Multivariate analysis of putative measures of activity, exploration, emotionality, and spatial behavior in the hooded rat (Rattus norvegicus).

Abstract

Hooded rats were tested in six situations representing the variables of activity, exploration, emotionality, and spatial preference, detection of change, and learning. The activity, exploration, and emotionality variables and spatial variables were analyzed in separate multivariate analyses, followed by an analysis of the entire set. The first of these resulted in four components: activity, exploration and emotionality, reactivity to handling, and autonomic reactivity (defecation). Four components, defined by the following variables, emerged from the spatial analysis: (a) the tendency to circle, circling direction, and spatial learning; (b) heading error in spatial learning and reversal and open-field directional preference; (c) spatial reversal and direction of turn to escape restraint; and (d) detection of change in spatial arrangement and directional preference in the detection task. The final analysis investigated relations between the activity, exploration, and emotionality variables and the spatial variables, finding only two. The clear dimensionality of these behavioral repertoires emphasizes how important it is to recognize the distinctions among them.

Development of ultrasonic vocalization responses in genetically heterogeneous National Institute of Health (N:NIH) rats. II. Associations among variables and behaviors

“…Multivariate studies indicate that self-grooming, defecation, and activity in adult rats are mutually associated in complex ways (Abel, 1991;Archer, 1973;Maier et al, 1988;Royce, 1977). For instance, females exhibit more activity in plus-maze studies, but at least some of this activity may be associated with anxiety (File, 1992).…”

“…Component 4 consists primarily of square crosses, with weight moderately related to the component, and ambient temperature negatively and moderately related; this component seems to reflect locomotor activity, influenced by maturity and ambient temperature. Because one criterion for stable (and therefore meaningful) component structures is their replicability in different populations (Gorsuch, 1983;Maier et al, 1988), and because it was of interest to determine whether there were different sets of associations for males and females, we did separate principal components analyses for each sex.…”

“…For example, a recent study (Sufka & Weed, 1994) used principal components analysis as a means of observing the convergence of behavioral indices of isolation-induced distress in chicks (vocalizations, behavioral postures, and so on). In adult rats, principal components analysis has been used both to determine commonalities among measures in different tests of emotionality (File, 1992;Maier, Vandenhoff, & Crowne, 1988), and distinctions between measures of emotionality in the same test (Whimbey & Denenberg, 1967).…”

Open-field behavior withstands drastic changes in arena size

“…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]. The controversy has extended to the structure of the apparatus itself, which was described as "a poor and explicitly aversive environment with excess light and open spaces that does not elicit exploratory motivation" [16].…”

Repeatability and heritability of exploratory behaviour in great tits from the wild

“…For instance, the effect of sequence and interval (Fig. 3) may indicate that the birds experienced less fear (Maier et al 1988;Budaev 1997) when recaptured shortly after the first capture, and that stress affected the behaviour during the first measurements. Despite these limitations, the behaviour in novel environments is likely to result in information acquisition and therefore reflects some aspects of exploration (Russell 1983).…”