THE UTAH INTRACORTICAL ELECTRODE ARRAY - A RECORDING STRUCTURE FOR POTENTIAL BRAIN-COMPUTER INTERFACES

We investigated the potential of the Utah Intracortical Electrode Arra y (UIEA) to provide signals for a brain-computer interface (BCI). The UIEA records from small populations of neurons which have an average s ignal-to-noise ratio (SNR) of 6:1. We provide specific examples that s how the activities of these populations of neurons contain sufficient information to perform control tasks. Results from a simple stimulus d etection task using these signals as inputs confirm that the number of neurons present in a recording is significant in determining task per formance. Increasing the number of units in a recording decreases the sensitivity of the response to the stimulus: decreasing the number of units in the recording, however, increases the variability of the resp onse to the stimulus. We conclude that recordings from small populatio ns of neurons, not single units, provide a reliable source of sufficie ntly stimulus selective signals which should be suitable for a BCI. In addition, the potential for simultaneous and proportional control of a large number of external devices may be realized through the ability of an array of microelectrodes such as the UIEA to record both spatia l and temporal patterns of neuronal activation. (C) 1997 Elsevier Scie nce Ireland Ltd.