preprints.org > biology and life sciences > anatomy and physiology > doi: 10.20944/preprints201806.0413.v1

Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Version 1 : Received: 25 June 2018 / Approved: 26 June 2018 / Online: 26 June 2018 (11:51:27 CEST)

We developed a temporal population receptive field model to differentiate the functional and hemodynamic responses in the human LGN. The hemodynamic response of the human LGN is dominated by the richly vascularized hilum, a structure that serves as a point of entry for blood vessels entering the LGN and supplying the substrates of central vision. The location of the hilum along the ventral surface of the LGN and the resulting gradient in the amplitude of the hemodynamic response across the extent of the LGN has made it difficult to segment the human LGN into its more interesting magnocellular and parvocellular regions that represent two distinct visual processing streams. Here, we show that an intrinsic clustering of the LGN responses to a variety of visual input reveals the hilum, and further that this clustering is dominated by the amplitude of the hemodynamic response. We introduce a temporal population receptive field model that includes both a sustained and transient temporal impulse response. When we account for the hemodynamic amplitude, we demonstrate that this temporal response model is able to functionally segregate the residual responses according to their temporal properties.

LGN; pRF; spatiotemporal; retinotopic; flicker; isoluminance; clustering

Biology and Life Sciences, Anatomy and Physiology