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1.
The effect of pattern of stimulus presentation on habituation of the cardiac component of the orienting response to an auditory stimulus was investigated in four experiments. The duration of stimulus presentation was held constant, but some animals were given six 10-sec stimulus presentations and others were given a single 60-sec stimulus. During the first 10 sec of the auditory stimulus, heart rate (HR) decreased approximately 40 beats per minute (bpm) in both groups, but during subsequent 10-sec epochs, the changes in HR were markedly different in the two groups. For those animals given a single 60-sec stimulus, the cardiac orienting response did not habituate; that is, HR either continued to decrease or remained approximately 40 bpm below baseline. In contrast, those animals given six 10-sec stimulus presentations showed smaller decreases in HR with each successive stimulus presentation, and after approximately four presentations, no detectable change in HR was observed. Despite these dramatic differences in habituation of the cardiac component of the orienting response, neither group oriented to the auditory stimulus when it was presented again following a short retention interval. Moreover, with increasing retention intervals, both groups showed the same forgetting function (reappearance of the orienting response). The implications of these findings for theories of the orienting response as well as theories of habituation are discussed. 相似文献
2.
The primary purpose of the present study was to assess the ontogeny of nonassociative learning and memory in 16-, 30-, and 75-day-old rats. In each of three experiments, habituation of the orienting response to a novel auditory stimulus was measured. The orienting response is an unconditioned reaction elicited by innocuous environmental stimulation that habituates with repeated stimulus presentations. Both an autonomic component (heart-rate deceleration) and a behavioral index (head jerk) of the orienting response were recorded in this study. Although no age differences in rate of habituation (i.e., rate of nonassociative learning) were found (see Experiment 1), a marked effect of age on retention of habituation was observed. Preweanling rats retained habituation of the orienting response to an auditory stimulus for less than 4 h (Experiment 2), whereas adult animals exhibited no forgetting even after a 1-week interval (Experiment 3). These results are discussed in terms of (1) demonstrations of age-related differences in associative memory, (2) the persistence of nonassociative memories in adults, and (3) the significance of the orienting response as a measure of retention of nonassociative learning. 相似文献
3.
In Experiment 1, rats experienced presentations of a discrete visual stimulus (Stage 1) until habituation of the orienting response (OR) occurred. On a test session given after an interval of 16 days (Stage 2) the OR reappeared. For control subjects that received no Stage 1 training but presentations of the light in Stage 2, habituation persisted during the test. All subjects then received conditioning trials on which the light preceded the delivery of food. They showed latent inhibition, acquiring the conditioned response less readily than control subjects that had not previously experienced the light. Experiment 2 confirmed that the latent inhibition effect survived the retention interval for subjects that received no habituation test session. This pattern of results implies that habituation of the OR and latent inhibition are determined by different mechanisms. 相似文献
4.
Three experiments measured orienting of rats to stimuli varying in intrinsic significance. In the first, rats showed greater reactivity to a recording of a conspecific’s distress squeal than to a simulated mimic squeal when the stimuli were presented at 100 dB but not at 80 dB, and orienting to all stimuli habituated rapidly with repeated stimulus exposures. Experiment 2 showed that, following several stimulus exposures, recovery of orienting after rest periods of 1 and 7 days was a function of the stimulus: Orienting to the distress squeal presented at 100 dB recovered more rapidly than did orienting to the mimic squeal at 100 dB or to either the mimic or the distress squeal presented at 80 dB. Experiment 3 showed that habituation to the most significant stimulus, the distress squeal presented at 100 dB, was retarded at long (24-h) interstimulus intervals, presumably a consequence of less stimulus-to-stimulus transfer of habituation with this stimulus. The results are discussed in terms of biological constraints on habituation of orienting and on recovery of orienting following habituation. 相似文献
5.
The relationship between the duration of stimuli and their conditioned reinforcing effect was investigated using a learning-tests procedure. In Experiment 1, stimuli were the same duration on training (stimulus → reward) and test (choice response → stimulus). Ten- and 30-sec stimuli provided effective differential conditioned reinforcement but 3-sec stimuli did not. In Experiment 2, different pigeons had each combination of the 3- and 30-sec stimuli on training and test trials. Evidence of conditioned reinforcement was obtained only for the birds with 30-sec stimuli on both training and test. The results were interpreted as indicating that stimuli become effective conditioned reinforcers on test trials only when their duration exceeds the duration of differential short-term memory cues resulting from a difference in the events that precede them on training and test trials. 相似文献
6.
In two experiments, behavioral stereotypies elicited by scheduled presentations of food and water were compared. In Experiment 1, pigeons were exposed to a fixed-time 30-sec (FT 30-sec) schedule of food or water deliveries with a brightening keylight stimulus signaling time to the unconditioned stimulus (UCS) on each trial. Food and water presentations both produced terminal autoshaped keypecking that was similarly distributed in the trial but differed in response topography and persistence. Locomotor interim behavior was different in the two motivational conditions: With food presentations, it consisted of a “retreat” to the rear of the chamber after UCS termination, followed by “pacing” in the midportion of trials. The water schedule produced very little locomotor activity with no regular distribution in the trial. Experiment 2, using a random-time 30-sec (RT 30-sec) schedule, showed that the differences in interim locomotor behavior persisted in the absence of temporal predictability of the UCS and the keypecking terminal response. The results are taken to support Timberlake’s (1983a) behavior-system theory. 相似文献
7.
Three experiments with rat subjects examined the effects of contextual stimuli on performance in appetitive conditioning. A 10-sec tone conditioned stimulus (CS) was paired with a food-pellet unconditioned stimulus (US); conditioning was indexed by the observation of headjerking, a response of the rat to auditory stimuli associated with food. In Experiment 1, a context switch following initial conditioning did not affect conditioned responding to the tone; however, when the response was extinguished in the different context, a return to the original conditioning context “renewed” extinguished responding. These results were replicated in Experiments 2 and 3 after equating exposure to the two contexts (Experiment 2) and massing the conditioning and extinction trials (Experiment 3). The results of Experiment 1 also demonstrated that separate exposure to the US following extinction reinstates extinguished responding to the tone; this effect was further shown to depend at least partly on presenting the US in the context in which testing is to occur (Experiments 2 and 3). Overall, the results are consistent with previous data from aversive conditioning procedures. In either appetitive or aversive conditioning, the context may be especially important in affecting performance after extinction. 相似文献
8.
In seven experiments, an effect of the intertriai interval (ITI) duration on barpressing by rats was studied. A stimulus signaled a 15-sec variable-interval trial. The first response after the interval elapsed turned the stimulus off and was rewarded with food. Trials were separated by long (about 300 sec) or short (about 10 sec) ITIs. A within-subjects design established that response rate on trials after long ITIs was lower than that after short ITIs (Experiments 1 and 3–7). The effect was not cumulative (the effect of one and five consecutive short ITIs was the same). Response rate after short and long ITIs was the same when a between-subjects design was used (Experiment 2). Response rate was higher after 160-sec ITIs than after 300-sec ITIs, suggesting that the ITI duration at which all longer ITIs are treated the same (i.e., the upper limit) is greater than 160 sec (Experiment 3). When food, the trial stimulus, a novel stimulus, or a familiar stimulus never paired with food, was presented 10 sec before the next trial during some of the long ITIs, response rate on the next trial was similar to that found after 10-sec ITIs (Experiments 4–6). This similarity suggested that these events could mark the start of the ITI. However, the familiar stimulus did so only when it reliably predicted that the next trial would occur after a short interval. The effect of ITI duration on responding was apparently attributable to response latency. Response latency was greater after long ITIs, but once responding began, it was similar after long and short ITIs (Experiment 7). 相似文献
9.
In Experiment 1, three food-deprived pigeons received trials that began with red or green illumination of the center pecking key. Two or four pecks on this sample key turned it off and initiated a 0- to 10-sec delay. Following the delay, the two outer comparison keys were illuminated, one with red and one with green light. In one condition, a single peck on either of these keys turned the other key off and produced either grain reinforcement (if the comparison that was pecked matched the preceding sample) or the intertrial interval (if it did not match). In other conditions, 3 or 15 additional pecks were required to produce reinforcement or the intertrial interval. The frequency of pecking the matching comparison stimulus (matching accuracy) decreased as the delay increased, increased as the sample ratio was increased, and decreased as the comparison ratio was increased. The results of Experiment 2 suggested that higher comparison ratios adversely affect matching accuracy primarily by delaying reinforcement for choosing the correct comparison. The results of Experiment 3, in which delay of reinforcement for choosing the matching comparison was manipulated, confirmed that delayed reinforcement decreases matching accuracy. 相似文献
10.
Experiment 1 investigated the behavior of rats trained to leverpress on a concurrent variable ratio (VR) 30 VR-30 schedule with a brief, 500-msec, light occurring at the midpoint of the ratio on one of the levers. Higher response rates were recorded on the lever associated with this stimulus, a finding that paralleled the effect produced by inserting primary reinforcement at the midpoint (i.e., by training on a concurrent VR-30 VR-15 schedule). Similar results were found in Experiment 2 using a concurrent VR-20 VR-20 schedule with a 2-sec visual stimulus presented midway through one of the components. In addition, a brief stimulus inserted midway through the VR-20 component of a concurrent VR-20 VR-10 schedule retarded the development of a difference in response rates between the components relative to a VR-20 VR-10 group lacking the signal. In Experiment 3, multiple VR VR schedules were used. Again, the response rate was higher in the component that had the added stimulus or, for a second group of subjects, on the component with the smaller response requirement. Probe-choice trials revealed a preference for the component that generated the higher rate in both groups. Presenting a stimulus partway through a ratio appears to reduce the effect on response rate and choice of a large ratio value. 相似文献
11.
The present experiment was run to test the hypothesis that, when shock was signaled, rats would develop effective coping responses so as to reduce the current flow through them. A 1-sec shock was delivered through a grid floor by a fixed impedance ac shock source. The current-flow measure was taken over the last 30 of 90 trials given over 3 days and indexed by “gross skin conductance” or GSC (shock). The rat under the signaled shock condition (n=15) showed higher GSC (shock) than did the rats under the unsignaled shock condition (n=14). Thus, the result contradicted the hypothesis. There was no indication that the rats developed any preparatory response during the 5-sec signal, in terms of either GSC (signal) or posture. The results were discussed with reference to the preparatory-response hypothesis and various other possibilities. 相似文献
12.
These experiments investigated habituation of two responses in the lizardAnolis carolinensis. In Experiment 1, intertrial intervals (ITI) of 5, 30, and 120 sec had various effects on habituation of dewlap distension and optokinetic response (OKR). Although there were no size differences noted for the OKR, smaller anoles (50–58 mm snout-vent length, SVL) failed to habituate under the 30- and 120-sec ITI of the dewlap response, while larger anoles (? 59-mm SVL) habituated under each ITI tested, with no response level differences between ITIs. Rates of habituation were similar within and across responses. In a second experiment, larger anoles were employed to study recovery and retention of dewlap distension and OKR habituation after 15-min and 24-h intervals. Complete recovery of both responses occurred in 24 h, with substantial recovery of both responses after 15 min. Retention was present for both responses after 15 min but not after 24 h. A multiple response-system approach is offered as a promising method for research and theories in habituation. Rather than concentrating upon a single response in one or more species, a multiple response-system approach examines similarities and differences in the habituation of various responses within a single species. 相似文献
13.
Alma E. Lantz 《Learning & behavior》1973,1(4):273-277
Three experiments were conducted to investigate the influence of variables during habituation of a CS on a subsequent conditioning to that CS in a conditioned emotional response paradigm. Experiment I varied the number of habituation trials received before conditioning, and it was found that additional habituation trials resulted in a further attenuation of conditioning. Experiment II varied the interstimulus interval of the habituating stimulus, and it was found that the longer intervals produced the greater attenuation in conditioning. Experiment III examined the effect of interpolating another stimulus between habituation and conditioning (dishabituation), and it was found that the dishabituating stimulus augmented subsequent conditioning. It was concluded that manipulations during habituation training that produce the greatest decrement in response to a stimulus, when assessed under equivalent conditions for all animals, have the greatest attenuating effect on subsequent conditioning to that stimulus. 相似文献
14.
In three experiments, rats received presentations of a diffuse 30-sec stimulus (a light) and of food, and their tendency to enter the food tray was monitored. Experiment 1 showed that when the light was made to signal the delivery of food, the response of entering the food tray increased in frequency during the stimulus. The acquisition of this conditioned response to the light was retarded in subjects that had received preexposure to the stimulus. In Experiments 2 and 3, subjects received preexposure to the stimulus, some in the same context as that subsequently used for stimulus-food pairings and some in a different context. Those experiencing the change of context acquired the response more readily. It is argued that these results demonstrate a latent inhibition effect that is attenuated by contextual change. 相似文献
15.
Experiment 1 employed a shock box in which light beams ran at 10, 15, 20, or 25 cm above the floor level of the box. Four groups of nine rats each were trained to avoid shock by cutting the light beams or letting them pass by, which the animal accomplished by upward or downward change of its posture. Training employed a discriminated avoidance paradigm, 60 trials per day for 5 days, with a 5-sec CS-US interval. Acquisition of the rearing avoidance response was observed only in the 15-cm condition. Using the same apparatus as in Experiment 1 and with a beam height of 15 cm, the rearing avoidance response was successfully conditioned in five rats using a nondiscriminated avoidance conditioning paradigm. There was good evidence of temporal discrimination in these animals. 相似文献
16.
Peter C. Holland 《Learning & behavior》2018,46(2):134-156
Prior exposure to a conditioned stimulus (CS) typically results in latent inhibition—slower acquisition of associative learning about that stimulus in subsequent training. Here, we found that CS preexposure had different effects on the appetitive conditioning of rats with a sucrose unconditioned stimulus (US) depending on training test procedures, the similarity of preexposure and training procedures, and the choice of response measure. Preexposure to a visual or an auditory stimulus produced facilitation of acquisition of food-cup-directed responding when both of those cues were (separately) paired with sucrose delivery in the training test (Experiments 1 and 3). By contrast, the same preexposure procedure resulted in latent inhibition of food-cup learning if the second stimulus in the test phase was of the same modality as the preexposed stimulus (Experiment 2). In Experiment 3, latent inhibition was enhanced if both phases included a single CS or both phases included both auditory and visual CSs, compared to treatments in which only one CS was presented in one phase but two CSs were presented in the other phase. In Experiment 4, preexposure of an auditory cue slowed subsequent learning about it if the context was salient but enhanced learning if the context was of weaker salience. Finally, a measure of general activity revealed latent inhibition after preexposure in all conditions in all 4 experiments. We discuss the results within several classes of latent inhibition theories, none of which provides a comprehensive account. 相似文献
17.
Nonreinforced exposure to a nontarget stimulus that was followed by nonreinforced exposure to a target/nontarget simultaneous
compound stimulus resulted in enhanced latent inhibition of the target. Conditioning was slower after this treatment than
after nonreinforced exposure to the target stimulus alone (Experiment 1). However, a salient auditory stimulus presented immediately
after the compound in the second phase reduced levels of latent inhibition, relative to the enhanced latent inhibition produced
when no such extracompound stimulus was presented (Experiments 2 and 3). This effect was not noted if the salient auditory
cue was presented 10 sec after the termination of the compound stimulus (Experiment 4). In Experiment 5, there was no disruption
of simple latent inhibition produced by a salient stimulus. These results are consistent with enhanced latent inhibition’s
being produced by the formation of within-compound associations, which are disrupted by the salient extracompound stimuli. 相似文献
18.
Linda A. Pinckney 《Learning & behavior》1976,4(4):467-472
In Experiment 1, three groups of rats received a tactile prepulse 0.5, 1, or 2 mA electric shock (to feet) .25, .5, 1, 5, 10, or 20 sec prior to an acoustic startle stimulus. The startle response was, maximally inhibited at the .25-sec interval and gradually recovered thereafter. Inhibition was larger with the intense stimuli, and for the .5-mA stimulus occurred reliably only in animals which responded to the prestimulus. In Experiment 2, the intensity of the prepulse was varied within subjects at intervals of .5, 1, and 2 sec. Inhibition was directly related to prestimulus intensity and was greatest at .5 sec. In Experiment 3, an EMG measure of startle reactivity allowed the use of shorter intervals. The maximal inhibitory interval between the prestimulus and startle stimulus was 40 msec compared with either a shorter 10-msec or a longer 250-msec separation. 相似文献
19.
In an attempt to explore the relation between the amount of variability in a stimulus and rate of habituation to that stimulus, 4 groups of infants 4 1/2--5 1/2 months of age were presented with repeated speech stimuli which were synthesized exemplars of [baba], natural exemplars of [baba] or [kaba], or novel syllables of each trial. Infants' cardiac responses to the auditory stimuli were recorded, and the number of trials to a proportional criterion of habituation of the heart-rate decelerative response was determined. Infants were found to habituate most rapidly to the synthesized [baba] stimulus which remained constant across trials and least rapidly to the speech syllables which changed from trial to trial. 相似文献
20.
We present an algebraic model of resistance to extinction that is consistent with research on resistance to change. The model assumes that response strength is a power function of reinforcer rate and that extinction involves two additive, decremental processes: (1) the termination of the reinforcement contingency and (2) generalization decrement resulting from reinforcer omission. The model was supported by three experiments. In Experiment 1, 4 pigeons were trained on two-component multiple variable-interval (VI) 60-sec, VI 240-sec schedules. In two conditions, resistance to change was tested by terminating the response-reinforcer contingency and presenting response-independent reinforcers at the same rate as in training. In two further conditions, resistance to change was tested by prefeeding and by extinction. In Experiment 2, 6 pigeons were trained on two-component multiple VI 150-sec schedules with 8-sec or 2-sec reinforcers, and resistance to change was tested by terminating the response-reinforcer contingency in three conditions. In two of those conditions, brief delays were interposed between responses and response-independent reinforcers. In both Experiments 1 and 2, response rate was more resistant to change in the richer component, except for extinction in Experiment 1. In Experiment 3, 8 pigeons were trained on multiple VI 30-sec, VI 120-sec schedules. During extinction, half of the presentations of each component were accompanied by a novel stimulus to produce generalization decrement. The extinction data of Experiments 1 and 3 were well described by our model. The value of the exponent relating response strength and reinforcement was similar in all three experiments. 相似文献