Figure 1. Posterior view of a cat's head illustrating the two coil positions used in these experiments. On the right the coil is shown in the flat medial aspect of the pinna, whereas on the left the coil is shown as far caudal on the pinna as possible. The vectors illustrate the convention used to describe changes in pinna position from a viewpoint directly behind the cat pointed in the same direction as the nose.
Figure 2. Images of a pinna movement to a visual target. Posterior views of Cat08's head from video recordings taken during an experimental session. Spon, Fix, and Down images were taken at the following points: during the spontaneous period before the onset of the trial (Spon), during the fixation period while fixating an LED at the primary position (Fix), and after the cat saccaded to the target (Down). The gray-white structure labeled hh is the head holder, and the structure labeled cr is the calibrating ring. Triangular markers were placed on the tip, medial, and lateral edges of each pinna, and the white dot on the right pinna marks the center of the implanted coil. Composite shows all three images superimposed in different colors (Spon, blue; Fix, red; Down, green).
Figure 3. Composite figures illustrating the changes in pinna position when the cat saccaded to targets to the Right, Left, and Up. Details as in Figure 2.
Figure 4. Pinna movement traces to visual targets from Cat08's right pinna. Each panel plots the vertical (top) and horizontal (bottom) component of pinna position synchronized to the onset of the target LED (lit for 1000 msec) at time 0 msec. The targets were located at (±18°,0°), (0°,18°), and (0°,
23°). Traces from several trials, including those shown in Figures 2 and 3, are plotted. The ordinates of these plots, as well as those of similar plots in subsequent figures, represent relative and not absolute pinna position.
Figure 5. Movements of Cat09's right pinna evoked by visual (left) and auditory (right) targets recorded with the standard saccade task. The fixation LED was at the primary position (0°,0°) in all cases, and the targets were at (±18°,0°), (0°,18°), and (0°,14°). All traces are plotted synchronized to the onset of the stimulus at Time, 0 msec.
Figure 6. Pinna movement latency to auditory and visual targets. Measurements, taken from visual and auditory standard saccade trials to targets ipsilateral to the pinna at (±18°,0°), are plotted as a function of eye movement latency. Data from five cats (Cat06, Cat09, Cat10, Cat11, and Cat14) are included; n = 249 (126 auditory trials and 123 visual trials; 7 trials with latencies >500 msec were excluded).
Figure 7. Pinna movements in delayed saccade trials. Visual and auditory targets were located at (18°,0°). The coil was implanted on the flat aspect of Cat06's right pinna (Fig. 1, right). From top to bottom: Horizontal eye position and Vertical and Horizontal pinna position. Delay duration, 500 msec. Notice the short-latency (solid arrows) and long-latency (open arrows) pinna movements in the auditory condition; n = 16 (8 visual and 8 auditory trials).
Figure 8. Short-latency component of pinna movements during sensory probe trials. Acoustic broadband (800 msec, broadband noise) probes were presented in random trials from speakers located at (±90°,0°), (±63°,0°), (±45°,0°), (±18°,0°), (±9°,0°), and (0°,0°) while the cat fixated an LED at (0°,0°). The end of the movement traces coincided with the delivery of the reward 200 msec after stimulus offset. Notice in the conditions with the largest movements that the pinna returns to the initial position shortly after stimulus offset. For both left and right pinnae the trials corresponding to contralateral speaker positions at ±90°, ±63°, and ±45° were recorded in a different session than the rest of the data.
Figure 9. Latencies of pinna movements evoked by broadband long-duration acoustic stimuli during sensory probe trials. The bars represent confidence intervals (2 × SEM). Cat14, 342 trials (132 left pinna, 210 right pinna), raw data are shown in Figure 8. Cat11, 195 trials (93 left pinna, 102 right pinna).
Figure 10. Relative changes in pinna position evoked by visual (hollow symbols) and auditory (filled symbols) targets located at (18°,0°) and (9°,0°) in delayed saccade trials; data from Figure 7 are included. The mean pinna position at the start of the trials (filled star) has been arbitrarily set at coordinates (0°,0°). Circles represent the change in pinna position for the targets at (9°,0°); triangles represent the change in pinna position for the targets at (18°,0°); and the standard bars represent ±2 SE of the sample mean; n = 62 (23 visual and 39 auditory trials).
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