fMRI and neural encoding models: Voxel receptive fields (continued)
A voxel receptive field model of visual cortex: Kay et al, Nature, 2008
A voxel receptive field model of visual cortex: Kay et al, Nature, 2008
A voxel receptive field model of visual cortex: Kay et al, Nature, 2008
A specific voxel’s receptive field
Generative and discriminative models From Christopher Bishop book: Pattern Recongition and Machine Learning
Huth et al. (2012) Semantic space in cortex
Principal Components Analysis (PCA) http://web.media.mit.edu/~tristan/phd/dissertation/figures/PCA.jpg
Representing categories in WordNet
Representing multiple semantic principal components
A closer look at semantic space
What do the components mean?
Highly distributed representations
How much of each region’s activation does the model explain?
Summary: Voxel receptive field models Generative model of neural activation, as opposed to a discriminative model Often called encoding models vs. decoding models Useful for synthesising (generating) inferred inputs, e.g. the image someone was seeing Still leaves lots of neural function unexplained, but a very useful step forward nonetheless