An inexpensive contact-sensing device

A detector is described that utilizes phase-shift techniques for the measurement of contact responses.     

An inexpensive silent unlocking device for manipulanda

An electromagnetically controlled armature was developed which silently unlocks manipulanda (shuttle box doors, wheels, levers) for response control in discrete trial situations. The device was found to produce no cue to Ss as to when responding was possible in a shuttlebox situation.     

An inexpensive activity measuring device for small animals

A satisfactory device for measuring activity of rats or other small animals has been a difficult problem. Several types of instruments have given incorrect measurements or are prohibitively expensive. Photocells give the same readout to a bobbing head as for a walk over a considerable distance requiring only the interruption of a light beam. Other devices require rotation of wheels or complex integrating circuits which must be replicated or scanned and recorded for simultaneous activity measurement of many animals. The device reported here utilizes the tilting of balanced cages to actuate a single microswitch coupled to an impulse counter for each cage. The system has functioned well for several years.     

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 and inexpensive click-free audio switch

This paper describes a click-free audio switch that functions by controlling the rate of onset and decay of a signal. The principle component of the switch is a device whose resistance is a function of the light intensity falling upon it. Circuit diagrams and suggested applications are provided.     

A simple and inexpensive computer-compatible shock circuit

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

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 reinforcement dispenser

An inexpensive (less than $35) solid food reinforcement dispenser was developed using commercially available parts for commonly found vending machines. This device proved to be reliable and efficient in repeated use with laboratory primates in a video task testing situation.     

An inexpensive retraction mechanism

An electric retraction mechanism, which is adaptable to a wide range of operant manipulanda, was developed. Miniaturized, inexpensive toy railroad equipment was used to simplify construction. The mechanism, utilized as a retractable rat lever, has operated reliably and uniformly over a range of independent retraction and extension times.