To cope with the pandemic, we need first to predict it. How does the human brain model epidemic dynamics? In February and March 2020, we conducted an online diary study, where each participant completed 14 days of predictions about the ongoing COVID-19 epidemic in China. Over 400 Chinese adults participated in our study, spanning a total of 40 days. On the group level, we find participants’ predictions of the ending date of the epidemic are correlated with daily new cases. Modeling analysis shows that participants’ predictions agree with a Gaussian process model that generalizes observed case numbers to the future by similarity-based function learning, but deviate from an ideal epidemic model. On the individual level, we find individuals’ pandemic predictions are correlated with their psychological traits or states, such as future time perspective and negative emotions (anxiety, depression, and stress).

The striatum is an important subcortical structure with extensive connections to other regions of the brain. These connections are believed to play important roles in behaviors such as reward-related processes and impulse control, which show significant sex differences. However, little is known about sex differences in the striatum-projected fiber connectivity. The current study examined sex differences between 50 Chinese males and 79 Chinese females in their fiber connections between the striatum and nine selected cortical and subcortical regions. Despite overall similarities, males showed stronger fiber connections between the left caudate and rostral cingulate cortex, between the right putamen and the lateral orbitofrontal cortex, between the bilateral putamen and the ventro-lateral prefrontal cortex, and between the right caudate and the ventro-lateral prefrontal cortex, whereas females showed stronger fiber connections between the right putamen and the dorsolateral prefrontal cortex, between bilateral caudate and hippocampus, and between the left putamen and hippocampus. These findings help us to understand sex differences in the striatum-projected fiber connections and their implications for sex differences in behaviors.