Introducing the brain: all human brains don't react the same (Introduction)

by David Turell , Friday, April 23, 2021, 20:53 (1096 days ago) @ David Turell

A new careful study of of frontal lobe reactions in a group of folks all watching the same movie:

https://advances.sciencemag.org/content/7/17/eabf7129?utm_campaign=toc_advances_2021-04...

"Abstract
How we process ongoing experiences is shaped by our personal history, current needs, and future goals. Consequently, ventromedial prefrontal cortex (vmPFC) activity involved in processing these subjective appraisals appears to be highly idiosyncratic across individuals. To elucidate the role of the vmPFC in processing our ongoing experiences, we developed a computational framework and analysis pipeline to characterize the spatiotemporal dynamics of individual vmPFC responses as participants viewed a 45-minute television drama. Through a combination of functional magnetic resonance imaging, facial expression tracking, and self-reported emotional experiences across four studies, our data suggest that the vmPFC slowly transitions through a series of discretized states that broadly map onto affective experiences. Although these transitions typically occur at idiosyncratic times across people, participants exhibited a marked increase in state alignment during high affectively valenced events in the show. Our work suggests that the vmPFC ascribes affective meaning to our ongoing experiences.
(my bold)

"INTRODUCTION
Our brains process complex information with incredible speed and efficiency. This information can be broadly categorized into two distinct classes. First, our brains directly process exogenous information about the external environment by transducing physical phenomena (e.g., changes in energy, molecular concentrations, etc.) into sensory perceptions that allow us to generate and maintain a sense of what is happening around us. Mental representations that are directly driven by the external world are likely to be highly similar across individuals who share the same sensory experience. Second, our brains also process endogenous information that reflects our current internal homeostatic states, past experiences, and future goals. The integration of exogenous and endogenous information allows us to meaningfully interpret our surroundings, prioritize information that is relevant to our goals, and develop action plans. Given the same input information, individuals may have unique interpretations, feelings, and plans, often leading endogenous representations to be idiosyncratic across individuals. How can we establish a broad functional commonality across individuals when these specific endogenous experiences may be unique to each individual?

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"Overall, we find that participants exhibit unique spatiotemporal response patterns in the vmPFC while viewing the same television episode. Our findings demonstrate that this cannot be solely accounted for by measurement issues (e.g., susceptibility artifacts and variations in hemodynamic response functions). These results present a significant challenge to traditional neuroimaging analysis methods that assume a common response profile across participants [e.g., two-level univariate analyses, resting-state analyses, multivariate pattern analysis approaches, intersubject synchrony, and functional alignment. Because subjective endogenous experiences are not typically shared across participants, regions like the vmPFC that appear to exhibit idiosyncratic stimulus–driven activity may be mischaracterized by these approaches. Our state-based analysis framework provides a means of characterizing this endogenous stimulus–driven activity, even when the response patterns do not align spatially or temporally across individuals, or to the external stimulus. Our approach may also be useful in translational applications where patient groups are often highly heterogeneous compared to healthy controls."

Comment: All the technical stuff is skipped. What this tells me is our oversized brains end up with individual results in complexification as we progress from infanthood to adulthood. This is the real picture we need to recognize. Our brains may be smaller than in our origin form from ongoing complexification, but we still complexify ourselves in very individual free-will fashion. God gave us this arrangement, knowing He wished us to have free will.