The symmetrical maze: An automated closed-field test series for rats

An automated “intelligence” test for rats is described. Supporting data indicate that this maze-problem series is sensitive to hypothyroidism-induced learning deficit and sex differences. Comparisons between this new problem set and the Rabinovitch-Rosvold (1951) closed-field tests are presented with respect to difficulty, internal consistency, and test-retest reliability.     

Successive incrementing non-matching-to-samples in rats: An automated version of the odor span task

The odor span task is a procedure frequently used to study remembering of multiple stimuli in rodents. A large arena is used and odor stimuli are presented using scented cups. Selection of each odor is reinforced when first presented, but not on subsequent presentations; correct selections depend on remembering which stimuli were previously presented. The use of an arena setting with manual stimulus presentation makes the odor span task labor-intensive and limits experimental control; thus, an automated version of the task would be of value. The present study used an operant chamber equipped with an olfactometer and trained rats using successive conditional discrimination procedures under an incrementing non-matching-to-samples contingency. High rates of responding developed to odor stimuli when they were session-novel with low rates of responding to subsequent presentations of that odor. Additional experiments assessed variations of the procedure to determine the role of the frequency of odor presentation and the retention interval separating sample and comparison. Discrimination was impaired with long retention intervals suggesting the importance of this variable. These findings confirmed that rats differentiate between stimuli that are session-novel and those previously encountered and support the use of an automated procedure as an alternative to the odor span task.     

An automated device for measuring locomotor activity in rats

An automated plus maze is described that is capable of recording the locomotor activity of 12 rats simultaneously. The system is built around an 8008 microprocessor chip from INTEL. The base of the system is formed by 12 plus mazes in which the activity of the animals under test can be monitored.     

An automated test development of parallel tests from a seed test

Binary programming models are presented to generate parallel tests from an itembank. The parallel tests are created to match item for item an existing seed test and match user supplied taxonomic specifications. The taxonomic specifications may be either obtained from the seed test or from some other user requirement. An algorithm is presented along with computational results to indicate the overall efficiency of the process. Empirical findings based on an itembank for the Arithmetic Reasoning section of the Armed Services Vocational Aptitude Battery are given.The Office of Naval Research, Program in Cognitive Science, N00014-87-C-0696 partially supported the work of Douglas H. Jones. The Rutgers Research Resource Committee of the Graduate School of Management partially supported the work of Douglas H. Jones and Ing-Long Wu. A Thomas and Betts research fellowship partially supported the work of Ing-Long Wu. The Human Resources Laboratory, United States Air Force, partially supported the work of Ronald Armstrong. The authors benefited from conversations with Dr. Wayne Shore, Operational Technologies, San Antonio, Texas. The order of authors' names is alphabetical and denotes equal authorship.     

An interaction model for odor quality and intensity

The perceived intensity and quality of binary odor mixtures are studied in relation to bow their components are perceived when presented separately. Subjects judged the perceived intensity and quality of 6 concentrations of pyridine, 6 concentrations ofn-butanol, and their 36 possible combinations. The results show that the perceived intensity of the mixture can be predicted from the perceived intensity of its components presented separately (R _A andR _B) by the Euclidian arithmetic model. The maximum probability of identifying a mixture as a “mixture” is reached whenR _A andR _B are equally strong. An interaction model for mixtures that relates perceived intensity and quality is presented and tested. The test reveals that both the perceived intensity of a mixture and the probability that it will be identified as the one or the other component can, by a simple interaction model, be successfully predicted fromR _A andR _B.     

An automated version of the digit symbol substitution test (DSST)

An automated version of the Digit Symbol Substitution Test is described that employs a relatively inexpensive, commercially available microcomputer to present and score the task. Advantages of the automated DSST include: (1) objective scoring of both speed and accuracy of test performance, (2) printed copies of test scores, (3) convenient administration under standardized test conditions, and (4) the capacity for repeated assessment of an individual’s performance over time. Task performance data for individual subjects following doses of pentobarbital are presented; these data illustrate both the stability of task performance under constant conditions and the within-subjects sensitivity of task performance to experimental manipulations.     

An automated exercise wheel for primates

Both adult and juvenile nonhuman primates can be unpredictable, difficult to handle, and potentially dangerous. Accordingly, in evaluating their activity level, they must be carefully confined. We have modified and redesigned an exercise system for primates. The exercise wheel was originally described by Curran, Wiegel, and Stevens (1972) and later adapted by Elizondo (1989). Our modifications and training procedures, which allowed us to bring the behavior of the monkey under stimulus control within 4 weeks, are described here.     

An automated sound-localization chamber

A completely automated free-field sound-localization apparatus is described along with a behavioral technique that provides several advantages over previously available methods. With the apparatus, the ability to localize the source of a sound has been tested in a wide variety of mammals including cats, rats, squirrel monkeys, hedgehogs, and tree shews.     

An automated system for primate instruction for behavioral neurophysiology

This paper describes a flexible hardware/software system developed for use with a PDP-8I computer for conducting research in behavioral neurophysiology. A real time monitor was designed to facilitate development, debugging, and modification of programs to run experiments. It relieves the programmer of the burden of dealing with hardware dependent functions such as interrupt handling and input/output. In addition, it provides the user with a large library of callable routines to perform functions commonly needed for conducting experiments. The monitor is modular in design and could be expanded or modified for use with many configurations of the PDP-8 family of computers.     

An automated eye movement laboratory for on-line electrooculography

This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people’s eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.     

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.     

An automated identification system for use with computer-controlled tasks

Monkeys of various species can use a joystick to perform a variety of computer-generated tasks. The purpose of this paper is to describe an automated system that determines which subject in a social group has completed a task. The system is based on a microchip that is easily injected into the forearm. The present paper demonstrates the technique with 1 animal that had a different chip in each arm.