Moving window generator for reading experiments

An inexpensive PC-based moving window generator with an eye movement recording system is described. The moving window technique, activated by current eye movements, has an advantage over the fixed window technique in measuring the effective visual field size during reading. A variable rectangular window, through which the subject observes the text, is generated on a PC-controlled CRT screen. The system includes a frame buffer memory, an analog-to-digital conversion unit, and an eye movement recording system. The system works well for measuring approximate field size during reading.     

How accurate is size and distance perception for very far terrestrial objects? Function and causality

This study investigated absolute estimation of size and distance for natural and artificial objects at viewing distances of 1.1–15.3 km (Experiments 1 and 2) and 0.4–5.0 m (Experiment 3). The main results were that, regardless of distance range, size and distance estimates (S′ andD′) were related to objective size and distance (S andD), respectively, by a power function with an exponent of unity, but great individual differences in exponent were obtained for the far objects. The ratioS′/D′ was reasonably represented byS′/D′ =Kθ ⁿ andS′/D′ = tan(aθ +b), rather thanS′/D′ = tan θ, where θ is the visual angle. Partial correlations were obtained to examine whether (1) apparent size is determined by taking apparent distance into account or (2) both apparent size and apparent distance are determined directly by external stimuli. The combined data for the far objects and the data for the close objects showed that there were high correlations betweenS andS′ and betweenD andD′ and a low correlation betweenD′ andS′. The data of Experiment 2 showed that bothD′ andS′ were highly correlated withS D, and θ, and there was a high positive correlation betweenD′ andS′. It was suggested that the direct-perception model is valid under some situations, but the taking-into-account model is not supported in any set of data.     

Wheatstone—Panum limiting case: Occlusion, camouflage, and vergence-induced disparity cues

We examined effects of binocular occlusion, binocular camouflage, and vergence-induced disparity cues on the perceived depth between two objects when two stimuli are presented to one eye and a single stimulus to the other (Wheatstone—Panum limiting case). The perceived order and magnitude of the depth were examined in two experimental conditions: (1) The stimulus was presented on the temporal side (occlusion condition) and (2) the nasal side (camouflage condition) of the stimulus pair on one retina so as to fuse with the single stimulus on the other retina. In both conditions, the separation between the stimulus pair presented to one eye was systematically varied. Experiment 1, with 16 observers, showed that the fused object was seen in front of the nonfused object in the occlusion condition and was seen at the same distance as the nonfused object in the camouflage condition. The perceived depth between the two objects was constant and did not depend on the separation of the stimulus pair presented to one eye. Experiment 2, with 45 observers, showed that the disparity induced by vergence mainly determined the perceived depth, and the depth magnitude increased as the separation of the stimulus pair was made wider. The results suggest that (1) occlusion provides depth-order information but not depth-magnitude information, (2) camouflage provides neither depth-order nor depth-magnitude information, and (3) vergence-induced disparity provides both order and magnitude information.     

Premovement facilitation of corticospinal excitability before simple and sequential movement

The purpose of this study was to investigate whether premovement facilitation of corticospinal excitability before sequential movement was different from that before simple movement. Each of 7 participants who performed choice reaction tasks with the right hand pressed a force transducer with the index finger in response to a start cue or pressed the transducers sequentially with the index finger, little finger, thumb, little finger, and index finger. Transcranial magnetic stimulation was delivered to the left motor cortex before the electromyographic burst in the first dorsal interosseous muscle and motor evoked potentials were recorded from the first dorsal interosseous muscle. The amplitude of the motor-evoked potential increased as its onset got closer to the onset of the electromyographic burst. The increase before the sequential movement was larger and began earlier than that before the simple movement. These findings indicate that premovement facilitation of corticospinal excitability is different in magnitude and timing between sequential and simple movements.     

Oculomotor responses of stereo‐anomalous observers to pulse and ramp disparities

We examined oculomotor responses to binocular disparities of one stereo‐normal and three stereo‐anomalous observers, who were identified through a stereoscopic depth‐discrimination task, in two experimental conditions. In the pulse disparity condition, crossed and uncrossed disparities (1–6°) were briefly presented (for .25–2.0 s). In the ramp disparity condition, disparities were varied continuously with constant velocities (.7–2.0°/s) and with an amplitude of 10°. The stereo‐normal observer showed vergence responses to both pulse and ramp disparities. The three stereo‐anomalous observers showed a marked reduction or absence of vergence responses to pulse disparities but showed vergence responses to ramp disparities. The results suggest the existence of separate sub‐systems mediating disparity vergence eye movements.     

Perceived distance of targets in convex mirrors

We investigated the perceived distance of targets in convex and plane mirrors. In Experiment 1, 20 subjects matched the distance of targets in a real scene to the distance of a virtual target in different mirrors. The matched distances were much larger for convex mirrors than for a plane mirror. In Experiment 2, 20 subjects viewed two targets in a mirror and adjusted their own positions so that the distance to the closer target was perceived to equal the distance between the targets. The mean distance to the closer target was smaller for the convex mirrors than for the plane mirror. In Experiment 3, 20 subjects adjusted the position of a target so that the distance to it in a mirror was perceived to equal the distance designated by the experimenter. The best-fitting power functions showed that the scaling factors were larger for the convex mirrors than for the plane mirror, but the exponents were smaller for the convex mirrors than for the plane mirror. It is suggested that distance in the convex mirrors was perceived to be larger than in the plane mirror, and that the growth of perceived distance in the convex mirrors was slower than in the plane mirror.     

Employee satisfaction and job climate: An empirical study of Japanese manufacturing employees

This study identified supportive supervision, co-worker social support, and job awareness as three factors that affect job satisfaction of employees from two mid-sized Japanese manufacturing companies. In addition to the significant main effects of supportive supervision and co-worker social support, a significant interaction effect between supportive supervision and job awareness was obtained. This interaction suggests that supportive supervision is very important in increasing job satisfaction when workers have low levels of job awareness.We appreciate the comments and assistance of Professor Y. Hara, Associate Professor M. Yano, S. Kobayashi, J. Nukata, and two anonymous reviewers for their valuable recommendations on the earlier version of the article.     

Emergence of response‐response relations

The present study examined whether bidirectional response‐response relations could be established without direct reinforcement. In AB training for 12 undergraduates, higher rates of touches to a white circle on the monitor screen (A1) produced two stimuli (B1 and B2) on half of the trials, whereas lower rates (A2) produced the same effect on the other half. Choosing one of the two stimuli was reinforced according to the preceding responding (A1B1 and A2B2). In BC training, touching a stimulus (B1 or B2) produced three white circles lined up horizontally on the screen, after which one of two different response sequences to the circles (left‐center‐right, C1 or C2, and right‐center‐left, C2 or C1) were reinforced, depending on the stimulus presented (B1C1 and B2C2). After AB and BC relations were established, 11 of 12 participants showed the emergence of untrained relations (BA, CB, AC, and CA) throughout five test sessions, and the remaining participant showed it in the first four test sessions. These response‐response relations were replicated with five other undergraduates and different trained relations.     

An Optimized Design of Choice Experiments: A New Approach for Studying Decision Behavior in Choice Task Experiments

In this paper, we present a new approach for the optimal experimental design problem of generating diagnostic choice tasks, where the respondent's decision strategy can be unambiguously deduced from the observed choice. In this new approach, we applied a genetic algorithm that creates a one‐to‐one correspondence between a set of predefined decision strategies and the alternatives of the choice task; it also manipulates the characteristics of the choice tasks. In addition, this new approach takes into account the measurement errors that can occur when the preferences of the decision makers are being measured. The proposed genetic algorithm is capable of generating diagnostic choice tasks even when the search space of possible choice tasks is very large. As proof‐of‐concept, we used this novel approach to generate respondent‐specific choice tasks with either low or high context‐based complexity that we operationalize by the similarity of alternatives and the conflict between alternatives. We find in an experiment that an increase in the similarity of the alternatives and an increase in the number of conflicts within the choice task lead to an increased use of non‐compensatory strategies and a decreased use of compensatory decision strategies. In contrast, the size of the choice tasks, measured by the number of attributes and alternatives, only weakly influences the strategy selection. Copyright © 2014 John Wiley & Sons, Ltd.