Thalia Semplonius

Impact of total sleep deprivation on behavioural neural processing of emotionally expressive faces.

Sleep deprivation impacts subjective mood states, but very little research has examined the impact on processing emotional information. In the current study, we investigated the impact of total sleep deprivation on neural responses to emotional facial expressions as well as the accuracy and speed with which these faces were categorized. Forty-nine participants completed two tasks in which they were asked to categorize emotional facial expressions as Happy, Sad, Angry, or Fearful. They were shown the ‘full’ expression of the emotions in one task and more subtle expressions in a second task in which expressions were ‘morphed’ with neutral faces so that the intensity of emotion varied. It was expected that sleep deprivation would lead to greater reactivity (indexed by larger amplitude N170 event-related potentials), particularly for negative and more subtle facial expressions. In the full face task, sleep-deprived (SD) participants were significantly less accurate than controls (C) at identifying Sad faces and slower to identify all emotional expressions. P1 was smaller and N170 was larger for the SD compared to C group, but for all emotions, indicating generalized impairment in low-level visual processing. In the more difficult morphed face task, SD participants were less accurate than C participants for Sad faces; as well, the group difference in reaction time was greatest for Sad faces. For the SD group, N170 increased in amplitude with increasing perceptual difficulty for the Fearful and Angry faces, but decreased in amplitude with increasing difficulty for Sad faces. These data illustrate that sleep deprivation led to greater neural reactivity for the threat-related negative emotions as they became more subtle; however, there was a failure to engage these perceptual resources for the processing of Sad faces. Sleep loss preferentially impacted the processing of Sad faces; this has widespread implications for sleep-deprived groups.

Attentional biases and recognition accuracy: What happens when multiple own- and other-race faces are encountered simultaneously?

Adults recognize own-race faces more accurately than other-race faces. We investigated three characteristics of laboratory investigations hypothesized to minimize the magnitude of the own-race recognition advantage (ORA): lack of competition for attention and instructions that emphasize individuating faces during the study phase, and a lack of uncertainty during the test phase. Across two experiments, participants studied faces individually, in arrays comprising multiple faces and household objects, or in naturalistic scenes (presented on an eye-tracker); they were instructed to remember everything, memorize faces, or form impressions of people. They then completed one of two recognition tasks—an old/new recognition task or a lineup recognition task. Task instructions influenced time spent looking at faces but not the allocation of attention to own- versus other-race faces. The magnitude of the ORA was independent of both task instructions and test protocol, with some modulation by how faces were presented in the study phase. We discuss these results in light of current theories of the ORA.

Psychosocial Adjustment Throughout University: A Longitudinal Investigation of the Roles of Sleep Quality and Emotion Dysregulation

Sleep problems and emotion dysregulation are associated with depressive symptoms and alcohol use but little research has examined the long-term associations and the direction of effects between these factors. We examined these relationships with 1132 undergraduates (70.5% female) over 5 years. Sleep problems and emotion dysregulation, sleep problems and depressive symptoms, and emotion dysregulation and depressive symptoms were all related bidirectionally. Tests of indirect effects indicated that sleep problems predicted depressive symptoms over time (and vice versa) via emotion dysregulation and emotion dysregulation predicted depressive symptoms over time (and vice versa) via sleep problems. The results highlight the need to assess direction of effects, given that many factors that are typically seen as “predictors” also can be framed as “outcomes”.

A person-centered analysis of sleep and emotion dysregulation: Short- and long-term links with depression and alcohol use

Abstract Objective: Our objective was to examine the co-occurrence of sleep problems and emotion dysregulation and its short- and long-term links to depressive symptoms and alcohol use in a sample of university students. Method: Participants included 1132 first-year university students from Southern Ontario (70.5% women). Time 1 data were collected in February/March, 2010, and Time 2 data (n = 746) were collected in February/March, 2014. Participants were surveyed about sleep problems and emotion dysregulation (Time 1), and depressive symptoms and alcohol use (Times 1 and 2). Results: A latent class analysis revealed four groups: (1) Low Co-Occurrence, (2) Sleep Problems Only, (3) Emotion Dysregulation Only, and (4) High Co-occurrence. Group 4 had more depressive symptoms than all other groups in both the short- and long-term. Conclusions: First year university students with high co-occurrence of sleep problems and emotion dysregulation may be a target group for programs focused on reducing adjustment difficulties.