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. Author manuscript; available in PMC: 2011 Mar 26.
Published in final edited form as: Eur J Neurosci. 2009 Mar 23;29(7):1477–1489. doi: 10.1111/j.1460-9568.2009.06695.x

Figure 2.

Figure 2

Measuring current threshold. (A) Detection rate is plotted as a function current for 20 stimulation trials (stim). The current threshold was defined as the amount of current required yielding a 50% detection rate that was 8 μA (arrow). Control trials indicate that the monkey depressed the lever less then 10% of the time when no stimulation was delivered (cont). (B) The latency to depress the lever following the termination of the fixation spot is shown for stimulation trials (stim) across different current levels. Standard errors of the mean are shown. The ‘x’ indicates that no latency measure was obtained for the zero current condition. The average latency to depress the lever for target trials is indicated by the dotted line (all latencies are with respect to the termination of the fixation spot). Data in A and B are from the same experiment in which a 100 ms train of 0.2 ms cathode-first pulses were delivered at 200 Hz to a V1 site at 1.25 mm below the cortical surface. Data are from monkey C. See Fig. 1 for other details.