Type Of Conditioned Stimuli Research Articles

Time will tell: Temporal processing in the sexual behavior system.

This paper describes several temporal factors that appear to play a role in sexual conditioning including the conditioned stimulus (CS)-unconditioned stimulus (US) interval, the C/T ratio, and trace conditioning. One commonality among these studies is the attention given to the stimuli and responses involved. This is contrary to traditional learning theories such as the general process theory. The general process theory is focused on identifying universal principles and commonalities of learning, without regard to the stimuli and responses involved. The research described in this paper has taken a different approach and made specific considerations of the stimuli and responses such as with the type of conditioned stimuli used and the use of more than one, and sometimes multiple, response measures with which to identify conditioned responding. The findings of these studies are best accounted for by the behavior systems approach. For example, one of the main findings is that during long-delay learning, a new conditioned response may emerge (increased locomotor activity) in lieu of a decrease or absence of the target conditioned response (approach behavior). The behavior systems approach accounts for this by describing the sexual behavior system as being on a continuum from consummatory behavior to focal search and general search. The nature of the conditioned response depends on where the CS is introduced along the continuum. This example and several other sexual conditioning experiments are described within this paper with an emphasis on their interpretation from a behavior systems perspective.

Stimulus-specific development of learning ability during habitat shift in pre to post-recruitment stage jack mackerel

Marine fishes often experience major habitat shifts during their life history, and previous studies have shown that the learning capability of fish change ontogenetically and in accordance with such habitat shifts. However, because all of these studies used a single type of conditioned stimuli (CS), they failed to detect qualitative changes in learning capability. Here we tested the hypothesis that preparedness for learning changes ontogenetically in jack mackerel Trachurus japonicus, which undergo a drastic change in habitat preference during their life history as they move from offshore pelagic waters to coastal and demersal rocky reefs. Groups of juveniles measuring 40 mm standard length (SL) (pelagic stage) and 60 mm SL (demersal stage) were conditioned to food rewards in response to three different CS; the presence of a surface structure, mid-water structure, and aeration. The results showed that small juveniles tended to become conditioned to the surface stimulus faster than they did to the mid-water stimulus. Conversely, large juveniles responded to the mid-water stimulus significantly more quickly than they did to the surface stimulus. These results suggest that stimulus-specific learning capability in T. japonicus changes ontogenetically, facilitating adaptation to their life-history strategy.

(648): Conditioned fear-induced pain modulation in humans: The influence of preparedness

Research suggests conditioned fear modulates pain. However, it is unknown whether any variables moderate this relationship. Preparedness theory predicts that some conditioned stimuli (CS) are more readily associated with an unconditioned stimulus (US) and lead to more rapid development of the conditioned fear response. Indeed, pictures depicting facial expressions of fear are more readily associated with an aversive shock US and lead to greater conditioned responses than happy expressions. Therefore, different types of CSs may moderate the influence of conditioned fear on pain. The present study used a differential fear conditioning procedure to examine the influence of conditioned fear on pain threshold (latency of finger withdrawal to radiant heat). Facial expressions (happy vs. fear) served as the CSs and aversive electric stimulation of the sural nerve as the US. Forty-one participants were randomly assigned to have either a fear or happy expression as the CS+ (stimulus paired with shock). The other facial expression served as the CS− (stimulus unpaired with shock). During the acquisition phase, each CS was presented in pseudorandom order, and the CS+ was always paired with shock. During the extinction phase, shock was no longer presented and pain threshold was tested during each CS. Psychophysiological and self-report measures of emotion were used to verify participants’ reactions to CSs and results suggest that fear was effectively conditioned. However, only those people for whom the fear expression served as the CS+ evidenced any pain modulation (p=.01), with lower pain thresholds (hyperalgesia) during the CS+ relative to the CS−. People for whom a happy expression served as the CS+ did not have a significant difference in pain thresholds during the CS+ versus the CS− (p>.05). In sum, these data suggest that conditioned fear-induced pain modulation is moderated by the type of conditioned stimuli used.

Gustatory response and appetitive learning in Microplitis croceipes in relation to sugar type and concentration

Abstract Insects can be conditioned to respond to odours through associative learning. Various learning parameters, such as the rate of odour acquisition, are known to depend on the type of conditioned stimulus. Here we investigate to what extent appetitive conditioning in the parasitoid Microplitis croceipes is also affected by characteristics of the food reward (unconditioned stimulus). We tested 1 M solutions of eight sugars naturally occurring in nectar and honeydew with respect to their effect on parasitoid gustatory response and their suitability as an unconditioned stimulus in the process of associative odour learning. To test for concentration effects, a separate experiment compared parasitoid performance with 1 M and 0.25 M of sucrose, respectively. Only exposure to glucose, fructose, sucrose and melezitose enhanced feeding relative to control individuals provided water. Raffinose, mannose, galactose and melibiose did not increase or decrease consumption, indicating that these sugars are neither phagostimulants nor phagodeterrents. In the conditioning experiments, parasitoids were allowed to feed on a particular sugar solution while being exposed to the floral odour cineole. Parasitoids that had been trained with the stimulatory sugars subsequently showed a clear conditioned feeding response to the cineole. Conditioning with galactose, mannose and melibiose, on the other hand, did not lead to successful odour acquisition. Conditioning with raffinose increased the tendency of the parasitoid to exhibit a conditioned feeding response, even though this response was significantly shorter than the response following training with stimulatory sugars.The level of cineole response was not significantly influenced by the concentration of a sucrose solution, even though the 0.25 M concentration was a weaker feeding stimulant.Our findings indicate that gustatory perception is the principal unconditioned stimulus in appetitive learning. The results with raffinose indicate that postingestive feedback may be involved in food associative learning as well.

Differential effects of reward and punishment cues on response speed in anxious and impulsive individuals

Four groups of subjects—neurotic extraverts, stable extraverts, neurotic introverts, and stable introverts—were instructed to trace a circle template as slowly as possible. The tracing task was performed under one of three conditions: Condition Rw entailed the presence of reward cues, Condition Pn entailed the presence of punishment cues, and Condition G(while involving the presence of goal stimulus) entailed neither type of conditioned stimulus. As predicted, high impulsive (neurotic extravert) subjects exhibited inappropriately rapid tracing speeds (i.e. behaved impulsively) to a greater extent than did low impulsive (stable introvert) subjects in Conditions Rw. Although, as expected, high anxious (neurotic introvert) subjects manifested the fastest tracing speeds among the four subject groups in the presence of punishment cues (i.e. in Condition Pn), they did not trace significantly faster than low anxious (stable extravert) subjects. Finally, replicating earlier research in which the presence of a salient goal stimulus was sufficient to engender rapid responding, high impulsive subjects traced significantly faster than did low impulsives in Condition G. These results are discussed in the context of a model of impulsive behavior that is primarily a synthesis of Eysenck's ( The biological basis of personality, 1967) personality theory and Gray's ( Elements of a two-process theory of learning, 1975) three arousal model. This synthesis maps the extraversion dimension onto the relative strengths of Gray's behavioral activation and inhibition systems, and identifies the neuroticism dimension with Gray's nonspecific arousal system.

Humoral link in the mechanism of formation of the food refusal conditioned response in the snail.

1. Hemolymph from donor snails conditioned to refuse food facilitates the development of refusal of the same type of food in intact recipients. Hemolymph of pseudoconditioned donors inhibits conditioning in recipients. 2. The facilitating effect manifests itself variously depending on the type of conditioned stimulus (preferred or nonpreferred food) and the amount of injected hemolymph. At certain doses the facilitating effect gives way to an inhibitory effect. 3. Facilitation of conditioning is of a seasonal nature.