Detecting and predicting visually induced motion sickness with physiological measures in combination with machine learning techniques.

Visually induced motion sickness (VIMS) is a common sensation when using visual displays such as smartphones or Virtual Reality. In the present study, we investigated whether Machine Learning (ML) techniques in combination with physiological measures (ECG, EDA, EGG, respiration, body and skin temperature, and body movements) could be used to detect and predict the severity of VIMS in real-time, minute-by-minute. A total of 43 healthy younger adults (25 female) were exposed to a 15-minute VIMS-inducing video. VIMS severity was subjectively measured during the video using the Fast Motion Sickness Scale (FMS) as well as before and after the video using the Simulator Sickness Questionnaire (SSQ). Thirty-one participants (72%) experienced VIMS in the present study. Results showed that changes in facial skin temperature and body movement had the strongest relationship with VIMS. On a minute-by-minute basis, ML models revealed a medium correlation between the physiological measures and the FMS scores. An acceptable classification score distinguishing between sick and non-sick participants was found. Our findings suggest that physiological measures may be useful for measuring VIMS, but they are not a reliable standalone method to detect or predict VIMS severity in real-time.

Examining potential effects of arousal, valence, and likability of music on visually induced motion sickness.

The present study investigated how valence, arousal, and subjective liking of music affect visually induced motion sickness (VIMS). VIMS is a common side effect when interacting with virtual environments, resulting in discomfort, dizziness, and/or nausea. Music has previously been shown to reduce VIMS, but the precise nature of this effect remains unknown. Eighty participants watched a video of a bicycle ride filmed from a first-person perspective. First, participants (n = 40) were randomly assigned to one of four groups that listened to pre-selected, classical music excerpts varying in valence and arousal (happy, peaceful, agitated, sad) while watching the video. Second, the level of subjective liking of music was maximized by asking participants to select their favourite music (n = 20), which was then played during the video. A control group (n = 20) watched the video without music. VIMS was measured using the Fast Motion Sickness Scale (FMS) and the Simulator Sickness Questionnaire (SSQ). No effects of valence or arousal on VIMS symptoms were found. Instead, we found that VIMS was significantly reduced when music liking was maximized: Participants who listened to their favourite music reported less VIMS compared to those who did not listen to music at all or to pre-selected music that they liked less. Music that is highly liked can, under certain circumstances, successfully reduce VIMS. These effects appear to be independent of the valence and arousal characteristics of the music.

Sex differences in salivary cortisol reactivity to the Trier Social Stress Test (TSST): A meta-analysis.

Some, but not all studies using the Trier Social Stress Test (TSST) have demonstrated evidence in support of sex differences in salivary cortisol. The aim of the current meta-analysis is to examine sex differences in salivary cortisol following exposure to the TSST. We further explored the effects of modifications to the TSST protocol and procedural variations as potential moderators. We searched articles published from January, 1993 to February, 2016 in MedLine, PsychINFO, and ProQuest Theses and Dissertations. This meta-analysis is based on 34 studies, with a total sample size of 1350 individuals (640 women and 710 men). Using a random effects model, we found significant heterogeneity in salivary cortisol output across sexes, such that men were observed to have higher cortisol values at peak and recovery following the TSST compared to women. Modifications to the sampling trajectory of cortisol (i.e., duration of acclimation, peak sampling time, and duration of recovery) significantly moderated the heterogeneity across both sexes. Further, there are observed sex differences at various time points of the reactive cortisol following the TSST. Lastly, current results suggest that these sex differences can be, at least in part, attributed to variations in methodological considerations across studies. Future research could advance this line of inquiry by using other methods of analyses (e.g., area under the curve; AUC), in order to better understand the effects of methodological variations and their implications for research design.

Subjective Sleep Quality as a Possible Mediator in the Relationship between Personality Traits and Depressive Symptoms in Middle-Aged Adults.

This study explored the mediating role of sleep in the relationship between personality traits and depressive symptoms in a group of community-dwelling men and women (Mage = 57.92, SD = 4.00). Participants completed the short form NEO Five Factor Inventory (NEO-FFI), Pittsburgh Sleep Quality Index (PSQI), and the Center for Epidemiologic Studies Depression Scale (CES-D). High neuroticism and low conscientiousness was associated with poor sleep, as well as greater depressive symptom severity. Partial indirect mediation effects were found between personality traits (i.e., neuroticism and conscientiousness) and depressive symptoms through self-report sleep measures. An alternative model was also explored, entering depression as the mediator; however a smaller portion of the variance was explained by this model, compared with the hypothesized model. The current study provides preliminary information regarding the mechanisms that influence the relationship between personality traits, sleep, and depression among a group of community-dwelling middle-aged adults. Implications and future directions are discussed.

Music and Memory in Alzheimer's Disease and The Potential Underlying Mechanisms.

With population aging and a projected exponential expansion of persons diagnosed with Alzheimer's disease (AD), the development of treatment and prevention programs has become a fervent area of research and discovery. A growing body of evidence suggests that music exposure can enhance memory and emotional function in persons with AD. However, there is a paucity of research that aims to identify specific underlying neural mechanisms associated with music's beneficial effects in this particular population. As such, this paper reviews existing anecdotal and empirical evidence related to the enhancing effects of music exposure on cognitive function and further provides a discussion on the potential underlying mechanisms that may explain music's beneficial effect. Specifically, this paper will outline the potential role of the dopaminergic system, the autonomic nervous system, and the default network in explaining how music may enhance memory function in persons with AD.