Implicit chaining in cotton-top tamarins (Saguinus oedipus) with elements equated for probability of reinforcement

Abstract

Three experiments examined the implicit learning of sequences under conditions in which the elements comprising a sequence were equated in terms of reinforcement probability. In Experiment 1 cotton-top tamarins (Saguinus oedipus) experienced a five-element sequence displayed serially on a touch screen in which reinforcement probability was equated across elements at .16 per element. Tamarins demonstrated learning of this sequence with higher latencies during a random test as compared to baseline sequence training. In Experiments 2 and 3, manipulations of the procedure used in the first experiment were undertaken to rule out a confound owing to the fact that the elements in Experiment 1 bore different temporal relations to the intertrial interval (ITI), an inhibitory period. The results of Experiments 2 and 3 indicated that the implicit learning observed in Experiment 1 was not due to temporal proximity between some elements and the inhibitory ITI. The results taken together support two conclusion: First that tamarins engaged in sequence learning whether or not there was contingent reinforcement for learning the sequence, and second that this learning was not due to subtle differences in associative strength between the elements of the sequence.

The Temporal Dynamics of Regularity Extraction in Non‐Human Primates

“…It has already been shown that monkeys can learn regular patterns within the serial RT paradigm by displaying faster RTs after sufficient exposure to these patterns (Heimbauer et al, 2012;Locurto et al, 2010Locurto et al, , 2013Procyk et al, 2000). Several attempts have even been made to study the learning of non-adjacent dependencies (Newport, Hauser, Spaepen, & Aslin, 2004) and monkeys' sensitivity to the grammar of human natural language (Saffran et al, 2008).…”

“…Thus, cotton-top tamarins were able to discriminate a word from a non-word or a part-word after having been exposed to an artificial language in a protocol similar to Saffran (Hauser, Newport, & Aslin, 2001). Moreover, experiments using the serial response time task (SRT; Nissen & Bullemer, 1987), a task in which a participant have to respond to sequences of stimuli that appear one-by-one at various locations on a computer screen, showed that non-human primates can also use statistical cues to learn a predictable motor sequence (Heimbauer, Conway, Christiansen, Beran, & Owren, 2012;Locurto, Dillon, Collins, Conway, & Cunningham, 2013;Locurto, Gagne, & Nutile, 2010;Procyk, Ford Dominey, Amiez, & Joseph, 2000). On these grounds, we chose to test a group of Guinea baboons (Papio papio) instead of humans.…”

Implicit sequence learning in ring‐tailed lemurs ( Lemur catta )

“…For instance, we did not include any intertrial interval between stimuli or between repetitions of the sequence, whereas tamarin monkeys received a 5‐s white screen prior to the first element in a chain and a 20‐second black screen following the final element (Locurto et al, , , & Experiment 1 of 2013), or a 1‐s ITI between every pair of elements (Locurto et al, , Experiment 2). It could be that forcing subjects to pause between responses encouraged perceptual encoding of the responses.…”

Implicit learning in cotton-top tamarins (Saguinus oedipus) and pigeons (Columba livia)

“…All three subjects had served previously in implicit-learning experiments (viz. Locurto et al, 2013;Locurto et al, 2009;Locurto et al, 2010). The tamarins were born and housed individually at the New England Primate Research Center, Southborough, Massachusetts, and were maintained under the guidelines of the Committee on Animals of the Harvard Medical School.…”

“…Two subsequent series of studies using tamarins have extended this basic procedure (Locurto, Dillon, Collins, Conway, & Cunningham, 2013;Locurto et al, 2010). These studies revealed that, in the format of presenting elements in an A → E pattern with reinforcement at the end of the chain, a visually based task in which the elements were defined as different images rather than as different spatial locations of the same image produced approximately the same levels of implicit learning (Locurto et al, 2010, Exp.…”