Arrow Research search

Author name cluster

Ram Adapa

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

2 papers
1 author row

Possible papers

2

YNIMG Journal 2022 Journal Article

Network dynamics scale with levels of awareness

  • Peter Coppola
  • Lennart R.B. Spindler
  • Andrea I. Luppi
  • Ram Adapa
  • Lorina Naci
  • Judith Allanson
  • Paola Finoia
  • Guy B. Williams

Small world topologies are thought to provide a valuable insight into human brain organisation and consciousness. However, functional magnetic resonance imaging studies in consciousness have not yielded consistent results. Given the importance of dynamics for both consciousness and cognition, here we investigate how the diversity of small world dynamics (quantified by sample entropy; dSW-E 1 1 dSW-E= dynamic small world entropy ) scales with decreasing levels of awareness (i. e. , sedation and disorders of consciousness). Paying particular attention to result reproducibility, we show that dSW-E is a consistent predictor of levels of awareness even when controlling for the underlying functional connectivity dynamics. We find that dSW-E of subcortical, and cortical areas are predictive, with the former showing higher and more robust effect sizes across analyses. We find that the network dynamics of intermodular communication in the cerebellum also have unique predictive power for levels of awareness. Consequently, we propose that the dynamic reorganisation of the functional information architecture, in particular of the subcortex, is a characteristic that emerges with awareness and has explanatory power beyond that of the complexity of dynamic functional connectivity.

YNICL Journal 2015 Journal Article

Factoring the brain signatures of anesthesia concentration and level of arousal across individuals

  • Pablo Barttfeld
  • Tristan A. Bekinschtein
  • Alejo Salles
  • Emmanuel A. Stamatakis
  • Ram Adapa
  • David K. Menon
  • Mariano Sigman

Combining resting-state functional magnetic resonance imaging (fMRI) connectivity and behavioral analysis during sedation, we factored out general effects of the anesthetic drug propofol and a specific index of conscious report, participants' level of responsiveness. The factorial analysis shows that increasing concentration of propofol in blood specifically decreases the connectivity strength of fronto-parietal cortical loops. In contrast, loss of responsiveness is indexed by a functional disconnection between the thalamus and the frontal cortex, balanced by an increase in connectivity strength of the thalamus to the occipital and temporal regions of the cortex.

v2026.09.13