Environment tracking and signal following in a reinforcer-ratio reversal procedure

Timing compound stimuli: Relative reinforcer probabilities divide stimulus control in the multiple peak procedure.

“…Our results are consistent with a growing body of research demonstrating that when reinforcer availability changes consistently across time since a marker event, elapsed time itself competes for, and often gains, discriminative control over behavior (e.g., Cowie et al, 2017;Davison & Cowie, 2019;Gomes-Ng et al, 2018a;Rayburn-Reeves, Molet, & Zentall, 2011;Rayburn-Reeves et al, 2017;see McMillan et al, 2017 for a review). Our findings also share similarities with studies of temporal averaging, in which separately trained light and tone stimuli, which each signal a different FI schedule, are occasionally presented simultaneously in peak trials.…”

“…The similarities between response patterns at early times in Both FI 2, Color FI 2, and Color FI 8 trials, and between response patterns at later times in Both FI 8, Color FI 2, and Color FI 8 trials, provide some support for this suggestion—subjects appeared to behave as if an FI 2-s schedule was arranged at early times, and as if an FI 8-s schedule was arranged at later times, consistent with some control by elapsed time (i.e., by “what is likely to happen now”). Indeed, such control by elapsed time has been demonstrated in similar procedures to that arranged here; when changes in reinforcer availability are correlated with the passage of time and with additional nontemporal stimuli (e.g., keylight color), both elapsed time and the nontemporal stimuli control behavior (e.g., Cowie et al, 2017; Davison & Cowie, 2019; Gomes-Ng et al, 2018a; Rayburn-Reeves, Qadri, Brooks, Keller, & Cook, 2017; see McMillan, Spetch, Sturdy, & Roberts, 2017 for a review).…”

“…Previous research suggests that when control shifts away from a stimulus signaling the time to reinforcer delivery and toward a stimulus that provides no such temporal information, temporal discrimination accuracy and/or precision worsens (Aum, Brown, & Hemmes, 2007; Cowie, Davison, & Elliffe, 2017; Gomes-Ng, Elliffe, & Cowie, 2018a; McMillan & Roberts, 2013; Sutton & Roberts, 2002). Based on such research, the absence of substantial changes in temporal discrimination in the present experiment may be related to the absence of substantial shifts in stimulus control from one stimulus dimension to the other.…”