Motion sickness-induced pica in the rat.

Two experiments investigating the effects of motion sickness on pica (the consumption of non-nutritive substances) are reported. In the first experiment rats subject to rotational stimulation subsequently engaged in geophagia (clay consumption). In the second experiment use of a conditioned aversion paradigm confirmed that the method of rotational stimulation used in the first experiment causes motion sickness in rats. The results of these experiments indicate that simple gastrointestinal malaise in the absence of a deficiency state or acute toxemia will elicit pica. It is suggested that gastrointestinal distress may be a significant factor in the etiology of pica and its relationship to other causes of pica is discussed.