Figure 6.

Anticipatory responses of IC cells. (A) Average-evoked potential recorded from the IC in response to sounds presented at 3 s intervals following aversive stimulation of the mesencephalic central gray (MCG) with (dashed line) and without (solid line) curare. MCG stimulation occurred at a fixed interval of 30 s (thus, 0 s post-MCG stimulation may be thought of as 30 s pre-MCG stimulation for the following trial). (B) Representative example of a multi-unit response to sound presentation following rewarding stimulus. Sounds were played at varying intervals (up to 180 s) following reward, and the next reward was delivered after a second variable interval. Note that no error bars were provided in the source materials for panels (A,B) so the variability and potential statistical significance of the finding cannot be assessed. (C,D) Average response (± standard error) of IC cell population time-locked to sound onset (C) and reward onset (D). Briefly, monkeys fixated on an LED while a sound was played. The LED was extinguished and the monkeys made a saccade to the auditory target. They were rewarded if the auditory saccade was within the appropriate fixation window (8–11°, depending on target distance from LED). Both rewarded and unrewarded trials were included in this analysis. Adapted from (A) Ruth et al. (1974); (B) Nienhuis and Olds (1978); (C,D) Metzger et al. (2006).