José Luis Peña

The overall objective of my research is to understand the neural bases of perception and behavior. Owls provide an ideal system to study the neural computations underlying auditory localization. They exhibit a characteristic orienting response towards sound sources, its behavior is highly reproducible and readily measured, the variables involved in triggering specific behaviors are well characterized, and it affords progressively deeper levels of approaching the neural structures involved in the computation. Whereas spatial selectivity of neurons in the owl’s auditory system is initially broad and ambiguous, sharply-tuned space-specificity emerges in high-order neurons, in a computation that takes no longer than 10 milliseconds. In the midbrain, a map of auditory space is computed based on differences in time and intensity of the acoustic signals that arrive at each ear. These binaural cues are processed in parallel pathways that converge on the space-specific neurons. I have focused on two regions of the brain that are crucial for this synthetic process: the nucleus laminaris, where the difference between the arrival times of the sound to each ear is initially derived, and the external nucleus of the inferior colliculus, where space-specific neurons respond to sounds coming from unique directions. We found that well-defined computations, which match predictions made by studies of sound localization in humans, underlie the emergent response properties of these neurons. Thus, the owl provides a system to test models of psychoacoustics at levels from single cells to networks of neurons. In the future, we plan to study how information flows in the avian sound localization pathway using behavioral and physiological approaches.

 

Selected Publications

Christianson GB, Peña JL (2007) Preservation of spectrotemporal tuning between the nucleus laminaris and the inferior colliculus of the barn owl. J Neurophysiol., in press.

Christianson GB, Peña JL (2006) Noise reduction of coincidence detector output by the inferior colliculus of the barn owl. J Neurosci 26:5948-54.

Pérez ML, Peña JL (2006) Comparison of midbrain and thalamic space-specific neurons in barn owls. J Neurophysiol 95: 783-790.

Peña JL, Konishi, M (2004) Robustness of multiplicative processes in auditory spatial tuning. J Neurosci 24: 8907-8910.

Peña JL (2003) Binaural processing in the synthesis of auditory spatial receptive fields. Biol Cybern 89: 371-377.

Peña JL, Konishi M (2002) From postsynaptic potentials to spikes in the genesis of auditory spatial receptive fields. J Neurosci 22: 5652-5658.

Peña JL (2002) Neurons that encode sound direction. Rev. Neurologia, 34: 265-271.

Peña JL, Viete S, Funabiki K, Saberi K, Konishi M (2001) Cochlear and neural delays for coincidence detection in owls. J Neurosci 21: 9455-9459.

Peña JL, Konishi M (2001) Auditory spatial receptive fields created by multiplication. Science 292: 249-252.

Peña JL, Konishi M (2000) Cellular mechanisms for resolving phase ambiguity in the owl's inferior colliculus. Proc Nat Acad Sci USA 97: 11787-11792.