Testosterone biases automatic memory processes in women towards potential mates.

Female mate choice involves the comparative evaluation of potential mates. Females use a pooled comparison of sampled males to maximize the perceived reproductive fitness of their partner, implying the memorization of sampled males. However, hormonal and reproductive states influence female choosiness, and women's preference and memory for masculinity. Here, we investigated whether testosterone biases memory processes in women towards male faces using functional MRI. A single nasal testosterone dose was administered to healthy women in their early follicular phase, in a double-blind, placebo-controlled, crossover design. Testosterone increased the difference in reaction times to categorize male and female faces during encoding, without influencing subsequent recognition accuracy or response bias. The imaging results showed that testosterone shifted memory formation in the hippocampus and inferior temporal gyri from the encoding of female faces towards the encoding of male faces. In contrast, testosterone shifted memory formation in the left inferior frontal gyrus from the encoding of male faces towards the encoding of female faces. Furthermore, the hippocampal contribution to memory retrieval also shifted from female towards male faces. These results indicate that testosterone biases memory processes towards the relatively automatic encoding and retrieval of males in temporal brain regions and elaborate encoding of females in frontal brain regions, suggesting that testosterone may support female mate sampling and comparison by biasing automatic memory processes towards the encoding and retrieval of potential mates.