Reaction times reveal the contribution of the different receptor components in luminance perception

Piéron (1914, 1920, 1952) demonstrated that simple reaction time decays as a hyperbolic function of luminance. Similarities between cell latencies and reaction time (RT) to luminance suggest that this relationship may be determined by retinal processes. If the exponent of the Piéron function is specific to a given sensory modality, as assumed by some authors (e.g., Bonnet, 1992a, 1992b; Norwich, 1987), it should reflect receptor activities. Consequently, functions with different exponents should fit data for different luminance ranges. In a contrast-discrimination experiment, we investigated this question with a large range of luminance levels in a two-alternative spatial forced-choice task. The results of the experiment show that three functions with different exponents fit RT to the three luminance ranges (scotopic, mesopic, and photopic). The exponent decreases with increasing luminance. The findings indicate that the exponent and the asymptotic latency of the RT function reflect receptor activities of the visual system.     

On the relation between stimulus intensity and processing time: Piéron’s law and choice reaction time

Piéron (1914, 1920, 1952) demonstrated that simple reaction time (SRT) decays as a hyperbolic function of luminance in detection tasks. However, whether such a relationship holds equally for choice reaction time (CRT) has been questioned (Luce, 1986; Nissen, 1977), at least when the task is not brightness discrimination. In two SRT and three CRT experiments, we investigated the function that relates reaction time (RT) to stimulus intensity for five levels of luminance covering the entire mesopic range. The psychophysical experiments consisted of simple detection, two-alternative forced choice (2 AFC) with spatial uncertainty, 2 AFC with semantic categorization, and 2 AFC with orientation discrimination. The results of the experiments showed that mean RT increases with task complexity. However, the exponents of the functions relating RT to stimulus intensity were found to be similar in the different experiments. This finding indicates that Piéron’s law holds for CRT as well as for SRT. It describes RT as a power function of stimulus intensity, with similar exponents, regardless of the complexity of the task.     

Relationships between the Vocational Preference Inventory and the Edwards Personal Preference Schedule

The Vocational Preference Inventory and the Edwards Personal Preference Schedule were administered to 372 undergraduates. The two instruments were compared using canonical analysis. The analysis revealed three significant relationships between components of the two instruments. The relationships were viewed as supportive of Holland's theory of personality types.     

Properties of curvilinear vection

Approximately linear relationships were observed between contrast, spatial frequency, temporal frequency, or velocity of stimulation and perceived velocity of curvilinear vection—that is, a visually induced self-motion in a curved path. Similarly, linear relationships were also found between the perceived degree of curvature of curvilinear vection and spatial frequency or velocity of stimulation. Since the perceived velocity of curvilinear vection varies with contrast, spatial frequency, temporal frequency, and angular velocity, and the perceived degree of curvature of curvilinear vection varies only with spatial frequency and angular velocity, peripheral vision is not sufficient for computing accurately the curvilinear component of induced self-motion in a curved path. Concurrently, it was shown that the perceived direction of curvilinear vection is not always unambiguously perceived (Sauvan & Bonnet, 1989). Consequently, it is suggested that two different types of visual processing, which involve the peripheral or the central vision, underlie the processing of curvilinear vection.     

Les corrélats comportementaux et conjugaux des attentes d'efficacité en matière de résolution de problèmes personnels

L'objectif de cette recherche est d'étudier la relation entre les attentes d'efficacité personnelle en matière de résolution de problèmes, diverses conduites de résolution de problèmes et le degré de satisfaction conjugale des sujets. L'échantillon se compose de 40 couples qui ont complété l'Échelle d'Ajustment Dyadique, l'Inventaire de Résolution de Problèmes Personnels et qui ont participé à une discussion filmée sur ruban magnétoscopique. Les comportements sont codifiés à l'aide du Système Global de Cotation des Interactions Conjugales. Les résultats confirment la présence d'une relation entre les attentes d'efficacité personnelle, les comportements observés en situation de résolution de problèmes et le degré de satisfaction conjugale des femmes et des hommes. Les résultats obtenus démontrent aussi que les variables comportementales ont des fonctions de cumul dans la relation entre les attentes d'efficacité personnelle et la satisfaction conjugale. Les implications théoriques de ces résultats sont discutées.