Selective Attention to Visual Stimuli Reduces Cochlear Sensitivity in Chinchillas

Abstract

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.

Additive effects of emotional, endogenous, and exogenous attention: Behavioral and electrophysiological evidence

“…In addition, experiments using crossmodal manipulations have demonstrated interactions between emotional and exogenous attention in the form of decreased P3 amplitude to auditory startle probes when emotionally intense visual stimuli are presented concurrently (Cuthbert, Schupp, Bradley, McManis, & Lang, 1998;Keil et al, 2007). In animal work, crossmodal interactions between different attention systems may even affect sensory processing at the level of sensory transduction (e.g., in the cochlea, see Delano, Elgueda, Hamame, & Robles, 2007). Altogether, these findings suggest that the different attention systems may initially operate relatively independently (i.e., not tap into each other's resources), but may compete and interact at later time points (e.g., at the level of the P3 component) or when different sensory modalities are integrated.…”

Neuronal Activity of Mitral-Tufted Cells in Awake Rats During Passive and Active Odorant Stimulation

“…Thus the observed increase in MT cells inhibitory responses during the discrimination task may arise from the activation of the piriform cortex-OB circuit. It cannot be rule out, however, that because both PE and TA tasks required previous extensive learning, increased inhibition would not reflect learning but other cognitive process, such as attention, which would reflect as a top down modulation of lower level structures (Delano et al 2007;Reynolds and Desimone 1999).…”

Neural Mechanisms of Selective Auditory Attention in Rats (Dissertation)

“…In other studies, Hocherman et al (Hocherman et al, 1981;Hocherman and Yirmiya, 1990) showed that responses of auditory cortical neurons as well as thalamic neurons in In line with the notion that attention may be able to influence early stages of auditory sensory pathway, several early study in cats (Hernandez-Peon et al, 1956;Oatman, 1971Oatman, , 1976Oatman, 1988) and a recent study in chinchillas (Delano et al, 2007) showed that visual attention during a visual discrimination task can significantly decrease cochlear sensitivity, measured by sound-evoked auditory-nerve compound action potentials and cochlear microphonics, and cochlea nucleus responses. In contrast, when the animal is performing an auditory discrimination task, little effect on the early auditory processing pathway was observed.…”