title: Kinetic assessment of the effects of task difficulty, microencephaly, and a response manipulandum alteration on the rate of fixed-ratio discrimination acquisition.
abstract: Fixed-ratio discrimination (FRD) training session-accuracy curves were constructed using first-order, nonlinear regression and probit analyses to determine maximal (asymptotic) accuracy and the number of sessions required to reach half-maximal accuracy. Increased FRD difficulty (reductions in the differences between the 2 fixed-ratio values to be discriminated) and a training parameter change each increased the number of sessions required to reach half-maximal accuracy and decreased maximal FRD accuracy (i.e., session-accuracy curves were shifted down and to the right) regardless of analysis procedure. These findings indicate that the above manipulations induced mixed competitive-noncompetitive inhibition of the rate of FRD learning. Microencephalic rats were more sensitive to increases in FRD difficulty, whereas control rats were more sensitive to the training parameter change.
authors.affiliation: Department of Pharmacology and Toxicology, University of Kansas, School of Pharmacy, Lawrence 66045-2505, USA. tessel@dole.lsi.ukans.edu
authors.forename: Richard E
authors.initials: RE
authors.lastname: Tessel
authors.forename: Pippa S
authors.initials: PS
authors.lastname: Loupe
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Schroeder
authors.forename: John
authors.initials: J
authors.lastname: Schloss
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology*; D005260:Female; D007700:Kinetics; D008746:Methylazoxymethanol Acetate / Q000031:analogs & derivatives* / Q000494:pharmacology; D008831:Microcephaly / Q000139:chemically induced / Q000503:physiopathology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D013647:Task Performance and Analysis; D013723:Teratogens / Q000494:pharmacology
chemical_list: D013723:Teratogens; D008746:Methylazoxymethanol Acetate; C030667:methylazoxymethanol