Ph. Hartline et al., EFFECTS OF EYE POSITION ON AUDITORY LOCALIZATION AND NEURAL REPRESENTATION OF SPACE IN SUPERIOR COLLICULUS OF CATS, Experimental Brain Research, 104(3), 1995, pp. 402-408
The maps of visual and auditory space within the superior colliculus a
re in approximate register both with each other and with the underlyin
g motor maps associated with orienting responses. The fact that eyes a
nd ears can move independently poses a problem for the sensorimotor or
ganization of these two modalities. By monitoring eye and pinna positi
ons in alert, head-fixed cats, we showed that the accuracy of saccadic
eye movements to auditory targets was little affected by eye eccentri
city (range +/-15 deg) at the onset of the sound. A possible neural ba
sis for this behavioral compensation was suggested by recordings from
superior colliculus neurons. The preferred sound directions of some ne
urons in the deep layers of this midbrain nucleus exhibited a shift wi
th the direction of gaze, while in others the response throughout the
auditory receptive field was either increased or decreased, suggesting
that changes in eye position alter the gain of the auditory response.