The Movie After-Effect: widespread adaptation of human cortex following naturalistic sensory experience
Neural systems adapt to prolonged sensory input through mechanisms such as gain control or homeostatic plasticity to maintain stable operating ranges. However, this phenomenon has so far been documented under extreme, non-ecological stimuli targeting specific sensory systems. Here, we reveal a widespread adaptation process across diverse human cortical regions following naturalistic movie…
A groundbreaking study has uncovered a fascinating phenomenon known as the "Movie After-Effect" (MvAE), where prolonged naturalistic movie watching leads to widespread adaptation across diverse regions of the human cortex. This effect was observed in 87% of the 251 cortical regions examined, following 170 participants watching 14 movie clips, interspersed with rest periods.
Utilizing functional magnetic resonance imaging (fMRI) data from the Human Connectome Project (HCP), researchers found compelling evidence for the MvAE, which manifests as a significant reduction in activity within voxels that were highly activated during the movie. This voxel-population inversion effect was directly proportional to the initial activation levels observed during the movie clips.
Conversely, voxels that remained consistently inactive during the movie experienced heightened activity above baseline during the rest periods.
Perhaps most intriguing, the MvAE allowed for the successful decoding of the specific rest periods that followed each movie clip. This suggests that under naturalistic conditions, cortical neurons dynamically adjust their "gain" to maintain a homeostatic balance, similar to a process known as batch instance normalization in artificial neural networks.
While the study's findings provide valuable insights into the brain's adaptive mechanisms, the researchers emphasize that the potential cognitive and memory-related implications of this widespread adaptation process warrant further investigation.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
