Time Outs Research Articles

A comparison of forward and backward procedures for the acquisition of response chains in pigeons

Four pigeons each learned two separate four-link response chains on a nine-key intelligence panel. One chain was acquired with forward chaining, and the other was learned with backward chaining. The first chain employed four colors as the discriminative stimuli (SDs), and the second presented four forms. Completion of each chain produced 3 sec access to mixed grain, a 3-sec intertriai interval (ITI), and the next trial. Incorrect responses produced a 3-sec timeout (TO). During ITI and TO, all illumination in the experimental chamber was eliminated. All four birds made fewer errors in whichever chaining procedure they learned first, forward or backward.

Concurrent sequential matching in the pigeon

Two pigeons were trained to peck two pairs of matching stimuli in sequence. Each trial presented four illuminated keys, two pairs of matching stimuli. A response to any key darkened the key. A response to the other key presenting the same stimulus that was extinguished by the first response darkened that key. A response to each of the remaining two keys presenting the other matching stimuli darkened those keys and produced a fifth key illuminated with white. A response to this key produced 3 sec access to grain, a 3-sec intertriai interval (ITI), and the next trial. An error (i.e., pecking two different stimuli) produced a 5-sec time-out (TO). During Phase 1, two of three colors (red, green, and yellow) were presented on each trial. Phase 2 used combinations of two forms and a color: an “X,” a circle, and yellow. Phase 3 employed three novel stimuli: horizontal line, vertical line, and blue. Both birds showed an initial increase in errors across phases. Both pigeons demonstrated first-response stimulus preferences (i.e., responded to green first during Phase 1, yellow during Phase 2, and blue during Phase 3). The various spatial configurations of keys and stimuli influenced the errors made by both birds.

An experimental study of by-products of successive discrimination learning in the pigeon

Four experimental groups and a control group, of five pigeons each, were trained to successively discriminate a vertical amber line from one oriented either 30 or 60 deg to the right. Depending on group, pecks were intermittently reinforced by either 2.5 or 5.0 sec access to the food hopper. During discrimination, the subjects were provided a second response key, a peck upon which provided a 5-sec time-out (TO) from either the positive or the negative stimulus. Frequency of response on both the TO key and the discrimination key was monitored throughout. After the discrimination training, all subjects were given a postdiscrimination generalization test. Although peak shift was not obtained, the results support the hypothesis that by products of successive discrimination learning are functions of magnitude of S+ reinforcement and degree of S+/S− separation. It was concluded that the results are consistent with a conflict theory of by-products of discrimination learning.

A Chaining Analogue to Delayed Matching to Sample

Pigeons were trained on an analogue to a delayed matching-to-sample procedure requiring explicit, sample-specific, mediating responses during the delay. Each trial consisted of a three-link chain. The first and third links of the chain were the sample and choice components respectively of matching to sample. During the second link, different mediating pecks, dependent on the sample, were reinforced with the presentation of the choice component on a variable-interval schedule (VI 1.5 sec to VI 70 sec). Incorrect mediating pecks resulted in a timeout (TO). Matching accuracy during the third link was over 90% even with average delays of 70 sec, while accuracy of second-link mediating pecks tended to decrease as the delay interval increased. These findings were confirmed using fixed-interval and variable-time schedules during the second link of the chain. The results suggest that mediating behavior may function as a discriminative stimulus for correct choices under delayed matching to sample.

Discrete-trial control of cocaine self-injection behaviour in squirrel monkeys: effects of morphine, naloxone, and chlorpromazine

Intravenous cocaine self-injection behaviour was studied using a new discrete-trials procedure in monkeys. Daily sessions consisted of two sets of 40 discrete trials, separated by a 5-min time out (TO) period; the intertrial interval during each segment of the session was equal to 50 s. In the first experiment, cocaine self-injection behaviour (15 μg/kg per injection) was suppressed in a dose-dependent manner by morphine pretreatment (1–5.6 mg/kg, im). When cocaine self-injection responding was suppressed by morphine pretreatment (3 or 5.6 mg/kg, im), the morphine antagonist, naloxone (0.01–1.0 mg/kg, im), reinstated drug-taking behaviour; the effect depended upon the dose of the antagonist and upon the amount of morphine given to suppress cocaine self-administration behaviour. When monkeys were pretreated with chlorpromazine (0.03–5.6 mg/kg, im) before a cocaine self-injection session, small doses marginally increased responding and larger doses exerted a suppressive effect. These effects were observed when cocaine was available at a unit dose of 15 μg/kg per injection. When the unit dose of cocaine was increased to 300 μg/kg per injection, small doses of chlorpromazine (0.03–1 mg/kg, im) exerted no clearly detectable effects, though responding for drug injections was profoundly suppressed when sessions were preceded by chlorpromazine pretreatment at doses of 3 and 5.6 mg/kg, im. In this experiment, drug intake per session was greater when a large injection dose (300 μg/kg per injection) was available for self-administration than when a small dose (15 μg/kg per injection) could be self-injected; the frequency of drug self-injection was reduced, however, when the larger unit dose of cocaine replaced the smaller one. When considered in relation to the results of other experiments, it is evident that control of cocaine self-injection responding by a discrete-trials procedure results in schedule-dependent behaviours that differ in relative sensitivity to drug pretreatments from cocaine-reinforced responding controlled by fixed-ratio schedules of drug reinforcement.

Electrophysiological measurement during a time-out procedure in stuttering and normal speakers

Eight stuttering and eight normal speaking subjects were given a time-out (TO) procedure during reading. Simultaneous measures of heart rate and galvanic skin response were obtained in order to infer anxiety level during the TO period. Multivariate and univariate analysis of variance procedures indicated that stutterers, when compared to normals, initially relax during a TO period compared to base rate levels. Near the latter part of the TO period stutterers anticipate the onset of speech and become relatively more anxious. This anxiety level increases even more during the actual speech intervals. Normal speakers resent the intrusion of the TO interval and become more anxious during this period.

Discrete-trial control of morphine self-injection behaviour in squirrel monkeys: effects of naloxone, morphine, and chlorpromazine

Intravenous morphine self-injection behaviour was studied using a new discrete-trials procedure in monkeys. Morphine self-injection was most probable when small unit doses (10–100 μg/kg per injection) were available and least frequent, even in comparison with saline substitution, at doses of 300 and 400 μg/kg per injection. Despite variation of the inter-trial interval from 50 to 300 s small injection doses (25 and 100 μg/kg per injection) continued to sustain more frequent self-injection responding than a larger unit dose (400 μg/kg per injection). When daily sessions consisted of 40 trials at an inter-trial interval of 50 s, morphine self-injection behaviour (100 μg/kg per injection) was neither increased nor consistently decreased by naloxone pretreatment (0.1–1.0 mg/kg im). In subsequent experiments, daily sessions consisted of two sets of 40 discrete trials, separated by a time-out (TO) period. When monkeys were pretreated with morphine (5.6 mg/kg im) before a given session, responding for drug injections was suppressed; the effect was reversed by naloxone (1 mg/kg im) which, if injected at TO, reinstated morphine self-administration behaviour. When an injection of chlorpromazine (5.6 mg/kg im) preceded a given session, responding for morphine injections was also suppressed; naloxone (1 mg/kg im) failed to reinstate chlorpromazine-suppressed responding, indicating that naloxone acted as an acute morphine antagonist under some circumstances, but did not otherwise influence behaviour. When the unit dose of morphine was increased to 200 μg/kg per injection, naloxone (1–3 mg/kg im) elicited agitation and occasional vomiting in each monkey tested, but did not suppress their drug-taking behaviour. Though small increases in morphine intake were observed after naloxone pretreatment, substantial increases in response output during the inter-trial interval, with a consequent loss of stimulus control normally exerted by the trial signal, were observed. These results were interpreted in terms of acute, antagonist-precipitated withdrawal signs, not evident in response to naloxone pretreatment when drug self-injection responding was maintained on a daily basis by a limited number of smaller unit injection doses of morphine (50 or 100 μg/kg per injection).

Behavioral contrast and inhibitory stimulus control

Two experiments examined the presumed relationship between behavioral contrast and inhibitory stimulus control. In Experiment I, pigeons were exposed to mult VI 1-min VI 1-min or mult VI 5-min VI 5-min during baseline training prior to mult VI 1-min VI 5-min discrimination training. Half of the subjects received a timeout (TO) component during baseline in order to reduce the degree of contrast during discrimination training. Only 3 of 8 subjects receiving the TO showed contrast while all other subjects showed various degrees of contrast. Postdiscrimination generalization gradients indicated excitatory rather than inhibitory control by the stimulus associated with the VI 5-min schedule. During baseline training in Experiment II, responding to all the generalization stimuli was reinforced. In addition, some subjects received the TO stimulus. The subjects were next exposed to mult VI 1-min EXT, mult VI 1-min VI 5-min, or just the VI 5-min component. Generalization gradients indicated inhibitory control by the stimulus associated with EXT or VI 5-min for 19 of 20 subjects even though some subjects did not show contrast. These results question the presumed relationship between behavioral contrast and inhibitory stimulus control.

Managing a hospital behavior problem: Malingering

Malingering can pose a serious problem to attending medical personnel. A technique employed at the Children's Asthma Research Institute and Hospital (CARIH) in order to modify this behavioral pattern—time-out (T.O.) from positive reinforcement—is described. In addition, procedures were presented both for shaping up socially-appropriate behaviors and for insuring that gains were maintained when the subject returned home.

Response-contingent time out: Important parameters in behavior modification with children

The present paper delineates and discusses eight parameters of response-contingent time out (TO) procedures that need to be considered in treating children and conducting research. In general, the parameters have not been systematically controlled or investigated.

Emotional and Instrumental Effects of Reward Shift

Two groups of rats received 150 training trials and 60 test trials in a Skinner box on 2 linked Fixed ratio 25 (FR25) schedules separated by a 10-sec. time-out (TO) period. During training Group R received reward at the end of the first FR, Group N did not. The second FR was followed by reward for both groups. During test all Ss received a random 50/50 presentation of reward/ nonreward following the first component. For both groups TO responding following nonreward was greater than that following reward. There was little effect on subsequent instrumental responding. Results are discussed in terms of possible emotional and instrumental effects of frustration.

The differential effects of timeout and shock on DRL responding in the CER paradigm

A within-Ss design with hooded rats and a DRL 10-sec reinforcement schedule was used to study the effects of timeout (TO) and shock on baseline responding in the CER paradigm. Results indicated that all Ss accelerated responding during the preTO stimulus and suppressed responding during the preshock stimulus. Although the findings with shock were consistent with those of previous investigations, the results with TO were exactly the opposite of those obtained in earlier studies with rats.

Time-Out from Reinforcement: Effect on Sibling Aggression

Time-out (TO) from social reinforcement (5-min isolation) was made contingent upon each occurrence of aggressive behavior (i.e., hitting, biting, kicking, shoving, or taking a toy away) against an 11-month-old boy by his 26-month-old sister. Aggressive behaviors occurred at a relatively high rate during a 10-day Baseline period. Aggressive behaviors were reduced to essentially a zero rate by the TO contingency during the first 10-day Experimental period. Aggressive behaviors partially recovered during a 10-day Reversal period (no time-out contingency), but were reduced again by contingent TO during a second 10-day Experimental period. Incidental behavioral changes observed during the two Experimental periods included increased cooperative play with the brother, increased affectional approach to the parents and brother, and decreased oppositional behavior.

Instruction-dependent facilitation during a pretimeout stimulus in human subjects

Two groups of human Ss were run for monetary reward in baseline and test conditions using timeout (TO) as a US in a CER paradigm. Groups differed only with respect to experimental instructions. The F group received instructions which established the TO discrimination, whereas the R group received similar instructions which did not. A facilitatory effect during CS in the test phase was found to be mainly a function of those instructions which did not specify the significance of the TO stimulus.

Erratum to: Identification and localization within digit and letter spans

Two groups of human Ss were run for monetary reward in baseline and test conditions using timeout (TO) as a US in a CER paradigm. Groups differed only with respect to experimental instructions. The F group received instructions which established the TO discrimination, whereas the R group received similar instructions which did not. A facilitatory effect during CS in the test phase was found to be mainly a function of those instructions which did not specify the significance of the TO stimulus.

Operant rate of planarians as a function of time out from photic stimulation

Four groups of 10 D. dorotocephala were tested over a 1 h period in a free operant situation. A response of breaking a photobeam provided a time out (TO) from.4 log ft-c for periods of 0, 15, 30, and 60 sec. The 15- and 30-sec TO groups produced the same mean response rates, which were significantly different from the other two groups. The response rates declined for each of the four groups during successive 15-min periods but was least noticeable for the 15-sec TO.

MODIFICATION OF OBSERVING BEHAVIOR1

The effects on monitoring performance of a limited hold (LH) terminated by a bell or by electric shock and of periodic rest periods were investigated. The sensitivity of basal skin conductance to different monitoring conditions was also studied. Humans monitored a visual display in several 2-hr sessions under the Holland procedure. In each session, signals were programmed by one of the following three multiple schedules: a variable interval of 6 min (VI 6) and a VI 6 with a limited hold (LH) terminated by a bell; a VI 6 and a VI 6 LH terminated by electric shock; a VI 6 LH terminated by shock and a time-out (TO). The two components of each schedule alternated at 15-min intervals. The average observing response rate of eight subjects was lowest during the VI 6 periods, higher in periods when the LH was terminated by a bell, and highest when the LH was terminated by shock. Periodic TO periods did not appreciably increase the response rate under the VI 6 LH shock component. A differential level of palmar skin conductance under the two components of a schedule was present only under the mult VI 6 LH shock-TO.

DISCRIMINATIVE FUNCTIONS BASED ON A DELAY IN THE REINFORCEMENT RELATION.

Pigeons were shown to come under discrimination control when the S(D) and S(Delta) were temporally separated from reinforcement and non-reinforcement. S(D) and S(Delta) consisted of distinctive key illuminations presented separately. Responding on an FR 5 in the presence of S(D) or S(Delta) produced a third stimulus containing a schedule requirement. If this third (or interpolated) stimulus was preceded by S(D), responding in its presence produced reinforcement followed by a time-out (TO). If, on the other hand, the third stimulus was preceded by S(Delta), responding produced TO alone. In this fashion, the same stimulus and the same response requirement were imposed between S(D) and the reinforcement as between S(Delta) and the TO. In Experiment I, the schedule employed during the interpolated stimulus was FR; in Experiment II, FI. Discrimination reversal was accomplished in both experiments.

Spontaneous recovery after extinction with periodic time-outs

Three pigeons were trained on a variable-interval schedule. Following this, they were extinguished. During extinction, 1-min. periods of time-in (TI) and time-out (TO) alternated. The Ss responded only in TI. When extinction was complete, TO was removed in the middle of a session. All Ss begain responding shortly after the removal of TO.

ESCAPE FROM SD ASSOCIATED WITH FIXED-RATIO REINFORCEMENT.

Throughout ascending and descending fixed-ratio (FR) sequences, rats were allowed to terminate the FR stimulus control by pressing a time-out (TO) lever. To minimize chance or accidental responses on this second lever, three presses were required to produce the 30-sec S(Delta) period. As FR performance became more "strained," there was an increased predisposition to escape from the time-in stimulus complex. The generality of this finding was extended by obtaining recoverability (independent of the direction of stimulus change) of the FR-TO function in the descending series. Typically, escapes were produced only during the post-reinforcement pause; however, under a mixed FR FR schedule, their occurrence shifted to a point within the inter-reinforcement interval corresponding to the unreinforced completion of the lower ratio component. It appears that the point where the rat can discriminate the size of the ratio requirement will be the place where TOs are imposed. This inference was supported by a substantial increase in TO frequency accompanying a shift from CRF to extinction on the FR lever. Finally, the escape lever was placed on a progressively increasing FR schedule and later extinguished to demonstrate that the TO condition was in fact reinforcing.