Converging evidence from a variety of fields, including psychiatry, suggests that
the temporal correlates of the brain’s resting state could serve as essential markers of a
healthy and efficient brain. We use ketamine to induce schizophrenia-like states in 32
healthy individuals to examine the brain’s resting states using fMRI. We found a global
reduction in temporal variability quantified by the time series’ standard deviation and an
increase in scale-free properties quantified by the Hurst exponent representing the signal
self-affinity over time. We also found network-specific and frequency-specific effects of
ketamine on these temporal measures. Our results confirm prior studies in aging, sleep,
anesthesia, and psychiatry suggesting that increased self-affinity and decreased temporal
variability of the brain resting state could indicate a compromised and inefficient brain
state. Our results expand our systemic view of the temporal structure of the brain and
shed light on promising biomarkers in psychiatry
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/34105 |
| Date | January 2016 |
| Creators | Ayad, Omar |
| Contributors | Northoff, Georg |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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