title: Cue competition effects in the planarian.
abstract: The learning abilities of planarian worms (Dugesia tigrina) were assessed by using a number of Pavlovian conditioning paradigms. Experiment 1 showed that planaria were susceptible to basic conditioning in that they readily developed a conditioned response to a change in ambient luminance when it was consistently paired with an electric shock over a number of trials. In Experiment 2, the change in luminance was presented in a compound with a vibration stimulus during conditioning. Subsequent tests revealed poor conditioning of the elements compared with control groups in which the animals were conditioned in the presence of the elements alone, an instance of overshadowing. In Experiment 3, pre-training of one of the elements before compound conditioning resulted in blocking of learning about the other element. These results add to other studies that have reported cue competition effects in animal species belonging to different phyla (chordate, mollusk, arthropod), suggesting that learning in these phyla could be ruled by similar principles. The results are discussed adopting an evolutionary-comparative approach.
authors.affiliation: School of Psychology, University of Leicester, Lancaster Road, Leicester, LE1 9HN, UK. jpg19@le.ac.uk
authors.forename: Jose
authors.initials: J
authors.lastname: Prados
authors.forename: Beatriz
authors.initials: B
authors.lastname: Alvarez
authors.forename: Joanna
authors.initials: J
authors.lastname: Howarth
authors.forename: Katharine
authors.initials: K
authors.lastname: Stewart
authors.forename: Claire L
authors.initials: CL
authors.lastname: Gibson
authors.forename: Claire V
authors.initials: CV
authors.lastname: Hutchinson
authors.forename: Andrew M J
authors.initials: AM
authors.lastname: Young
authors.forename: Colin
authors.initials: C
authors.lastname: Davidson
mesh_terms: D000818:Animals; D003214:Conditioning, Classical; D003463:Cues; D004597:Electroshock; D010775:Photic Stimulation; D010932:Planarians