Laughing Rats Are Optimistic

High-frequency ultrasonic vocalizations in rats in response to tickling: The effects of restraint stress

(2012) Piotr Popik et al.   BEHAVIOURAL BRAIN RESEARCH

Evidence That Emotion Mediates Social Attention in Rhesus Macaques

(2012) Emily J. Bethell et al.   PLoS One

Agitated Honeybees Exhibit Pessimistic Cognitive Biases

(2011) Melissa Bateson et al.   CURRENT BIOLOGY

Measuring judgement bias and emotional reactivity in sheep following long-term exposure to unpredictable and aversive events

(2011) Rebecca E. Doyle et al.   PHYSIOLOGY & BEHAVIOR

Stereotyping starlings are more ‘pessimistic’

(2010) Ben O. Brilot et al.   ANIMAL COGNITION

Cognitive bias in the chick anxiety–depression model

(2010) Amy L. Salmeto et al.   BRAIN RESEARCH

Dogs showing separation-related behaviour exhibit a ‘pessimistic’ cognitive bias

(2010) Michael Mendl et al.   CURRENT BIOLOGY

Neural Activity Associated with the Passive Prediction of Ambiguity and Risk for Aversive Events

(2009) D. R. Bach et al.   JOURNAL OF NEUROSCIENCE

Ambiguous-Cue Interpretation is Biased Under Stress- and Depression-Like States in Rats

(2009) Thomas Enkel et al.   NEUROPSYCHOPHARMACOLOGY

Ultrasonic vocalizations of rats (Rattus norvegicus) during mating, play, and aggression: Behavioral concomitants, relationship to reward, and self-administration of playback..

(2008) Jeffrey Burgdorf et al.   JOURNAL OF COMPARATIVE PSYCHOLOGY