Heritability of movie-evoked brain activity and connectivity

The neural bases of sensory processing are conserved across people but no two individuals experience the same stimulus in exactly the same way. Recent work has established that the idiosyncratic nature of subjective experience is underpinned by individual variability in brain responses to sensory information. However, the fundamental origins of this individual variability have yet to be systematically investigated. Here, we establish a genetic basis for individual differences in sensory processing by quantifying (1) the heritability of high-dimensional brain responses to movies and (2) the extent to which this heritability is grounded in lower-level aspects of brain function. Specifically, we leverage 7T fMRI data collected from a twin sample to first show that movie-evoked brain activity is heritable across the cortex, and that this heritability is greater for information encoded in lower temporal frequencies, especially in more associative cortical areas. Next, we use hyperalignment to decompose this heritability into genetic similarity in where vs. how sensory information is processed. We also show that the heritability of brain activity patterns can be partially explained by the heritability of the neural timescale, a one-dimensional measure of local circuit functioning. Finally, we generalize our findings by illustrating a similar pattern of results for the heritability of movie-evoked functional connectivity. These results demonstrate that brain responses to complex stimuli are heritable, and that this heritability is due, in part, to genetic control over stable aspects of brain function.