Visual spatial interactions between dotted line segments

This study examines the interactions that occur between dotted line segments as a function of their separation and orientation using a dotted target detection paradigm. The results of the experiment indicate that it is the separation between interacting pairs of lines rather than shifts in retinal locus that account for the observed decline in detectability as the separation increases. However, factors of global organization or figural goodness seem also to exert a powerful influence on the detectability of the pattern. The results are interpreted in terms of a central, rather than a peripheral, model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21917/1/0000324.pd

Oscillations in the amplitude of human peripheral nerve action potentials during repetitive stimulation

Repetitive stimulation of human peripheral nerves in situ produces an amplitude oscillation of the evoked action potentials. The purpose of this experiment was to describe the dynamics of the response as a function of the characteristics of the electrical stimuli. Two attempts to define precisely the origin of the response have proved ineffective.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47431/1/422_2004_Article_BF00291087.pd

The effect of deviations from linearity on the detection of dotted line patterns,

Four experiments were carried out to determine the detectability of dotted line stimulus patterns embedded in backgrounds of randomly dotted visual noise. The results indicate that straight lines are more easily detected than curves or angles. This finding holds robustly even though interdot spacings (local geometry) are held constant in each experiment. The global organization of the stimulus, therefore, is a strong determinant of the ease of visual pattern detection. The implications of these findings for pattern recognition theory are considered using an optical computer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33798/1/0000053.pd

Computer Studies Of Neurophysiological And Psychological Events

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116309/1/nyas00059.pd

Rotation and translation effects on stereoscopic acuity

This study examined the effects of rotation or translation on the detectability of a dotted target plane embedded in a dotted masking cube. Julesz-type stereograms were generated in real time, using a small laboratory computer. Subjects displayed an excellent ability to compensate for x-y projected density variations produced by changes in the angle of rotation of the target plane so that performance was equal at all rotations. This finding indicates that dot density is being processed in a three- rather than a two-dimensional manner. Translation of a frontoparallel plane from the back of the stereoscopically defined cube to its front produced systematic changes in performance. Performance was best at the central fixation distance and decreased as either crossed or uncrossed disparity increased. Thus, it appears that stereo acuity decreases symmetrically with increases in disparity in either direction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22020/1/0000436.pd

Complexity effects in form detection

This study examines the effect of pattern complexity on the detectability of dotted target patterns presented in dotted visual noise. The effects of complexity on performance in this detection task were shown to be substantial. Discrepancies between the psychophysical scores and the prediction of a previously described autocorrelation theory of form detection (Uttal, 1975) point to specific deficiencies in the theory's sensitivity to particular classes of geometrical form.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23051/1/0000623.pd

Long-term evolution of the coupled boundary layers (STRATUS) mooring recovery and deployment cruise report NOAA Research Vessel R H Brown • cruise RB-01-08 9 October - 25 October 2001

This report documents the work done on cruise RB-01-08 of the NOAA R/V Ron Brown. This was Leg 2 of R/V Ron Brown’s participation in Eastern Pacific Investigation of Climate (EPIC) 2001, a study of air-sea interaction, the atmosphere, and the upper ocean in the eastern tropical Pacific. The science party included groups from the Woods Hole Oceanographic Institution (WHOI), NOAA Environmental Technology Laboratory (ETL), the University of Washington (UW), the University of California, Santa Barbara (UCSB), and the University Nacional Autonoma de Mexico (UNAM). The work done by these groups is summarized in this report. In addition, the routine underway data collected while aboard R/V Ron Brown is also summarized here.Funding was provided by the National Oceanic and Atmospheric Administration under Grant Numbers NA96GPO429 and NA17RJ1223

Overview of the MOSAiC expedition - Atmosphere

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic