Over the last decade, increased effort has been made to acquire three dimensional images of knee joints under weight-bearing condition. Cone-beam CT systems are popular because of their high flexibility with respect to patient position and scan trajectory. However, scans in a standing or squatting patient position are affected by involuntary patient motion during the acquisition, which results ...

Motion detectors in the locust optic lobe and brain fall into two categories: neurones that respond selectively to approaching vs. receding objects and neurones that respond selectively to a particular pattern of image motion over a substantial part of the eye, generated by the locust's own movements through its environment. Neurones from the two categories can be differentiated on the basis of...

Motion trajectory can be an informative and descriptive clue that is suitable for the characterization of motion. Studying motion trajectory for effective motion description and recognition is important in many applications. For instance, motion trajectory can play an important role in the representation, recognition and learning of most long-term human or robot actions, behaviors and activitie...

While the percentage of older people in our society is steadily increasing, knowledge about perceptual changes during healthy aging is still limited. We investigated age effects on visual motion perception in order to differentiate between general decline and specific vulnerabilities. A total of 119 subjects ranging in age from 20 to 82 years participated in our study. Perceptual thresholds for...

The direction of apparent motion in a complex pattern comprising a static 1-cycle/degree (c/deg) grating and a moving 3-c/deg grating changes with stimulus duration. At durations longer than about 150 msec, motion is seen almost veridically; the motion of the 3-c/deg grating, which is seen correctly, merely induces in the 1-c/deg grating a weak apparent motion in the opposite direction. At shor...