Cortical responses to cochlear implant stimulation: channel interactions.

摘要: This study examined the interactions between electrical stimuli presented through two channels of a cochlear implant. Experiments were conducted in anesthetized guinea pigs. Multiunit spike activity recorded from auditory cortex reflected cumulative effects electric field cochlea as well any neural along ascending pathway. The was stimulated electrically 6-electrode intracochlear array. stimulus on each channel single 80-µs/phase biphasic pulse. Channel quantified changes thresholds for elevation cortical rates. Experimental parameters interchannel temporal offset (0 to ±2000 µs), interelectrode spacing (1.5 or 2.25 mm), electrode configuration (monopolar, bipolar, tripolar), and relative polarity (same inverted). In most conditions, presentation subthreshold pulse one reduced threshold second channel. Threshold shifts greatest simultaneous pulses, but appreciable reductions could persist offsets up 640 µs. varied strongly with configuration: increased magnitude order tripolar, monopolar. greater closer spacing. results have implications design speech processors implants.