Not only conferences, but many prize committees suffer from the same unintentional biases, awarding women with fewer than 10% (and sometimes 0%) of awards. Here are a few examples:

Swartz Prize for Theoretical and Computational Neuroscience – Awarded since 2008, to 8 men, no women (current selection committee: 7 men, 1 woman)

The Brain Prize – Awarded since 2011, to 19 men and 2 women (current selection committee: 6 men, 3 women)

Koetser Award – Awarded by the Betty & David Koetser Foundation for Brain Research since 2006, to 11 men and 1 woman, jointly awarded with her husband (selection committee not publicly available)

This lack of women recipients is not due to lack of women engaged in prize-worthy cutting-edge neuroscience research, as apparent from prizes that are awarded to women proportionally to their base-rate in science:

Edward M. Scolnick Prize in Neuroscience – Awarded since 2004, to 10 men and 4 women (current selection committee: 4 men, 2 women)

Base rate of women researchers in neuroscience: 24% as estimated by the percentage of women faculty in top neuroscience programs in USA

Base rate of women researchers in computational neuroscience: 17-18% as estimated from the percentage of women attendees at COSYNE