Self-motion perception training: thresholds improve in the light but not in the dark

We investigated perceptual learning in self-motion perception. Blindfolded participants were displaced leftward or rightward by means of a motion platform and asked to indicate the direction of motion. A total of eleven participants underwent 3,360 practice trials, distributed over twelve (Experiment 1) or 6 days (Experiment 2). We found no improvement in motion discrimination in both experiments. These results are surprising since perceptual learning has been demonstrated for visual, auditory, and somatosensory discrimination. Improvements in the same task were found when visual input was provided (Experiment 3). The multisensory nature of vestibular information is discussed as a possible explanation of the absence of perceptual learning in darkness.

Cathodal HD-tDCS on the right V5 improves motion perception in humans

Brain lesions in the visual associative cortex are known to impair visual perception, i.e., the capacity to correctly perceive different aspects of the visual world, such as motion, color, or shapes. Visual perception can be influenced by non-invasive brain stimulation such as transcranial direct current stimulation (tDCS). In a recently developed technique called high definition (HD) tDCS, small HD-electrodes are used instead of the sponge electrodes in the conventional approach. This is believed to achieve high focality and precision over the target area. In this paper we tested the effects of cathodal and anodal HD-tDCS over the right V5 on motion and shape perception in a single blind, within-subject, sham controlled, cross-over trial. The purpose of the study was to prove the high focality of the stimulation only over the target area. Twenty one healthy volunteers received 20 min of 2 mA cathodal, anodal and sham stimulation over the right V5 and their performance on a visual test was recorded. The results showed significant improvement in motion perception in the left hemifield after cathodal HD-tDCS, but not in shape perception. Sham and anodal HD-tDCS did not affect performance. The specific effect of influencing performance of visual tasks by modulating the excitability of the neurons in the visual cortex might be explained by the complexity of perceptual information needed for the tasks. This provokes a "noisy" activation state of the encoding neuronal patterns. We speculate that in this case cathodal HD-tDCS may focus the correct perception by decreasing global excitation and thus diminishing the "noise" below threshold.

Perceptual motion standstill in rapidly moving chromatic displays

In motion standstill, a quickly moving object appears to stand still, and its details are clearly visible. It is proposed that motion standstill can occur when the spatiotemporal resolution of the shape and color systems exceeds that of the motion systems. For moving red-green gratings, the first- and second-order motion systems fail when the grating is isoluminant. The third-order motion system fails when the green/red saturation ratio produces isosalience (equal distinctiveness of red and green). When a variety of high-contrast red-green gratings, with different spatial frequencies and speeds, were made isoluminant and isosalient, the perception of motion standstill was so complete that motion direction judgments were at chance levels. Speed ratings also indicated that, within a narrow range of luminance contrasts and green/red saturation ratios, moving stimuli were perceived as absolutely motionless. The results provide further evidence that isoluminant color motion is perceived only by the third-order motion system, and they have profound implications for the nature of shape and color perception.

High speed film motion analysis system. Final report.

Mode of access: Internet.

Measurement of pedestrian behavior: a handbook for identifying the behaviors to measure and the measurement systems for use in countermeasure evaluation. Interim report.

National Highway Traffic Safety Administration, Washington, D.C.

Motion picture.

1911-Dec. 1954 as v. 1-v. 90, no. 5; Jan. 1955- as v. 44- (no. 529- ).

The use of films and television in mathematics education, December 1957.

Mode of access: Internet.

Teaching films for use in Louisiana schools : a catalog of films available on loan from State film libraries /

Includes listing by subject.

Films for the community in wartime,

"Film information and distribution agencies": p. 51-70.

Sound equipment, motion picture projection, public address systems,

"This new book constitutes the sixth edition of Motion picture projection, the second edition of Public address systems and the second edtion of Questions and answers on sound projection."--p. [1]

Records relating to American prisoners of war and missing in action from the Vietnam War /

Includes index.

The Illinois production guide : '97/'98 : a directory of film, television, video services and personnel in Illinois /

Includes: Supplement, additional listings (various categories) June 1997.

Motion picture classic.

Volume numbering irregular: Sept. 1915-Feb. 1922 called v. 1-13; Mar. 1922-May 1923 called v. 9-11, no. 3; June 1923-A7ug. 1931 called v. 17-33.

Motion picture discrimation; an annotated bibliography,

Mode of access: Internet.

John Wojtowicz (with mustache) at "Cruising" film rally in Sheridan Square with a friend

General note: Title and date provided by Bettye Lane.