Demonstrations of neophobia and enhanced neophobia in the albino rat.

Abstract

The conditions under which neophobia and enhanced neophobia occur in the albino rat were studied. Neophobia to a .1% saccharin solution was demonstrated in a 10-min single-bottle test. This neophobia was enhanced by pairing water ingestion with a radiation exposure of 100 r. or an injection of lithium chloride 24 hr prior to the saccharin test. In addition, it was found that the differences in consumption of saccharin in a 10-min single-bottle test due to neophobia and enhanced neophobia were produced by consistent differences in drinking rates which appeared early in the 10-min period. The disappearance of neophobia and enhanced neophobia in a 1-hr single-bottle test suggested that the effects of neophobia and enhanced neophobia are short-lived and are best measured in a brief single-bottle test. Finally, enhanced neophobia was not found when 2 days of water drinking were interposed between LiCl poisoning and saccharin testing.

A contingency analysis of taste aversion conditioning

“…The present finding that eight preexposures to a small amount of lithium chloride did not affect subsequent saccharin acceptance should perhaps not be too surprising, however. Domjan reported that the effect was not reliably produced, and Carroll et al (1975) found the effect only within 24 h following administration of a dosage of lithium which was four times that used in the present study. It appears likely that enhanced neophobia may only be produced under certain optimal conditions, including pretreatment with large dosages of toxins.…”

“…Powerful nonassociative effects are often found in taste aversion studies, including the attenuation of flavor neophobia through preexposure to the flavor (Domjan, 1976(Domjan, , 1977Siegel, 1974) or enhancement of neophobia through pretreatment with a toxin (Carroll, Dinc, Levy, & Smith, 1975;Domjan, 1975). Both the number and the duration of prior flavor exposures influence the extent of increase in subsequent flavor intake (Domjan, 1976).…”

Overshadowing of environmental cues by an odor in toxicosis-based conditioning in rats

“…In the present experiment, a total of 144 h intervened between the rats' last LiCI experience and their exposure to the novel odor. The difference between the two studies may be explained by the fact that Carroll et al (1975) gave their animals only one LiCI exposure, whereas the animals in the present study were given two. The extent to which neophobia is enhanced and the temporal parameters of this effect may vary as a function of the number of occasions on which the animal experiences the lithium distress prior to its initial contact with the taste or odor stimulus.…”

“…While these investigators used a taste stimulus to demonstrate the enhancement effect, it is possible that the phenomenon is applicable to odor as well. The only difficulty with this generalization from the Carroll et al (1975) study is that, in their experiments, no enhancement of neophobia was found when a period of 48 h intervened between the LiCI exposure and the enhancement test. In the present experiment, a total of 144 h intervened between the rats' last LiCI experience and their exposure to the novel odor.…”

Resistance to extinction of a learned taste aversion varies with time of conditioning

“…Carroll, Dinc, Levy, and Smith (1975) have suggested that the degree of neophobia resulting from the initial presentation of a taste solution might be a good predictor of the strength of a learned aversion subsequently conditioned to the same solution. In the present study, the 15-min CS presentation was the first exposure these rats had to sucrose.…”