The Influence of Partial Reinforcement on Serial Autoshaping with Pigeons

Abstract

The effect of partial reinforcement on the rate of responding during the first element of a serial compound was investigated using autoshaping in pigeons. Experiment I employed the illumination of a response key by two different colours as the elements of the compound. Responding during the first element was faster when this stimulus was intermittently paired with the second element and the unconditioned stimulus than when a continuous reinforcement schedule was employed. Experiment II demonstrated that this effect of partial reinforcement is unaffected by maniuplating the associative strength of the second element at the outset of compound conditioning. A similar effect of partial reinforcement was also found in Experiment III which used a tone as the first element of the serial compound.

Determinants of pigeons’ choice between certain and probabilistic outcomes

“…It may be that choice proportions reflect the joint contribution of the lower rate of primary reinforcement and the higher value of the 50% food terminal link, whereas rate of responding during the terminal links leading to food reflects only the latter. Dunn and Spetch (1990) and Spetch et al (1990) noted that results from the percentage reinforcement procedure were analogous to findings from serial autoshaping studies, in which responding to a stimulus that had an intermittent relationship to the occurrence of a stimulus associated with food was higher than responding to a stimulus that was always followed by a stimulus associated with food (Collins & Pearce, 1985;Collins, Young, Davies, & Pearce, 1983). However, Pearce and Collins (1987) used choice probes to test preference between stimuli that were intermittently or perfectly predictive of a stimulus associated with food, and found that their measures of preference did not mirror the difference in response rates found in serial autoshaping.…”

Amount of training effects in representationmediated food aversion learning: No evidence of a role for associability changes

“…Thus, on reinforced trials the US would have been similarly processed in both conditions. Note too that the high level of US expectancy in the PRF condition would tend to maximize the surprise effect of the omission of the US on nonreinforced trials in the PRF condition, increasing the chance of enhancement of processing of the CS on those trials, as was intended in Experiment 3 and as was observed by Pearce and his colleagues Collins et al, 1983).…”

“…Thus, the associability of a CS should be maintained at a higher value with partial reinforcement procedures than with consistent reinforcement procedures. Using orienting responses as an indicator of associability, Pearce and colleagues (e.g., Collins, Young, Davies, & Pearce, 1983;Kaye & Pearce, 1984;Pearce, Kaye, & Collins, 1985) found substantially greater associability of CS trained with a variety of partial reinforcement procedures than of that trained with consistent reinforcement procedures.…”

Disconnection of the amygdala central nucleus and the substantia innominata/nucleus basalis magnocellularis disrupts performance in a sustained attention task.

“…One interpretation of this latter finding is that the rats allocated less attention to the PRF cues than to the CRF cues within the 5-cue array and hence performance to PRF cues was more disrupted by the further demands placed on attentional processing by shortening their duration. Thus, unlike in tasks that assess the acquisition of new learning (e.g., Collins & Pearce, 1985;Collins et al, 1983, Kaye & Pearce, 1984, partially-reinforced cues control less attention than consistently-reinforced in the task studied here.…”

“…Next, we assessed the effects of a cue duration challenge, in which the duration of the cues was reduced first to 250 ms and then to 100 ms. If PRF cues control more attention than CRF cues in this task, as they do in tasks that measure rates of new learning about cues (Collins & Pearce, 1985;Collins et al, 1983;Kaye & Pearce, 1984), then responding to the PRF cues should be less susceptible to the cue-duration challenge. By contrast, if rats devote fewer attentional resources to PRF cues than to CRF cues, then responding to PRF cues should be more susceptible to that challenge.…”