The Noisy Brain: Power of Resting-State Fluctuations Predicts Individual Recognition Performance

• Main Authors: Shany Grossman, Erin M. Yeagle, Michal Harel, Elizabeth Espinal, Roy Harpaz, Niv Noy, Pierre Mégevand, David M. Groppe, Ashesh D. Mehta, Rafael Malach
• Format: Article
• Language: English
• Published: Elsevier 2019-12-01
• Series: Cell Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124719315724

Summary: The unique profile of strong and weak cognitive traits characterizing each individual is of a fundamental significance, yet their neurophysiological underpinnings remain elusive. Here, we present intracranial electroencephalogram (iEEG) measurements in humans pointing to resting-state cortical “noise” as a possible neurophysiological trait that limits visual recognition capacity. We show that amplitudes of slow (<1 Hz) spontaneous fluctuations in high-frequency power measured during rest were predictive of the patients’ performance in a visual recognition 1-back task (26 patients, total of 1,389 bipolar contacts pairs). Importantly, the effect was selective only to task-related cortical sites. The prediction was significant even across long (mean distance 4.6 ± 2.8 days) lags. These findings highlight the level of the individuals’ internal “noise” as a trait that limits performance in externally oriented demanding tasks. : The amplitude of neural fluctuations during rest varies between individuals and cortical networks. Using intracranial recordings in patients, Grossman et al. find that the amplitudes of slow (<1 Hz) fluctuations during rest are predictive of individual differences in recognition memory performance, a link that is specific to task-relevant cortical sites. Keywords: resting state, neural noise, individual differences, cognitive abilities, iEEG, ECoG, spontaneous fluctuations, 1-back task, neural variability