7% female; mean age=35.75, SD=16.07; 30.6% veterans) completed a questionnaire battery and a multi-task protocol, including a gambling feedback task (Gehring & Willoughby, 2002), while electroencephalography (EEG) was collected using a 96-channel EEG system. Exploratory factor analysis (EFA) was conducted across 20 self-report suicide items selected to index SI and SB from several suicide-relevant questionnaires. EFA results produced 2 factors, corresponding to SI and SB. Time-frequency principal component analyses produced measures across all frequency bands (i.e., delta-FN/P3, delta-SW, theta-FN, alpha, beta-1, beta-2, and gamma). Results. Excepting alpha amplitude, all measured frequencies were related to SB, and not SI (across loss and gain, with some loss-gain differences). Alpha, uniquely, showed a relationship to SI and not to SB (across loss and gain, no loss-gain differences). Robust regressions confirmed that the delta, theta, and high-frequency (HF; beta-1, beta-2, and gamma as combined HF loss, gain, and loss-gain difference factors) measures were each independently related to SB. Discussion. Broadly, the results indicate that individuals with SB showed heightened neurophysiological response across multiple ERP components (except alpha) to gambling feedback, with significantly greater increases to loss stimuli relative to gain stimuli. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The study was funded by a Department of Defense grant. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Florida State University gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.