Show simple item record

Investigation of the Pursuit Eye Movement Under-Registration Hypothesis (Tracking).

dc.contributor.authorSullivan, John Michael
dc.date.accessioned2020-09-09T02:32:28Z
dc.date.available2020-09-09T02:32:28Z
dc.date.issued1986
dc.identifier.urihttps://hdl.handle.net/2027.42/161329
dc.description.abstractThree models, which propose that pursuit eye-movement velocity is poorly sensed by human observers, were described and tested. All of the models explain why the speed and extent of the movements of tracked visual targets are underestimated by suggesting that pursuit eye-movement velocity is under-registered. The models differ in the particular way velocity is hypothesized to be under-registered. The constant-velocity under-registration model, suggests a fixed loss of approximately 1(DEGREES)/sec occurs during pursuit. Another model suggests that a proportional loss in perceived velocity occurs. A third model suggests that velocity is not directly registered; instead a fixed-velocity assumption of .1(DEGREES)/sec to 1(DEGREES)/sec is substituted by the perceptual system. Specific predictions that these models make about localization accuracy as a function of pursuit eye-movement velocity and extent were examined in Experiment I. Although localization errors were consistent with the general under-registration hypothesis, differences in localization were observed for conditions that the specific models predicted would produce no differences. Retinal slip of the tracked target, produced at the start of the target's movement, was next examined as a possible reason for the failure to find support for the models. Unlike constant-velocity target motion, harmonically ramped target motion is reputed to be tracked with less retinal slip of the target. Experiment II measured the effects of both constant and harmonically ramped target velocity on localization accuracy. Ramped target velocities were (1) tracked with less retinal slip, and (2) resulted in greater localization errors than did constant-velocity targets. The pattern of localization errors, however, continued to be inconsistent with the models' predictions. A different strategy was next employed to test a property that all three models share: that under-registration effects should add together. Experiment III tested the hypothesis that under-registration errors cancel in the pursuit of reciprocally moving targets. No evidence of cancellation was found. In particular, the reciprocal-tracking data resembled the pattern found when only the second half of the reciprocal trajectory was tracked. Experiment IV directly compared localization after reciprocal and non-reciprocal tracking, matched so that the second half of the reciprocal trajectory was the same as the non-reciprocal trajectory. Little evidence of a difference between the two conditions was found, suggesting that additivity of under-registration does not occur. Four plausible explanations of the non-additivity effect were proposed.
dc.format.extent123 p.
dc.languageEnglish
dc.titleInvestigation of the Pursuit Eye Movement Under-Registration Hypothesis (Tracking).
dc.typeThesis
dc.description.thesisdegreenamePhDen_US
dc.description.thesisdegreedisciplineExperimental psychology
dc.description.thesisdegreegrantorUniversity of Michigan
dc.subject.hlbtoplevelSocial Sciences
dc.contributor.affiliationumcampusAnn Arbor
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/161329/1/8702840.pdfen_US
dc.owningcollnameDissertations and Theses (Ph.D. and Master's)


Files in this item

Show simple item record

Remediation of Harmful Language

The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.

Accessibility

If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.