Nature 452, 352-355 (20 March 2008) | doi:10.1038/nature06713; Received 16 June 2007; Accepted 17 January 2008; Published online 5 March 2008

Identifying natural images from human brain activity

Kendrick N. Kay1, Thomas Naselaris2, Ryan J. Prenger3 & Jack L. Gallant1,2

  1. Department of Psychology, University of California, Berkeley, California 94720, USA
  2. Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
  3. Department of Physics, University of California, Berkeley, California 94720, USA

Correspondence to: Jack L. Gallant1,2 Correspondence and requests for materials should be addressed to J.L.G. (Email: gallant@berkeley.edu).

A challenging goal in neuroscience is to be able to read out, or decode, mental content from brain activity. Recent functional magnetic resonance imaging (fMRI) studies have decoded orientation1, 2, position3 and object category4, 5 from activity in visual cortex. However, these studies typically used relatively simple stimuli (for example, gratings) or images drawn from fixed categories (for example, faces, houses), and decoding was based on previous measurements of brain activity evoked by those same stimuli or categories. To overcome these limitations, here we develop a decoding method based on quantitative receptive-field models that characterize the relationship between visual stimuli and fMRI activity in early visual areas. These models describe the tuning of individual voxels for space, orientation and spatial frequency, and are estimated directly from responses evoked by natural images. We show that these receptive-field models make it possible to identify, from a large set of completely novel natural images, which specific image was seen by an observer. Identification is not a mere consequence of the retinotopic organization of visual areas; simpler receptive-field models that describe only spatial tuning yield much poorer identification performance. Our results suggest that it may soon be possible to reconstruct a picture of a person's visual experience from measurements of brain activity alone.


These links to content published by NPG are automatically generated.


I can see what you see

Nature Neuroscience News and Views (01 Mar 2009)

Imaging orientation selectivity: decoding conscious perception in V1

Nature Neuroscience News and Views (01 May 2005)