eprintid: 10050673 rev_number: 22 eprint_status: archive userid: 608 dir: disk0/10/05/06/73 datestamp: 2018-06-20 09:36:06 lastmod: 2021-10-18 00:36:01 status_changed: 2018-06-20 09:36:06 type: article metadata_visibility: show creators_name: Sobhanian, MJ creators_name: Agarwal, R creators_name: Meltzer, E creators_name: Kildebeck, E creators_name: Frohman, BS creators_name: Frohman, AN creators_name: Galetta, SL creators_name: Saidha, S creators_name: White, O creators_name: Villoslada, P creators_name: Paul, F creators_name: Petzold, A creators_name: Rennaker, RL creators_name: Martinez-Lapiscina, EH creators_name: Balcer, LJ creators_name: Kardon, R creators_name: Frohman, EM creators_name: Frohman, TC title: Identification and treatment of the visual processing asymmetry in MS patients with optic neuritis: The Pulfrich phenomenon ispublished: pub subjects: MOOR subjects: UCH divisions: UCL divisions: B02 divisions: C07 divisions: D07 keywords: Asymmetric visual transmission, Neutral density filter, Pulfrich phenomenon, Visual illusion note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: BACKGROUND: The Pulfrich phenomenon (PF) is the illusory perception that an object moving linearly along a 2-D plane appears to instead follow an elliptical 3-D trajectory, a consequence of inter-eye asymmetry in the timing of visual object identification in the visual cortex; with optic neuritis as a common etiology. OBJECTIVE: We have designed an objective method to identify the presence and magnitude of the PF, in conjunction with a cooresponding strategy by which to abolish the effect; with monocular application of neutral density filters to the less affected fellow eye, in patients with MS and a history of optic neuropathy (e.g. related to acute optic neuritis or subclinical optic neuropathy). METHODS: Twenty-three MS patients with a history of acute unilateral or bilateral optic neuritis, and ten healthy control subjects (HC) were recruited to participate in a pilot study to assess our strategy. Subjects were asked to indicate whether a linearly moving pendulum ball followed a linear 2-D path versus an illusory 3-D elliptical object-motion trajectory, by reporting the ball's approximation to one of nine horizontally-oriented colored wires that were positioned parallel to one another and horizontal to the linear pendulum path. Perceived motion of the bob that moved along wires behind or in front (along the 'Z' plane) of the middle reference wire indicated an illusory elliptical trajectory of ball motion consistent with the PF. RESULTS: When the neutral density filter titration was applied to the fellow eye the severity of the PF decreased, eventually being fully abolished in all but one patient. The magnitude of neutral density filtering required correlated to the severity of the patient's initial PF magnitude (p < 0.001). CONCLUSIONS: We ascertained the magnitude of the visual illusion associated with the PF, and the corresponding magnitude of neutral density filtering necessary to abolish it. date: 2018-04-15 date_type: published official_url: http://dx.doi.org/10.1016/j.jns.2018.01.029 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1546860 doi: 10.1016/j.jns.2018.01.029 pii: S0022-510X(18)30037-6 lyricists_name: Petzold, Axel lyricists_id: APETZ95 actors_name: Allington-Smith, Dominic actors_id: DAALL44 actors_role: owner full_text_status: public publication: Journal of the Neurological Sciences volume: 387 pagerange: 60-69 event_location: Netherlands issn: 1878-5883 citation: Sobhanian, MJ; Agarwal, R; Meltzer, E; Kildebeck, E; Frohman, BS; Frohman, AN; Galetta, SL; ... Frohman, TC; + view all <#> Sobhanian, MJ; Agarwal, R; Meltzer, E; Kildebeck, E; Frohman, BS; Frohman, AN; Galetta, SL; Saidha, S; White, O; Villoslada, P; Paul, F; Petzold, A; Rennaker, RL; Martinez-Lapiscina, EH; Balcer, LJ; Kardon, R; Frohman, EM; Frohman, TC; - view fewer <#> (2018) Identification and treatment of the visual processing asymmetry in MS patients with optic neuritis: The Pulfrich phenomenon. Journal of the Neurological Sciences , 387 pp. 60-69. 10.1016/j.jns.2018.01.029 <https://doi.org/10.1016/j.jns.2018.01.029>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10050673/1/Petzold_EMF%20Final%20Edits%20Pulfrich-ap.pdf