title: Perceptual learning in patients with macular degeneration.
abstract: Patients with age-related macular degeneration (AMD) or hereditary macular dystrophies (JMD) rely on an efficient use of their peripheral visual field. We trained eight AMD and five JMD patients to perform a texture-discrimination task (TDT) at their preferred retinal locus (PRL) used for fixation. Six training sessions of approximately one hour duration were conducted over a period of approximately 3 weeks. Before, during and after training twelve patients and twelve age-matched controls (the data from two controls had to be discarded later) took part in three functional magnetic resonance imaging (fMRI) sessions to assess training-related changes in the BOLD response in early visual cortex. Patients benefited from the training measurements as indexed by significant decrease (p = 0.001) in the stimulus onset asynchrony (SOA) between the presentation of the texture target on background and the visual mask, and in a significant location specific effect of the PRL with respect to hit rate (p = 0.014). The following trends were observed: (i) improvement in Vernier acuity for an eccentric line-bisection task; (ii) positive correlation between the development of BOLD signals in early visual cortex and initial fixation stability (r = 0.531); (iii) positive correlation between the increase in task performance and initial fixation stability (r = 0.730). The first two trends were non-significant, whereas the third trend was significant at p = 0.014, Bonferroni corrected. Consequently, our exploratory study suggests that training on the TDT can enhance eccentric vision in patients with central vision loss. This enhancement is accompanied by a modest alteration in the BOLD response in early visual cortex.
authors.affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Plank
authors.affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Rosengarth
authors.affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Schmalhofer
authors.affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Goldhacker
authors.affiliation: Department of Ophthalmology, University Medical Center Regensburg Regensburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Brandl-Rühle
authors.affiliation: Institute for Experimental Psychology, University of Regensburg Regensburg, Germany.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Greenlee
keywords: cortical plasticity; fMRI BOLD; macular degeneration; perceptual learning; visual cortex