Two open source designs for a low‐cost operant chamber using Raspberry Pi™

After almost a century of use and development, operant chambers remain a significant financial investment for scientists. Small powerful single‐board computers such as the Raspberry Pi? offer researchers a low‐cost alternative to expensive operant chambers. In this paper, we describe two new operant chambers, one using nose‐poke ports as operanda and another using a touchscreen. To validate the chamber designs, rats learned to perform both visual discrimination and delayed alternation tasks in each chamber. Designs and codes are open source and serve as a starting point for researchers to develop behavioral experiments or educational demonstrations.     

A multi-user on-line 8080 microcomputer system

A laboratory control system based upon the Imsai 8080 microcomputer is described. This system is capable of programming separate events in each of five animal operant chambers and recording the resulting behavioral data. The interface between the computer and the chambers is compatible with the 28-V dc nature of these chambers and various peripheral devices, such as cumulative recorders. At present, system software is based on the 8080 assembly language, while the BASIC language is used for data analysis. Cost considerations and comparisons with minicomputers are discussed.     

FOCLAB: A language for computer-controlled psychology research

The FOCLAB system, a dialect of FOCAL, provides complete real-time experiment control and data acquisition capabilities in the area of experimental psychology. The language provides digital and analog input/output, graphics (including alphanumerics) on a refresh CRT, and a powerful set of time measurement operations. With these facilities FOCAL may be used in cognitive and operant, as well as psychophysiological research. FOCLAB will operate with either PDP-8 or PDP-12 systems, and can control most of the currently existing lab interface options for these computers. The system will operate on 8K core-only machines, as well as under OS/8.     

Steps and pips in the history of the cumulative recorder

From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his colleagues to its perfection in the 1950s, and then into the 1960s when it proliferated as different scientific instrument companies began marketing their own models of the cumulative recorder. With the rise of digital computers, the demise of the cumulative recorder as a scientific instrument was inevitable; however, the value of the cumulative record as a monitoring device to assess schedule control of behavior continues. The cumulative recorder remains, along with the operant conditioning chamber, an icon of Skinner's approach to psychology.     

Meeting novel experimental needs with an Apple Pascal controlled interfacing system

In this article, we describe how to combine an inexpensive interface with an independent timing card to solve some common timing and programming problems. Problems were encountered when we tried, by modifying commercial software, to create novel programs that would accurately control events in our operant conditioning chambers. The solution was to combine a Life Science Associates (LSA) Apple Interfacing System with an Applied Engineering Timemaster II H.O. timing card. Three aspects of the solution are described: (1) LSA’s interfacing hardware; (2) the Timemaster II H.O. timing card; and (3) the Pascal commands necessary to access the timing card. An example, a program to control a concurrent variable-interval schedule, shows how the timing card is used in conjunction with the interface to control and monitor experiments. The system offers many advantages over earlier researcher-built approaches and provides a flexible, accurate, and inexpensive alternative to commercial systems.     

Hardware debugging for on-line psychologists

As computers become more prevalent as laboratory equipment, psychologists and graduate assistants will be more likely to be involved with interfacing the experiment to the computer. This paper presents some general ideas about the design and construction of digital computer interfaces and ways to facilitate their check-out and integration into the computer system. The suggestions center around the identification of functional modules within the interface or device from the beginning of the design process. These modules are preserved in the design and construction and are tested separately where possible. Specification of the interface signals between these functional units speeds debugging of a new device and facilitates maintenance of the device at a later date if adequately documented. It is important to ensure that these signals are readily available through test points and/or indicators. The paper suggests minimal equipment necessary to construct and debug an interface. It is suggested that an interactive construction procedure may be the most successful. The device is constructed in stages, with each part being verified as it is built, A simple interface is suggested for the beginner which gives him practice and a useful debugging aid as well.     

Computer control for operant oriented laboratories

A process control procedure using base rate polling within interrupt driven routines, segmentation of time dependent events, and a branch table execution structure was developed for an operant oriented behavioral pharmacology laboratory. Efficient independent control and analysis for eight experimental chambers was obtained utilizing the similarities between various operant techniques.     

A Commodore 64-based interface system for the operant laboratory

A system of interfaces for the Commodore 64 (C-64) microcomputer for use in the operant laboratory is described. This system frees the experimenter from limitations on the number of I/O lines available on the user port of the C-64 and offers the control of operant chambers for a low cost. Subroutines in machine code to control the interfaces, offering millisecond timing of external events, are presented. A sample BASIC program demonstrates how the subroutines are called from BASIC to run a simple discrimination experiment.     

MIDI and Macintosh: Searching for a better mousetrap

This paper will explore how MIDI (musical instrument digital interface)-technology can benefit researchers interested in using Apple Macintosh computers for stimulus control and response timing. One example presented here will illustrate how MIDI equipment can be adapted to provide millisecond precision response timing that cannot be obtained with solely software-based timing techniques. Another example will show how to use MIDI to control sound-generating devices that far surpass the sound-producing capabilities built into the Macintosh. There will also be a discussion of how certain MIDI equipment can provide information on the velocity and the duration of a response that is not available with traditional laboratory hardware. The examples presented here rely on a commercial software library called MIDIBASIC that was designed to be used with Microsoft QuickBasic. The availability of a millisecond timer that can be called from QuickBasic may offer a special advantage for researchers who have previously written programs in an Apple II environment using AppleSoft Basic.     

NOVA SKED: A behavioral notation language for Data General minicomputers

A state notation language (NOVA SKED) for the experimental control and collection of data from operant behavior experiments by Data General NOVA series minicomputers is described. NOVA SKED is based on the SKED system written for the Digital Equipment Corporation PDP8 series of minicomputers. The NOVA SKED state notation syntax enables diagramming experimental procedures directly and precisely by the operant experimenter, who need not be familiar with computers. This syntax can then be compiled by the computer into programs that operate under the SKED run-time system (RTS). The SKED RTS operates in a timesharing mode that allows up to 16 experimental stations to function simultaneously and independently from each other. NOVA SKED is a “stand-alone” system that collects and stores data on digital magnetic tape.     

Computer attitudes and the use of computers in psychology courses

Students enrolled in four psychology courses in which computers were used for different purposes completed both pre- and postcourse surveys regarding their prior computer experience, their attitudes toward computers, and their locus of control. A fifth psychology course in which computers were not used served as a control. Results showed that participation in the courses that involved computer activities led to more positive attitudes toward computers than did the control condition. In addition, the positive changes in computer attitudes were found to be independent of initial student characteristics and unrelated to course performance. There was also some suggestion that courses that have higher levels of direct involvement with computer applications may lead to the most positive attitude changes.     

The matching law in and within groups of rats

In each of the two experiments, a group of five rats lived in a complex maze containing four small single-lever operant chambers. In two of these chambers, food was available on variable-interval schedules of reinforcement. In Experiment I, nine combinations of variable intervals were used, and the aggregate lever-pressing rates (by the five rats together) were studied. The log ratio of the rates in the two chambers was linearly related to the log ratio of the reinforcement rates in them; this is an instance of Herrnstein's matching law, as generalized by Baum. Summing over the two food chambers, food consumption decreased, and response output increased, as the time required to earn each pellet increased. In Experiment II, the behavior of individual rats was observed by time-sampling on selected days, while different variable-interval schedules were arranged in the two chambers where food was available. Individual lever-pressing rates for the rats were obtained, and their median bore the same “matching” relationship to the reinforcement rates as the group aggregate in Experiment I. There were differences between the rats in their distribution of time and responses between the two food chambers; these differences were correlated with differences in the proportions of reinforcements the rats obtained from each chamber.     

Context specificity of operant discriminative performance in pigeons: II. Necessary and sufficient conditions

Six experiments were performed to explore the necessary and sufficient conditions for producing context specificity of discriminative operant performance in pigeons. In Experiment 1, pigeons learned a successive discrimination (red S+/blue S−) in two chambers that had a particular odor present and between which they were frequently switched. The birds subsequently learned the reversal (blue S+/ red S−) in one of these chambers with a different odor present. When switched to the alternative chamber, although the odor and the reinforcement contingency were still appropriate to the reversal, performance appropriate to the original discrimination recurred in subjects for which the houselights were on during training and testing but not for those for which the houselights were off. This indicated the importance of visual contextual cues in producing context specificity. Experiment 2 showed that the frequent switching between boxes in initial training was of no consequence, presumably because the apparatus cues were highly salient to the subjects. Experiment 3 showed significantly less context specificity when odor cues were omitted. Experiment 4 showed that simply using a different reinforced stimulus in each phase of training was ineffective in producing context specificity. Experiment 5 showed that the generalization test procedure used in Experiment 4 was sensitive to context specificity when discrimination-reversal training was used with different odors in the two training phases. Experiment 6 replicated the results of Experiment 4, but then showed that when different odors accompanied the two training phases, context specificity was obtained with the single-stimulus paradigm. Thus in both single-stimulus and discrimination-reversal paradigms, redundant odor cues potentiated learning about apparatus cues.     

The effect of rearing environments on the contrafreeloading phenomenon in rats

Eight naive rats were reared in enriched or impoverished environments for 39 days after weaning and then lived in operant chambers, in which they could obtain food pellets freely or by lever pressing, for 25 or 30 days. The animals raised in an impoverished environment acquired the bar-press response quickly when placed in the operant chambers and maintained a preference for obtaining food via bar pressing. Animals raised in an enriched environment did not learn to lever press, as demonstrated by low levels of responding and the lack of bar pressing when free food was subsequently removed. It was concluded that restricting animals' postweaning environments facilitated learning in a choice situation, probably because of increased activity levels. The results are interpreted in relation to previous studies on rearing environments and on contrafreeloading.     

Using an Apple II microcomputer for real-time control in a behavioral laboratory

This report describes the hardware and software developed to implement an Apple II (48 KB) as a real-time control device for operant experiments. The hardware has a straightforward design, so that it is readily understandable and can be built by individuals with only minimal experience in the use of integrated circuits and other electronic components. The software routines listed below represent an approach to controlling and handling the data generated by an operant experiment. Using these routines, we are able to record each response and experimental event, the time of the occurrence, and the conditions at that time.     

A multiplexed vectored interface logic system for control of behavioral experiments

An interface was constructed which enabled a minicomputer to control operant conditioning experiments with a minimal amount of software recognition and input/output instructions. The hardware consisted of a real-time clock, logic to input a unique number with each change of state of digital input, and logic and solid state drivers to control standard, commercial 24 V behavioral stimuli.     

Positive affect and learning: exploring the “Eureka Effect” in dogs

Animals may experience positive affective states in response to their own achievements. We investigated emotional responses to problem-solving in dogs, separating these from reactions to rewards per se using a yoked control design. We also questioned whether the intensity of reaction would vary with reward type. We examined the response (behavior and heart rate) of dogs as they learned to gain access to different rewards: (1) food (2) human contact, and (3) dog contact. Twelve beagles were assigned to matched pairs, and each dog served as both an experimental and a control animal during different stages of the experiment. We trained all dogs to perform distinct operant tasks and exposed them to additional devices to which they were not trained. Later, dogs were tested in a new context. When acting as an experimental dog, access to the reward was granted immediately upon completion of trained operant tasks. When acting as a control, access to the reward was independent of the dog’s actions and was instead granted after a delay equal to their matched partner’s latency to complete their task. Thus, differences between the two situations could be attributed to experimental dogs having the opportunity to learn to control access to the reward. Experimental dogs showed signs of excitement (e.g., increased tail wagging and activity) in response to their achievements, whereas controls showed signs of frustration (e.g., chewing of the operant device) in response to the unpredictability of the situation. The intensity of emotional response in experimental dogs was influenced by the reward type, i.e., greatest response to food and least to another dog. Our results suggest that dogs react emotionally to problem-solving opportunities and that tail wagging may be a useful indicator of positive affective states in dogs.     

Homogeneous chains, heterogeneous chains, and delay of reinforcement

Three pigeons responded on two-component chain schedules in which the required response topography in the initial and terminal links was similar (a homogeneous chain) or dissimilar (a heterogeneous chain). Key-peck responding in the initial link under a variable-interval 60-second (VI 60) schedule produced a terminal link in which, in different conditions, either key pecking or foot treadling was reinforced according to a VI 60 schedule. Multiple VI 60 VI 60 schedules, in which the responses required in the chain schedules were maintained by primary reinforcement in the two components, preceded and followed each type of chain. These multiple schedules were used to ensure that both responses occurred reliably prior to introducing the chain schedule. Key-peck response rates in the initial link of the chain consistently were higher during the homogeneous chain than during the heterogeneous chain. These results illustrate that intervening events during a period separating an operant response from primary reinforcement influence that operant, independently of the delay between the response and reinforcement.     

Expected performance at the human/computer interface as a function of user proficiency and system power

How do managers expect the proficiency of users and the power of the computers to determine overall performance? Five different models are proposed: (a) a matching model in which optimal performance is achieved when the power of the system is judged to be compatible with the proficiency of the user, (b) an averaging model in which expected performance is the average of the values of user proficiency and system power, (c) a multiplying model in which performance is the product of the values of user proficiency and system power, (d) a human/computer ratio model in which performance is determined by the ratio of system power over total effort, and (e) a computer/human ratio model in which performance is determined by the ratio of user proficiency over total effort. The applicability of these models was assessed by having managers and students of management predict performance in human/computer systems from information about the user's proficiency with computers and the power of the system. Participants rated 16 combinations of user proficiency and system power from a 4 × 4 factorial design. The pattern of ratings indicated that 51 per cent used a multiplying model and 25 percent used an averaging model; whereas, only 6 percent used the matching model and 4 percent used a ratio model. The remaining 14 percent did not follow any model clearly. Implications of these results were discussed for the design of the human/ computer interface, training and selection of users, and the cost-benefit tradeoffs for investment in user training versus equipment acquisition.     

Apple slide tachistoscope

We outline a BASIC program and subsidiary machine language timing routines that enable the Apple II series of computers to be employed as control devices for the tachistoscopic presentation of 35-mm slides and the collection of response latencies. The program is functional for experiments that require pictorial stimuli to be presented in up to three separate fields, with precise display times, precise interstimulus and intertriai intervals, and the collection of manual or vocal reaction times with millisecond accuracy. The major advantages of this system are that initial setup costs are substantially lower than those for other similar systems (e.g., Loftus, Gillispie. Tigre, & Nelson, 1984) and that user customization of the program may be accomplished by anyone possessing rudimentary knowledge of the BASIC programming language.