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| Olfactory Stimulus Relations in Nonhumans |
| Saturday, May 29, 2010 |
| 1:30 PM–2:50 PM |
| Lone Star Ballroom Salon F (Grand Hyatt) |
| Area: EAB/VBC; Domain: Experimental Analysis |
| Chair: Mark Galizio (University of North Carolina, Wilmington) |
| Discussant: William V. Dube (University of Maryland Medical System) |
| Abstract: Research on complex stimulus control is rarely reported in rodents, perhaps because their performances are relatively poor using typical laboratory stimulus modalities (e.g., visual, auditory). Although olfactory stimuli are more difficult to arrange and control in laboratory settings, recent reports of sophisticated and complex stimulus control with this modality commend it for further research. The three presentations in this symposium offer a series of methodological advances and explorations in the study of olfactory stimulus relations in rodents. Lionello-DeNolf and Mihalick will present data on olfactory discrimination reversals and identity matching in rats using a novel apparatus. Galizio, Poerstal & Bruce will present data from an incrementing olfactory non-match-to-sample procedure that permits the study of olfactory memory capacity, and Dr. Iversen will present data on cross-modal matching-to-sample using olfactory and tactile stimuli. Dr. Dube will integrate and discuss the three presentations. Taken together, these presentations will provide a snapshot of the state of research on relational learning and olfactory stimulus control in rodents. |
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| Simple Discrimination Reversal and Conditional Discrimination of Odor Stimuli by Rats |
| KAREN M. LIONELLO-DENOLF (University of Massachusetts Medical School), Sheila Mihalick (University of Massachusetts Boston) |
| Abstract: Despite the prevalent use of rats in research, their superior olfactory abilities have seldom been exploited on behaviorally based tasks. Possibly, this is related to difficulties with presenting and controlling olfactory stimuli. Using a fully automated apparatus that can present up to six unique olfactory stimuli in any of five locations, we have developed a training protocol wherein rats respond with a nose poke in the appropriate aperture. Six rats were first trained on a series of simple discrimination and reversal problems in which stimulus presentation varied across five locations over trials. All rats acquired the initial discriminations in a maximum of 15 sessions and the reversals in a maximum of 25 sessions. Next, these same rats were trained on matching to sample with the odors used in the first simple discrimination task. Rats were required to nosepoke on both the sample and correct comparison. Matching accuracy steadily increased from chance to approximately 80% over the first 20-30 sessions, but then began deteriorating without recovery. Possible explanations for this failure will be discussed, including data on remedial procedures we conducted, and comparison data from rats that were trained on simple discriminations with odors presented in only three of the five locations. |
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| Matching- and Non-matching-to-sample with Olfactory Stimuli |
| MARK GALIZIO (University of North Carolina, Wilmington), L. Brooke Poerstal (University of North Carolina, Wilmington), Katherine Ely Bruce (University of North Carolina, Wilmington) |
| Abstract: We report data from several procedures involving matching- and non-matching-to-sample with olfactory stimuli. Complex relational stimulus control is readily acquired with some of our procedures (e.g., arena olfactory span task) but is more difficult to demonstrate with others (e.g., three-choice olfactometer). For example, in the olfactory span task rats are exposed to incrementing non-match-to-sample trials where a new stimulus is added on each trial. This procedure permits analysis of stimulus control by multiple sample stimuli and measurement of olfactory memory span. Rats acquire this complex task rapidly and performances show excellent control by as many as 36 different stimuli. In contrast, identity matching-to-sample in an olfactometer is acquired slowly in most rats, but not at all by some. Taken together these data suggest that use of the olfactory modality is not sufficient to produce rapid learning and relational control, but that other variables are important determinants of the successful acquisition of olfactory stimulus control. |
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| Cross-modal Matching-to-sample Procedures |
| IVER H. IVERSEN (University of North Florida) |
| Abstract: The presentation will offer a review of existing procedures for studies of cross-modal matching where the sample is from one sensory modality while the comparisons are from a different sensory modality. A particular emphasis will be placed on automated procedures that use olfactory or tactile stimuli as samples. Data will be presented from on ongoing project where rats engage a sampling port with olfactory or tactile stimuli and select among different visual comparison stimuli (steady vs. blinking lights) conditional upon the sample. The method can present one of two sample stimuli from one modality automatically. Rats are first trained with identity matching using visual stimuli as samples to ensure that they can indeed respond correctly under the overall procedure. After high accuracy of identity matching is obtained, the procedure is changed to a cross-modal matching task with olfactory or tactile sample stimuli. Acquisition of matching will be compared using different olfactory stimuli and different tactile stimuli as samples. The research seeks to expand the domain of sensory modalities used in laboratory research on matching-to sample. |
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