ABSTRACT
Recent work has focused on a learning diathesis model in which specific personality factors such as behavioral inhibition (BI) may influence associative learning and in turn increase risk for the development of anxiety disorders. We have found in a series of studies that individuals self-reporting high levels of BI exhibit enhanced acquisition of conditioned eyeblinks. In the study reported here, hypotheses were extended to include distressed (Type D) personality which has been found to be related to BI. Type D personality is measured with the DS-14 scale which includes two subscales measuring negative affectivity (NA) and social inhibition (SI). We hypothesized that SI, which is similar to BI, would result in enhanced acquisition while the effect of NA is unclear. Eighty nine participants completed personality inventories including the Adult Measure of Behavioral Inhibition (AMBI) and DS-14. All participants received 60 acquisition trials with a 500â¯ms, 1000â¯Hz, tone CS and a co-terminating 50â¯ms, 5â¯psi corneal airpuff US. Participants received either 100% CS-US paired trials or a schedule of partial reinforcement where 50% US alone trials were intermixed into CS-US training. Acquisition of CRs did not differ between the two training protocols. Whereas BI was significantly related to Type D, SI, and NA, only BI and SI individuals exhibited enhanced acquisition of conditioned eyeblinks as compared to non-inhibited individuals. Personality factors now including social inhibition can be used to identify individuals who express enhanced associative learning which lends further support to a learning diathesis model of anxiety disorders.
Subject(s)
Affect , Conditioning, Eyelid , Inhibition, Psychological , Personality , Social Behavior , Adolescent , Adult , Analysis of Variance , Association Learning , Auditory Perception , Female , Humans , Male , Psychological Tests , Psychometrics , Young AdultABSTRACT
1. Two lines of rats specifically bred for alcohol preference were exposed to two different behavioral tasks that required behavioral inhibition to successfully solve. 2. Learning and performance of a step-down passive avoidance task and a differential reinforcement of low-rate responding task were studied in P/NP and HAD1/LAD1 rats. 3. While the P rats had difficulty in learning both tasks, HAD1, LAD1 and NP rats performed at control levels. 4. These data suggest that P rats, but not HAD1 rats, may have problems learning tasks that require inhibition of ongoing or previously learned behaviors.
Subject(s)
Avoidance Learning , Central Nervous System Depressants/pharmacology , Ethanol/pharmacology , Animals , Behavior, Animal/drug effects , Conditioning, Operant , Female , Male , Rats , Rats, Inbred Strains/geneticsABSTRACT
BACKGROUND: This study was undertaken as one of a series of experiments designed to examine basic behavioral characteristics present in rats bred specifically for alcohol preference. The basic premise for these experiments has been the idea that alcohol-preferring and -nonpreferring rats may differ in basic activation and inhibition control mechanisms that govern behavior and that different lines of alcohol-preferring rats may demonstrate differential deficits in behavioral activation and behavioral inhibition tendencies. In the present experiment, conditioned approach and avoidance behaviors were studied in alcohol-naïve high-alcohol-drinking (HAD), low-alcohol-drinking (LAD), and N/NIH rats to evaluate behavioral activation in this line of rats. METHODS: High alcohol drinking (HAD1), low alcohol drinking (LAD1), and N/Nih stock rats were trained to press a response bar during a tone signal to avoid a mild foot shock or receive a food reward. In addition, HAD2 and LAD2 rats, independently-bred replicate lines of the HAD1/LAD1 rats, were trained on the avoidance task. RESULTS: Although the HAD1 rats easily learned the appetitive version of the bar-pressing task, they did not learn the avoidance response. The LAD1 and N/Nih rats learned both the approach and the avoidance tasks normally. Similar to HAD1 rats, the HAD2 rats did not learn the avoidance response whereas LAD2 rats showed significant avoidance performance levels. CONCLUSIONS: The present data demonstrated that both HAD1 and HAD2 rats had a rather specific behavioral activation deficit: although they easily learned to press a bar to receive food reinforcement, they did not learn to press the bar to avoid a foot shock. We speculate that this failure to learn the avoidance response may be related to heightened anxiety in the HAD rats and that this excessive anxiety may lead to the development of high levels of alcohol consumption in these selectively bred rats.
Subject(s)
Alcoholism/genetics , Arousal/genetics , Avoidance Learning , Conditioning, Classical , Animals , Appetitive Behavior , Female , Genotype , Inhibition, Psychological , Male , Rats , Rats, Inbred Strains , Selection, GeneticABSTRACT
Although numerous biochemical and physiological differences have been shown to be correlated with alcohol preference, less is known about behavioral factors that may correlate with alcohol preference. Using a signaled barpressing task, alcohol-preferring (P; n = 18) and alcohol-nonpreferring (NP; n = 19) rats were compared for their ability to learn an appetitive and an aversive task. Results showed that P rats had difficulty learning the tasks in comparison with NP and nonselected, control rats when appetitive training was given first. However, if aversive training came first, the NP rats performed poorly in comparison with the P and nonselected rats. These results suggest that these lines of rats may differ in behavioral inhibition and sensitivity to conditioned fear. Furthermore, these behavioral differences may offer a richer analysis of the traits that were co-selected with the alcohol-seeking and alcohol-avoiding phenotypes.
