AI Insight
Using intracranial EEG recordings (sEEG) from 43 epilepsy patients, this study tracked how the brain prepares to grasp an object versus passively observing it. Neural activity first arose in visual brain areas, then split into two parallel routes: a parietal pathway that processed spatial information similarly regardless of intent, and a prefrontal pathway that progressively filtered stimuli by behavioral relevance. Crucially, area 46 of the lateral prefrontal cortex showed sustained, selective responses to action-relevant objects that preceded equivalent selectivity in premotor and motor regions, positioning it as an orchestrating node in action preparation.
Why it matters
Understanding how the brain distinguishes actionable targets from irrelevant objects could inform the development of more precise brain-computer interfaces and neuroprosthetic devices, as well as deepen insight into executive control deficits seen in conditions such as frontal lobe disorders or Parkinson's disease.
⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
The lateral prefrontal cortex (LPFC) actively contributes to the adaptive control of goal-directed behavior. Evidence suggests that the LPFC encodes the behavioral relevance of stimuli, distinguishing action targets from irrelevant objects; however, how this selectivity emerges over time and integrates within large-scale cortical dynamics underlying action preparation remains unclear. We recorded stereo-electroencephalography (sEEG) activity from 43 patients affected by drug-resistant epilepsy while they prepared to grasp an object and compared it with passive observation of the same object. Gamma-band responses were used to characterize cortical responsiveness and to track the spatiotemporal propagation of activity during action preparation. Neural activity first emerged in the occipitotemporal cortex in both experimental conditions and then progressed along two parallel pathways: an intraparietal and a prefrontal one. The intraparietal pathway showed highly similar dynamics during both action preparation and passive observation, suggesting largely intention-independent visuospatial processing. In contrast, the prefrontal pathway exhibited progressively stronger selectivity for behaviorally relevant objects as activity advanced rostrally. Within this pathway, area 46 exhibited sustained responses selectively associated with action relevant objects, preceding the similarly selective engagement of premotor and motor regions. Overall, our findings identify area 46 as a key node in whole-brain dynamics that orchestrates action preparation by integrating object relevance into executive control signals guiding premotor and motor engagement.
Source: Behavioral Relevance Coding in Human Area 46 Precedes Selective Motor Activation to Action Targets