Examining the link between multisensory and socio-emotional processing in anxiety and post-traumatic stress disorder

There is firm evidence of altered multisensory processes in individuals with socio-emotional deficits (e.g. autism spectrum disorders), but very few studies examining similar processes in individuals with post-traumatic stress disorder (PTSD). This project will address this research-gap and clarify the role of multisensory integration in Virtual Reality Exposure Therapy (VRET).
Individuals with PTSD show altered emotion regulation and interpersonal difficulties. It has been suggested that an individual's ability to effectively regulate affective states and interact with others may be influenced by their ability to efficiently process multisensory socio-emotional cues. As PTSD has previously been classified as an anxiety disorder, and exhibits similar socio-emotional deficits as anxiety, high trait anxiety may be used as a useful analogue measure in non-clinical samples to study transdiagnostic processes that could be associated with impaired multisensory integration. Koizumi et al. (2011) carried out a study in individuals with low vs. high trait anxiety where they found that multisensory integration is modulated by the degree of anxiety in a way that impairs emotion recognition, compared to those with low trait anxiety, by amplifying processing of negative threat-related cues.
Previous studies investigating emotion recognition have largely focused on processing of just one type of stimulus within one sensory modality- emotional faces (vision). This is despite the multisensory nature of VRET used with clinical populations, and evidence of disrupted multisensory processes in disorders characterised by socio-emotional deficits.
I will examine whether:
1) multisensory integration is modulated by trait anxiety, and whether these effects of anxiety on multisensory processes are mediated by the degree of autistic traits;
3) multisensory processing is affected in PTSD;
4) facilitating adaptive multisensory integration using VR has therapeutic implications;
5) we can derive and select interpretable features in the data, relating to any differences observed in multisensory integration and any links/interactions with socio-emotional deficits, from all 3 studies to design a classification algorithm that allows us to discriminate between PTSD patients and individuals with high levels of anxiety compared to healthy individuals
The first study will address aims 1 and 2 by testing the link between multisensory abilities, trait anxiety and degrees of autistic traits in the general population. Multisensory abilities will be measured in the socio-emotional domain using multiple types of emotional stimuli and compared to general multisensory abilities. The second study will seek to build on this in a clinical population by comparing individuals with PTSD and matched controls using a similar study design. Study 3 will examine aim 4 by looking at the effects of using unimodal vs. bimodal VR conditions in people with PTSD and a matched control group. It is hoped that this research can be applied to optimise the therapeutic effects of VRET for PTSD by manipulating the multisensory presentation of stress-inducing cues. The research is expected to show a specific impairment of multisensory processes in the integration of emotional cues in high trait anxiety and PTSD that may be linked to specific transdiagnostic processes, such as abnormalities in empathy/perspective-taking, that operate across disorders with socio-emotional deficits.