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Fig. 4. Interruption rate as a function of time within a session. Interruption rate
for the first call (white bars) and last call (dark bars) for the Begin, End
and Random experimental conditions. There was no difference in interruption
rate between the first and last calls in a session in any of the experimental
conditions. Values are means ± s.e.m. (for number of calls in each
condition, see Table 1).