m2a
Describing the spatiotemporal organization of the mismatch negativity in The Virtual Brain

DESCRIPTION

The mismatch negativity (MMN) is a brain response to violations of a rule, established by a sequence of sensory stimuli (typically in the auditory domain) [1]. The MMN reflects the brain’s ability to perform automatic comparisons between consecutive stimuli and provides an electrophysiological index of sensory learning and perceptual accuracy. Although the MMN has been studied extensively, the neurophysiological mechanisms underlying the MMN are not well understood. This project uses a computer model of the brain with realistically connected brain areas, that is, The Virtual Brain [2,3] to investigate the spatiotemporal organization of MMN for different sensory modalities. The results will characterize the pattern formation and provide testable predictions for altering the effects.
The presentation of an oddball or deviant event, embedded in a stream of repeated or familiar events, the standards, results in an evoked brain response that can be recorded non-invasively with electrophysiological techniques such as electro-encephalography (EEG) and magnetoencephalography (MEG). The MMN is the negative component of the waveform obtained by subtracting the event-related response to the standard event from the response to the deviant event. Given its automatic nature, the MMN might be associated with pre-attentive cognitive operations in audition and, for this reason, it has been suggested that it reflects ‘primitive intelligence’ in the auditory cortex [4]. Similar effects have been found for other systems such as the visual and the somatosensory system.

WORK PLAN
(i) Familiarize with The Virtual Brain
(ii) Implementation of a oddball paradigm (which areas to target, which frequency for the sequence)
(iii) Analyze simulated brain signals: on the level of brain areas, and M/EEG (event-related potentials, event-related (de)dynchronization, functional connectivity, calculate ‘classical’ MMN)
(iv) Characterize the simulated brain activity (MMN) in time and space
(v) Comparison of the results with the dynamic causal modeling study by [5] (focus on auditory system, and there the characteristics of A1, A2, STG, IFG)
(vi) How do the results relate to the dual stream hypothesis (e.g., [6])

TRAINING GOALS

  • Conducting a scientific, computational study
  • Using computer models for describing brain dynamics
  • Skills for The Virtual Brain
  • Learning principles of dynamical systems
  • Reviewing the proposed mechanisms for the MMN
  • Writing a scientific report

REFERENCES
[1] Näätänen R. Attention and brain function. Hillsdale, NJ: Lawrence Erlbaum 1992
[2] www.thevirtualbrain.com
[3] Sanz-Leon P, Knock SA, Spiegler A, Jirsa VK (2015) Mathematical framework for large-scale brain network modeling in The Virtual Brain. Neuroimage 111:385-430.
[4] Näätänen R, Tervaniemi M, Sussman E, Paavilainen P, Winkler I (2001) ‘‘Primitive intelligence” in the auditory cortex. Trends Neurosci 24:283–8.
[5] Garrido MI, Friston KJ, Kiebel SJ, Stephan KE, Baldeweg T, Kilner JM (2008) The functional anatomy of the MMN: A DCM study of the roving paradigm. Neuroimage 42:936-44.
[6] Bizley JK, Cohen YE (2013) The what, where and how of auditory-object perception. Nat Rev Neurosci 14:693-707.

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