Recent advances in operant conditioning technology: A versatile and affordable computerized touchscreen system

We report the construction of a new operant chamber that incorporates modern computer, touchscreen, and display technologies. An LCD display was housed in the front wall of a lightweight Plexiglas chamber. An Apple eMac computer was used to present visual stimuli on the monitor and to control other chamber events. Responses to the stimuli were recorded using a transparent resistive-type touchscreen that overlaid the monitor. The resulting system is simple and inexpensive to construct but powerful and flexible enough to explore a broad range of issues in animal learning and behavior.     

A computer touch-screen apparatus for training visual discriminations in rats.

We describe an operant conditioning apparatus that uses computerized touch-screen technology and is designed for the versatile and highly controlled testing of rats in a potentially wide variety of behavioral paradigms. Although computer-controlled touch-screen systems have been developed for use with pigeons, monkeys, and humans, analogous technologies and methods have not yet been developed for rats. The development of a touch-screen system for rats could enhance the efficiency of behavioral research with rats, and may offer a unique tool for studying animal learning. In the first test of the utility of the apparatus, 3 Sprague-Dawley rats learned to activate the touch screen only after the touch-screen panel was made slightly movable. These animals then learned to discriminate visual stimuli presented on the computer monitor, but only after the food magazine and pellet dispenser were moved to the rear of the chamber opposite the stimulus display and response window. In a test of the utility of the modified apparatus, 6 Long-Evans rats learned to activate the touch screen and learned one of three different simple discriminations using computer-generated, visually presented stimuli. A basic method for training rats to activate the computer touch screen and for visual discrimination training is described. Results show that rats learned to activate the touch screen and discriminate visual stimuli presented on a computer monitor. Potential applications and advantages of the touch-screen-equipped rat operant conditioning chamber are discussed.     

Design and evaluation of a touchscreen apparatus for operant research with pigeons

We developed a touchscreen apparatus for pigeons and conducted a series of experiments that assessed its utility for free-operant procedures. The apparatus incorporated an on-board Windows computer, an electromechanical interface, an amplified speaker, and the touchscreen. We found that merely projecting a virtual key on the screen was insufficient; too many pecks missed the key. Adding a visual target in the center of the key and providing visual feedback for on-key pecks both failed to improve response accuracy. Accuracy was improved by imposing a timeout after off-key pecks or providing a physical boundary around the key. With the physical boundary, response accuracy was comparable to that obtained with conventional plastic keys, and response acquisition via autoshaping also was comparable. Mixing the color elements of the screen's pixels produced color stimuli, but the colors did not function as pure wavelengths of light in tests of stimulus generalization. Both colors and geometric shapes functioned as discriminative stimuli in multiple schedules with variable-interval and extinction components or rich and lean fixed-ratio components. In general, our touchscreen apparatus is a viable alternative to conventional pigeon chambers and increases the experimenter's options for visual stimuli, auditory stimuli, and the number and location of response keys.     

The touchscreen cognitive testing method for rodents: how to get the best out of your rat

The touchscreen testing method for rodents is a computer-automated behavioral testing method that allows computer graphic stimuli to be presented to rodents and the rodents to respond to the computer screen via a nose-poke directly to the stimulus. The advantages of this method are numerous; however, a systematic study of the parameters that affect learning has not yet been conducted. We therefore sought to optimize stimuli and task parameters in this method. We found that when parameters were optimized, Lister Hooded rats could learn rapidly using this method, solving a discrimination of two-dimensional stimuli to a level of 80% within five to six sessions lasting ~30 min each. In a final experiment we tested both male and female rats of the albino Sprague-Dawley strain, which are often assumed to have visual abilities far too poor to be useful for studies of visual cognition. The performance of female Sprague-Dawley rats was indistinguishable from that of their male counterparts. Furthermore, performance of male Sprague-Dawley rats was indistinguishable from that of their Lister Hooded counterparts. Finally, Experiment 5 examined the ability of Lister Hooded rats to learn a discrimination between photographic stimuli. Under conditions in which parameters were optimized, rats were remarkably adept at this discrimination. Taken together, these experiments served to optimize the touchscreen method and have demonstrated its usefulness as a high-throughput method for the cognitive testing of rodents.     

Millisecond accuracy video display using OpenGL under Linux

To measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this may be done within X Windows using the OpenGL rendering system. A test of this system is reported that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively large errors in measuring the display time.     

Characteristics of implicit chaining in cotton-top tamarins (Saguinus oedipus)

In human cognition there has been considerable interest in observing the conditions under which subjects learn material without explicit instructions to learn. In the present experiments, we adapted this issue to nonhumans by asking what subjects learn in the absence of explicit reinforcement for correct responses. Two experiments examined the acquisition of sequence information by cotton-top tamarins (Saguinus oedipus) when such learning was not demanded by the experimental contingencies. An implicit chaining procedure was used in which visual stimuli were presented serially on a touchscreen. Subjects were required to touch one stimulus to advance to the next stimulus. Stimulus presentations followed a pattern, but learning the pattern was not necessary for reinforcement. In Experiment 1 the chain consisted of five different visual stimuli that were presented in the same order on each trial. Each stimulus could occur at any one of six touchscreen positions. In Experiment 2 the same visual element was presented serially in the same five locations on each trial, thereby allowing a behavioral pattern to be correlated with the visual pattern. In this experiment two new tests, a Wild-Card test and a Running-Start test, were used to assess what was learned in this procedure. Results from both experiments indicated that tamarins acquired more information from an implicit chain than was required by the contingencies of reinforcement. These results contribute to the developing literature on nonhuman analogs of implicit learning.     

Touchscreen-enhanced visual learning in rats.

The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination. It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking, and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage. This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving genetic and physiological interventions.     

Touchscreen-enhanced visual learning in rats

The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination. It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking, and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage. This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving genetic and physiological interventions.     

A multistimulus,portable, and programmable conditioning panel for pigeons

A portable two-response-key conditioning panel for pigeons is described. It can be attached to the subjects’ home cages and allows around-the-clock experimentation. Visual stimuli are presented with light-diode display matrices. Food rewards are dispensed directly onto the stimulus/response keys with separate solenoid dispensers. Several platforms can be simultaneously controlled by a single personal computer with programs written in a simple language adapted for on-line operation. Two experiments exploring the effects of prolonged conditioning sessions upon responding and learning demonstrated the effectiveness of the system. The apparatus is an efficient and inexpensive alternative to a conventional conditioning chamber.     

Color of computer display frame in work performance, mood, and physiological response

The effects of the color of a personal computer screen on work performance, psychological mood, and autonomic response were investigated. 24 subjects were asked to perform visual tasks presented on the computer display. Three types of computer monitor, which were colored red, blue, or beige, were employed to present visual cognitive tasks. The mood measure, the Japanese Stress Arousal Check List, and heart rate measurement were administered before and after work on each color of computer monitor. Analysis of a low-demand task (Exp. 1) showed that the red computer monitor reduced visual task performance compared to that with the blue, while the blue monitor decreased visual task performance on a high-demand task (Exp. 2). The color of the monitor did not affect mood or heart rate. Based on these findings, the effect of the color of environmental cues on work was discussed.     

A vision research apparatus for broad luminance range displays.

Lightness, the perceived gray shade of a surface, and the perception of self-luminous surfaces--that is, surfaces that appear to glow--have most often been studied with paper displays and computer-generated stimuli presented on CRT monitors. Although both methods are often effective, experiments that require a wide range of luminance values in the same display are often difficult to conduct with paper and computer displays alone. Also, color mode appearance is often an issue when surface color perception is the topic of research; CRT monitors are essentially light sources themselves and often appear in the luminous mode of color appearance. Here, we describe an apparatus in which the target is an undetected aperture whose luminance is adjustable. Whereas a typical CRT monitor offers a luminance range of about 100:1, much broader luminance ranges are possible with the described apparatus. Unlike a CRT monitor, the stimulus background will always appear in the surface mode of color perception, and the target(s) can appear as either surface colors or luminous colors. Apparatus modifications are possible, including the addition of a stereoscope or an embedded CRT for creating an adjustable region that is computer controlled.     

A vision research apparatus for broad luminance range displays

Lightness, the perceived gray shade of a surface, and the perception of self-luminous surfaces—that is, surfaces that appear to glow—have most often been studied with paper displays and computer-generated stimuli presented on CRT monitors. Although both methods are often effective, experiments that require a wide range of luminance values in the same display are often difficult to conduct with paper and computer displays alone. Also, color mode appearance is often an issue when surface color perception is the topic of research; CRT monitors are essentially light sources themselves and often appear in the luminous mode of color appearance. Here, we describe an apparatus in which the target is an undetected aperture whose luminance is adjustable. Whereas a typical CRT monitor offers a luminance range of about 100:1, much broader luminance ranges are possible with the described apparatus. Unlike a CRT monitor, the stimulus background will always appear in the surface mode of color perception, and the target(s) can appear as either surface colors or luminous colors. Apparatus modifications are possible, including the addition of a stereoscope or an embedded CRT for creating an adjustable region that is computer controlled.     

Direct measurement of the system latency of gaze-contingent displays

Gaze-contingent displays combine a display device with an eyetracking system to rapidly update an image on the basis of the measured eye position. All such systems have a delay, the system latency, between a change in gaze location and the related change in the display. The system latency is the result of the delays contributed by the eyetracker, the display computer, and the display, and it is affected by the properties of each component, which may include variability. We present a direct, simple, and low-cost method to measure the system latency. The technique uses a device to briefly blind the eyetracker system (e.g., for video-based eyetrackers, a device with infrared light-emitting diodes (LED)), creating an eyetracker event that triggers a change to the display monitor. The time between these two events, as captured by a relatively low-cost consumer camera with high-speed video capability (1,000 Hz), is an accurate measurement of the system latency. With multiple measurements, the distribution of system latencies can be characterized. The same approach can be used to synchronize the eye position time series and a video recording of the visual stimuli that would be displayed in a particular gaze-contingent experiment. We present system latency assessments for several popular types of displays and discuss what values are acceptable for different applications, as well as how system latencies might be improved.     

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.     

Ultrafast display buildup with standard VGA on MS-DOS computers

Tachistoscopic examinations, determinations of reaction times after visual stimuli, and latency measurements of visual evoked potentials require well-defined and often very fast display buildup on the monitor. Display buildup takes at least 14 msec when a VGA board is used in standard video modes. This time can be reduced to 4 msec or less by reprogramming some registers of the display adapter.     

Visual dissociation of digitized photographs

Visual dissociation occurs when a visual marker from one display in a rapidly presented sequence (e.g., 9 item/sec) is perceived as having occurred in a temporally adjacent display. Three experiments that evaluated the application of computer graphics technology to study this phenomenon with digitized color photographs are reported. The primary concern was that visible phosphor persistence might artificially increase the frequency of integration errors. In Experiment 1, visible phosphor persistence was assessed using a multiple-repetition shutter test to determine which stimulus conditions did not yield reportable persistence. On the basis of these results, visual dissociation performance when the same color photographs were presented using mechanical 16-mm projection (as in previous research) and when they were presented on a computer monitor were compared in Experiments 2 and 3. The results supported computer application, in that computer presentation yielded the same pattern of errors and accuracy levels as did research using mechanical projection.     

Predispositions to approach and avoid are contextually sensitive and goal dependent

The authors show that predispositions to approach and avoid do not consist simply of specific motor patterns but are more abstract functions that produce a desired environmental effect. It has been claimed that evaluating a visual stimulus as positive or negative evokes a specific motor response, extending the arm to negative stimuli, and contracting to positive stimuli. The authors showed that a large congruency effect (participants were faster to approach pleasant and avoid unpleasant stimuli, than to approach unpleasant and avoid pleasant stimuli) could be produced on a novel touchscreen paradigm (Experiment 1), and that the congruency effect could be reversed by spatial (Experiment 2) and nonspatial (Experiment 3) response effects. Thus, involuntary approach and avoid response activations are not fixed, but sensitive to context, and are specifically based on the desired goal.     

Sequential responding and planning in chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta)

Chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta) selected either Arabic numerals or colored squares on a computer monitor in a learned sequence. On shift trials, the locations of 2 stimuli were interchanged at some point. More errors were made when this interchange occurred for the next 2 stimuli to be selected than when the interchange was for stimuli later in the sequence. On mask trials, all remaining stimuli were occluded after the 1st selection. Performance exceeded chance levels for only 1 selection after these masks were applied. There was no difference in performance for either stimulus type (numerals or colors). The data indicated that the animals planned only the next selection during these computerized tasks as opposed to planning the entire response sequence.     

An inexpensive and automated method for presenting olfactory or tactile stimuli to rats in a two-choice discrimination task

An inexpensive and automated method for presentation of olfactory or tactile stimuli in a two-choice task for rats was implemented with the use of a computer-controlled bidirectional motor. The motor rotated a disk that presented two stimuli of different texture for tactile discrimination, or different odor for olfactory discrimination. Because the solid olfactory stimuli were placed outside the chamber in metal pods with a mesh at front for odor sampling, "washout" of odors between trials was not necessary. To avoid differential auditory cues from motor rotation, the stimuli were arranged such that on each trial the motor always rotated exactly one quarter revolution (in 1 s), left or right, to present the next stimulus at trial start. To illustrate the use of the equipment, 2 rats were trained on tactile discrimination and 2 rats on olfactory discrimination. The rats sampled the stimulus on the disk through a port on the back wall by sniffing at it (olfactory) or touching it (tactile). The task was a go-left/go-right discrimination with the stimulus on the disk being discriminative for which lever provided reinforcement. The rats reached a stable level above 90% correct after 21 and 32 training sessions for tactile and olfactory discrimination, respectively. The article outlines how the equipment was constructed from low-cost components. Inputs from and outputs to the equipment were implemented through the parallel port of a personal computer without the use of a commercial interface board. The method of automated and low-cost presentation of olfactory or tactile stimuli should be of use for a variety of experimental situations such as matching-to-sample and cross-modal discrimination.     

指尖上的学习：触屏学习的作用

触屏学习是通过触屏软硬件设备呈现学习内容,并以手势触屏交互方式获取知识或技能的过程。目前触屏学习基础性研究处于探索阶段,在有效性上,研究发现触屏学习本身可能是有效的,但在相对优势上结果具有较大异质性;在学习后效上,触屏学习有助于提高学习动机,但没有稳定地促进知识保持、知识理解以及二维到三维的学习迁移。针对触屏学习的促进或阻碍作用,以往研究分别从具身认知或认知负荷等理论视角给予解释。学习者、学习材料、学习环境等可能是影响触屏学习效果的重要因素。广泛地将触屏设备应用于学习或课堂场景为时尚早,呼吁未来研究从理论建构、影响因素、特点分析及行为/神经机制角度考察触屏学习的作用。