Anais Llorens

Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex

Abstract:

Orbitofrontal cortex (OFC) is classically linked to inhibitory control, emotion regulation, and reward processing. Recent perspectives propose that the OFC also generates predictions about perceptual events, actions, and their outcomes. We tested the role of the OFC in detecting violations of prediction at two levels of abstraction (i.e., hierarchical predictive processing) by studying the event-related potentials (ERPs) of patients with focal OFC lesions (n = 12) and healthy controls (n = 14) while they detected deviant sequences of tones in a local–global paradigm. The structural regularities of the tones were controlled at two hierarchical levels by rules defined at a local (i.e., between tones within sequences) and at a global (i.e., between sequences) level. In OFC patients, ERPs elicited by standard tones were unaffected at both local and global levels compared to controls. However, patients showed an attenuated mismatch negativity (MMN) and P3a to local prediction violation, as well as a diminished MMN followed by a delayed P3a to the combined local and global level prediction violation. The subsequent P3b component to conditions involving violations of prediction at the level of global rules was preserved in the OFC group. Comparable effects were absent in patients with lesions restricted to the lateral PFC, which lends a degree of anatomical specificity to the altered predictive processing resulting from OFC lesion. Overall, the altered magnitudes and time courses of MMN/P3a responses after lesions to the OFC indicate that the neural correlates of detection of auditory regularity violation are impacted at two hierarchical levels of rule abstraction.

Authors:

  • Olgerta Asko

  • Alejandro Omar Blenkmann

  • Sabine Liliana Leske

  • Maja Dyhre Foldal

  • Anais Llorens

  • Ingrid Funderud

  • Torstein R Meling

  • Robert T Knight

  • Tor Endestad

  • Anne-Kristin Solbakk

Date: 2024

DOI: https://doi.org/10.7554/eLife.86386

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Ramping dynamics and theta oscillations reflect dissociable signatures during rule-guided human behavior

abstract:

Contextual cues and prior evidence guide human goal-directed behavior. The neurophysiological mechanisms that implement contextual priors to guide subsequent actions in the human brain remain unclear. Using intracranial electroencephalography (iEEG), we demonstrate that increasing uncertainty introduces a shift from a purely oscillatory to a mixed processing regime with an additional ramping component. Oscillatory and ramping dynamics reflect dissociable signatures, which likely differentially contribute to the encoding and transfer of different cognitive variables in a cue-guided motor task. The results support the idea that prefrontal activity encodes rules and ensuing actions in distinct coding subspaces, while theta oscillations synchronize the prefrontal-motor network, possibly to guide action execution. Collectively, our results reveal how two key features of large-scale neural population activity, namely continuous ramping dynamics and oscillatory synchrony, jointly support rule-guided human behavior.

Authors:

  • Jan Weber

  • Anne-Kristin Solbakk

  • Alejandro O. Blenkmann

  • Anais Llorens

  • Ingrid Funderud

  • Sabine Leske

  • Pål Gunnar Larsson

  • Lugoslav Ivanovic

  • Robert T. Knight

  • Tor Endestad

  • Randolph F. Helfrich

Date: 2024

DOI: https://doi.org/10.1038/s41467-023-44571-7

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