Which is not difficult. A fixed ratio contingency selectively reinforcers high rates (the faster the subject responds, the sooner it gets reinforced), so that's where we usually see high rates. It's also easy to more specifically shape rates -- requiring (as Stephen said) shorter and shorter inter-response times for reinforcement. I had students doing this in cases where they had trouble building high ratios with rats. Usually had them reinforce first two responses with less than a one second IRT, then three.... when they got up to five they almost always had a high overall rate, with the usual topographic shift, And back when I was investigating the effects of ethanol on behavior I shaped rats on a reaction time task; requiring successively short latencies after a stimulus presentation for reinforcement.
On Apr 22, 2009, at 12:30 AM, sbl...@ubishops.ca wrote: > On 21 Apr 2009 at 17:24, Ken Steele wrote: > >> I have had a few rats that have produced very high response >> rates. In one case, the rat was grabbing the bar with its teeth >> and shaking the bar like it had caught a prey. I've also observed this -- a classic case of an existing genetically determined behavior being co-opted by reinforcement contingencies and becoming an operant. I also found it typical on ratio schedules for rats to put one paw above the lever and one below it and flutter the lever faster than a simple gravity return. Again, the effect of the ratio contingency; not explicit shaping. The weirdest lever pressing topography I ever had was a rat who learned to press a lever by sitting on it! > Of course if you want _really_ high rates, you have to selectively > reinforce for them (progressively targeting shorter inter-response > times). > > I've heard that you can get a pigeon to peck fast enough that way > to melt > its beak, undoubtedly an exaggeration, and fortunately, because the > PETA > people would be rather put out if it were true. > > Ken also said, in another post: > >> Many people who work with rats for a long time develop various >> kinds of allergic reactions to the rats. > > Doesn't have to be long. And it can be rabbits too. I offer myself > as a > prime example of a victim of both. Arriving in graduate school I was > assigned a desk...a few feet from a rack of cages full of rats. Not > having been warned about this nasty consequence, and never having > experienced an allergy before, it took me a long time to catch on. > In the > meantime I wondered why my nose was always running, my itchy eyes > bulged > out from rubbing them, I had coughing fits, and my lungs gurgled > when I > breathed. Finally, one day after running out of the lab feeling I was > either having a heart attack or suffocating, it dawned on me. > > I dealt with it mostly by taking anti-histamines, which only partially > worked and left me feeling spaced-out. Protective clothing and a mask > were hot and uncomfortable, and I don't even want to talk about > sneezing > into your mask while doing stereotaxic surgery. Looking back, I'd > have to > say it was a dangerous thing to do, and I'd advise anyone with a > similar > problem nowadays to switch to human research. > > But when I get the allergy question from doctors, I enjoy telling > them, > yes, to rats. This puzzles 'em. Paul Brandon Emeritus Professor of Psychology Minnesota State University, Mankato paul.bran...@mnsu.edu --- To make changes to your subscription contact: Bill Southerly (bsouthe...@frostburg.edu)
