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

: (Alternative Format Thesis)

Abstract

To allow us to extract meaningful information from the overwhelming sensory signals in our environment, we must constantly integrate information from multiple sensory modalities. This is particularly true when interpreting others’ emotional states, as emotions can often be complex and ambiguous, and are normally expressed via multiple senses. Difficulties in multisensory processing are therefore likely to disrupt socio-emotional processing, which may contribute to affective and interpersonal problems. Individuals with high trait anxiety, a personality trait characterised by frequent worried thoughts and high physiological arousal, and/or post-traumatic stress disorder (PTSD), a stress-related mental health condition observed after psychological trauma, are shown to exhibit negative biases when processing emotions. However, most previous studies of anxiety and PTSD have focused on emotion processing using only single sensory cues. In this thesis, I aim to clarify how multisensory emotion processing is altered in the context of anxiety and PTSD and consider the potential implications of such alterations for cognitive theories about how these disorders are developed and maintained.
First, I present a narrative review of the existing literature to evaluate how multisensory processing might be altered by anxiety, psychological trauma and PTSD. The review concludes that despite limited previous research, there is preliminary evidence to indicate that multisensory integration may be less efficient in anxious compared to non-anxious samples. Furthermore, the existing research also indicates that anxiety-related negative emotional biases observed in unisensory processing might extend also to multisensory processing.
Next, I address some of these hypotheses experimentally using an audiovisual emotion recognition paradigm to investigate multisensory emotion processing with analogue samples. Analogue studies include individuals with varying levels of trait anxiety and individuals exposed to a virtual reality trauma simulation, which is a commonly used experimental psychopathology model used to study processes relevant to psychological trauma and the development of PTSD. From these studies, I find evidence that enhanced multisensory processing of threat is associated with higher trait anxiety and increased frequency of distressing, intrusive memories after exposure to an analogue trauma simulation. I also find that individual differences in multisensory emotion perception are linked to higher trait anxiety and the frequency of intrusive memories after induced trauma in the absence of effects for unisensory processing. This suggests that differences in multisensory emotion processing may be a more sensitive cognitive marker of anxiety and the acute emotional response to trauma compared to differences in processing information from single senses. In contrast, when using a multisensory electroencephalography (EEG) paradigm with PTSD patients, I find no evidence of differences in emotion processing that are specific to threat-related information or multisensory stimuli but evidence of broader difficulties processing complex emotional stimuli in general.
The findings of this thesis extend existing cognitive theories of anxiety by suggesting that anxiety-related threat biases not only influence how information is attended to and interpreted, but also how information is integrated. The findings of the thesis further suggest that multisensory emotion processing likely plays a different role in the aetiology of PTSD, with PTSD patients requiring more cognitive resources to process positive emotional stimuli across sensory modalities. The differences in emotion processing in PTSD observed here could contribute to biased estimations of emotional salience and depletion of contextual processing resources. This is consistent with cognitive models of PTSD which suggest that reduced contextual processing and biased appraisals of traumatic events are key to the aetiology of PTSD symptoms.

Date of Award	23 Nov 2022
Original language	English
Awarding Institution	University of Bath
Supervisor	Karin Petrini (Supervisor), Chris Ashwin (Supervisor), Anke Karl (Supervisor) & Krasimira Tsaneva-Atanasova (Supervisor)