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The effect of cycling female estradiol levels on retinal-based smooth pursuit eye movements (SPEM) and post-target offset persistence

dc.contributor.advisorWesner, Michael
dc.contributor.authorCurrie, Emily
dc.date.accessioned2015-06-15T20:12:08Z
dc.date.available2015-06-15T20:12:08Z
dc.date.created2015
dc.date.issued2015-06-15
dc.identifier.urihttp://knowledgecommons.lakeheadu.ca/handle/2453/634
dc.description.abstractEstradiol has primarily been associated with the female reproductive system; however, estradiol receptors have been located in the retinas of male and female humans, as well as throughout the central nervous system (CNS) including lower brainstem areas associated with oculomotor functioning. The present study investigated the significance of estradiol in relation to smooth pursuit eye movements (SPEM) with the specific intention of localizing estradiol effects on realtime and on extrapolated SPEM tracking after target termination. This was accomplished in two ways. First, testing occurred at two opposing stages of the female menstrual cycle: the late follicular and the late luteal phases, where estradiol levels are known to be high and low respectively. Second, we selected participants symptomatically categorized into three groups: women who did not have Premenstrual Syndrome (PMS)-type symptoms and who were not using hormonal contraception within the last three months (control group), women who were hormonally sensitive due to the presence of PMS-type symptoms and were not using hormonal contraception (PMS-type group), and women who were using the hormonal contraceptive Alesse™ or the generic form Aviane™ (Alesse™ user group). Horizontal SPEMs were measured using a 60 Hz infrared eye tracker. We found deviations from nominal sinusoidal eye movement patterns between our control, PMStype and Alesse™ user groups in which the hormonally sensitive and regulated groups (PMS-type and Alesse™ users) showed shorter durations of persistence (defined as duration of movement that statistically followed an extrapolated track after target termination), greater amplitude excursions, and a left-to-right excursion bias. These findings suggest that further efforts should be made in order to better understand the modulatory interactions of stable estradiol- or low progesterone-based affective symptoms and their underlying common neural circuitry with SPEM maintenance. The relevant SPEM neural circuitry includes the cerebellar vermis and flocculus, the medial vestibular nucleus, and other areas where estradiol has been reported to exert its effects.en_US
dc.language.isoen_USen_US
dc.subjectEstradiolen_US
dc.subjectSmooth pursuit eye movements (SPEM)en_US
dc.subjectEstradiol and visual perceptual functioningen_US
dc.subjectOculomotor system overviewen_US
dc.subjectEstradiol and oculomotor activityen_US
dc.subjectMenstrual cycle overviewen_US
dc.subjectEstradiol and brain plasticityen_US
dc.titleThe effect of cycling female estradiol levels on retinal-based smooth pursuit eye movements (SPEM) and post-target offset persistenceen_US
dc.typeThesisen_US
etd.degree.nameM.A.en_US
etd.degree.levelMasteren_US
etd.degree.disciplinePsychologyen_US
etd.degree.grantorLakehead Universityen_US


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