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1.
To examine the generality of the interreward response effects shown by rats under periodic food delivery, we presented .10 ml of water at minimum interwater intervals that ranged from 8 to 512 sec. Use of a 24-h multiresponse environment allowed evaluation of interdrink responses with respect to their excessiveness, patterning, and functional relationship to the interwater interval. In contrast to the extensive activity-inducing effects of periodic food, the only major excitatory effect of periodic water was increased attention to the water source. Although there were a few bitonic and direct relationships between interwater interval and changes in responding, the great majority of functions were inverse or inconsistent. Further, unlike the increase in drinking under periodic food, total eating decreased under periodic water. The major similarity with food reward was the apparent separation of interreward behavior into three general classes of reward-appropriate foraging responses: area-restricted search after reward, more general search (and waiting), and focal search preceding the next reward delivery. 相似文献
2.
In the presence and absence of an externalinterfood clock stimulus (a sequence of flashing lights), rats showed a multimodal behavior pattern during successive quarters of interfood intervals (IFI) ranging from 12 to 192 sec. Responses near the feeder peaked before and just after food presentations, whereas locomotion remote from the feeder peaked toward the middle of the IFI. The temporal patterns of nosing in the feeder and remote locomotion were scalar (the time at which a response peaked in the IFI was proportional to the IFI length), whereas the patterns of postfood feeder-directed behavior, rearing, and pawgrooming were time bound (peaking at a fixed time after food, regardless of IFI length). Responses varied in their control by the external clock stimulus. During the last half of the IFI, rats nosed in the feeder more with an external clock, but only at intermediate IFIs. During the first quarter of the IFI, rats pawgroomed more with an external clock, but only at the longest IFI. The general sequence of responses during the interfood clock was consistent with the view that food delivery engages an organized sequence of search states that are expressed through a variety of responses. 相似文献
3.
Schedule-induced drinking and food-magazine contacts were examined in rats receiving either true- or pseudodiscriminative conditioning. Schedule-induced drinking was largely confined to S? following true discrimination training, but when SI and S2 were unrelated to food deliveries (pseudo condition), drinking occurred after food ingestion. A stimulus generalization test for drinking yielded an excitatory postdiscrimination gradient around S? after the true discrimination and a flat gradient after the pseudo discrimination. Additional observations showed S? drinking to be closely related to the amount of food consumed during the immediately preceding S+ trial. These data suggested that both the predictive feature of S? and postprandial stimuli can control schedule-induced drinking. It was argued that these variables represent two general processes—induction and selection—both of which are necessary conditions requiring further study. Magazine contacts during S+ did not distinguish the true from the pseudo condition and were not influenced by test stimuli during a generalization test. 相似文献
4.
Three experiments delivered food at fixed or random intervals independently of the rat’s behavior, always less than the amount eaten with food freely available. The results revealed a Polydipsie response to this experimental suppression of eating, and total drinking decreased as total eating increased. When we added a lever that signaled each food delivery, leverpressing and drinking rose far above their baseline levels; both responses decreased as total eating increased. When a similar schedule presented lever and food independently, rats still became Polydipsie, but showed no sign of autoshaped leverpressing. A fourth experiment revealed a hypophagic response to schedules that suppressed drinking; total eating increased with total drinking. As mutual substitutes in the economic sense, one behavior falls as the other rises; as mutual complements in the economic sense, the two behaviors rise or fall together. We discuss polydipsia and autoshaping in terms of drinking as an intrinsic substitute for eating, and leverpressing as a learned substitute for eating. The results suggest a revision of conservation theory, which views drinking and eating as substitutes when the schedule suppresses eating but as complements when the schedule suppresses drinking. 相似文献
5.
Pigeons were trained on a variant of the autoshaping procedure in which a keylight stimulus of increasing brightness was used to signal the passing of a 30-sec interfood interval (IFI). Key-pecking developed in all subjects within the first session (65 trials). Within trials, pecking began midway through the IFI, increased throughout the remainder, and decreased just before food delivery. Other behavioral stereotypies were also recorded: Low light levels were associated with a retreat to the rear of the test chamber, and medium light levels (during the midportion of the IFI) were associated with high rates of pacing toward and away from the food source. Probe trials revealed that pecking, pacing, and retreat were all under strong stimulus control; that is, when the light was held constant at its lowest or highest brightness, or when the brightness ramp was presented in reverse order, the behavior pattern almost invariably remained tied to stimulus brightness. Results are discussed in terms of associative and nonassociative sources of the form and sequential characteristics of the behavior. 相似文献
6.
Newly hatched chicks were force-fed food and water throughout rearing, and food, water, or sand reinforcers during exposure to an omission-training procedure. The chicks were thus prevented from performing approach and contact responses to the reinforcer at any time in their lives. Nevertheless, the subjects displayed approach and species-specific feeding or drinking reactions directed toward an illuminated key paired with food or water, but not with sand. Illumination of a key either uncorrelated or negatively correlated with food or water did not engender appreciable responding. Feeding and drinking reactions were topographically distinct, determined by the type of reinforcer, but were not elicited by the reinforcer. These findings support a “learned release” view of autoshaping, according to which phylogenetically preorganized behavior patterns are triggered by distal stimuli paired with biologically significant proximal stimulation, and suggest a close relationship between autoshaping and primitive instances of visual object recognition. 相似文献
7.
T. J. Roper 《Learning & behavior》1981,9(4):433-440
The term “schedule-induced” implies that the overall frequency of a behavior is greater in the presence of an intermittent schedule of reinforcement than in the absence of such a schedule. Consequently, the occurrence of interreinforcement behavior is not in itself sufficient evidence of schedule induction: a test of induction requires comparison between an intermittent-schedule condition and a nonschedule baseline. The relative merits of different types of nonschedule baseline are examined, and it is concluded that the best test of schedule-induction involves both an extinction and a massed-reinforcer baseline. A working definition of schedule-induction is suggested on this basis. Studies purporting to show schedule induction of activities other than drinking are critically reviewed, and it is concluded that schedule induction may be less general than is usually supposed. It may therefore be more fruitful to seek an explanation of schedule-induced drinking which focuses specifically on the interaction between food and water ingestion in the rat, rather than an explanation involving concepts such as stress, frustration, or arousal. 相似文献
8.
Five rats were exposed to fixed-time food schedules, ranging from 30 to 480 sec. Three rats displayed a postfood pattern of schedule-induced drinking, with short latencies from food delivery to drinking at all interfood interval durations. In contrast, drinking for the other 2 subjects tended to occur at lower overall levels, and drinking bouts frequently began in the middle of the interfood interval, such that the latency from food delivery to drinking increased dramatically as the interfood interval increased. Observation of these 2 subjects revealed that another form of licking-pawgrooming-occurred reliably after food delivery and before drinking bouts. A between subject comparison of the 3 postfood drinkers and the 2 pawgroomers revealed that, in addition to a common topography (repetitive licking), pawgrooming and drinking were similar with respect to their temporal locus, relation to the interfood interval, and extinction baseline levels. These similarities suggest that drinking and pawgrooming are induced by a common mechanism. Cohen, Looney, Campagnoni, and Lawler’s (1985) two-state model of reinforcer-induced motivation provides a useful framework for the interpretation of these results. 相似文献
9.
Lashley and Rosellini (1980) have recently suggested that schedule-induced polydipsia (SIP) is determined by the occurrence of absolute periods within schedules of periodic food delivery which are associated with a low probability of food delivery, that is, CS? periods. To assess this hypothesis, SIP was examined in the present experiments under three schedules—fixed time, variable time, and random time (RT)—which differed in probability of occurrence and/or duration (Experiment 1), and under a range of RT schedules in which the CS? period was systematically varied by changing the interpellet interval (Experiment 2). In both experiments, the level and temporal distribution of SIP did not seem to be related to the absolute period associated with the absence of food. Instead, SIP was more systematically related to the average length of the interpellet interval and, therefore, to the average period associated with no food. It was suggested that drinking under intermittent schedules of pellet delivery, that is, SIP, is determined by an average CS? period and not by an absolute period associated with the unavailability of food. 相似文献
10.
Charles H. M. Beck Thomas J. S. Huh Dave G. Mumby Marian E. Fundytus 《Learning & behavior》1989,17(1):49-62
Food-deprived rats develop polydipsia on an intermittent schedule (fixed time 60 sec) of food pellet delivery, but not on an identical schedule of food powder delivery. This result was demonstrated with separate groups receiving each type of food and was replicated using rats as their own controls. Powdered food not only prevented the development of polydipsia, but it abruptly terminated ongoing polydipsia in rats that were switched from the scheduled delivery of pellets to powder. Ethological analysis of the behavior showed that the rats receiving powder were not engaging excessively in some behavior other than drinking. After discounting several factors, we concluded that the amount of oral activity associated with feeding, which occurred immediately after food delivery, was reciprocally related to the level of drinking. 相似文献
11.
Food-deprived rats that receive intermittent delivery of small amounts of food develop excessive drinking--specifically, schedule-induced polydipsia (SIP). A main characteristic of SIP is its occurrence at the beginning of interfood intervals. The purpose of this study was to demonstrate that SIP can be developed toward the end of interfood intervals, in closer proximity to upcoming than to preceding food delivery. In Experiment 1, two groups were exposed to a fixed-time (FT) 30-sec food schedule with water available during the first or the last 15 sec of each interfood interval. Two additional groups, which had access to water throughout, were exposed to FT 30-sec or FT 15-sec schedules of food presentation. The FT 30-sec group with free access to water developed the highest level of intake; similar and intermediate levels were induced in all the remaining groups. In Experiment 2, three groups of rats were exposed to an FT 90-sec food schedule with water available during the first, the second, or the last 30 sec of each interfood interval. One additional group with access to water throughout was exposed to the FT 90-sec schedule of food presentation. The group with free access to water developed a higher level of consumption than did the other groups, but by the end of training none of the four groups showed statistical differences in polydipsic drinking. Results show that adjunctive drinking can be developed in proximity to upcoming food delivery even with long interfood intervals. 相似文献
12.
Rats barpressed for food on a variable-interval schedule and then received food in a runway for one of three degrees of effort. Finally, all animals again barpressed for food. Requiring five runway shuttles per food pellet produced a greater subsequent rate of barpressing than reward for each shuttle, which, in turn, yielded more barpressing than free food. A follow-up study showed the five-shuttle treatment to produce more subsequent barpressing than a control condition which omitted any runway treatment. Another experiment indicated that the higher rate of barpressing following the five-shuttle treatment was not due to greater conditioned general activity, since the five-shuttle treatment failed to increase the number of grid crossings to the cue of food presentation and produced no more unconditioned barpressing than following free food in the runway. Two possible interpretations of the results were compared: (1) The degree of accustomed effort per reinforcer becomes a generalized component of instrumental behavior, (2) high effort increases the habituation of frustration-produced disruptive responses. 相似文献
13.
In Experiment 1, 12 rats were exposed to an FT 60 schedule of food reinforcement, followed either by extinction or by a massed-food control condition, in the presence of a wood block. In 9 rats, wood-chewing behavior increased systematically during the FT 60 condition and declined again during extinction or massed food, while the other 3 rats showed virtually no chewing behavior at any stage of the experiment. In Experiment 2, frequency and bout duration of wood-chewing under an FT 60 schedule of food reinforcement declined as body weight increased, in 7 rats. We conclude that wood-chewing qualifies as a schedule-induced behavior, and that it resembles schedule-induced drinking in its dependence on body weight. Unlike drinking, however, induced chewing occupied the middle region of the 60-sec interreinforcement interval, declined markedly within the session, and showed considerable within- and between-subject variability. 相似文献
14.
Jennifer J. Higa 《Learning & behavior》1997,25(2):177-184
The present experiment examined temporal control of wait-time responses by interfood interval (IFI) duration. We exposed rats to a sequence of intervals that changed in duration at an unpredictable point within a session. In Phase 1, intervals changed from 15 to 5 sec (step-down) or from 15 to 45 sec (step-up). In Phase 2, we increased the intervals by a factor of four. We observed rapid timing effects during a transition in both phases of the experiment: A step-down and a step-up transition significantly decreased and increased wait time in thenext interval, respectively. Furthermore, adjustment of wait times during step-down was largely complete by the third transition IFI. In contrast, wait times gradually increased across several transition IFIs during step-up. The results reveal dynamic properties of temporal control that depend on the direction in which IFIs change. 相似文献
15.
Edward P. Sarafino 《Learning & behavior》1978,6(2):235-243
Twenty-four male rats were reared under three feeding conditions. These conditions manipulated the number and variety of exploratory behaviors required to obtain diets of powdered food and water in feeding boxes. One group performed minimal exploratory responses to obtain their diets. Another group shuttled between two feeding stations, thereby executing several exploratory components, primarily locomotor. The third group performed a considerable number and variety of exploratory components in search of their diets, located unsystematically throughout the feeding box. Adult testing occurred without food and water in an apparatus resembling the feeding boxes. The results showed that exploratory behavior was affected by feeding conditions, enhanced with increased dietary deprivation, and reduced across both trials and within-trial intervals. These results indicate that the particular exploratory behavior measured must be selected by reference to the subjects’ prior experience. 相似文献
16.
Marvin Z. Deluty 《Learning & behavior》1976,4(4):436-440
Rats’ responding was maintained on a random-interval 1-min food schedule. In addition, non-contingent pellets were delivered, independently of the animals’ behavior, at either fixed intervals (Experiment 1) or at random intervals (Experiment 2). As the rate of delivery of the periodic and aperiodic free reinforcers increased, the rate of responding decreased. But these free reinforcers, in addition to having this inhibitory effect, had also a local excitatory effect upon responding: lever-pressing increased to a level above its mean rate following the delivery of a free food pellet. The time course of this behavioral aftereffect of free reinforcers, for both fixed and random intervals, was dependent upon the proportion of the interval between successive free food deliveries. The relation of these results to those obtained with response-contingent reinforcement, free punishment, and in schedule-induced phenomena is discussed. 相似文献
17.
Douglas Reberg 《Learning & behavior》1980,8(1):120-128
Four pairs of rats were studied in a yoked control design intended to determine if an interim activity (schedule-induced drinking) was sensitive to operant contingencies. Food was always presented on a fixed-time 30-sec schedule. Additionally, a positive or negative operant contingency was in effect during the first 6 sec of each interval. The positive (drink/food) contingency produced an extra food presentation at the 6th second of an interval if the lead rat drank at least once in the first 6 sec. The negative (no-drink/food) contingency produced an extra food presentation only if the lead rat did not drink in the first 6 sec. Two pairs of rats were first exposed to the positive contingency and then to the negative contingency. Two pairs received training in the reverse order. In drink/food training, all lead rats developed patterns of drinking that produced extra food presentations in most intervals. There were some indications that the positive contingency facilitated early acquisition of drinking, but the yoked rats eventually developed temporal distributions and asymptotic levels of drinking comparable to those that occurred in lead rats. In no-drink/food training, the two lead rats initially exposed to the positive contingency showed high levels of drinking inappropriate to the negative contingency, but the two lead rats initially exposed to the negative contingency showed appropriately low levels of drinking. The latter effects seem attributable to the no-drink/food contingency. 相似文献
18.
Rats were trained to leverpress for food and subsequently exposed to either arithmetic series or random variable-interval reinforcement schedules. Adjunctive drinking developed in all subjects exposed to arithmetic variable-interval reinforcement, but did not develop in six of the eight animals trained on the random schedule. The results suggest that adjunctive drinking is the result of an interaction between the tendency of rats to drink after eating and the ability of locally low probabilities of reinforcement within schedules to induce conditioned behavioral states. 相似文献
19.
Pigeons were given the opportunity to terminate certain segments of fixed intervals by pecking a control key. When 30-sec segments of negative and positive stimuli alternated across the interreinforcement interval (Experiment 1), most birds terminated a large proportion of negative segments. However, few control-key responses were made during the negative segment immediately following food presentation. Under schedules during which only one negative segment was programmed, during the first 30 sec of 1-min intervals (Experiment 2), control-key responses, when they occurred at all, were made after several seconds of the interval had elapsed. Similar findings were obtained when a peck on the control key merely changed the color on the food key (Experiment 3). These findings suggest that the post-reinforcement extinction state (Schneider, 1969) during fixed-interval schedules consists of two phases: an immediate postreinforcement inhibitory phase, followed by a second phase during which a control-key response may occur. These two phases and their associated behavior may be related to Staddon’s (1977) distinction between interim and facultative activities. 相似文献
20.
Eight food-deprived Wistar rats developed stable patterns of lever pressing and licking when exposed to a fixed-time 30-s schedule of food pellet presentation. The rats were trained to lever press by presenting the lever 10 s before the programmed food delivery, with the food pellet being delivered immediately upon a lever press. The operant contingency was then removed and the lever was inserted through the entire interfood interval, being withdrawn with food delivery and reinserted 2 s later. On successive phases of the study, a protective contingency postponed food delivery if responses (lever presses or licks) occurred within the last 1, 2, 5, 10, 20, or 25 s of the interfood interval. Lever pressing was reduced at much shorter response–food delays than those that reduced licking. These results demonstrate that reinforcement contributes to the maintenance of different response patterns on periodic schedules, and that different responses are differentially sensitive to delays. 相似文献