The Cockatoo in 'The Market' (IMAGE) University of Vienna Caption This image shows both hands of the experimenter, each containing a different food reward. Credit Copyright: Alice Auersperg Usage Restrictions Copyright: Alice Auersperg License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.