Abstract
Reversal learning requires an animal to learn to discriminate between two stimuli but reverse its responses to these stimuli every time it has reached a learning criterion. Thus, different from pure discrimination experiments, reversal learning experiments require the animal to respond to stimuli flexibly, and the reversal learning performance can be taken as an illustration of the animal's cognitive abilities. We herein describe a reversal learning experiment involving a simple spatial discrimination task, choosing the right or left side, with octopus. When trained with positive reinforcement alone, most octopuses did not even learn the original task. The learning behavior changed drastically when incorrect choices were indicated by a visual signal: the octopuses learned the task within a few sessions and completed several reversals thereby decreasing the number of errors needed to complete a reversal successively. A group of octopus trained with the incorrect-choice signal directly acquired the task quickly and reduced their performances over reversals. Our results indicate that octopuses are able to perform successfully in a reversal experiment based on a spatial discrimination showing progressive improvement, however, without reaching the ultimate performance. Thus, depending on the experimental context, octopus can show behavioral flexibility in a reversal learning task, which goes beyond mere discrimination learning.
Highlights
A reversal learning experiment is a classic experiment to investigate the cognitive abilities of an individual and was originally used by Bitterman and colleagues to compare the learning abilities of different species (Bitterman, 1965)
Studying the cognitive abilities of Octopus vulgaris is of particular interest, as this species, belonging to the mollusks, is usually considered to possess extraordinary or “vertebrate-like” cognitive abilities (Mather et al, 2010) such as its ability to learn from observing conspecifics (Fiorito and Scotto, 1992)
Ov2 did not drastically improve its performance over reversals (F-statistics; Ov2 F = 0.7, df = 3, p = 0.46); the number of errors even increased during the last reversal; as the animal stopped cooperating completely thereafter, we assumed that its performance in its last completed reversal had already been caused by a cease in motivation as usually occurring at a late point in octopus’ training
Summary
A reversal learning experiment is a classic experiment to investigate the cognitive abilities of an individual and was originally used by Bitterman and colleagues to compare the learning abilities of different species (Bitterman, 1965). Studying the cognitive abilities of Octopus vulgaris is of particular interest, as this species, belonging to the mollusks, is usually considered to possess extraordinary or “vertebrate-like” cognitive abilities (Mather et al, 2010) such as its ability to learn from observing conspecifics (Fiorito and Scotto, 1992). During a reversal learning task, the animal first has to learn to discriminate between two stimuli to a predefined criterion during the acquisition phase. A number of reversals are conducted to test whether the animal will show progressive improvement in such a serial reversal learning experiment; progressive improvement is defined as a decrease in the number of errors per reversal
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
