Publications by authors named "Amaro Tuninetti"

We introduce two EEG techniques, one based on conventional monopolar electrodes and one based on a novel tripolar electrode, to record for the first time auditory brainstem responses (ABRs) from the scalp of unanesthetized, unrestrained big brown bats. Stimuli were frequency-modulated (FM) sweeps varying in sweep direction, sweep duration, and harmonic structure. As expected from previous invasive ABR recordings, upward-sweeping FM signals evoked larger amplitude responses (peak-to-trough amplitude in the latency range of 3-5 ms post-stimulus onset) than downward-sweeping FM signals.

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Big brown bats echolocate using wideband frequency-modulated (FM) ultrasonic pulses, perceiving target range from echo delay and target size from echo amplitude. Echolocation pulses contain two prominent down-sweeping harmonics (FM1, ∼55-22 kHz; FM2, ∼100-55 kHz), which are affected differently by propagation to the target and back to the bat. Previous work demonstrates that big brown bats utilize the low frequencies in FM1 for target ranging, while FM2 only contributes if FM1 is also present.

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We challenged four big brown bats to maneuver through abrupt turns in narrow corridors surrounded by dense acoustic clutter. We quantified bats' performance, sonar beam focus, and sensory acquisition rate. Performance was excellent in straight corridors, with sonar beam aim deviating less than 5° from the corridor midline.

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