Luc Granger

Piagetian object-permanence in Cebus capucinus, Lagothrica flavicauda and Pan troglodytes

Object-permanence was studied with one chimpanzee (Pan troglodytes) and two New World monkeys (Lagothrica flavicauda and Cebus capucinus). The chimpanzee and the capucinus attained stage VI, while Lagothrica reached stage Va. The data show that tests of object-permanence are suitable for comparison among species. This study also attempts to propose an experimental scheme that could allow for a more valid comparison among species. Use of an operant conditioning procedure is suggested and discussed.

Voluntary control of autonomic responses: a case for a dialogue between individual and group experimental methodologies.

This paper discusses the general methodological controversy between individual and group research approaches by comparing the main characteristics of these two methods as applied to the specific context of basic research on voluntary heart rate control. A review of the literature published over the past 19 years in this area of study shows an imbalance in the frequency of utilization of these two methods that strongly favors short-term group designs. Implications of this research tendency are discussed. The relevance and the advantages of applying the individual approach to voluntary autonomic control research are outlined. This area is particularly amenable to the individual approach because the phenomena under study seem to be characterized by, among other things, a smaller intrasubject than intersubject variability. It is suggested that the present imbalanced tendency in the choice of a research method be corrected and that researchers adopt a more flexible attitude in the choice of the best method for studying each specific problem.