Ten subjects from the minimally instructed group and 10 subjects from the ratio- instructed group were exposed to 25 trials on a FI 10-s schedule of reinforcement followed immediately by 50 trials on a conjunctive FT 10-s FR 1 schedule.
On the conjunctive schedule one or more responses at any time during the FT10-s interval produced the message and a single 1-s tone at the end of the interval, and when the screen cleared the next interval began immediately.
As outlined earlier the FT 10-s FR 1 conjunctive schedule does not guarantee response- reinforcer contiguity, and thus delays between a given response and the delivery of a point may occur on this schedule.
five or more responses per interval) and short PRP durations (less than 5 s) on FI 10-s followed by a decrease in response rates and an increase in PRPs during exposure to the conjunctive FT 10-s FR 1 schedule.
Subject S1 showed a gradual increase in response rate and inconsistent PRPs across trials on the FI and, initially, on the conjunctive schedule.
All subjects emitted predominantly low response rates on the conjunctive schedule (the first 1-s delay always occurred within the first six trials).
Five subjects (11, 14, 15, 17, and 20) showed mainly short PRPs on the conjunctive with an abrupt shift to extended PRPs on the FI; this shift occurred toward the end of the session for S14 and S17.
Eight subjects (all but S23 and S25) showed high response rates and short PRP durations on FI 10-s followed by a decrease in response rates and an increase in PRPs during exposure to the conjunctive FT 10-s FR 1 schedule.