Figure 1.

Cross-modal attention task. The color of the fixation point indicated whether a given trial was a visual trial or an auditory trial. A green fixation point meant a visual trial, and the monkey was to attend to the visual stimulus (a spot in the receptive field of the TRN neuron). A red fixation point denoted an auditory trial, and the monkey was to attend to the auditory stimulus (a tone). During both visual and auditory trials, the visual spot either dimmed or remained constant, and, independently, the auditory tone either dimmed or remained constant. The possible dimming of either stimulus did not depend on the trial type. The monkey was rewarded by correctly reporting whether the attended stimulus (indicated by the color of the fixation point) dimmed or not. For details, see Materials and Methods.