Continuity effects with alternately sounding tones under dichotic presentation

An experiment is reported in which 10 Ss possessing normal hearing were required to make discriminations of continuity or interruption in a longer less intense signal (Tone A) which alternated in time with a shorter more intense signal (Tone B). The signals were presented dichotically with Tone A at the right ear. Three Tone B frequencies of 300, 1000, and 4000 cps and five Tone A frequencies somewhat near each of the Tone B frequencies were employed. The results demonstrated that as Tone A was nearer to Tone B in frequency, continuity thresholds in Tone A occurred at longer durations of Tone B. The results are discussed in terms of a central neural model.     

Some observations and measurements of the Pulfrich phenomenon

The Pulfrich pendulum was evaluated as a potential screening device for the detection of anomalies of binocular vision. For this purpose, a booth was set up at the Kentucky State Fair (1964) and the general public invited to observe the pendulum and record their responses with the equipment provided. The obtained results indicate that a dichotomy can be achieved between those who have binocular vision and those who do not. However, gradations of binocular vision from poor to good cannot be achieved with the pendulum as presently understood. Contrary to explanatory theory the characteristic shape of the seen pendulum path was asymmetrical following the rule that the path was displaced away from the observer on the side of the filtered eye.     

Carbon dioxide as a reinforcer in escape conditioning

The effects of varying CO₂ concentration, and intervals between CO₂ presentations, were determined from the performance by five pigeons of a learned motor act which eliminates CO₂ from the inspired air. The length of time from the onset of an externally-produced increase in inspired CO₂ to the performance of the learned motor response terminating the CO₂ presentation was inversely related to the CO₂ concentration presented (3 per cent and 5 per cent) and directly related to the inter-trial interval (3 minutes and 1.5 minutes). Chemoreceptors on the ventrolateral surfaces of the medulla are postulated to be the initial site of stimulation in the chain of events leading to the behavioral bioregulation of inspired CO₂ concentration.