The open-field test: A critical review.

Abstract

Over the past 40 years the open field has evolved as a commonly used tool for the measurement of animal behavior. This review takes a critical look at the use of this instrument, especially with regard to the development of a standard form for its use. The various procedures and their shortcomings are discussed, with particular reference to the seemingly inconsequential details which have been shown to modulate open-field performance per se. Dependent parameters arc considered both with regard to their reliability and their validity for the measurement of such underlying constructs as emotionality.Since its introduction some 40 years ago, the open-field test has attained the status of one of the most widely used instruments in animal psychology. Its popularity probably stems in large part from the simplicity of the apparatus, the easy and rapid measurement of clearly defined behaviors, and a generally accepted interpretation of these behaviors. In addition, certain of the measured behaviors are sensitive to a wide range of genetic, experiential, physiological, and pharmacological manipulations and are sufficiently reliable under standardized conditions to give repeatable measures on an enormous range of independent variables. Simplicity, ease of quantification, and wide applicability are therefore probably the prime determinants of its popularity.However, in spite of its status as one of the most widely used tests of animal behavior, the open-field test has survived for 40 years with only one major review (Archer, 1973), and this was limited to a-consideration of its usefulness for estimating emotionality in rodents. Apparatus, techniques, subjects, parameters, analyses, and interpretations have We would like to express our gratitude to Otto

Open-field behavior withstands drastic changes in arena size

“…Other past observations in rats, mice and gerbils, suggest however, that ambulating increases with increase in arena size [35]. This does not necessarily contradict the present results, since as shown below, such an increase was also seen in the present study, not reaching statistical significance as in previous studies [35].…”

“…Applying these parameters in assessing the amount of activity, revealed no significant change in activity, as if voles possess a fixed amount of activity, independent of the space available for locomotion [7]. Other past observations in rats, mice and gerbils, suggest however, that ambulating increases with increase in arena size [35]. This does not necessarily contradict the present results, since as shown below, such an increase was also seen in the present study, not reaching statistical significance as in previous studies [35].…”

“…The open field [19] is the most widely used test in animal psychology [35]. In this test an animal (usually a rodent) is introduced into a plain and illuminated arena [16] and observed for periods ranging from acute exposure of a few minutes [7] to repeated exposures of several hours [30].…”

“…Open-field behavior in rodents, mainly laboratory rats and mice, is commonly regarded as a fundamental index of their general behavior. Indeed, open-field locomotion is predictive of locomotor scores in other novel environments [35]. The open-field test has been criticized, arguing that it evaluates emotional reaction more than exploratory motivation, thus contributing to the fallacy of taking general motor patterns as the sole expression of any specific motivation [22].…”

“…activity and of the sequential (spatio-temporal) structure of behavior [6,35]. Disorder in the spatio-temporal organization of behavior is a feature of obsessive-compulsive disorder and schizophrenia in humans, or cage stereotypies in animals [20].…”