Chris Klink & Matthew SelfNeuroscience Symposium
De Neuroscience Symposia worden wekelijks georganiseerd door het Nederlands Herseninstituut. De presentaties worden gegeven door de onderzoekers van het Instituut of door gastsprekers. De titel en de inhoud van het symposium wordt doorgaans in de week voorafgaand aan de presentatie bekend gemaakt.
Colloquium zaal – Nederlands Herseninstituut
16:00 – Chris Klink | Benchmarking population receptive fields with fMRI and large-scale neurophysiology in non-human primates
16:30 – Matthew Self | A fovea-like representation of space in mouse visual cortex
17:00 – Discussie en borrel
Benchmarking population receptive fields with fMRI and large-scale neurophysiology in non-human primates
Population receptive field (pRF) mapping (Dumoulin & Wandell, 2008) is a popular method to quantitatively estimate the retinotopic organization of the human brain using fMRI. The method fits receptive field properties to the hemodynamic BOLD response with the assumption that this signal reflects the cumulative neuronal receptive field properties of large populations of neurons within each voxel. While the fMRI-based visual field maps are qualitatively in accordance with classic single cell receptive fields obtained from invasive recordings in animals, it remains unclear what aspect of the underlying neuronal signal the BOLD signal reflects. This question is especially relevant when the pRF-mapping method is used to make inferences about cognitive functions, for instance in clinical studies. In an attempt to answer this question, we performed fMRI and large-scale neurophysiological recordings in awake non-human primates and compared the population receptive field estimates derived from the BOLD signal against those derived from multi-unit spiking activity and different frequency bands of the local field potential. These intraspecies crossmodal comparisons can provide insight into the neurophysiological basis of the BOLD signal, and directly benchmark visual field maps that are obtained with non-invasive methods against more precise invasive measures that are generally impossible to record in humans on this scale.
A fovea-like representation of space in mouse visual cortex
I will present data revealing a previously unsuspected organization of the visual cortex of mice. Using population receptive-field (pRF) mapping techniques we found that mouse visual cortex contains a region in which pRFs are considerably smaller. This region represents a location in space directly in front of, and slightly above, the mouse. This organization superficially resembles that of the fovea in primates and has important implications for the use of the mouse model of vision.