Objective: This research aimed to develop a paradigm measuring perceptual decision making (PDM) to test the hypothesis of impaired PDM in cervical dystonia patients.

Background: Cervical dystonia (CD) is a hyperkinetic motor neurological disorder characterised by involuntary neck movements and postures where pathophysiology remains elusive. Beyond its motor classification, CD often exhibits non-motor symptoms (NMS) such as depression, anxiety, and sensory perception deficits, significantly impacting their quality of life. With increasing recognition of NMS, CD is hypothesised as a syndrome involving dysfunction within the collicular-pulvinar-amygdala network, with the primary hub in the Superior colliculus (SC). SC dysfunction is also implicated in impaired perceptual decision making (PDM), which is the ability to make prompt decisions using incoming sensory information. Due to the limited studies exploring the relationship between impaired PDM and CD as a product of SC dysfunction, this warrants a need to establish this relationship to aid in earlier diagnosis and the development of new treatment strategies.

Method: To test the validity of the novel paradigm, twelve age-matched healthy participants were recruited to assess PDM using a dichromatic Dynamic Translational glass pattern task, while 24-channel EEG recordings were collected to examine Centro-parietal positivity (CPP), a recognised neural marker of PDM. Baseline impulsivity was tested using the Eriksen Flanker task, and cognitive (MOCA) and mood (BDI, BAI) assessments were also conducted prior to testing.

Results: As predicted, psychometric fitting displayed that positive priors showed statistically significant (p < 0.01) improvement in response accuracy. Positive priors also led to faster reaction times, suggesting the generation of choice bias by continuously updating and assessing incoming sensory evidence. Finally, the detection of CPP before the response confirmed its status as a neural signature of PDM.

Conclusion: Healthy controls displayed intact PDM ability, reflecting normal SC functioning. The study is currently testing this paradigm in individuals with cervical dystonia to determine whether they would display impaired PDM, having the potential to serve as a new biomarker for CD.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/investigating-impaired-perceptual-decision-making-in-cervical-dystonia-a-novel-paradigm-integrating-behavioural-and-neural-measures/