Influences of High-Level Features, Gaze, and Scene Transitions on the Reliability of BOLD Responses to Natural Movie Stimuli

• Published in: PLOS ONE Vol. 11; no. 8; p. e0161797
• Main Authors: Lu, Kun-Han, Hung, Shao-Chin, Wen, Haiguang, Marussich, Lauren, Liu, Zhongming
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science (PLoS) 26.08.2016; Public Library of Science
• Subjects: Adult; Biology and Life Sciences; Biomedical engineering; Brain; Brain - physiology; Brain Mapping; Brain research; Computer engineering; Engineering and Technology; Eye movements; Female; Functional magnetic resonance imaging; Gaze; Human subjects; Humans; Levels; Magnetic resonance; Magnetic Resonance Imaging; Male; Medical imaging; Medicine; Medicine and Health Sciences; Motion pictures; Neural networks; Neuroimaging; Neurons; Neurosciences; Photic Stimulation; Physiological aspects; Q; R; Regression Analysis; Reproducibility; Reproducibility of Results; Research and Analysis Methods; Research Article; Retrospective Studies; Science; Sensory stimulation; Social Sciences; Studies; Vision, Ocular; Visual Cortex; Visual Cortex - physiology; Visual Pathways; Visual stimuli; Young Adult; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0161797

Complex, sustained, dynamic, and naturalistic visual stimulation can evoke distributed brain activities that are highly reproducible within and across individuals. However, the precise origins of such reproducible responses remain incompletely understood. Here, we employed concurrent functional magnetic resonance imaging (fMRI) and eye tracking to investigate the experimental and behavioral factors that influence fMRI activity and its intra- and inter-subject reproducibility during repeated movie stimuli. We found that widely distributed and highly reproducible fMRI responses were attributed primarily to the high-level natural content in the movie. In the absence of such natural content, low-level visual features alone in a spatiotemporally scrambled control stimulus evoked significantly reduced degree and extent of reproducible responses, which were mostly confined to the primary visual cortex (V1). We also found that the varying gaze behavior affected the cortical response at the peripheral part of V1 and in the oculomotor network, with minor effects on the response reproducibility over the extrastriate visual areas. Lastly, scene transitions in the movie stimulus due to film editing partly caused the reproducible fMRI responses at widespread cortical areas, especially along the ventral visual pathway. Therefore, the naturalistic nature of a movie stimulus is necessary for driving highly reliable visual activations. In a movie-stimulation paradigm, scene transitions and individuals' gaze behavior should be taken as potential confounding factors in order to properly interpret cortical activity that supports natural vision.