Stimulus Discriminability in Free‐operant and Discrete‐trial Detection Procedures

McCarthy, Dianne; Davison, Michael; Jenkins, Peter E.

doi:10.1901/jeab.1982.37-199

Cited by 14 publications

(17 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Davison and Tustin's (1978) analysis assumes that the values for sensitivity to reinforcement in Equations 1 and 2 above, an and an, are equal. Indeed, McCarthy and Davison have reported several failures to find consistent differences between an and an and have argued that the magnitude of an and an should be unrelated to stimulus difference (McCarthy & Davison, 1980a;McCarthy, Davison, & Jenkins, 1982). For the present data, slopes of the functions for 0° (an) were .62 and .50 for Birds G4 and G5, respectively.…”

Section: Resultsmentioning

confidence: 41%

A note on the measurement of stimulus discriminability in conditional discriminations

White

Pipe

McLean

1985

Bull. Psychon. Soc.

View full text Add to dashboard Cite

In a conditional discrimination, pigeons' responses on a right key were reinforced in the presence of a 0° line orientation, and responses on a left key were reinforced in the presence of any of five other orientations, 15° through 75°. Variable-interval schedules of reinforcement for right and left responses were changed over five experimental conditions. Values for a measure of discriminability of 0° from other orientations increased as orientation difference increased. Sensitivity of the choice between right and left in the different orientations, to reinforcers for right and left responses, changed with orientation difference. The effect of reinforcers in one component of a conditional discrimination on responding in another may therefore be modulated by the discriminability of the stimuli signaling the components.In a simple successive discrimination, two stimuli alternate in succession, each associated with a reinforcement schedule. A discrimination may develop as long as the stimuli and their associated schedules differ. The most obvious evidence that the discrimination depends on differential reinforcement is the absence of differential responding when the reinforcer rates are the same in the presence of the two stimuli. We have argued that if the reinforcer differential is varied over several experimental conditions, it is possible to obtain an index of the extent of control by the discriminative stimuli independently of the effects of the reinforcer differentials that otherwise maintain the discrimination (White, Pipe, & McLean, 1983, 1984. This index is the exponent of the power function relating ratios of responses in the two stimuli to ratios of reinforcers.Traditional methods for obtaining measures of discriminability of successively presented stimuli independently of reinforcement effects rely on successive conditional discriminations. For example, standard detection procedures involve discrete trials in which the stimuli to be discriminated are presented successively across trials and the choice or detection response is made within trials. Because the choice response involves a simultaneous discrimination (e.g., between left and right, or red and green, or yes and no), the detection procedure introduces an additional discrimination. That is, detection and other conditional procedures require discriminations between successive stimuli and also between the simultaneous stimuli signaling the choice response (White et al., 1984). The advantage of the additional simultaneous discrimination is that it allows errors to occur. In the context of traditional treatments of detection performance, the occurrence of errors is essential if analyses are designed to separateThe authors' mailing address is: Department of Psychology. Victoria University of Wellington. Wellington. New Zealand.153 the effects of stimulus discriminability from response bias toward reporting one or another stimulus.In our earlier work (White et al., 1983), we had found that, as stimulus separation between successively presented line or...

show abstract

Section: Resultsmentioning

confidence: 41%

A note on the measurement of stimulus discriminability in conditional discriminations

White

Pipe

McLean

1985

Bull. Psychon. Soc.

View full text Add to dashboard Cite

show abstract

“…As their independent variable, they used the ratio of overall (sessional) reinforcer frequencies -that is, the variable that was manipulated over experimental conditions. The present research tested the applicability of Equations 1 to 4 in the free-operant detection procedure under two types of biasing manipulations: First, the frequency of component presentations was varied (as in McCarthy et al, 1982); second, the within-component reinforcer rates were varied (as in conventional multiple-schedule research). These two biasing manipulations were conducted with both highly discriminable and with indiscriminable stimuli.…”

Section: Response Pi P2mentioning

confidence: 99%

“…In a series of experiments (reviewed by McCarthy & Davison, 1981aDavison, , 1981b, we have shown how this model describes performance in the discrete-trials detection paradigm by providing measures of both the discriminability of the stimuli and the sensitivity of detection performance to reinforcer-frequency variation. The second step applied the same model to the free-operant analog of the discrete-trials detection procedurethat is, to multiple-concurrent schedule performances (Davison & Mc-Carthy, 1980;McCarthy, Davison, &Jenkins, 1982). In the multiple-concurrent procedure, one response was reinforced intermittently and the alternative response was under extinction.…”

mentioning

confidence: 99%

Component Probability and Component Reinforcer Rate as Biasers of Free‐operant Detection

Davison

McCarthy

Jensen

1985

J Exper Analysis Behavior

Self Cite

View full text Add to dashboard Cite

Six pigeons were trained on multiple schedules whose components were concurrent variable-interval extinction and concurrent extinction variable-interval schedules. In Experiments 1a and 1b the stimuli signaling the components were two different light intensities, and in Experiments 2a and 2b they were two identical intensities. The components of the multiple schedule changed probabilistically after each reinforcer. In Experiments 1a and 2a, the probability of presenting the components was varied over five conditions and a replication. In Experiments 1b and 2b, the component probability was .5 and the component reinforcer rates were varied systematically over five conditions and a replication. The data, analyzed according to the Davison-Tustin behavioral detection model, confirmed that the discriminability of the stimuli signaling the components was high when the stimuli were different, and low when the stimuli were the same. Discriminability, measured by log d, was unaffected by component probability variation and by component reinforcer-rate variation. When discriminability was high, bias, or the response allocation between the two keys, was more strongly affected by variation of reinforcer rate within components than by variation of component probability, but the reverse was found when discriminability was low. The results suggest that free-operant detection performance is controlled by the rates of reinforcers in periods of time in which stimuli signal differential contingencies. These periods comprise the components when the component stimuli are discriminable, and comprise the total session when the components are indiscriminable. An extension of the Davison-Tustin behavioral detection model that incorporates these results is presented.

show abstract

“…(See McCarthy & Davison, 1981a, 1981b, for extensive reviews of this model.) On this task, pigeons are trained to report which stimulus had been presented by emitting one of two choice responses either in the presence of (e.g., McCarthy, Davison, &Jenkins, 1982) or immediately following presentation of (e.g., McCarthy & Davison, 1979) the discriminative stimuli. For example, in terms of Figure 1, red-key pecks are correct and reinforced when a bright center-key light (Si) is presented, and green-key pecks are correct and reinforced when a dull center-key light (S2) is presented.…”

mentioning

confidence: 99%

Delayed Signal Detection, Differential Reinforcement, and Short‐term Memory in the Pigeon

Harnett

McCarthy

Davison

1984

J Exper Analysis Behavior

Self Cite

View full text Add to dashboard Cite

In two discrete-trial delayed-detection experiments, six pigeons were trained on dependent concurrent variable-interval schedules. Pecking a red side key was reinforced when the brighter of two white lights (S1) had been presented on the center key, and pecking a green side key was reinforced when the duller of two white lights (S2) had been presented on the center key. Incorrect responses were red side-key pecks following S2 presentations and green side-key pecks following S1 presentations; these resulted in three-second blackouts. In Experiment 1, the time between presentation of S1 or S2 on the center key and the onset of the red and green side keys was varied nonsystematically from 0.06 seconds to 19.69 seconds across experimental conditions. Stimulus discriminability decreased as the stimulus-choice delay increased. A rectangular-hyperbolic function better described this decrease in discriminability over time than did a negative-exponential function. In Experiment 2, at each of three stimulus-choice delays (0.06, 3.85, and 10.36 seconds), relative reinforcer frequency for correct responses to the red and green side keys was varied by changing the values of the dependent concurrent variable-interval schedules. The sensitivity of choice to relative reinforcer frequency was independent of the decrease in stimulus discriminability with increasing stimulus-choice delay.

show abstract

Stimulus Discriminability in Free‐operant and Discrete‐trial Detection Procedures

Cited by 14 publications

References 15 publications

A note on the measurement of stimulus discriminability in conditional discriminations

A note on the measurement of stimulus discriminability in conditional discriminations

Component Probability and Component Reinforcer Rate as Biasers of Free‐operant Detection

Delayed Signal Detection, Differential Reinforcement, and Short‐term Memory in the Pigeon

Contact Info

Product

Resources

About