Master thesis presentation by Courtney Keeler and Georg Brant: “Data analysis on pupillometry and microsaccadic behavior in Autism spectrum disorder subjects”
On 26 September, 2016, Courtney Keeler and Georg Brant will be presenting their master thesis with the title “Data analysis on pupillometry and microsaccadic behavior in Autism spectrum disorder subjects”
When: 13:00 pm. 26 September, 2016
Where: MedTech West conference room, Röda stråket 10B, Sahlgrenska University Hospital
Examiner: Justin Schneiderman
Autism spectrum disorder (ASD) is a genetically heterogeneous group of neurological disorders that impairs a person’s ability to relate and communicate socially, and also causes stereotyped behavior with unusually narrow interests accompanied with abnormal attention. There is a need to find biomarkers of ASD, as they could allow for such things as early diagnosis, subdivision of ASD into clinically meaningful subgroups, and tracking the progress of the treatment. Magneto- and Electroencephalography (M/EEG) methods can provide such useful physiological biomarkers of ASD.
This thesis proposes several methods for data analysis of eye motion to reveal underlying group differences in high-order cognitive functions, such as executive control and direction of attention. The first part focuses on microsaccadic eye movements, the twitch-like movements that happen during fixation. The second part concerns analysis of the fluctuations in pupil diameter (pupillometry), which can be used to learn about the visual pathway and attention. By combining pupillometry with magnetoencephalography (MEG) information about brain activity, this chapter also investigates more specifically the correlation between spontaneous pupil fluctuation and brain activity in the alpha region.
The results present a left biased lateralization in both ASD and NT groups. This suggests normal lateralization of the attentional system in ASD subjects.
The pupillometry results show tendency towards the expected group differences in the pupillary light reflex, with ASD subjects exhibiting longer latencies and decreased response amplitudes (p = 0.42 and p = 0.10, respectively). Positive correlations between pupil fluctuation and brain activity in the alpha band (8-12 Hz) in the visual cortex were also found, which matches the literature.