Individual Differences in Auditory Signal Detection Task: Subject-oriented Study

Effects of extraversion, impulsivity, neuroticism and achievement motivation were investigated in prolonged signal detection task. Sixty-five subjects detected threshold auditory signal mixed with noise background. RT, d`, decision-making criterion index, bias of response confidence and measures of their dynamics were recorded. The introverts showed higher sensory sensitivity and stability of task performance in comparison with extraverts. High impulsive subjects used less strict criterion than low impulsive ones. The subjects with high scores of achievement motivation were more stable in the performance of signal detection: their indeces of variability of both RT and criterion were significantly lower. The effects of factor interactions of achievement motivation*extravertion, extravertion*inpulsivity and extravertion*neurotism on strictness of criterion were also discovered. The analysis of response confidence bias revealed the phenomenon of response overconfidence. Activity of observer during experiment and significance of individual differences are still underestimated in psychophysics. Domination of so called “object paradigm” (Bardin et al. 1991; Bardin, Indlin, 1993) which simplifies substantially the process of signal detection (discrimination) is the result of this underestimation. In this context psychophysics measurement becomes similar to instrumental one and observer’s activity is described with mathematical models analogous to functioning of technical systems. Consequently, the corresponding methodological approach to psychophysics measurement is to eliminate the influence of observer’s peculiarities, which are understood as measurement artifacts. In Russian psychophysics alongside with traditional psychophysics analysis the experimental and theoretical approach is being developed and is tended to reveal the role of observer’s personal activity in sensory measurements (Asmolov, Mikhalevskaya, 1973; Bardin et al., 1991; Zabrodin et al., 1981). This “subject oriented” approach (Bardin et al., 1991) combines traditional psychophysical paradigm with activity tradition in psychology and investigation of individual differences. In the frames of the approach any psychophysics measurement is understood as the process of sensory task being solved by subject. The process has its operational structure and is mediated by different forms of personal activity. For example, the task of signal detection is complicated and intensive and it demands making decisions in high uncertainty and time shortage conditions. It suggests both actualization of complicated forms of motivation and volitional control; some cognitive and activation resources are also involved. So, we are sure that the research of observer’s individual peculiarities role in solving threshold signal detection task is especially important.