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Alcohol impairs the functioning of visual spatial attention and disrupts the shift of attention from one spatial locus to another. The consumption of alcoholic beverage negatively affects the performance of individual on tasks which require more visual attention. The offset task after consumption of alcohol demands more spatial attention because an increase in display area enhances the reaction time. Alcohol has no significant influence on onset tasks.

Objective: Transient visual events cause a rapid allocation of attention to the event location. We studied the effect of alcohol on this aspect of attention. Method: Subjects responded to targets presented either left or right of fixation and the time between target presentation and response (reaction time: RT) was measured both before and after ingestion of either alcohol or a placebo. Transient cues were presented prior to each target presentation. Cues were, variously, a brightening of either the box in which the target was to occur ('valid'), the box on the opposite side of the display from where the target was to occur ('invalid') or the fixation stimulus ('neutral'). The interval between cue and target presentation (stimulus onset asynchrony: SOA) was variously 50, 100, 150 or 800 msecs. Results: At short SOAs, RT was faster to targets presented following valid cues relative to the other cues. At 800 msecs the opposite pattern was found. Alcohol selectively slowed RT only following neutral or invalid cues at short SOAs. Conclusions: Alcohol does not disrupt the normal attentional allocation to visual transients. It may delay the subsequent response to events at other locations, however. (J. Stud. Alcohol 61: 232-238, 2000), A SUBSTANTIAL LITERATURE indicates that the allocation of attention can be disrupted by alcohol ingestion. It has been reported, for example, that the extent of alcohol-related impairment on information processing [...]

Presents the results of a study conducted on the role of feedback pertaining to the formation of acute tolerance to alcohol. Methodology used in the study; Timeline depicting the sequence of measurements during experimental session; Statistical information on participants' apparent concomitant motion gain for both feedback and no-feedback conditions during the study.

The resting focus of accommodation was measured in the same subjects with both a laser optometer and a high-speed infrared optometer. Although i.r. optometer and laser optometer measures produce similar estimates of the mean resting-focus level in some subjects, others were found to have different levels of resting focus with the two techniques. Control studies demonstrated that these differences were not due to the temporal sampling characteristics of the laser optometer. but resulted instead from making judgments about the direction of speckle motion during the laser optometer procedure. The temporal stability of the resting focus of accommodation was also investigated with i.r. measures obtained several minutes. 1 day, and 1 and 2 weeks apart Results indicated long-term variability similar to that previously reported with the laser optometer. [ABSTRACT FROM AUTHOR]

Previous investigation have shown that, in dim illumination and empty visual fields, accommodation in most observers is for an intermediate distance referred to as the dark focus or resting focus of accommodation. Dynamic properties of the resting focus were examined in the present study with a high-speed infrared optometer. All subjects displayed fluctuations of accommodation in darkness that were primarily characterized by frequency components below 05 Hz. These fluctuations were substantially attenuated during cycloplegia or viewing a bright, high-contrast target. Both the mean resting-locus position and the magnitude of fluctuations varied from one subject to another and from day-to-day. A weak association was found between the mean and standard deviation of accommodation responses in the dark. The present findings suggest that the accommodation mechanism in most observers is somewhat unstable under degraded viewing conditions In addition. the mean resting-focus value for a large sample of subjects was found to be lower for optometer measurements than for previous investigations employing a laser optometer. [ABSTRACT FROM AUTHOR]

We compared the resting (dark) focus of accommodation before and after adapting to accommodative stimuli placed nearer or farther from an initial baseline resting focus. Short-term monocular adaptation (> 2 min) did not result in consistent after-effects that were correlated wit the adaptation stimulus. After short-term adaptation, accommodation returned to its resting level in 2 - 15 s. Long-term monocular adaptation (30 min) to a 6-D near stimulus resulted in a small (0.5-D) average increase in the resting focus of accommodation beyond the normal 2-15-2 short-term decay. These observations illustrate a tonic adaptation of accommodation that is small and requires longer durations of adaptation than an analogous adaptation of the fusional vergence system to prism. [ABSTRACT FROM AUTHOR]

When a video of someone speaking is paused, the stationary image of the speaker typically appears less flattering than the video, which contained motion. We call this the frozen face effect (FFE). Here we report six experiments intended to quantify this effect and determine its cause. In Experiment 1, video clips of people speaking in naturalistic settings as well as all of the static frames that composed each video were presented, and subjects rated how flattering each stimulus was. The videos were rated to be significantly more flattering than the static images, confirming the FFE. In Experiment 2, videos and static images were inverted, and the videos were again rated as more flattering than the static images. In Experiment 3, a discrimination task measured recognition of the static images that composed each video. Recognition did not correlate with flattery ratings, suggesting that the FFE is not due to better memory for particularly distinct images. In Experiment 4, flattery ratings for groups of static images were compared with those for videos and static images. Ratings for the video stimuli were higher than those for either the group or individual static stimuli, suggesting that the amount of information available is not what produces the FFE. In Experiment 5, videos were presented under four conditions: forward motion, inverted forward motion, reversed motion, and scrambled frame sequence. Flattery ratings for the scrambled videos were significantly lower than those for the other three conditions. In Experiment 6, as in Experiment 2, inverted videos and static images were compared with upright ones, and the response measure was changed to perceived attractiveness. Videos were rated as more attractive than the static images for both upright and inverted stimuli. Overall, the results suggest that the FFE requires continuous, natural motion of faces, is not sensitive to inversion, and is not due to a memory effect., Psychology