摘要:

After learning to press keys in a predetermined serial position sequence, with timeouts scheduled as a consequence of errors, monkeys developed stereotyped errors. As soon as a new trial started, the animals would make an error. On trial after trial, they pressed the same incorrect key at the first member of the sequence, even though they had previously learned the sequence. First‐member errors occurred even when sequences of fully bright keys marking correct choices were presented. When timeout was eliminated as a consequence of one first‐member error, subjects switched to an error that did produce the timeout. When all first‐member errors failed to produce timeout the monkeys ceased responding. Both prefeeding and reduction in reinforcement density resulted in stereotyped errors occurring earlier in the se

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-3

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A bottlenose dolphin, already highly proficient in two‐choice auditory discriminations, was trained over a nine‐day period on auditory delayed matching‐to‐sample and then tested on 346 unique matching problems, as a function of the delay between the sample and test sounds. Each problem used new sounds and was from five to 10 trials long, with the same sound used as the sample for all trials of a problem. At each trial, the sample was projected underwater for 2.5 sec, followed by a delay and then by a sequence of two 2.5‐sec duration test sounds. One of the test sounds matched the sample and was randomly first or second in the sequence, and randomly appeared at either a left or right speaker. Responses to the locus of the matching test sound were reinforced. Over nine, varying‐sized blocks of problems, the longest delay of a set of delays in a block was progressively increased from 15 sec initially to a final value of 120 sec. There was a progressive increase across the early blocks in the percentage of correct Trial 1 responses. A ceiling‐level of 100% correct responses was then attained over the final six blocks, during which there were 169 successive Trial 1 responses bracketed by two Trial 1 errors (at 24‐ and 120‐sec delays). Performance on trials beyond the first followed a similar trend. Finally, when the sample duration was decreased to 0.2 sec or less, matching performance on Trial 1 of new problems dropped

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-19

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Nine children, ages 4 through 7 yr, matched‐to‐sample on fixed‐ratio, fixed‐interval, variable‐ratio, and variable‐interval schedules of reinforcement. Simultaneous, zero‐delay, and 2‐sec delay matching were employed. Distributions of errors, in which the greatest number of errors occurred at the ordinal position immediately after reinforcement with fewer errors occurring at subsequent positions in the ratio, were produced by six of six children on fixed‐ratio schedules for zero‐delay and both of two children for 2‐sec delay matching. Only two children of seven produced similar error distributions on simultaneous matching for fixed‐ratio reinforcement. Variable‐ratio schedules produced slightly lower accuracy for most subjects and no systematic error patterns for any subject. Error distributions occurred for all of the five children who experienced fixed‐interval schedules for zero‐delay matching. Peak error production occurred in the second fourth of the interval. Similar patterns were not produced on variable‐interval schedules of equal reinforcement density. Schedule control of complex discriminated operants in children resembles control over simila

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-27

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

To determine the effect of a negative discriminative stimulus on the response producing it, two pigeons were each studied in a three‐key conditioning chamber. During alternating periods of unpredictable duration, pecking the center (food) key either was reinforced with grain on a variable‐interval schedule or was never reinforced. On equal but independent variable‐interval schedules, pecking either of the side (observing) keys changed the color of all keys for 30 sec from yellow to either green or red. When the schedule on the center key was variable‐interval reinforcement, the color was green (positive discriminative stimulus); when no reinforcements were scheduled, the color was red (negative discriminative stimulus). Since pecking the side keys did not affect grain deliveries, changes in the rate of pecking could not be ascribed to changes in the frequency of primary reinforcement. In subsequent sessions, red was withheld as one of the possible consequences of pecking a given side key. When red was omitted, the rate on that key increased, and when red was restored, the rate decreased. It was concluded that red illumination of the keys, the negative discriminative stimulus, had a suppressive effect on the response that prod

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-37

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Rats bar pressing on a 1‐min fixed‐interval schedule for 45‐mg food pellets became Polydipsic when water was concurrently available. They were then exposed to conditions in which each lick on the drinking tube produced a timeout period during which the food‐schedule lever was retracted and the fixed‐interval timer either did or did not continue to operate. Licks occurring within a timeout period extended its duration. As the duration of the lick‐initiated timeout period was increased logarithmically through four values from 10 sec to 80 sec, lick rates as well as water intake rates generally decreased for all three subjects. As timeout duration was progressively increased, the rate of licks occurring in the absense of, but producing, timeouts decreased for all three rats, whereas the rate of licks occurring in the presence of timeout periods remained essentially constant. Water‐intake rates and, with one exception, lick rates were suppressed more by timeout periods during which the fixed‐interval timer did not continue to operate. These results indicate that lick‐contingent timeout from positive reinforcement reduces schedule‐induced drinking, and this suppressive effect is greater when the timeout period necessarily increases the interreinforcement interval beyond its minimum duration th

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-45

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Three experiments were conducted to assess the aversive properties of a visual stimulus in the presence of which one group of birds received response‐contingent shock (discriminated punishment) while a yoked group of birds received non‐contingent shocks (conditioned suppression). In Experiment 1, presentation of the visual stimulus contingent on key pecking reduced the response rate (conditioned punishment effect) for birds under the conditioned suppression procedure but did not reduce the response rate of birds under the discriminative punishment procedure. Non‐contingent shocks also produced greater suppression of responding maintained by positive reinforcement in the presence of a visual stimulus than did response‐contingent shocks. In Experiment 2, a greater shock intensity (2 mA) was used. All the differences between the two groups found in Experiment 1 were also found in Experiment 2. Experiment 3 demonstrated that response‐contingent shock did not result in a conditioned punishment effect even when positive reinforcers were unavailable during the discriminative punishment schedule. The exteroceptive stimulus that was paired with shock in the conditioned suppression procedure acquired the ability to punish behavior. The exteroceptive stimulus in the discriminative punishment schedule did not acquire thi

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-57

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Three groups of four pigeons, trained to press a treadle on a free‐operant avoidance schedule, were given auditory discrimination training. Alternating 2‐min components of avoidance and no shock were paired with either a tone or white noise. The pigeons were subsequently given two types of generalization tests, with and without avoidable shocks scheduled. Two of the groups, trained interdimensionally, produced excitatory and inhibitory generalization gradients along the tone frequency dimension. A predicted post‐discrimination gradient was computed from the algebraic summation of these gradients of excitation and inhibition. The predicted gradient was compared with the actual post‐discrimination gradient obtained from the third group of pigeons that had been given intradimensional discrimination training on the tone frequency dimension. The predicted postdiscrimination gradient agreed in shape with the empirical postdiscrimination gradient. The results in general support Spence's (1937) gradient interaction

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-75

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Pigeons were trained on multiple schedules in which a fixed number of pecks produced either a fixed or a variable period of access to food, the average variable‐duration reinforcement equalling the fixed. Pecking rates were generally higher during the variable‐duration component. Subsequent performance on concurrent schedules revealed an initial preference for variable‐duration reinforcement for all subjects; for most subjects, this preference was sustained. For one subject, the average variable duration was gradually reduced to half the fixed duration: continued preference for the variable component resulted in a loss of up to 30% of available reinforcement time. A return to multiple schedules with unequal pay‐off shifted the preference to the greater fixed duration, and this preference was maintained even when the variable duration was again raised to equal the fixed duration. For the remaining subjects, the initial variable‐duration preference on concurrent schedules was gradually replaced by a side preference. When the range of variable durations was varied, keeping the average variable duration equal to the fixed, the occasional longer reinforcers sustained a preference for variable‐reinforcer durations for three of the fo

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-89

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

On one key, pigeons' pecks were reinforced according to a variable‐interval schedule in the presence of vertical lines, and were not reinforced in the presence of oblique lines. On a second key, pecks were reinforced according to a variable‐interval schedule in the presence of blue, according to a signalled variable‐interval schedule in the presence of red, and were not reinforced in the presence of white. Subsequently, during extinction, stimulus‐control gradients were obtained by presenting eight different line orientations on the first key concurrent with each of the three colors on the second key. On the first key, line‐orientation gradients tended to be lower, narrower, and less shifted in peak or area when the second‐key stimulus was blue or red, the stimuli respectively correlated with unsignalled and signalled reinforcement, than when it was white, the stimulus correlated with extinction. Thus, the effect on first‐key line‐orientation gradients depended on second‐key stimuli correlated with concurrent reinforcement, whether or not these stimuli were also correlated with concurrent responding. As a function of first‐key line orientation, an inverted gradient was obtained on the second key during blue; during both red and white, rates of pecking on the second

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-99

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Three pigeons were required to peck a single key at a higher and a lower rate, corresponding to two classes of shorter and longer concurrently reinforced interresponse times. Food reinforcers arranged by a single variable‐interval schedule were randomly allocated to the two reinforced interresponse times. The absolute durations of reinforced interresponse times were varied while the total reinforcements per hour was held constant and the relative duration,i.e., the relative reciprocal, of the shorter reinforcer class was held constant at 0.70. Preference for the higher rate of responding, as measured by the relative frequency of responses terminating interresponse times in the shorter reinforced class, depended on the absolute reinforced response rates. Preference for the higher reinforced rate increased from a level of near‐indifference (0.50) at high reinforced response rates, through the matching level (0.70) at intermediate reinforced response rates, to a virtually exclusive preference (>0.90) at low reinforced response rates. These results resemble corresponding preference functions obtained with two‐key concurrent‐chains schedules and thereby provide another sense in which it may be said that interresponse‐time distributions from interval schedules estimate preference functions for the component response rates corresponding to different classes of reinforced interrespo

ISSN:0022-5002    

DOI:10.1901/jeab.1974.21-109

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY