title: Complex mixture discrimination and the role of contaminants.
abstract: Rats were trained in a 2-alternative odor choice task to discriminate between a 10-component odor mixture and the same mixture with one component removed and replaced with 1 of 3 concentrations of a different monomolecular odor (contaminant). All stimuli were presented within a training session, thus the rat essentially had to learn to discriminate the 10-component mixture from "not" the 10-component mixture. Rats performed most poorly discriminating the complete mixture from the mixture with one component removed and no contaminant added. As the concentration of the contaminant increased from 10 ppm to a concentration equal to the other components (100 ppm), discrimination improved linearly. In analyses of individual differences, rats that spent more time in the sampling port (sampling and making a decision) were more accurate than rats that spent less time. Together, these results emphasize the balance between perceptual stability and perceptual discrimination expressed by the olfactory system dealing with dynamic mixtures and the robust effects of contamination on those processes. In addition, they provide further support that modification of sampling/decision time is a strategy used by rats to deal with difficult discriminations of complex odors.
authors.affiliation: Erik Jonsson School of Engineering, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road GR41, Richardson TX 75080, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Lovitz
authors.forename: A M
authors.initials: AM
authors.lastname: Sloan
authors.forename: R L
authors.initials: RL
authors.lastname: Rennaker
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D045424:Complex Mixtures / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology*; D004192:Discrimination, Psychological / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004340:Drug Contamination; D008297:Male; D009812:Odorants / Q000032:analysis*; D051381:Rats; D020318:Rats, Long-Evans; D012684:Sensory Thresholds / Q000187:drug effects; D012903:Smell / Q000187:drug effects* / Q000502:physiology; D013268:Stimulation, Chemical; D013997:Time Factors
chemical_list: D045424:Complex Mixtures