A nerve electrode array includes one or more spiral electrically conductive filament bands each secured within a different electrically insulative loop among a plurality of loops configured in a helical array. Each loop is severed lengthwise of the array to allow it to be spread open independently of the other loops to partly encircle the nerve during surgical mounting thereon. The array is held together in the helical configuration by a linking member which intersects with and is fastened to each of the spaced-apart loops. Each filament band extends within its loop across the intersection of the loop and linking member. In one embodiment, the cuts through the loops are aligned lengthwise of the helical array and substantially parallel to the linking member, and each cut is approximately diametrically opposite the linking member. In another embodiment, the cuts through the loops are staggered relative to the linking member, lengthwise of the array. With the electrode array mounted on the nerve, the filament bands are positioned to electrically interact with the nerve to detect signals carried by the nerve and/or to electrically stimulate the nerve.