Sensory neuroprostheses show great potential for alleviating major sensory deﬁcits. It is not known, however, whether such devices can augment the subject’s normal perceptual range. Here we show that adult rats can learn to perceive otherwise invisible infrared light through a neuroprosthesis that couples the output of a head-mounted infrared sensor to their somatosensory cortex (S1) via intracortical microstimulation. Rats readily learn to use this new information source, and generate active exploratory strategies to discriminate among infrared sources in their environment. S1 neurons in these infrared-perceiving rats respond to both whisker deﬂection and intracortical microstimulation, suggesting that the infrared representation does not displace the original tactile representation. Hence, sensory cortical prostheses, in addition to restoring normal neurological functions, may serve to expand natural perceptual capabilities in mammals. Read Full Article Here
Infrared Movie S1: Introduction to the structure of the task. Two views of a rat performing a single trial of the IR-discrimination task. The IR light comes on, and when the rat orients toward the stimulus, an IR-signal is registered by an IR-detector on the rat’s head, and S1 is stimulated with a frequency that depends on detector’s output (Figure 1e). Guided by microstimulation, the rat approaches the reward port to receive water. In the floor-level view, you can see the infrared detector attached to the rat’s head. The audio track is the output of the microstimulator, which is not available to the rat.
Infrared Movie S2: Example of rat performing IR discrimination (top-down view). Movie shows three trials in a well-trained rat navigating the chamber actively foraging for IR sources. The ports are 90 degrees apart.
Infrared Movie S3: Example of IR-discrimination in difficult version of task. Multiple trials in a well-trained animal on a more difficult version of the task than shown in Movie 2: the reward ports are only 30° apart. Correct and incorrect trials are indicated.
Infrared Movie S4: Sample trials from a session with ‘blank’ trials interleaved. On random trials the IR light is activated, but is uncoupled from ICMS. Trial types (‘stim’ versus ‘no-stim’ trials) are indicated before each trial.
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