Detection theory analysis of scaling and discrimination tasks: Responses to noxious thermal stimuli

This study’s main purpose was to examine the sensitivity estimates obtained from scaling and discrimination approaches for nociception assessment in healthy individuals. This investigation may inform future applications in diagnostic procedures for painful conditions. Models of psychophysical judgment based on those of Durlach and Braida (1969), Laming (1984), and Irwin and Whitehead (1991) were used as the common analytical framework. Noxious thermal contact stimuli were used. The results show that the scaling approach produced lower detection theory sensitivity estimates than did the discrimination approach. The additional judgment variance in scaling tasks could explain this lowered sensitivity. The relative judgmental variance value of 2.18 obtained in this study is lower than variance values found in previous investigations. This discrepancy is probably due to the relatively smaller stimulus range employed in this study. The authors propose that the theoretical framework used in this study may be used in future studies to investigate the different dimensions of pain perception.