Salience modulation and associative inhibition interaction: Short but not long exposure to similar stimuli protects the salience of the unique elements

• Published in: Behavioural processes 2011-01, Vol.86 (1), p.21-29
• Main Authors: Contel, David M., Sansa, Joan, Artigas, Antonio A., Prados, Jose
• Format: Article
• Language: English
• Subjects: Acids; Animal ethology; Animals; Associative inhibition; Biological and medical sciences; Citric Acid; Conditioning, Operant - physiology; Discrimination Learning; Drinking; Female; flavor compounds; Fundamental and applied biological sciences. Psychology; Generalization, Stimulus; learning; Male; Perceptual learning; Psychology. Psychoanalysis. Psychiatry; Rats; Rats, Long-Evans; Salience modulation; Sodium Chloride; Sucrose; Taste - physiology; Vanilla; Water Deprivation
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2010.08.001

▶ The aim of the experiments reported was to assess how different perceptual learning mechanisms—salience modulation and associative inhibition—interact. ▶ The experiments show that relatively short alternated exposure to similar stimuli (AX and BX) protects the unique elements A and B from habituation. ▶ With prolonged exposure, however, the protection of habituation is not observed. ▶ Associative activation of A and B in the alternated BX and AX trials (via the X—A and the X—B associations) protects the salience of the unique features A and B after short preexposure; with further preexposure, however, inhibitory associations between A and B develop, counteracting the associative activation mechanism that protects from habituation. ▶ The results reported support the notion that perceptual learning is a multi-determined phenomenon that depends on salience modulation processes after relatively short preexposure, and on an associative inhibition mechanism after prolonged preexposure. In three experiments, rats were given preexposure to two similar flavour compounds, AX and BX. Following preexposure, conditioning trials took place in which AX was paired with an illness-induced unconditioned stimulus. Animals that were given short alternated preexposure to AX and BX, showed higher generalization of conditioned aversion to AX to a new compound, AN, than animals that were given blocked preexposure (short and long) and long alternated preexposure (Experiments 1 and 2); and showed less preference for A when they were given a choice between A and X (Experiment 3). These results have been taken to indicate that the salience of the A element is well preserved after short alternated preexposure, but declines when preexposure goes on for some more trials. The results reported support the notion that perceptual learning is a multi-determined phenomenon that depends on salience modulation processes after relatively short preexposure, and on an associative inhibition mechanism after prolonged preexposure.