Role of exteroceptive background context in taste-aversion conditioning and extinction

In two experiments, saccharin (CS) and lithium chloride (US) were paired in a context consisting of specific visual, auditory, tactual, and olfactory cues. The saccharin aversion was then extinguished in a context free from conditioning-context cues. Later, saccharin preference tests were given in the presence and absence of these cues. The results indicated that the background cues of the conditioning trial controlled the amount of saccharin drunk on extinction trials, and, furthermore, that extinction of the taste aversion was context specific; i.e., groups given extinction trials in a different (from conditioning) context retained their saccharin aversion in the conditioning context only. The results indicate an important role played by the exteroceptive context in taste-aversion conditioning.     

A comparison of learned aversions to gustatory and exteroceptive cues in rats

The experiment provides a direct comparison of the ability of subjects (rats) to associate gustatory and exteroceptive stimuli with illness. Previous experiments which have made similar comparisons between gustatory and exteroceptive cues have suffered from certain methodological problems involving stimulus control and compounding. The present experiment utilized a between-subjects design wherein half of the subjects had an auditory cue associated with poisoning and half had a taste cue. In both cases, the other cue was present, but was not predictive of poisoning, The auditory cue, like the taste cue, occurred only during drinking. This comparison was made in both an immediate and a delayed poisoning situation. The experiment found that while subjects were able to quickly associate a taste cue with illness, they were unable to form a similar association between poisoning and the exteroceptive stimulus. Results also showed that subjects will fail to acquire a taste aversion to a novel and salient gustatory cue when that cue is followed by illness only 50% of the time. This latter effect was more pronounced in the delayed poisoning situation.     

One-trial context fear conditioning with immediate shock: The roles of transport and contextual cues

In three experiments, using a total of 120 albino rats, we assessed whether transportation cues might evoke some of the freezing (i.e., defensive immobility) that we see in a context on a day following a footshock given immediately after placement in that context. The results suggested that immediate shock could directly condition strong fear to both simulated and actual transport cues. Although conditioning to transport cues explains some of the freezing that is seen on the test day, it does not explain all of it. We also found evidence that some of the freezing is due to conditioning to permanent features of the context in which the immediate shock is given. The results support a role for transport cues in theories of context conditioning and argue against shock-processing accounts of the conditioning deficit that results from immediate shock.     

Overshadowing of environmental cues by an odor in toxicosis-based conditioning in rats

It was demonstrated that an odor presented to rats in a distinctive environment can interfere with toxicosis-based conditioning to the environmental cues. Rats poisoned when they drank unflavored water in a black compartment odorized with oil of eucalyptus exhibited no suppression of water intake when they were subsequently tested in the same compartment minus the odor. In contrast, rats poisoned in the same compartment minus the odor later exhibited reduced water consumption in that environment. Oil of eucalyptus proved to be as effective an overshadowing stimulus as a taste cue (a 1.5% NaCl solution).     

An eye tracking comparison of external pointing cues and internal continuous cues in learning with complex animations

Two experiments used eye tracking to investigate a novel cueing approach for directing learner attention to low salience, high relevance aspects of a complex animation. In the first experiment, comprehension of a piano mechanism animation containing spreading-colour cues was compared with comprehension obtained with arrow cues or no cues. Eye tracking data revealed differences in learner attention patterns between the different experimental conditions. The second experiment used eye tracking with synchronized and non-synchronized cues to investigate the role of dynamic direction of attention in cueing effectiveness. Results of Experiment 1 showed that spreading-colour cues resulted in better targeting of attention to thematically relevant aspects and in higher comprehension scores than arrow cues or no cues. For Experiment 2, superior comprehension after the synchronized version together with eye tracking data indicated that cue effectiveness depended on attention direction being spatially and temporally coordinated with onsets of animation events having high thematic relevance to the learning task. The findings suggest the importance of perceptual cues and bottom-up processing.     

Effects of exteroceptive feedback and safe-box confinement durations on escape behavior in rats

In Experiment 1, rats received escape training in which an exteroceptive feedback cue occurred in the safe box, and safe-box confinement durations of 5 or 20 sec were combined orthogonally with shock-box confinement durations of 5 or 20 sec. Exteroceptive feedback reliably facilitated escape performance relative to no-feedback controls when safe-box confinement was relatively longer than shock-box confinement. Confinement duration also facilitated performance in the absence of exteroceptive feedback. In Experiment 2, escape training with or without feedback was followed by extinction either with the feedback condition of prior training or with the opposite feedback condition. Feedback presentations in extinction reliably increased responding. Feedback removal reliably decreased responding relative to feedback controls. Introduction of feedback in extinction reliably enhanced performance relative to no-feedback controls.     

US inflation with trace and simultaneous fear conditioning

Two experiments with rat subjects in a conditioned punishment paradigm are reported. These experiments attempted to determine if the events entering into association with the CS following conditioning with informative (forward) and noninformative (simultaneous) CSs were comparable. In Experiment 1, exposure to intense shock alone following trace (ISI = 10 sec) conditioning with moderate shock enhanced the suppressive effects of a 2-sec CS. A similar manipulation following explicitly unpaired CS-US presentations (ISI = 2 min) had no effect. These data were taken as evidence that the CS and US were associated during trace conditioning. Experiment 2 showed that exposure to intense shock following simultaneous conditioning also enhanced suppression to the CS. These results suggested that simultaneous and forward conditioning procedures yield similar forms of associative learning.     

Spontaneous recovery after Pavlovian conditioning with multiple outcomes

In four experiments using rats, a Pavlovian conditioned stimulus (CS) was paired with a positive outcome, either pellets or liquid sucrose. That outcome was then either omitted altogether or replaced by another outcome. Although performance to the CS deteriorated only when the outcome was omitted, both procedures resulted in the CS’s ability to evoke greater responding after the passage of time. These results suggest that a similar outcome-independent depressive process develops when a Pavlovian CS is paired either with nonreinforcement or with a different outcome; that process then appears to dissipate with time.     

Performance of rhesus monkeys on two-cue problems with cues separated

Relative performance on color and form dimensions during acquisition of two-cue problems by learning-set-sophisticated rhesus monkeys was evaluated with differential reinforcement. Six animals received 24 two-choice problems, each generated from three planometric stimuli, a reference stimulus, an alternate stimulus identical in color but differing in form, and one identical in form but differing in color. The reference stimulus appeared on every trial of a problem and was paired with one or the other alternate on a given trial On half of the problems, the reference stimulus was positive and on the remainder was negative. Acquisition was nearly equivalent on both cue dimensions with positive reference stimuli, but only one dimension was learned with negative reference stimuli. Results were interpreted as unfavorable to attention theory.     

Pavlovian conditioning with ingested saline solution as the US

Experience with 2% saline as the sole available fluid for drinking produced a decrement in preference for .9% saline in a two-bottle test with water as the alternative. This outcome was interpreted as a consequence of Pavlovian conditioning, with the taste of salt acting as the conditioned stimulus and postingestive consequences of saline ingestion acting as the unconditioned stimulus. An overshadowing group experienced salt mixed with vanilla as its sole fluid during the conditioning phase. This group showed an attenuated saline aversion relative to a group that drank 2% saline solution during the conditioning phase. In addition, a vanilla aversion developed in the former group. In the second experiment, conditioning of the aversion to the taste of vanilla mixed with 2% saline was attenuated by preexposing the vanilla. The results support a Pavlovian analysis of the modification of salt preference through experience with the postingestive consequences of saline ingestion.     

Enhanced Pavlovian conditioning with a change in appetitive reinforcer

In three experiments, rats received appetitive conditioning with two unconditioned stimuli (US₊ and US*) that supported a similar conditioned response. Stimulus A was first paired with US₊, and then, for a second stage of training, the compound AB was paired with US*. Subsequent test trials with A revealed an abnormally strong conditioned response. The findings from additional groups indicated that such enhanced conditioning with A depended on the presence of B in the second stage and on the use of US₊ and US* for the two training stages. A modification to a configural theory of conditioning is proposed in order to explain the results.     

Second-order conditioning: Different outcomes in fear and eyelid conditioning

Second-order conditioning has been frequently observed with the fear response but not with the eyelid response. The present experiments manipulated the temporal relationship between the second-order and first-order stimulus on second-order conditioning trials. Our results indicated that a trace second-order procedure is not effective with either response system. Second-order fear conditioning was most prominent when the second-order CS terminated at the onset of the first-order CS. This arrangement, however, did not produce second-order eyelid CRs. In eyelid conditioning, the second-order CS appears to inhibit responding to the first-order CS which immediately follows it.     

Effects of intertrial interval and exteroceptive feedback duration on discriminative avoidance acquisition in the gerbil

A series of studies of shuttlebox-avoidance learning in the gerbil evaluated the efficacy of an exteroceptive feedback stimulus (FS). Experiment 1 assessed the relative effectiveness of a FS at 30- and 90-sec intertriai intervals (ITIs), and found that the FS and warning signal termination contingencies were additive sources of avoidance reinforcement; i.e., they produced “supernormal acquisition” at the short ITI, but not at the 90-sec ITI. The effectiveness of a FS at the 30-sec ITI was further explored in Experiments 2 and 3, in which FS duration was varied in delayed and trace avoidance conditioning, respectively. In both studies, a FS facilitated acquisition but FS duration was not a critical determinant of performance. These results were interpreted in terms of an expectancy account of the informational value of a FS, and the problem of experimentally distinguishing between cognitive and inhibition-of-fear accounts of avoidance learning was discussed.     

《三十二式太极剑》提示语的研究

通过文献查阅和实验对比等方法,归纳总结出《三十二式太极剑》提示语,并对105名实验组和88名对照组进行了对照性研究。结果表明:《三十二式太极剑》提示语教学缩短了教学时间,有利于教师的教和学生的学,有效的提高了教学效果。     

The role of oral and postingestional cues in the conditioning of taste preferences based on differing caloric density and caloric outcome in weanling and mature rats

Experiments 1, 2, and 3 demonstrated that 23-day-old rat pups can acquire a conditioned taste preference for a flavor paired with either a more calorically dense diet or a diet that provides more calories than another diet of equal caloric density. Experiment 4 showed that 42–49-day-old rats also can acquire conditioned taste preferences based on differing caloric density and differing caloric outcome. Experiments 5 and 6 demonstrated that adult rats form conditioned taste preferences based only on caloric density. Although these experiments indicate that young rats are apparently capable of more diverse learning than adult rats, the question of what US underlies conditioned taste preferences based on diets of differing caloric density remains unresolved.