Relative reinforcer rates determine pigeons’ attention allocation when separately trained stimuli are presented together

Abstract

Previous research suggests that organisms allocate more attention to stimuli associated with higher reinforcer rates. This finding has been replicated several times when stimuli are trained together as compounds, but not in other procedures. Thus, the generality of the relation between relative reinforcer rates and divided attention is not well established. Therefore, we investigated whether relative reinforcer rates determine attention allocation when stimuli are trained separately and then encountered together. Pigeons learned to associate two colors and two frequencies of key light on/off alternation with a left or right comparison key in a symbolic 0-s delayed matching-to-sample task. Across conditions, we varied the probability of reinforcement associated with each stimulus dimension during training. After training, we introduced test trials in which a color and flash-frequency stimulus were presented simultaneously. During sample-stimulus presentation in test trials, all pigeons preferred the stimulus associated with the higher reinforcer rate, suggesting that more attention was allocated to that stimulus. Interestingly, such attention allocation did not result in preference for the comparison that matched that stimulus. Instead, all pigeons preferred the comparison that was physically closer to the stimulus associated with the higher reinforcer rate, suggesting that comparison choice was controlled by the location of that stimulus. Nevertheless, overall, our results provide the first evidence that relative reinforcer rates determine divided attention between separately trained stimuli and thus demonstrate the generality of the relation between relative reinforcement and attention allocation. We suggest several avenues for future research to establish further the generality of this relation.

Is superstitious responding a matter of detectability? A replication of Killeen (1978)

“…Alternatively, a more parsimonious explanation is that food deliveries affect behaviors implicated in performance. In MTS procedures, subjects may learn to orient toward the correct comparison (e.g., Davison, 2018;Gomes-Ng et al, 2019) or engage in other mediating behaviors that bridge the gap between sample and comparison stimuli (e.g., Blough, 1959;Urcuioli, 1984Urcuioli, , 1985Urcuioli & Honig, 1980;Weaver et al, 1999). For example, Urcuioli (1985) showed that comparison choice was controlled by differential behavior during the sample phase rather than by the identity of the sample, so disrupting sample-specific behaviors reduced matching performance.…”

Divided stimulus control depends on differential and nondifferential reinforcement: Testing a quantitative model

“…Like Shahan and Podlesnik, Davison and Elliffe found that as the probability of reinforcer deliveries for correct responses according to one dimension increased, so did the frequency of correct responses according to that dimension, whereas correct responses according to the other dimension decreased. Thus, these experiments demonstrate that divided control between compoundstimulus dimensions depends on relative reinforcer rates (see also Davison, 2018;Gomes-Ng et al, 2019a, 2019bPodlesnik et al, 2012;Shahan & Podlesnik, 2007, 2008. Davison and Elliffe (2010) likened the contingencies in their experiment to those in a "reinforcementfor-errors" procedure, in which some reinforcers are delivered after incorrect responses.…”

“…Although these dimensions may differ in their discriminability-color is discriminable immediately, whereas alternation frequency is only discriminable across time-we presented the sample stimulus for at least 5 s and arranged maximally different alternation frequencies with the goal to enhance the discriminability of the alternation-frequency dimension. We have previously used these two stimulus dimensions in other studies of divided stimulus control (Cowie et al, 2020;Gomes-Ng et al, 2019a, 2019b, and previous research-including Davison and Elliffe (2010)-shows that pigeons can discriminate well between frequencies of keylight-color alternation (e.g., Cowie et al, 2020;Gomes-Ng et al, 2019a, 2019bKrägeloh & Davison, 2003;Roberts, 1997;Roberts et al, 2000;Roberts & Mitchell, 1994).…”

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

“…The pigeons were housed in a colony room with a time-shifted environment (lights on at 12 a.m., off at 4 p.m.). All pigeons had previous experience in a symbolic DMTS procedure (Gomes-Ng, Elliffe, & Cowie, 2019), but never with the peak procedure.…”