There is a long-standing debate about the neurocognitive implementation of mental imagery. One form of mental imagery is the imagery of visual motion, which is of interest due to its naturalistic and dynamic character. However, so far only the mere occurrence rather than the specific content of motion imagery was shown to be detectable. In the current study, the application of multi-voxel pattern analysis to high-resolution functional data of 12 subjects acquired with ultra-high field 7. T functional magnetic resonance imaging allowed us to show that imagery of visual motion can indeed activate the earliest levels of the visual hierarchy, but the extent thereof varies highly between subjects. Our approach enabled classification not only of complex imagery, but also of its actual contents, in that the direction of imagined motion out of four options was successfully identified in two thirds of the subjects and with accuracies of up to 91.3% in individual subjects. A searchlight analysis confirmed the local origin of decodable information in striate and extra-striate cortex. These high-accuracy findings not only shed new light on a central question in vision science on the constituents of mental imagery, but also show for the first time that the specific sub-categorical content of visual motion imagery is reliably decodable from brain imaging data on a single-subject level.
Bibliographical noteFunding Information:
This work was supported by the European Research Council (ERC) under European Union's Seventh Framework Programme FP7/2007–2013/ERC (Grant Agreement Number 269853 ). We would like to thank Franziska Dambacher, Felix Dücker, Tom de Graaf, Lars Hausfeld, Valentin Kemper, and Giancarlo Valente for their help.
© 2015 The Authors.
- Functional magnetic resonance imaging
- Multi-voxel pattern analysis
- Ultra-high field MRI
- Visual mental imagery