About the Authors

Pier F Ferrari

To whom correspondence should be addressed. E-mail: ferrari@biol.unipr.it

Affiliations Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, Parma, Italy , Dipartimento di Neuroscienze, Università di Parma, Parma, Italy

Elisabetta Visalberghi

Affiliation Istituto di Scienze e Tecnologie della Cognizione, National Research Council, Rome, Italy

Annika Paukner

Affiliation Laboratory of Comparative Ethology, The National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America

Leonardo Fogassi

Affiliations Dipartimento di Neuroscienze, Università di Parma, Parma, Italy , Dipartimento di Psicologia, Università di Parma, Parma, Italy

Angela Ruggiero

Affiliation Laboratory of Comparative Ethology, The National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America

Stephen J Suomi

Affiliation Laboratory of Comparative Ethology, The National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

PFF, EV, LF, and SJS conceived and designed the experiments. PFF, EV, and AR performed the experiments. PFF and AP analyzed the data. PFF, EV, and SJS wrote the paper.