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 operant chamber interface for the VIC 20 microcomputer

An inexpensive interface to connect the VIC 20 (or other Commodore microcomputer) to a single operant chamber is described. This interface is equipped to accept as inputs three separate switch closures and produces five outputs, including one to elevate a food hopper. The uses of this interface for controlling experimental events and acquiring data in real time are discussed.     

An inexpensive,efficient cage for small birds

A simple cage system is described which is particularly applicable for housing small birds such as sparrows and finches that have been trapped in the wild. The cages are constructed of inexpensive, readily available materials.     

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.     

The origin of the autokinetic effect

The effects of unbalanced fatigue of the ocular and neck musculature on the auto- kinetic effect are described. It is shown that after deviation of the eyes to an extreme position, fixation of a small light source with the eye in the central position gives rise to an immediate and pronounced autokinetic effect. This apparent movement is typically in the same meridian as that of the ocular deviation and is often, at all events at first, in the opposite direction. Similar, though less clear-cut, results are obtained after induction of unbalanced fatigue in the neck musculature. It is argued that the autokinetic effect observed under these conditions warrants treatment as a primary illusion of movement and does not involve a “framework” or standard of reference. In an appendix, a speculative model of the ocular control system and some preliminary observations are presented. It is concluded that the autokinetic effect is principally due to spontaneous minor fluctuations in the neural system which monitors the outward signals controlling eye movement.