Animal Training

Clicker Training

by Rebecca on November 7, 2010

in Animal Training

From Wikipedia:

Clicker training is an operant conditioning method for training an animal using a clicker, or small mechanical noisemaker, as a marker for behavior. The method uses positive reinforcement – it is reward based. The clicker is used during the acquisition phase of training a new behavior, to allow the animal to rapidly identify that a behavior is sought and also the precise behavior of interest.

File:ClickerDogFxwb.jpg 

Clicker training was originated through Marian Bailey (neé Kruse) and Keller Breland, who as graduate students of psychologist and eminent behaviorist B.F. Skinner taught wild-caught pigeons to bowl while participating in military research. According to their work, animal training was being needlessly hindered because traditional methods of praise and reward did not inform the animal of success with enough promptness and precision to create the required cognitive connections for speedy learning. Similar methods were later used in training at least 140 species including whales, bears, lions and domestic dogs and cats, and even humans.

Advantages

One of the challenges in training an animal is communicating exactly when the animal has done the behavior that the handler is attempting to reinforce. As a simple example, consider teaching a dog to turn in a circle (spin). At the instant that the dog completes the turn, the handler must let the dog know that it has done the correct thing. However, the traditional “good dog!” takes so long to say that the dog might already have moved on to some other behavior. At the least it is not immediately obvious that the “good boy” is earned at the precise moment of completing a circle. By the time the dog realizes it is being praised, it might be sitting and scratching or looking for something else to do.

In the laboratory behavioral researchers including Norm Guttman, Marian Kruse and Keller Breland, realized that rats always stop what they are doing when they hear the hopper make a sound indicating it was beginning to deliver food, and they tend to do more of what they were doing when the sound occurred. Under the instruction of B.F. Skinner, they decided to try using a sound to mark behavior outside the operant chamber. Toy crickets, the earlier equivalent of today’s clicker, were common in those days, and served the purpose very well. The clicker is likened to the surgeon’s scalpel; it allows for precise timing and clear communication about what specific behavior is being reinforced, and enables the trainer to teach complex and difficult skills to the animal without the use of force or punishment.

At least one study has shown that the clicker can reduce training time by 1/3.

As this type of training was practiced and improved upon, it became apparent that the variability of the human voice, and its presence during all activities make it a less than salient tool for marking behavior. Besides the imprecision in timing, using the trainer’s voice for feedback means that the actual sounds for feedback will vary. A handler’s voice, pronunciation, tone, loudness, and emphasis may change even during the same training session. Clicker trainers believe that it is better to use a “click” sound to avoid variations in sound. Many trainers opt to use clickers for training that requires precision and continue to use their voices in the form of praise for behaviors that do not need to be precise.

There is also some circumstantial evidence which suggests that the sound of the clicker is the kind of stimulus — like a bright flash of light or a loud, sudden sound — that reach the amygdala (the center of emotion in the brain) first, before reaching the cortex (the thinking part of the brain). Clicker trainers often see rapid learning, long retention and a “joy” response to the sound of the click in the learning animal. This idea is not universally accepted, and no known research has confirmed it. Any reinforcer can produce joyful behaviors in learners if delivered correctly.

Tasks learned with the clicker are retained even years after the fact and with no additional practice after the initial learning has taken place. This is probably due to the fact that the animal participates fully in the learning process and applies itself to it, learning by trial and error rather than acting out of habit or a momentary response to a situation. Clicker–trained animals become great problem–solvers, develop confidence, and perform their work enthusiastically. This retention of learning is present in positive reinforcement training (including but not exclusive to clicker training), but does not happen with any regularity with correction-based training.

The marker can be any signal that the animal can perceive, so long as the signal is brief (to prevent the problem of imprecise timing) and consistent (to prevent the problem of variations that may confuse the animal). For large sea animals the marker is usually a whistle rather than a clicker. However, not all conditioned reinforcers are sounds. Goldfish and birds such as falcons and hawks can be trained using a quick flash of a flashlight as their “clicker”.] Deaf dogs can be trained with a vibrating collar.

As pointed out by Lindsay the advantages of the clicker may be particularly strong in some situations: “…the clicker’s simplicity and clarity provide a significant advantage for some training activities…”

Science News

ScienceDaily (Nov. 3, 2010) — In a finding that upends decades of scientific theory on reptile reproduction, researchers at North Carolina State University have discovered that female boa constrictors can squeeze out babies without mating. 

More strikingly, the finding shows that the babies produced from this asexual reproduction have attributes previously believed to be impossible.

Large litters of all-female babies produced by the “super mom” boa constrictor show absolutely no male influence — no genetic fingerprint that a male was involved in the reproductive process. All the female babies also retained their mother’s rare recessive color mutation.

This is the first time asexual reproduction, known in the scientific world as parthenogenesis, has been attributed to boa constrictors, says Dr. Warren Booth, an NC State postdoctoral researcher in entomology and the lead author of a paper describing the study. He adds that the results may force scientists to re-examine reptile reproduction, especially among more primitive snake species like boa constrictors.

The study is published online in Biology Letters, a Royal Society journal.

Snake sex chromosomes are a bit different from those in mammals — male snakes’ cells have two Z chromosomes, while female snakes’ cells have a Z and a W chromosome. Yet in the study, all the female babies produced by asexual reproduction had WW chromosomes, a phenomenon Booth says had not been seen before and was believed to be impossible. Only through complex manipulation in lab settings could such WW females be produced — and even then only in fish and amphibians, Booth says.

Adding to the oddity is the fact that within two years, the same boa mother produced not one, but two different snake broods of all-female, WW-chromosome babies that had the mother’s rare color mutation. One brood contained 12 babies and the second contained 10 babies. And it wasn’t because she lacked options: Male snakes were present and courted the female before she gave birth to the rare babies. And the versatile super-mom had previously had babies the “old-fashioned way” by mating with a male well before her two asexual reproduction experiences.

Booth doubts that the rare births were caused by environmental changes. He notes that while environmental stresses have been associated with asexual reproduction in some fish and other animals, no changes occurred in the mother boa’s environment or routine.

It’s possible that this one snake is some sort of genetic freak of nature, but Booth says that asexual reproduction in snakes could be more common than people think.

“Reproducing both ways could be an evolutionary ‘get-out-of-jail-free card’ for snakes,” Booth says. “If suitable males are absent, why waste those expensive eggs when you have the potential to put out some half-clones of yourself? Then, when a suitable mate is available, revert back to sexual reproduction.”

A reptile keeper and snake breeder, Booth now owns one of the young females from the study. When the all-female snake babies reach sexual maturity in a few years, Booth will be interested to see if they mate with a male, produce babies without a mate, or — like their mother — do both. In any case, these WW-chromosomed females will continue their version of “girl power,” as any baby they produce will also be female.

Drs. Coby Schal and Ed Vargo co-authored the paper. Co-author Sharon Moore raised the snakes in the study. Co-author and veterinarian Daniel Johnson provided surgical sex testing on the snakes. NC State’s Department of Entomology is part of the university’s College of Agriculture and Life Sciences.

http://www.sciencedaily.com/releases/2010/11/101103111210.htm



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