CiteULike: Group: ACS-Basel - with tag animal

Food-Caching Western Scrub-Jays Keep Track of Who Was Watching When

Joanna Dally — 2006-07-24T13:59:25-00:00

Science, Vol. 312, No. 5780. (16 June 2006), pp. 1662-1665.

Western scrub-jays (Aphelocoma californica) hide food caches for future consumption, steal others' caches, and engage in tactics to minimize the chance that their own caches will be stolen. We show that scrub-jays remember which individual watched them during particular caching events and alter their recaching behavior accordingly. We found no evidence to suggest that a storer's use of cache protection tactics is cued by the observer's behavior. 10.1126/science.1126539

Social Modulation of Pain as Evidence for Empathy in Mice

Dale Langford — 2006-07-07T21:50:31-00:00

Science, Vol. 312, No. 5782. (30 June 2006), pp. 1967-1970.

Empathy is thought to be unique to higher primates, possibly to humans alone. We report the modulation of pain sensitivity in mice produced solely by exposure to their cagemates, but not to strangers, in pain. Mice tested in dyads and given an identical noxious stimulus displayed increased pain behaviors with statistically greater co-occurrence, effects dependent on visual observation. When familiar mice were given noxious stimuli of different intensities, their pain behavior was influenced by their neighbor's status bidirectionally. Finally, observation of a cagemate in pain altered pain sensitivity of an entirely different modality, suggesting that nociceptive mechanisms in general are sensitized. 10.1126/science.1128322

Risk-sensitive neurons in macaque posterior cingulate cortex

Allison Mccoy — 2005-08-27T03:41:31-00:00

Nature Neuroscience, Vol. 8, No. 9. (14 August 2005), pp. 1220-1227.

People and animals often demonstrate strong attraction or aversion to options with uncertain or risky rewards, yet the neural substrate of subjective risk preferences has rarely been investigated. Here we show that monkeys systematically preferred the risky target in a visual gambling task in which they chose between two targets offering the same mean reward but differing in reward uncertainty. Neuronal activity in posterior cingulate cortex (CGp), a brain area linked to visual orienting and reward processing, increased when monkeys made risky choices and scaled with the degree of risk. CGp activation was better predicted by the subjective salience of a chosen target than by its actual value. These data suggest that CGp signals the subjective preferences that guide visual orienting.

Human-like social skills in dogs?

Brian Hare — 2005-08-29T10:03:08-00:00

Trends in Cognitive Sciences, Vol. 9, No. 9. (September 2005), pp. 439-444.

Domestic dogs are unusually skilled at reading human social and communicative behavior - even more so than our nearest primate relatives. For example, they use human social and communicative behavior (e.g. a pointing gesture) to find hidden food, and they know what the human can and cannot see in various situations. Recent comparisons between canid species suggest that these unusual social skills have a heritable component and initially evolved during domestication as a result of selection on systems mediating fear and aggression towards humans. Differences in chimpanzee and human temperament suggest that a similar process may have been an important catalyst leading to the evolution of unusual social skills in our own species. The study of convergent evolution provides an exciting opportunity to gain further insights into the evolutionary processes leading to human-like forms of cooperation and communication.

Predicting risk sensitivity in humans and lower animals: risk as variance or coefficient of variation.

EU Weber — 2005-02-20T19:43:47-00:00

Psychol Rev, Vol. 111, No. 2. (April 2004), pp. 430-445.

This article examines the statistical determinants of risk preference. In a meta-analysis of animal risk preference (foraging birds and insects), the coefficient of variation (CV), a measure of risk per unit of return, predicts choices far better than outcome variance, the risk measure of normative models. In a meta-analysis of human risk preference, the superiority of the CV over variance in predicting risk taking is not as strong. Two experiments show that people's risk sensitivity becomes strongly proportional to the CV when they learn about choice alternatives like other animals, by experiential sampling over time. Experience-based choices differ from choices when outcomes and probabilities are numerically described. Zipf's law as an ecological regularity and Weber's law as a psychological regularity may give rise to the CV as a measure of risk.