Reinforcement modality influences performance in a quantity discrimination task in the dog.

REINFORCEMENT MODALITY INFLUENCES PERFORMANCE IN A QUANTITY DISCRIMINATION TASK IN THE DOG Simona Normando1, Elena Pietshmann1, Elena Carloni2, Valentina Beghelli2, Michela Mattioli2, Serena Ribolzi1, Pierattilio Accorsi2, Lucia Regolin3 1. Dipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, Italy; 2. Dipartimento di Scienze Mediche Veterinarie, Università degli Studi di Bologna, Italy; 3. Dipartimento di Psicologia Generale, Università degli Studi di Padova, Italy. Quantity discrimination has been assessed in a variety of species and with a variety of paradigms. AIM: This preliminary study aimed to investigate whether the way dogs (Canis familiaris) were reinforced influenced their performance in a quantity discrimination task. MATERIALS AND METHODS: The dog was kept on a lead, while the tester put two dishes (containing 1 and 8 food pieces) on the floor in front of it. The tester retreated and the dog was freed after it had looked at both dishes. Choice of a dish was scored the very first time the nose of the dog approached it at 10 cm. Three sessions of six trials each were performed. Differential reinforcement treatment (15 dogs): dogs could eat the content of the chosen dish. Non-differential reinforcement treatment (10 dogs), access to dish content was prevented, the owner gave the dog a standard treat after each choice. RESULTS: Three dogs of the non-differential treatment and 11 of the differential one reached binomial criterion for choosing the larger quantity significantly more often. Dogs from both groups chose above chance level in the first session of trials (and even in their very first spontaneous choice), but only those of the differential treatment were successful also in the second and third sessions. CONCLUSION: dogs have the cognitive ability to differentiate among quantities, but reinforcement modality can heavily affect their performance