Daniel Fallon

Negative contrast in goldfish (Carassius auratus)

Goldfish in a successive differential discrimination displayed strong negative contrast. A successive nondifferential shift in reward magnitude did not produce clear negative contrast, however. Response speed changed appropriately when reward magnitudes were changed. There was no indication of positive contrast in either condition.

A simple and versatile fear-conditioning chamber requiring no shock scrambler☆

Abstract A chamber is described which permits the direct administration of electric shock without an intervening polarity-scrambling device. The chamber design allows convenient manipulation of a variety of visual and auditory stimuli which may be programmed to serve as conditioned stimuli for fear.

Reward and reward omission: Time-dependent aftereffects in rats and fish

Both goldfish and rats responded faster on a trial following shortly after reward omission than on trials at longer intervals. On trials shortly after a reward, responding was slower than on similar trials presented at longer intervals. These reward omission effects are similar to the invigorating effects of frustrative nonreward.

Influence of fear and frustration on the motivation of self-punitive behavior

Abstract Rats were runway trained with reward. Then, each S underwent classical conditioning procedures during which frustrative nonreward was paired with one CS and painful electric shock was paired with another CS in a counterbalanced design. Finally, S s learned to escape from an electrified start box through an electrified runway to a safe goal box. During shockescape extinction, one-third of the S s received either a frustration CS, a fear CS, or a novel stimulus in the now safe start box. Half of the S s in each condition continued to receive shock in the runway. Higher resistance to extinction was observed with shock in the runway. Effect of start-box stimuli was also significant, with most persistence shown by fear CS groups, and least by frustration CS groups. Thus, ( a ) Mowrers “vicious-circle” hypothesis is supported, and ( b ) fear and frustration are discriminably different states.

A quick method for determining fluid preference: Saccharin preference in water-deprived rats as a function of time on deprivation schedule

A simple method of assessing fluid preference within a single 60-min period, with position preferences counterbalanced between and within Ss, is described. After 10 days of water deprivation, and at 80% of their predeprivation body weights, Ss preferred.1% saccharin to water. The preference for saccharin was even greater 21 days later. It is suggested that the preference for saccharin under water deprivation may be an index of concurrent hunger which grows with the increasing cumulative food deficit accompanying water deprivation.