Churchland lab

I am at Janelia Research campus this week, along with Lital Chartarifsky, a graduate student in my lab. The meeting organizers brought together researchers with highly diverse approaches to the problem of multisensory integration, from invertebrates, to rodents to primates. One feature of integration that appears to be common across these species is the ability to use the reliability of incoming inputs to guide the integration. That is, to down-weight noisy signals and up-weight reliable ones. This appears to be widespread, although whether common neural mechanisms support this ability in diverse species is unclear.

Image of the ellipsoid body (Tanya Wolff, Nirmala Iyer & Gerry Rubin)

An interesting talk on Day 1 came from Vivek Jayaraman’s lab. Vivek described responses in a part of the fly’s brain called the ellipsoid body (shown in the figure). His group measured neural responses in the ellipsoid body as the fly experienced a virtual reality environment in which its movements drove changes in a visual arena that surrounded it. The arena contained a visual bar and the bar’s position turns out to be key in driving responses in the ellipsoid body. In fact, by decoding the ellipsoid body neural activity, the researchers were able to estimate the fly’s orientation in the visual scene with remarkable precision. Surprisingly, the decode remained accurate for a while even when visual inputs to the fly’s brain were blocked. This last observation points to the ellipsoid body as driving an abstract representation of visual space, one that is derived from visual input and incorporated with self motion. This work was published just before the meeting in Nature.