Iver Iversen - Academia.edu (original) (raw)

Papers by Iver Iversen

Steady and blinking white lights were projected on three nose keys arranged horizontally on one w... more Steady and blinking white lights were projected on three nose keys arranged horizontally on one wall. The procedure was a conditional discrimination with a sample stimulus presented on the middle key and comparison stimuli on the side keys. Three rats acquired simultaneous "identity matching." Accuracy reached 80% in about 25 sessions and 90% or higher after about 50 sessions. Acquisition progressed through several stages of repeated errors, alternation between comparison keys from trial to trial, preference of specific keys or stimuli, and a gradual lengthening of strings of consecutive trials with correct responses. An analysis of the acquisition curves for individual trial configurations indicated that the matching-to-sample performance possibly consisted of separate discriminations.

European Journal of Behavior Analysis, 2012

The main theme of Catania’s discussion points at a conference on Quantitative Behavior Analysis i... more The main theme of Catania’s discussion points at a conference on Quantitative Behavior Analysis in Manchester, England, in 1980 was that mathematical analysis has supplanted rather than supplemented experimental analysis of behavioral data. Catania provided several examples from the published literature of misleading attempts to fit data to equations. In the 30+ years that have passed since that conference, the uses of mathematical analyses have in fact increased in the experimental literature and spread into the area of applied behavior analysis as evidenced by the appearance in recent years of mathematical curve-fitting practices in some publications in Journal of Applied Behavior Analysis. The recently published ABA Handbook of Behavior Analysis (Madden, Dube, Hackenberg, Hanley, & Lattal, 2013) similarly has several chapters in both basic and applied areas that feature mathematical modeling. One particular concern that Catania voiced was the reduction of absolute rates to relative rates in experimental arrangements with concurrent schedules of reinforcement. Two (or more) obtained measures of behavior in the dimension of responses/ minute are combined to form one measure that is in fact dimensionless (e.g., in a twokey chamber used for studies of concurrent schedules of reinforcement, a response rate of 25 resp/min on the left key and a rate of 50 resp/min on the right key yield a relative response rate on the left key of 0.333). Similar reduction in dimension occurs along the independent variables, where absolute rates of reinforcement on the two concurrent schedules in the dimension of reinforcers/minute are combined into one dimensionless number of relative (reinforcement) rate. The same issue of dropping the dimensions of the behavior and of the independent variables exists when absolute rates are placed in ratios (i.e. a rate of 25 resp/min divided by a rate of 50 resp/min yields a dimensionless ratio of 0.5). Such ratios derived from dividing response rates on the one hand and reinforcement rates on the other hand may then be reduced further to a single dimensionless number such as a slope of the relation between response ratios and reinforcement ratios. Here, I would like to provide two additional examples that illustrate the problems engendered with mathematical analyses. The first example shows how basic behavioral processes may be masked when data are averaged and placed into relative rates or ratios. The second example shows how considerably large amounts of data may quite literally be ignored in mathematical analyses. In the first example, Silberberg and Fantino (1970), using concurrent variable interval variable-interval (VI VI) performances with pigeons, demonstrated that pecks during a changeover delay (COD, reinforcement is not delivered during a COD) and pecks during non-COD periods were Commentary to A. C. Catania: Discussion: The

Classical Conditioning and Operant Conditioning, 1978

European Journal of Behavior Analysis, 2013

Dr. Edward Taub has developed an effective therapy for stroke victims called Constraint-Induced M... more Dr. Edward Taub has developed an effective therapy for stroke victims called Constraint-Induced Movement therapy. The foundation of this therapy is based entirely on behavior analysis principles, and intervention is a matter of applying contingencies of reinforcement for improving the movement of limbs impaired by different types of central nervous system damage. The result is a very efficacious therapy that produces large and clinically significant gains in performance that have been replicated numerous times across patients, clinics, and countries. Dr. Taub answers questions regarding the development of this therapy, which started with animal models, and offers insight into implementing behavior-analysis based treatments in medical settings.

Revista Mexicana De Biodiversidad, 2020

Fred Keller prepared two supplements for students to use in con- junction with Keller and Schoenf... more Fred Keller prepared two supplements for students to use in con- junction with Keller and Schoenfeld (1950), “Matters of History” and “Schedules of Reinforcement.” The latter was found in a to-be-discarded file of Murray Sidman’s reprints and other items after his death in May, 2019. After presenting evidence concerning the authorship of the supplement, the relation of the contents to the article to the teaching of behavior analysis to introductory psychology students in the course for which the Keller and Schoenfeld textbook was designed are discussed. The text is a remarkable example of the teaching of scientific principles and research methods - especially group and single-subject designs – because it is so rich with data derived from real experiments. It offered to introductory students facts and no fiction. It also is exemplary in its attention to relating scientific concepts to daily experience, a critical feature of scientific material directed to such introductory- level st...

Revista Mexicana De Biodiversidad, 2017

To examine operant response variability in detail, a lever was attached to the Thumbstick of a vi... more To examine operant response variability in detail, a lever was attached to the Thumbstick of a videogame controller, which functions as a joystick. The controller was mounted outside of a standard rodent operant chamber with the lever extending into the chamber. Movement of the lever was restricted to a vertical downward distance of 2 cm. Food pellet delivery was used as reinforcement of lever movement. Criteria for reinforcement were that the lever should be held between two criteria distances, one from the top resting position of the lever and one from the end position of full movement, and the holding response should last a certain duration. Apparatus construction and development of algorithms for response detection and display in graph format as actograms are described in detail. The use of the equipment is illustrated with two demonstration experiments that examined response variability in extinction and during acquisition. The recording method allows for display of considerabl...

Journal of the Experimental Analysis of Behavior, 2020

Murray Sidman's statements regarding variability, experimental control, and generality are in... more Murray Sidman's statements regarding variability, experimental control, and generality are interwoven with examples from the literature on conditional discrimination. Sidman's position was that statistical inferences from group studies produce no information about the behavior of individual subjects and that statistical treatment of individual subject data masks variability which may represent conditions that are not controlled. Sidman's work on conditional discrimination provides excellent examples of how complex discriminations should be examined in detail with accuracy levels obtained for each type of discrimination within an experiment. Sidman made important contributions to the foundation of behavior analysis with extensive basic research as well as applications of methods and principles to clinical and educational settings.

Journal of Applied Behavior Analysis, 2020

Murray Sidman's contributions to the science of behavior span many areas including avoidance beha... more Murray Sidman's contributions to the science of behavior span many areas including avoidance behavior, coercion and its effects, stimulus control, errorless learning, programmed learning, stimulus equivalence, and single-subject methodology. He was also a great mentor to many and helped shape the discipline we now call behavior analysis. In this memoriam, we briefly highlight his scholarly legacy and share some personal anecdotes.

European Journal of Behavior Analysis, 2014

Consequences (2012): “She has positioned the fundamental feature of behavior analysis as the cent... more Consequences (2012): “She has positioned the fundamental feature of behavior analysis as the centerpiece in a broad array of scientific work on selection by consequences, including evolutionary biology, epigenetics, and neuroscience.” For an exemplar, see Hull, Langman, and Glenn (2001)—the collaborative product three authors from three different natural science disciplines: conceptual immunology, evolutionary theory, and behavior analysis, respectively. Given the uncontestable reality of operant processes as the subject matter of our science, along with the effectiveness of its technology, its continual evolution should come as no surprise. Furthermore, why wouldn’t scientists in those related natural science areas be interested in our science? References

European Journal of Behavior Analysis, 2012

Using an example of a problem in interpretation of behavioral data, the paper asks whether behavi... more Using an example of a problem in interpretation of behavioral data, the paper asks whether behavior analysis is explanation of behavior or control of behavior. The paper argues that when two or more experimental conditions are compared, one condition is not necessarily superior to the other(s) and may not serve as an explanation of what happens in other conditions. Experimental subjects simply face different environmental conditions and behave differently in them. Successful behavior changes and management in clinic, laboratory, and school suggest that contemporary behavior analysis is behavioral engineering. But what criteria should be applied when one tries to explain behavior? Control of behavior and explanation of behavior may be separate forms of analysis with the latter incorporating elements that may not be approached directly in the manner of manipulating independent variables.

The Psychological Record, 1985

Rats’ lever pressing and wheel running were maintained on concurrently operating variable-interva... more Rats’ lever pressing and wheel running were maintained on concurrently operating variable-interval (VI) schedules of food reinforcement. When the schedule for lever pressing was changed to a multiple VI extinction (EXT) schedule, the probability of lever pressing decreased in EXT and increased in VI (positive behavior contrast). Simultaneously, the probability of wheel running increased in EXT and decreased in VI. Next, the wheel locked either in VI or in EXT. To hold reinforcement parameters constant when the wheel was locked, the schedule for wheel running was changed to response-independent reinforcement on a variable-time schedule. With the wheel locked in VI, the probability of VI lever pressing increased. With the wheel locked in EXT, the probability of wheel running increased in VI, and the probability of VI lever pressing simultaneously decreased resulting in prevention of positive behavior contrast. For one rat, lever pressing and wheel running developed into chained behaviors that were emitted simultaneously, and the results differed for that animal. The experiment shows that positive behavior contrast can depend upon concurrently reinforced behavior, even when reinforcement parameters are unchanged.

The Psychological Record, 1985

Two experiments investigated moment-to-moment interactions between collateral and operant behavio... more Two experiments investigated moment-to-moment interactions between collateral and operant behaviors. Rats’ lever pressing was reinforced with food on a variable-interval (VI) schedule. In Experiment 1, access to water was first freely available and then presented in 10-s probes at different times within the interreinforcement intervals on the VI schedule. With free access to water, drinking occurred immediately after food reinforcement and lever pressing was suppressed. Drinking occurred during probes and the extent of drinking and the degree of suppression of lever pressing depended upon the probe position within the VI schedule. In Experiment 2, access to wheel running was first presented in probes ranging from 2 to 128 s. Probes controlled a changeover to wheel running and caused a suppression in lever pressing. When wheel running was accessible most of the session time, periods of no access to running were scheduled as probes for 2 to 128 s. Cessation of wheel running during probes increased the momentary probability of lever pressing. In both experiments, restricted access to the collateral response resulted in an increase of the momentary probability of that response and a concomitant reduced probability of the operant response. The experiments demonstrate the feasibility of the probe technique in analyzing and controlling moment-to-moment patterns of collateral and operant behaviors.

The Psychological Record, 1976

The influence of collateral licking from a freely available water bottle upon lever pressing rein... more The influence of collateral licking from a freely available water bottle upon lever pressing reinforced with food pellets was investigated in rats. Lever pressing was maintained on a fixed-ratio schedule and the quality of the content of the bottle was manipulated. Lever pressing and licking were physically compatible responses. The overall lever pressing rate was inversely related to the mean licking duration, and the duration of single pauses in lever pressing after reinforcement was directly related to the duration of licking bursts. Behaviors other than licking interacted with lever pressing, and these behaviors were also recorded. The results show that the rate and patterning of reinforced behavior may depend upon the rate and patterning of collateral behavior.

European Journal of Behavior Analysis, 2016

ABSTRACT Literature on conditional discrimination tasks indicates that interpretation of data dep... more ABSTRACT Literature on conditional discrimination tasks indicates that interpretation of data depends on assumptions about what constitutes evidence of performance accuracy and change. According to one interpretation, performance after a procedural intervention (e.g., introduction of new stimuli in an identity matching-to-sample task) is compared to baseline performance before the intervention; if a decrease in performance is evident, then the conclusion is drawn that the intervention produced a deficit in performance. According to a different interpretation, performance from an intervention is compared not to baseline but to chance level; if performance is significantly different from chance level after the intervention, the conclusion is drawn that the intervention did not produce a deficit in performance. Evidence for presence or absence of stimulus control or concepts is extracted from such data depending on the method of comparison. In many cases, the intervention may produce a decrease in accuracy from a baseline of 90–100% accuracy to the 60–80% range, which may be significantly different from baseline but also significantly different from chance level of 50%, for two-choice tasks. Thus, different, if not opposite, conclusions might be drawn from the same set of data depending on the method of analysis (e.g., a change from a baseline of near 90% correct to 70% correct after the intervention is either a performance deficit or not depending on the method of analysis). Interpretations of results from conditional discrimination tasks may profitably be clarified when data are presented more objectively as percent stimulus control rather than as percent correct.

Acta neurobiologiae experimentalis, 1987

Rats with lesions in the neostriatal region that belongs to the prefrontal system were trained in... more Rats with lesions in the neostriatal region that belongs to the prefrontal system were trained in two versions of delayed alternation. They performed as proficiently as intact animals in a two-key operant chamber. The same operated rats took many more trials to reach criterion when subsequently compared with the same control group in a T-maze. This finding demonstrates that variants of delayed alternation are not equivalent for animals with lesions in the prefrontal system. Observations suggested that delayed alternation in the operant chamber may be mastered by positional mediation.

Journal of Neuroscience Methods, 1988

A method is presented for manual or automated recording of rats' spontaneous nose-poking ... more A method is presented for manual or automated recording of rats' spontaneous nose-poking ('visit') behaviors to a vertical holeboard with a matrix of 45 or 54 holes. Several behavior parameters are presented: visit frequency, visit duration, temporal visit pattern, spatial visit pattern, stereotype of visits, diversity of visits and variability of visit patterns. The paper describes the development of the apparatus and some methods of analyzing and presenting the multi-parametric data. The use of the apparatus is illustrated with a one-trial appetitive conditioning task. After 5 min in a single 10-min session, a food pellet is presented, only once in a given hole, to provide reinforcement of a spontaneous visit to that hole. The behavior parameters are compared before and after reinforcement. When the one-trial conditioning effect was challenged with d-amphetamine, the behavior parameters changed in a graded manner depending upon the dose (0.25-6.0 mg/kg). The apparatus has also proven useful for studies of exploratory behavior without using food reinforcement following lesion or drug interventions.

Primate Origins of Human Cognition and Behavior, 2008

Using written symbols is essential for human communication. Effective written communication requi... more Using written symbols is essential for human communication. Effective written communication requires that each subject can read and write or produce the visual symbols. Therefore, considerable worldwide educational efforts are expended to teach children symbols such as letters, signs, and numbers. Several studies of human-animal communication have established that nonhuman subjects can also be taught to discriminate visual symbols presented by humans. Of particular interest is the fact that several studies have shown that chimpanzees can learn to discriminate complex lexigrams (Rumbaugh 1977; Savage-Rumbaugh 1986; Tomonaga and Matsuzawa 1992) by pointing to them or moving them about (Premack 1976) in an appropriate manner. Chimpanzees have also been trained to compose symbols from their elements (Fujita and Matsuzawa 1990) and to produce signs with their fingers (Gardner and Gardner 1978).

Classical Conditioning and Operant Conditioning, 1978

The response rate in the presence of one stimulus and its associated schedule depends also upon t... more The response rate in the presence of one stimulus and its associated schedule depends also upon the schedules associated with temporally adjacent stimuli. Alternations between schedule components associated with different stimuli are traditionally referred to as multiple schedules (Ferster and Skinner, 1957). Reynolds (1961b) suggested that interactions in multiple schedules might be described as contrast or induction, depending upon whether the changes in response rate diverge or converge across schedule components. Furthermore, contrast and induction may be either positive or negative, depending upon direction of change in response rate. Positive contrast, for example, refers to an increase in response rate in one schedule component simultaneously with a decreased rate in an adjacent component.

Steady and blinking white lights were projected on three nose keys arranged horizontally on one w... more Steady and blinking white lights were projected on three nose keys arranged horizontally on one wall. The procedure was a conditional discrimination with a sample stimulus presented on the middle key and comparison stimuli on the side keys. Three rats acquired simultaneous "identity matching." Accuracy reached 80% in about 25 sessions and 90% or higher after about 50 sessions. Acquisition progressed through several stages of repeated errors, alternation between comparison keys from trial to trial, preference of specific keys or stimuli, and a gradual lengthening of strings of consecutive trials with correct responses. An analysis of the acquisition curves for individual trial configurations indicated that the matching-to-sample performance possibly consisted of separate discriminations.

European Journal of Behavior Analysis, 2012

The main theme of Catania’s discussion points at a conference on Quantitative Behavior Analysis i... more The main theme of Catania’s discussion points at a conference on Quantitative Behavior Analysis in Manchester, England, in 1980 was that mathematical analysis has supplanted rather than supplemented experimental analysis of behavioral data. Catania provided several examples from the published literature of misleading attempts to fit data to equations. In the 30+ years that have passed since that conference, the uses of mathematical analyses have in fact increased in the experimental literature and spread into the area of applied behavior analysis as evidenced by the appearance in recent years of mathematical curve-fitting practices in some publications in Journal of Applied Behavior Analysis. The recently published ABA Handbook of Behavior Analysis (Madden, Dube, Hackenberg, Hanley, & Lattal, 2013) similarly has several chapters in both basic and applied areas that feature mathematical modeling. One particular concern that Catania voiced was the reduction of absolute rates to relative rates in experimental arrangements with concurrent schedules of reinforcement. Two (or more) obtained measures of behavior in the dimension of responses/ minute are combined to form one measure that is in fact dimensionless (e.g., in a twokey chamber used for studies of concurrent schedules of reinforcement, a response rate of 25 resp/min on the left key and a rate of 50 resp/min on the right key yield a relative response rate on the left key of 0.333). Similar reduction in dimension occurs along the independent variables, where absolute rates of reinforcement on the two concurrent schedules in the dimension of reinforcers/minute are combined into one dimensionless number of relative (reinforcement) rate. The same issue of dropping the dimensions of the behavior and of the independent variables exists when absolute rates are placed in ratios (i.e. a rate of 25 resp/min divided by a rate of 50 resp/min yields a dimensionless ratio of 0.5). Such ratios derived from dividing response rates on the one hand and reinforcement rates on the other hand may then be reduced further to a single dimensionless number such as a slope of the relation between response ratios and reinforcement ratios. Here, I would like to provide two additional examples that illustrate the problems engendered with mathematical analyses. The first example shows how basic behavioral processes may be masked when data are averaged and placed into relative rates or ratios. The second example shows how considerably large amounts of data may quite literally be ignored in mathematical analyses. In the first example, Silberberg and Fantino (1970), using concurrent variable interval variable-interval (VI VI) performances with pigeons, demonstrated that pecks during a changeover delay (COD, reinforcement is not delivered during a COD) and pecks during non-COD periods were Commentary to A. C. Catania: Discussion: The

Classical Conditioning and Operant Conditioning, 1978

European Journal of Behavior Analysis, 2013

Dr. Edward Taub has developed an effective therapy for stroke victims called Constraint-Induced M... more Dr. Edward Taub has developed an effective therapy for stroke victims called Constraint-Induced Movement therapy. The foundation of this therapy is based entirely on behavior analysis principles, and intervention is a matter of applying contingencies of reinforcement for improving the movement of limbs impaired by different types of central nervous system damage. The result is a very efficacious therapy that produces large and clinically significant gains in performance that have been replicated numerous times across patients, clinics, and countries. Dr. Taub answers questions regarding the development of this therapy, which started with animal models, and offers insight into implementing behavior-analysis based treatments in medical settings.

Revista Mexicana De Biodiversidad, 2020

Fred Keller prepared two supplements for students to use in con- junction with Keller and Schoenf... more Fred Keller prepared two supplements for students to use in con- junction with Keller and Schoenfeld (1950), “Matters of History” and “Schedules of Reinforcement.” The latter was found in a to-be-discarded file of Murray Sidman’s reprints and other items after his death in May, 2019. After presenting evidence concerning the authorship of the supplement, the relation of the contents to the article to the teaching of behavior analysis to introductory psychology students in the course for which the Keller and Schoenfeld textbook was designed are discussed. The text is a remarkable example of the teaching of scientific principles and research methods - especially group and single-subject designs – because it is so rich with data derived from real experiments. It offered to introductory students facts and no fiction. It also is exemplary in its attention to relating scientific concepts to daily experience, a critical feature of scientific material directed to such introductory- level st...

Revista Mexicana De Biodiversidad, 2017

To examine operant response variability in detail, a lever was attached to the Thumbstick of a vi... more To examine operant response variability in detail, a lever was attached to the Thumbstick of a videogame controller, which functions as a joystick. The controller was mounted outside of a standard rodent operant chamber with the lever extending into the chamber. Movement of the lever was restricted to a vertical downward distance of 2 cm. Food pellet delivery was used as reinforcement of lever movement. Criteria for reinforcement were that the lever should be held between two criteria distances, one from the top resting position of the lever and one from the end position of full movement, and the holding response should last a certain duration. Apparatus construction and development of algorithms for response detection and display in graph format as actograms are described in detail. The use of the equipment is illustrated with two demonstration experiments that examined response variability in extinction and during acquisition. The recording method allows for display of considerabl...

Journal of the Experimental Analysis of Behavior, 2020

Murray Sidman's statements regarding variability, experimental control, and generality are in... more Murray Sidman's statements regarding variability, experimental control, and generality are interwoven with examples from the literature on conditional discrimination. Sidman's position was that statistical inferences from group studies produce no information about the behavior of individual subjects and that statistical treatment of individual subject data masks variability which may represent conditions that are not controlled. Sidman's work on conditional discrimination provides excellent examples of how complex discriminations should be examined in detail with accuracy levels obtained for each type of discrimination within an experiment. Sidman made important contributions to the foundation of behavior analysis with extensive basic research as well as applications of methods and principles to clinical and educational settings.

Journal of Applied Behavior Analysis, 2020

Murray Sidman's contributions to the science of behavior span many areas including avoidance beha... more Murray Sidman's contributions to the science of behavior span many areas including avoidance behavior, coercion and its effects, stimulus control, errorless learning, programmed learning, stimulus equivalence, and single-subject methodology. He was also a great mentor to many and helped shape the discipline we now call behavior analysis. In this memoriam, we briefly highlight his scholarly legacy and share some personal anecdotes.

European Journal of Behavior Analysis, 2014

Consequences (2012): “She has positioned the fundamental feature of behavior analysis as the cent... more Consequences (2012): “She has positioned the fundamental feature of behavior analysis as the centerpiece in a broad array of scientific work on selection by consequences, including evolutionary biology, epigenetics, and neuroscience.” For an exemplar, see Hull, Langman, and Glenn (2001)—the collaborative product three authors from three different natural science disciplines: conceptual immunology, evolutionary theory, and behavior analysis, respectively. Given the uncontestable reality of operant processes as the subject matter of our science, along with the effectiveness of its technology, its continual evolution should come as no surprise. Furthermore, why wouldn’t scientists in those related natural science areas be interested in our science? References

European Journal of Behavior Analysis, 2012

Using an example of a problem in interpretation of behavioral data, the paper asks whether behavi... more Using an example of a problem in interpretation of behavioral data, the paper asks whether behavior analysis is explanation of behavior or control of behavior. The paper argues that when two or more experimental conditions are compared, one condition is not necessarily superior to the other(s) and may not serve as an explanation of what happens in other conditions. Experimental subjects simply face different environmental conditions and behave differently in them. Successful behavior changes and management in clinic, laboratory, and school suggest that contemporary behavior analysis is behavioral engineering. But what criteria should be applied when one tries to explain behavior? Control of behavior and explanation of behavior may be separate forms of analysis with the latter incorporating elements that may not be approached directly in the manner of manipulating independent variables.

The Psychological Record, 1985

Rats’ lever pressing and wheel running were maintained on concurrently operating variable-interva... more Rats’ lever pressing and wheel running were maintained on concurrently operating variable-interval (VI) schedules of food reinforcement. When the schedule for lever pressing was changed to a multiple VI extinction (EXT) schedule, the probability of lever pressing decreased in EXT and increased in VI (positive behavior contrast). Simultaneously, the probability of wheel running increased in EXT and decreased in VI. Next, the wheel locked either in VI or in EXT. To hold reinforcement parameters constant when the wheel was locked, the schedule for wheel running was changed to response-independent reinforcement on a variable-time schedule. With the wheel locked in VI, the probability of VI lever pressing increased. With the wheel locked in EXT, the probability of wheel running increased in VI, and the probability of VI lever pressing simultaneously decreased resulting in prevention of positive behavior contrast. For one rat, lever pressing and wheel running developed into chained behaviors that were emitted simultaneously, and the results differed for that animal. The experiment shows that positive behavior contrast can depend upon concurrently reinforced behavior, even when reinforcement parameters are unchanged.

The Psychological Record, 1985

Two experiments investigated moment-to-moment interactions between collateral and operant behavio... more Two experiments investigated moment-to-moment interactions between collateral and operant behaviors. Rats’ lever pressing was reinforced with food on a variable-interval (VI) schedule. In Experiment 1, access to water was first freely available and then presented in 10-s probes at different times within the interreinforcement intervals on the VI schedule. With free access to water, drinking occurred immediately after food reinforcement and lever pressing was suppressed. Drinking occurred during probes and the extent of drinking and the degree of suppression of lever pressing depended upon the probe position within the VI schedule. In Experiment 2, access to wheel running was first presented in probes ranging from 2 to 128 s. Probes controlled a changeover to wheel running and caused a suppression in lever pressing. When wheel running was accessible most of the session time, periods of no access to running were scheduled as probes for 2 to 128 s. Cessation of wheel running during probes increased the momentary probability of lever pressing. In both experiments, restricted access to the collateral response resulted in an increase of the momentary probability of that response and a concomitant reduced probability of the operant response. The experiments demonstrate the feasibility of the probe technique in analyzing and controlling moment-to-moment patterns of collateral and operant behaviors.

The Psychological Record, 1976

The influence of collateral licking from a freely available water bottle upon lever pressing rein... more The influence of collateral licking from a freely available water bottle upon lever pressing reinforced with food pellets was investigated in rats. Lever pressing was maintained on a fixed-ratio schedule and the quality of the content of the bottle was manipulated. Lever pressing and licking were physically compatible responses. The overall lever pressing rate was inversely related to the mean licking duration, and the duration of single pauses in lever pressing after reinforcement was directly related to the duration of licking bursts. Behaviors other than licking interacted with lever pressing, and these behaviors were also recorded. The results show that the rate and patterning of reinforced behavior may depend upon the rate and patterning of collateral behavior.

European Journal of Behavior Analysis, 2016

ABSTRACT Literature on conditional discrimination tasks indicates that interpretation of data dep... more ABSTRACT Literature on conditional discrimination tasks indicates that interpretation of data depends on assumptions about what constitutes evidence of performance accuracy and change. According to one interpretation, performance after a procedural intervention (e.g., introduction of new stimuli in an identity matching-to-sample task) is compared to baseline performance before the intervention; if a decrease in performance is evident, then the conclusion is drawn that the intervention produced a deficit in performance. According to a different interpretation, performance from an intervention is compared not to baseline but to chance level; if performance is significantly different from chance level after the intervention, the conclusion is drawn that the intervention did not produce a deficit in performance. Evidence for presence or absence of stimulus control or concepts is extracted from such data depending on the method of comparison. In many cases, the intervention may produce a decrease in accuracy from a baseline of 90–100% accuracy to the 60–80% range, which may be significantly different from baseline but also significantly different from chance level of 50%, for two-choice tasks. Thus, different, if not opposite, conclusions might be drawn from the same set of data depending on the method of analysis (e.g., a change from a baseline of near 90% correct to 70% correct after the intervention is either a performance deficit or not depending on the method of analysis). Interpretations of results from conditional discrimination tasks may profitably be clarified when data are presented more objectively as percent stimulus control rather than as percent correct.

Acta neurobiologiae experimentalis, 1987

Rats with lesions in the neostriatal region that belongs to the prefrontal system were trained in... more Rats with lesions in the neostriatal region that belongs to the prefrontal system were trained in two versions of delayed alternation. They performed as proficiently as intact animals in a two-key operant chamber. The same operated rats took many more trials to reach criterion when subsequently compared with the same control group in a T-maze. This finding demonstrates that variants of delayed alternation are not equivalent for animals with lesions in the prefrontal system. Observations suggested that delayed alternation in the operant chamber may be mastered by positional mediation.

Journal of Neuroscience Methods, 1988

A method is presented for manual or automated recording of rats' spontaneous nose-poking ... more A method is presented for manual or automated recording of rats' spontaneous nose-poking ('visit') behaviors to a vertical holeboard with a matrix of 45 or 54 holes. Several behavior parameters are presented: visit frequency, visit duration, temporal visit pattern, spatial visit pattern, stereotype of visits, diversity of visits and variability of visit patterns. The paper describes the development of the apparatus and some methods of analyzing and presenting the multi-parametric data. The use of the apparatus is illustrated with a one-trial appetitive conditioning task. After 5 min in a single 10-min session, a food pellet is presented, only once in a given hole, to provide reinforcement of a spontaneous visit to that hole. The behavior parameters are compared before and after reinforcement. When the one-trial conditioning effect was challenged with d-amphetamine, the behavior parameters changed in a graded manner depending upon the dose (0.25-6.0 mg/kg). The apparatus has also proven useful for studies of exploratory behavior without using food reinforcement following lesion or drug interventions.

Primate Origins of Human Cognition and Behavior, 2008

Using written symbols is essential for human communication. Effective written communication requi... more Using written symbols is essential for human communication. Effective written communication requires that each subject can read and write or produce the visual symbols. Therefore, considerable worldwide educational efforts are expended to teach children symbols such as letters, signs, and numbers. Several studies of human-animal communication have established that nonhuman subjects can also be taught to discriminate visual symbols presented by humans. Of particular interest is the fact that several studies have shown that chimpanzees can learn to discriminate complex lexigrams (Rumbaugh 1977; Savage-Rumbaugh 1986; Tomonaga and Matsuzawa 1992) by pointing to them or moving them about (Premack 1976) in an appropriate manner. Chimpanzees have also been trained to compose symbols from their elements (Fujita and Matsuzawa 1990) and to produce signs with their fingers (Gardner and Gardner 1978).

Classical Conditioning and Operant Conditioning, 1978

The response rate in the presence of one stimulus and its associated schedule depends also upon t... more The response rate in the presence of one stimulus and its associated schedule depends also upon the schedules associated with temporally adjacent stimuli. Alternations between schedule components associated with different stimuli are traditionally referred to as multiple schedules (Ferster and Skinner, 1957). Reynolds (1961b) suggested that interactions in multiple schedules might be described as contrast or induction, depending upon whether the changes in response rate diverge or converge across schedule components. Furthermore, contrast and induction may be either positive or negative, depending upon direction of change in response rate. Positive contrast, for example, refers to an increase in response rate in one schedule component simultaneously with a decreased rate in an adjacent component.