Casarrubea M

T-pattern analysis for the study of temporal structure of animal and human behavior: A comprehensive review

A basic tenet in the realm of modern behavioral sciences is that behavior consists of patterns in time. For this reason, investigations of behavior deal with sequences that are not easily perceivable by the unaided observer. This problem calls for improved means of detection, data handling and analysis. This review focuses on the analysis of the temporal structure of behavior carried out by means of a multivariate approach known as T-pattern analysis. Using this technique, recurring sequences of behavioral events, usually hard to detect, can be unveiled and carefully described. T-pattern analysis has been successfully applied in the study of various aspects of human or animal behavior such as behavioral modifications in neuro-psychiatric diseases, route-tracing stereotypy in mice, interaction between human subjects and animal or artificial agents, hormonal-behavioral interactions, patterns of behavior associated with emesis and, in our laboratories, exploration and anxiety-related behaviors in rodents. After describing the theory and concepts of T-pattern analysis, this review will focus on the application of the analysis to the study of the temporal characteristics of behavior in different species from rodents to human beings. This work could represent a useful background for researchers who intend to employ such a refined multivariate approach to the study of behavior.

Discovering Hidden Temporal Patterns in Behavior and Interaction

Discovering hidden recurring patterns in observable behavioral processes is an important issuefrequently faced by numerous advanced students and researchers across many research areas, includingpsychology, biology, sports, robotics, media, finance, and medicine. As generally, themany powerful methods included in statistical software packages were not developed for this kind ofanalysis, discovering such patterns has proven a particularly difficult task, due to a lack of a) adequateformalized models of the kinds of patterns to look for, b) corresponding detection algorithms and c)their implementation in available software.The research described in this book is based on the application of such pattern types, algorithms andsoftware developed from the late seventies to the present in the context of researchin collaboration with human and animal behavioral research teams at internationally leadinguniversities in the US and Europe, thus testing the usefulness and validity of the pattern types,algorithms and software in numerous research areas. With the (scale independent statistical hierarchical and fractal-like) T-Pattern at its heart, a set ofproposed pattern types, called the T-System, forms the basis for the search algorithms implemented asthe software THEME (TM) (vs. 6), which is easily available in free educational and full commercialversions.

Multivariate temporal pattern analysis applied to the study of rat behavior in the elevated plus maze: methodological and conceptual highlights.

Aim of this article is to illustrate the application of a multivariate approach known as t-pattern analysis in the study of rat behavior in elevated plus maze. By means of this multivariate approach, significant relationships among behavioral events in the course of time can be described. Both quantitative and t-pattern analyses were utilized to analyze data obtained from fifteen male Wistar rats following a trial 1-trial 2 protocol. In trial 2, in comparison with the initial exposure, mean occurrences of behavioral elements performed in protected zones of the maze showed a significant increase counterbalanced by a significant decrease of mean occurrences of behavioral elements in unprotected zones. Multivariate t-pattern analysis, in trial 1, revealed the presence of 134 t-patterns of different composition. In trial 2, the temporal structure of behavior become more simple, being present only 32 different t-patterns. Behavioral strings and stripes (i.e. graphical representation of each t-pattern onset) of all t-patterns were presented both for trial 1 and trial 2 as well. Finally, percent distributions in the three zones of the maze show a clear-cut increase of t-patterns in closed arm and a significant reduction in the remaining zones. Results show that previous experience deeply modifies the temporal structure of rat behavior in the elevated plus maze. In addition, this article, by highlighting several conceptual, methodological and illustrative aspects on the utilization of t-pattern analysis, could represent a useful background to employ such a refined approach in the study of rat behavior in elevated plus maze.

The effects of different basal levels of anxiety on the behavioral shift analyzed in the central platform of the elevated plus maze

The aim of the present research was to study the effects of different basal levels of anxiety on the behavioral shift studied in the central platform of the elevated plus maze. To this purpose, quantitative and multivariate analyses, the latter based on transition matrix elaboration, were carried out on Wistar and on DA/Han rats the latter belonging to a strain characterized by different reactivity to anxiogenic stimuli. Wistar rats spent 74.11±5.11 s in the central platform, whereas DA/Han significantly more: 127.08±9.87. Per cent distributions evidenced a clear-cut difference in walking activities (46.25% in Wistar, 28.4% in DA/Han rats) and in the sniffing activities (45.82% in Wistar, 62.54% in DA/Han). Mean frequencies of each behavioral element showed in DA/Han strain a value significantly lower than in Wistar for central-platform entry, open arm-entry and closed-arm entry and a significant higher value for central- platform sniffing, open-arm sniffing and corner-rearing. Moreover, the ratio open-arm entry/open-arm sniffing and closed-arm entry/closed-arm-sniffing showed significant higher values in the Wistar strain. Finally, by means of hierarchical clustering analysis, strong differences between the two strains were observed in the behavioral architecture: a cascade-shaped dendrogram, branching from Walking activities, indicates that Wistar rat behavior is oriented to cross the central platform so to rapidly reach an arm; on the contrary, the dendrogram of DA/Han rats displays a behavior heavily oriented toward the permanence in the central platform. The results show that different basal levels of anxiety provoke significant differences in the behavioral shift studied in the central platform of the elevated plus maze. Such differences, evidenced by means of transition matrices elaboration, might represent the behavioral expression of anxiety-induced modifications of decision making process underlying behavioral shift activities.