2009 WinawerDoughertyWandell

Project Title - Retinotopic maps in MNI space

Much of the visual cortex is organized into visual field maps: nearby neurons have receptive fields at nearby locations in the image. These maps are usually identified in individual subjects. The precise location of each map may be different in different brains. For this project, we asked how the quality of the maps would compare using (a) standard retinoptic methods on individual brains or (b) group-averaged brains projected into MNI space.

Background

Retinotopic maps

You can use subsections if you like. Below is an example of a retinotopic map. Or, to be precise, below will be an example of a retinotopic map once the image is uploaded. To add an image, simply put text like this inside double brackets 'MyFile.jpg | My figure caption'. When you save this text and click on the link, the wiki will ask you for the figure.

Below is another example of a reinotopic map in a different subject.

Figure 2

MNI space

MNI is an abbreviation for Montreal Neurological Institute.

Methods

Measuring retinotopic maps

Retinotopic maps were obtained in 5 subjects using Population Receptive Field mapping methods Dumoulin and Wandell (2008). These data were collected for another research project in the Wandell lab. We re-analyzed the data for this project, as described below.

Subjects

Subjects were 5 healthy volunteers.

MR acquisition

Data were obtained on a GE scanner. Et cetera.

MR Analysis

The MR data was analyzed using mrVista software tools. All data were slice-time corrected, motion corrected, and repeated scans were averaged together to create a single average scan for each subject. Et cetera.

PRF model fits

PRF models were fit with a 2-gaussian model.