Towards an Effectve Arousal Detecton System for Virtual Reality

Immersive technologies offer the potential to drive engagement and create exciting experiences. A better understanding of the emotional state of the user within immersive experiences can assist in healthcare interventions and the evaluation of entertainment technologies. This work describes a feasibility study to explore the effect of affective video content on heart-rate recordings for Virtual Reality applications. A lowcost reflected-mode photoplethysmographic sensor and an electrocardiographic chest-belt sensor were attached on a novel non-invasive wearable interface specially designed for this study. 11 participants responses were analysed, and heart-rate metrics were used for arousal classification. The reported results demonstrate that the fusion of physiological signals yields to significant performance improvement; and hence the feasibility of our new approach

Functional equivalence revisited: Costs and benefits of priming action with motor imagery and motor preparation.

The functional equivalence (FE) hypothesis suggests motor imagery (MI) is comparable with the planning stages of action. A strong interpretation of this hypothesis suggests MI can prime subsequent actions in a way that should be indistinguishable from motor preparation (MP). Alternatively, MI could involve more richly informative motor plans than MP, producing different effects on the performance of subsequent actions. Although past research has demonstrated MI can prime action, little research has directly compared it with MP, and so the value of a strong FE interpretation for understanding MI remains unclear. In the present study, a precueing paradigm was used in 4 experiments, and congruency effects of MI and MP on subsequent action were compared. Precues instructed participants to prepare for (MP condition) or imagine (MI condition) a corresponding response prior to making a real response to the imperative stimulus, which was either congruent or incongruent with the precue information. Experiment 1 provided first evidence favoring our alternative hypothesis that imagery-primed responses should result in larger response priming effects than prepared-responses, suggesting that MI might involve more richly informative motor plans than preparation for action alone. In experiment 2, we manipulated interstimulus foreperiods and replicated the MI-priming effect, showing it to be independent of differences in temporal uncertainty between MI and MP. Experiment 3 showed the MI-priming effect is present in both foot and finger responses, and Experiment 4 suggested the larger congruency effects in the MI condition could not be explained by differences in cognitive load between MI and MP. These results suggest that a strong FE hypothesis does not hold. Findings are discussed in line with the predictive processing models of action and MI. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

Emerging Affect Detection Methodologies in VR and future directions.

The uses of Virtual reality are constantly evolving, from healthcare treatments to evaluating commercial products, all of which would benefit from a better understanding of the emotional state of the individual. There is ongoing research into developing specially adapted methods for the recognition of the user’s affect while immersed within Virtual Reality. This paper outlines the approaches attempted and the available methodologies that embed sensors into wearable devices for real-time affect detection. These emerging technologies are introducing innovative ways of studying and interpreting emotion related data produced within immersive experience

Consumption of glucose drinks slows sensorimotor processing: double-blind placebo-controlled studies with the Eriksen flanker task.

Modulations of blood glucose concentration (BGC) in the normal range are known to facilitate performance in memory and other cognitive tasks but few studies have investigated the effects of BGC variations on complex sensorimotor task so far. The present study aimed to examine glucose effects with the Eriksen flanker task. This task was chosen because it can dissociate between the effects of BGC on sensorimotor processing and cognitive control by assessing congruency effects. In two linked double-blind placebo-controlled experiments BGC was elevated within the normal BGC range (4-7 mmol/l) by approx. 1.5 mmol/l with glucose drinks and compared to a placebo drink condition while a flanker task with either strong or weak stimulus-response (SR) mapping was performed. Modulation of the performance in the flanker task by glucose was linked to the strength of the SR mapping but not congruency effects. Under weak SR mapping, reaction times (RTs) were slowed in the glucose condition compared to placebo while error rates remained unchanged, whereas cognitive control was not affected by glucose. When SR mapping was strong, no differences were found between glucose and placebo. Enhanced glucose levels differentially affect behavior. Whereas the literature mainly reports facilitating characteristics of enhanced glucose levels in the normal range, the present study shows that higher glucose levels can slow RTs. This suggests that glucose does not have a uniform effect on cognition and that it might be differential depending on the cognitive domain

Quantitative electroencephalography and behavioural correlates of daytime sleepiness in chronic stroke.

Sleepiness is common after stroke, but in contrast to its importance for rehabilitation, existing studies focus primarily on the acute state and often use subjective sleepiness measures only. We used quantitative electroencephalography (qEEG) to extract physiological sleepiness, as well as subjective reports, in response to motor-cognitive demand in stroke patients and controls. We hypothesised that (a) slowing of the EEG is chronically sustained after stroke; (b) increased power in lower frequencies and increased sleepiness are associated; and (c) sleepiness is modulated by motor-cognitive demand. QEEGs were recorded in 32 chronic stroke patients and 20 controls using a Karolinska Drowsiness Test protocol administered before and after a motor priming task. Subjective sleepiness was measured using the Karolinska Sleepiness Scale. The findings showed that power density was significantly increased in delta and theta frequency bands over both hemispheres in patients which were not associated with subjective sleepiness ratings. This effect was not observed in controls. The motor priming task induced differential hemispheric effects with greater increase in low-frequency bands and presumably compensatory increases in higher frequency bands. The results indicate sustained slowing in the qEEG in chronic stroke, but in contrast to healthy controls, these changes are not related to perceived sleepiness

A reliable and robust online validation method for creating a novel 3D Affective Virtual Environment and Event Library (AVEL).

This paper describes the development and validation of 3D Affective Virtual environments and Event Library (AVEL) for affect induction in Virtual Reality (VR) settings with an online survey; a cost-effective method for remote stimuli validation which has not been sufficiently explored. Three virtual office-replica environments were designed to induce negative, neutral and positive valence. Each virtual environment also had several affect inducing events/objects. The environments were validated using an online survey containing videos of the virtual environments and pictures of the events/objects. They survey was conducted with 67 participants. Participants were instructed to rate their perceived levels of valence and arousal for each virtual environment (VE), and separately for each event/object. They also rated their perceived levels of presence for each VE, and they were asked how well they remembered the events/objects presented in each VE. Finally, an alexithymia questionnaire was administered at the end of the survey. User ratings were analysed and successfully validated the expected affect and presence levels of each VE and affect ratings for each event/object. Our results demonstrate the effectiveness of the online validation of VE material in affective and cognitive neuroscience and wider research settings as a good scientific practice for future affect induction VR studies

Motor planning in chronic upper-limb hemiparesis: evidence from movement-related potentials.

BACKGROUND: Chronic hemiplegia is a common long-term consequence of stroke, and subsequent motor recovery is often incomplete. Neurophysiological studies have focused on motor execution deficits in relatively high functioning patients. Much less is known about the influence exerted by processes related to motor preparation, particularly in patients with poor motor recovery. METHODOLOGY/PRINCIPAL FINDINGS: The current study investigates motor preparation using a modified response-priming experiment in a large sample of patients (n = 50) with moderate-to-severe chronic hemiparesis. The behavioural results revealed that hemiparetic patients had an increased response-priming effect compared to controls, but that their response times were markedly slower for both hands. Patients also demonstrated significantly enhanced midline late contingent negative variation (CNV) during paretic hand preparation, despite the absence of overall group differences when compared to controls. Furthermore, increased amplitude of the midline CNV correlated with a greater response-priming effect. We propose that these changes might reflect greater anticipated effort to respond in patients, and consequently that advance cueing of motor responses may be of benefit in these individuals. We further observed significantly reduced CNV amplitudes over the lesioned hemisphere in hemiparetic patients compared to controls during non-paretic hand preparation, preparation of both hands and no hand preparation. Two potential explanations for these CNV reductions are discussed: alterations in anticipatory attention or state changes in motor processing, for example an imbalance in inter-hemispheric inhibition. CONCLUSIONS/SIGNIFICANCE: Overall, this study provides evidence that movement preparation could play a crucial role in hemiparetic motor deficits, and that advance motor cueing may be of benefit in future therapeutic interventions. In addition, it demonstrates the importance of monitoring both the non-paretic and paretic hand after stroke and during therapeutic intervention

Towards valence detection from EMG for Virtual Reality applications

The current practical restraints for facial expression recognition in Virtual Reality (VR) led to the development of a novel wearable interface called Faceteq. Our team designed a pilot feasibility study to explore the effect of spontaneous facial expressions on eight EMG sensors, incorporated on the Faceteq interface. Thirty-four participants took part in the study where they watched a sequence of video stimuli while self-rating their emotional state. After a specifically designed signal pre-processing, we aimed to classify the responses into three classes (negative, neutral, positive). A C-SVM classifier was cross-validated for each participant, reaching an out-of-sample average accuracy of 82.5%. These preliminary results have encouraged us to enlarge our dataset and incorporate data from different physiological signals to achieve automatic detection of combined arousal and valence states for VR applications

Remote Collection of Physiological Data in a Virtual Reality Study

Recent pandemic related events have effectively put a stop to most in-lab data collection which has a profound negative impact on many research fields. Online and remote data collection, without the need to travel to a laboratory, starts to be used as a valuable alternative in some scenarios. This approach does not only help to resume some research activities, it also has an enormous potential to change how research is conducted in future. With the use of our biometric sensing system for Virtual Reality (emteqGO), we designed a VR experience autonomously guiding participants through the study. The combination of hardware posted to participants, alongside software solutions handling the setup, data collection, quality assurance and upload for immediate access enables a fully remote, unsupervised approach to data collection. While this approach might be the only feasible solution for some researchers, it has also laid the groundwork for possible future direction of research where remote data collection isa new way to enhance access to participants who typically would not travel to the laboratories. In designing these solutions, we found that for unsupervised remote data collection to work effectively, setup procedures must be easy to follow to obtain high quality data and the entire process must be highly robust, reliable, and built with a high degree of redundancy. Post-pandemic, there are many benefits of an ongoing use of remote research paradigms. These include ameliorating the diversity problem afflicting current research by widening the participant pool, improved research quality by collecting data in more naturalistic environments, and improving protocol standardisation using virtual reality

The relationship between dietary restraint and deficits in reasoning about causes of obesity.

Objective: Increased levels of dietary restraint are associated with deficits on many cognitive tasks. Less is known about how individual differences in restraint influences complex cognition such as reasoning which is the focus of this research.Design: Two experimental studies are reported. In study 1, participants (n = 158) completed a causal conditional reasoning task with statements about weight-related and general causal relationships. Study 2 replicated and extended study 1. Participants (n = 108) completed a causal conditional reasoning task focusing on behavioural causes of weight change or general statements.Main outcome measure: Causal conditional reasoning task performance.Results: In study 1, levels of dietary restraint were negatively associated with reasoning abilities for weight-related statements only. Study 2 replicated the negative association between dietary restraint and reasoning finding the effect in both weight-related, and general, causal judgements.Conclusion: The novel findings show that individual differences in dietary restraint have a wider relationship with cognition than previously demonstrated. Results tentatively support theoretical explanations of a reduction in cognitive capacity, rather than differences in belief, explaining reasoning deficits. These findings open an interesting avenue for research and might have implications for effective decision making about personal health behaviours, such as food choice