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.     

Behavioural conversion in a compliance paradigm: A replication and a refinement

While a compliance strategy induced almost all subjects to agree to forego first a lunch and then a dinner and the following breakfast, simply observing an accomplice break his commitment to forego lunch was enough to produce a significant reduction in subjects' commitment to forego two meals, even though the effect was not immediate. This pattern of influence, similar to a ‘behavioural conversion’, appeared if the accomplice had first agreed to the initial request and only later refused to continue, but not if he refused to make the commitment at the outset.     

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.     

Are movements/proprioception effective time-keeping mediators? The input hypothesis re-visited

Based upon the experimental literature surveyed, and given that time-keeping accuracy (i.e., constant error, absolute error, beneficial anticipation) is the appropriate performance dimension to consider, there appears to be virtually no support for the speculation that proprioception serves as an effective mediator for conscious time-keeping judgements. For the most part, individuals afforded movements during the interval to be timed did not perform significantly more precisely than did those people deprived of such time-filling movements, nor did they consistently estimate time with significantly less variability. On this basis, and because other predictions of the Input Hypothesis examined herein (left/right hand covariance, practice by movement group interaction and effect of different levels of proprioception) were not experimentally supported, the validity of the Input Hypothesis was rejected.     

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.