A simple and inexpensive computer-compatible shock circuit

A circuit for computer control of shock stimulation that uses an optically isolated triac is described.     

An electronic audio switch

This article describes an electronic switch that allows presentation of sine wave stimuli without the often undesirable transient thump, thud, or click usually caused by ordinary electromechanical switches.     

A simple inexpensive computer-controlled tone generator

A simple circuit for a keyed tone generator is described. The total construction cost is less than $5. Various adaptations and modifications of the circuit are discussed.     

A simple,inexpensive stimulus waveform generator

A simple circuit for a sine wave generator is described. The total cost for construction is approximately $30.00. At present, the unit is used to generate a sinusoidally modulated light stimulus for steady state visual evoked response experiments. Modifications of the circuit for other applications are discussed.     

A simple and inexpensive startle transducer with high output

A piezoelectric film material laminated to a sheet of flexible Plexiglas shows promise as a simple, high-performance startle transducer. It is an improvement over many other startle transducers because of its high output, insensitivity to vibrational and electrical artifacts, simplicity of instrumentation, and modest cost. Although discussed in terms of its application to measurement of the startle response, the material has potential for use in many situations that require a movement transducer.     

An inexpensive electronic switch with adjustable gain

A simple electronic switch, based on the Motorola MFC 6040 electronic attenuator integrated circuit, is described. The circuit is useful in the slow-speed switching of audio signals where key click and switch bounce cannot be tolerated.     

An inexpensive sound-activated switch for experiments measuring vocal-response times

An inexpensive sound-activated switch suitable for experiments measuring vocal-response times is described. This switch is comparable to many commercially produced switches in terms of its control over input sensitivity and response delay times, but it can be assembled for a fraction of the cost. Additionally, the present switch provides many features not found on standard commercial models such as a built-in speaker for monitoring the input signal and output jacks to facilitate simultaneous recording of this signal. Reliability estimates suggest that performance for this switch is comparable to that of a Scientific Prototype Model 761-G when both units are equated for frequency sensitivity and response delay time. In all, this switch offers a reliable and practical alternative to commercially produced devices for experiments in which the onset of an auditory signal must be accurately detected.     

A simple and inexpensive method to measure urinary excretion in nonhuman primates

A simple and inexpensive automated method is described for simultaneous recording of time of day and frequency of urinary excretion. A 24-h event record for eight rhesus monkeys illustrates possible usefulness of the method in determining individual differences, response to environmental factors, and diumal patterns.     

A simple,inexpensive, constant-flow pump for delivering liquid reinforcers

A liquid reinforcer, controlled by a solenoid valve venting to atmospheric pressure, eliminates the chance of interrupted flow due to a clogged valve. The device maintains a constant flow at adjustable rates, and is inexpensive and easy to construct.     

A simple and inexpensive telemetry system for measuring deep body temperature in rodents

An easily constructed telemetry system for measuring deep body temperatures in rodents is described and data collected with the system is presented. The system allows continual monitoring of core temperature without interfering with concomitant behavioral or physiological measurements.     

A simple and inexpensive transducer for quantitative measurements of penile erection during sleep

The construction of a mercury strain-gauge transducer for measuring penile erection and scoring rules for tumescence episodes are described. The gauge device has been found to be cheap, reliable, and easy to construct. It is capable of transducing changes in circumference in the penis of adults and infants, the clitoris of congenital adrenal hyperplasia patients, and the nipples of adult females.     

A simple,inexpensive, liquid-tight swivel connection for use in chronic infusion systems

This note describes the fabrication of a simple, inexpensive, liquid-tight swivel joint for twist-free coupling of small, freely moving animals to infusion systems. The device uses a disposable hypodermic needle and syringe as the main components, and fabrication requires only readily available hand tools and minimal mechanical expertise.     

A build-it-yourself inexpensive lock-out device

This paper describes a low-cost easily constructed and readily portable "lock-out system" suitable for college bowl and related quiz games. Suggestions on how to use the device are presented.     

Conditioned withdrawal in goldfish: a simple and inexpensive preparation for the study of classical fear conditioning in vertebrates

Summary.-A preparation for the study of classical fear conditioning in vertebrates is described. Its unique features are that it is inexpensive and easy to construct and operate. The following classical conditioning phenomena are demonstrated using this preparation: excitatory conditioning, extinction, contextual conditioning, blocking, a conditioned inhibition discrimination, and latent inhibition.