Artículo de revista
Selective Attention to Visual Stimuli Reduces Cochlear Sensitivity in Chinchillas
Fecha
2007-04Registro en:
JOURNAL OF NEUROSCIENCE, V.: 27, issue: 15, p.: 4146-4153, APR 11 2007.
0270-6474
Autor
Délano, Paul H.
Elgueda, Diego
Hamamé, Carlos M.
Robles Wobbe, Luis
Institución
Resumen
It is generally accepted that during periods of attention to specific stimuli there are changes in the neural activity of central auditory
structures; however, it is controversial whether attention can modulate auditory responses at the cochlear level. Several studies performed
in animals as well as in humans have attempted to find a modulation of cochlear responses during visual attention with contradictory
results. Here, we have appraised cochlear sensitivity in behaving chinchillas by measuring, with a chronically implanted roundwindow
electrode, sound-evoked auditory-nerve compound action potentials and cochlear microphonics, a measure of outer hair cell
function, during selective attention to visual stimuli. Chinchillas were trained in a visual discrimination or in an auditory frequency
discrimination two-choice task. We found a significant decrease of cochlear sensitivity during the period of attention to visual stimuli in
the animals performing the visual discrimination task, but not in those performing the auditory task, demonstrating that this physiological
effect is related to selective attention to visual stimuli rather than to an increment in arousal level. Furthermore, the magnitude of
the cochlear-sensitivity reductions increased in sessions performed with shorter target-light durations (4–0.5 s), suggesting that this
effect is stronger for higher attentional demands of the task. These results demonstrate that afferent auditory activity is modulated by
selective attention as early as at sensory transduction, possibly through activation of olivocochlear efferent fibers.