Running in an activity wheel yields conditioned aversion to a taste solution consumed before the running, but its underlying physiological mechanism is unknown. According to the claim that energy expenditure or general stress caused by physical exercise is a critical factor for this taste-aversion learning, not only running but also other…

Previous research has found that swim stress during a classical conditioning trial attenuates conditioned taste aversion (CTA). In the current study, rats were used to examine the effects of inescapable swim stress on the habituation of neophobia to a flavored solution and reacquisition of an extinguished conditioned taste aversion. In Experiment…

A greater understanding of implicit cognition can provide important information regarding the etiology and maintenance of psychological disorders. The current study sought to determine the utility of the Implicit Relational Assessment Procedure (IRAP) as a measure of implicit aversive bias toward spiders in two groups of known variation, high fear…

Previous studies have shown that pouched rats can detect the presence of "Mycobacterium tuberculosis," which causes tuberculosis, in human sputum samples obtained from clinical facilities. Although pouched rats evaluate sputum samples quickly, preparing the samples is relatively slow. The present study evaluated whether the rats can detect…

It has been demonstrated that rattlesnakes can discriminate between envenomed and nonenvenomed rodent prey based on venom-related cues deposited during the strike. This behavior is crucial to the snake's ability to choose the chemical trail left by an envenomed rodent fleeing the strike area and aids in the snake's ability to relocate the rodent.…

In conditioned taste aversion (CTA), a taste, the conditioned stimulus (CS), is paired with an illness-inducing stimulus, the unconditioned stimulus (US), to produce CS-US associations at very long (hours) intervals, a result that appears to violate the law of contiguity. The specific length of the maximum effective trace interval that has been…

The current study examined the variables that influence postreinforcement pause (PRP) duration in rats when wheel running serves as the reinforcing consequence. The relationship between revolutions and PRP duration when revolutions were manipulated within a session and the effect of changing the response requirement from fixed to variable on PRP…

Eight western diamondback rattlesnakes ("Crotalus atrox") were exposed to 6 stimuli: (1) clean, unused bedding; (2) an adult male mouse; (3) an adult lactating female mouse; (4) an adult lactating female mouse with a litter; (5) 2 adult nonlactating female mice, to control for the extra surface area in Condition 4; and (6) a litter of newborn…

Extinction and recovery of the discriminative stimulus effects of nicotine (0.3 mg/kg) was investigated with a devalued food reinforcer (rats sated). Sixteen rats were trained in a counterbalanced one manipulandum (nose-poke) drug discrimination procedure with the roles of nicotine and saline counterbalanced as S[superscript D] and S[superscript…

Operant extinction contingencies can undermine the discriminative stimulus effects of drugs. Here, nicotine (0.4 mg/kg) and ethanol (0.8 g/kg) first functioned as either an S[superscript D] or S[superscript Delta], in a counterbalanced one-lever go/no-go (across sessions) operant drug discrimination procedure. Pavlovian extinction in the training…

Within the past decade, giant pouched rats have been used successfully to detect landmines. This manuscript summarizes how these rats are trained and used operationally. The information provided is intended to be of practical value toward strengthening best practices in using "Cricetomys" for humanitarian purposes while simultaneously…

The present study assessed the effects of systematically separating the cue from the response in temporally defined schedules of delayed signaled reinforcement. Identical schedules were used to study the effects of the independent variable on response acquisition and response maintenance. In the first experiment, 8 groups of 3 naive rats were…

Pigeons were trained in two experiments that used the concurrent-chains procedure. These experiments sought to identify the variables controlling the preference of pigeons for a constant duration over a variable duration of exposure to an aperiodic, time-based, terminal-link schedule. The results indicated that two variables correlated with the…

Recently, Redford (2010) found that monkeys seemed to exert metacognitive control in a category-learning paradigm. Specifically, they selected more trials to view as the difficulty of the category-learning task increased. However, category-learning difficulty was determined by manipulating the family resemblance across the to-be-learned exemplars.…

Six tree shrews and 8 rats were tested for their ability to infer transitively in a spatial discrimination task. The apparatus was a semicircular radial-arm maze with 8 arms labeled A through H. In Experiment 1, the animals were first trained in sequence on 4 discriminations to enter 1 of the paired adjacent arms, AB, BC, CD, and DE, with right…