Navigation Links
Dolphins and whales experience pleasure
Date:8/14/2014

Sam Ridgway has spent most of his life learning about dolphins and whales. Over his five-decade career he has asked these cetaceans various questions, including how deep they can dive and how depth affects their hearing. As he trained each animal to answer his questions, he rewarded them with tasty fish treats, and each time that they received a reward he remembers that they squealed. Initially he thought that the squeals were food signals, where animals communicate the presence of food to nearby members of their species. It was only when his wife Jeanette suggested that the squeals reminded her of delighted children that he began to ponder whether there was more to the cetaceans' cries: could they be genuine expressions of delight? Ridgway publishes his discovered that the time delay between dolphins and whales receiving a reward and their squeals is the same as the delay between a pleasant experience and dopamine release suggesting that dolphins and whales experience pleasure in the Journal of Experimental biology at http://jeb.biologists.org.

Humans train animals by rewarding them with tasty treats and trainers couple the reward with a sound, such as a buzz or a whistle. Once the animal has mastered the task, the trainer stops dispensing food, relying instead on the whistle or buzzer to inform the animal that it has performed successfully and that it will be rewarded with food later. What impressed Ridgway was that even though there was no food reward at the time, the whales and dolphins squealed in response to the sound that substituted for the food reward. And when he trained dolphins and beluga whales to switch off a sound after diving hundreds of metres, Ridgway was impressed that the animals produced the same squeals of victory when the sound stopped. 'The [squealing] behaviour had transferred over to another stimulus that wasn't food', says Ridgway. The behaviour also reminded him of studies in the 1950s when animals appeared to derive as much pleasure from electrical stimulation of a region of the brain that released dopamine a chemical that stimulates the sensation of pleasure as they did when receiving a food reward. Had the trained dolphins and beluga whales transferred the release of dopamine from the brain's pleasure centres from the food reward to the trainer's reward signal?

Delving back through decades of recordings of experiments designed to test the abilities of dolphins and beluga whales that he had conducted with Patrick Moore, Don Carder and Tracy Romano, Ridgway then measured the delay between the trainer's signal and the victory squeals. As dopamine release takes 100 ms, Ridgway realised that the animals could be expressing pleasure if the delay between the promise of a reward and the animals' squeals was longer then the dopamine release period.

'Normally we worked in open waters in the San Diego Bay or out in the ocean Our recordings sometimes have a lot of background noise, so most of the analysis has to be done by hand using the human ear', recalls Ridgway. However, after months of painstaking analysis, Ridgway was convinced that the beluga whales and dolphins were expressing pleasure through their squeals. 'The dolphins take an average of 151 ms extra time for this release, and with the belugasit's about 250 ms delay', says Ridgway. He concludes with a smile, 'We think we have demonstrated that it [the victory squeal] has emotional content', before adding that he is keen to find out more about the cognitive abilities of these expressive animals.


'/>"/>
Contact: Kathryn Knight
kathryn@biologists.com
44-012-234-25525
The Company of Biologists
Source:Eurekalert

Related biology news :

1. Size matters: Large Marine Protected Areas work for dolphins
2. Dolphins cultivate loose alliances
3. Mercury in dolphins: Study compares toxin levels in captive and wild sea mammals
4. Do dolphins think nonlinearly?
5. New maps may reduce tourism impacts on Hawaiian dolphins
6. Eating right key to survival of whales and dolphins: UBC research
7. Dolphins inspire new radar system to detect hidden surveillance and explosive devices
8. Deepwater Horizon NRDA study shows possible oil impact on dolphins
9. For bats and dolphins, hearing gene prestin adapted for echolocation
10. Study assesses shark attacks on Atlantic spotted dolphins near the Bahamas
11. Genetic survey of endangered Antarctic blue whales shows surprising diversity
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... 2017 KEY FINDINGS The global ... a CAGR of 25.76% during the forecast period of ... factor for the growth of the stem cell market. ... MARKET INSIGHTS The global stem cell market is ... geography. The stem cell market of the product is ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University (PolyU) ... ground breaking 3D fingerprint minutiae recovery and matching technology, pushing contactless ... use in identification, crime investigation, immigration control, security of access and ... ... A research team led by Dr Ajay Kumar ...
(Date:3/27/2017)... , March 27, 2017  Catholic Health ... and Management Systems Society (HIMSS) Analytics for achieving ... Adoption Model sm . In addition, CHS previously ... U.S. hospitals using an electronic medical record (EMR). ... its high level of EMR usage in an ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... ... 27, 2017 , ... Mitotech S.A, a Luxembourg based clinical stage biotechnology company, ... LHON is a rare devastating genetic disease that leads to a sudden and rapid ... of 20 patients carrying 11778, 14484 and 3460 mutations and having experienced the onset ...
(Date:4/27/2017)... Orleans, La. (PRWEB) , ... ... ... Monitoring Technologies today announced a comprehensive rebrand and a name change to ... for the industrial and laboratory monitoring of polymer and biopharmaceutical manufacturing processes ...
(Date:4/26/2017)... ... 26, 2017 , ... Looking for gift ideas for mom ... offers one-of-a-kind gifts, ranging from gourmet cooking experiences to Farmer’s Market Tours and ... inspired with new cooking tips and techniques, thanks to Chef Jodi Abel’s expertise ...
(Date:4/26/2017)... ... April 26, 2017 , ... NextSteps ... and North America this May on the following dates: , ?    London, ... Taylor, Chairman of the Learning and Performance Institute will be the opening ...
Breaking Biology Technology: