Manfred MacKeben

Affiliate Scientist

Ph.D.

Work in this laboratory is devoted to researching facts and developing tools to help the rehabilitation of people with low vision, especially those with macular vision loss.

Contact Information:

Email: mm@ski.org

Office Phone: (415) 345-2112

Lab Phone: (415) 345-2005

Fax: (415) 345-8455


2318 Fillmore Street

San Francisco, CA 94115

Publications

Lei, D. ., Stepien, N. N., Morash, V. S., & Mackeben, M. . (2019). Effect of modulating braille dot height on reading regressions. PLOS ONE, 14, 1-17. 10.1371/journal.pone.0214799 (Original work published 2019)

Ivanov, I. . , V, Kuester, S. ., Mackeben, M. ., Krumm, A. ., Haaga, M. ., Staudt, M. ., … Trauzettel-Klosinski, S. . (2018). Effects of visual search training in children with hemianopia. PloS One, 13, e0197285.

Ivanov, I. . , V, Mackeben, M. ., Vollmer, A. ., Martus, P. ., Nguyen, N. X., & Trauzettel-Klosinski, S. . (2016). Eye movement training and suggested gaze strategies in tunnel vision-a randomized and controlled pilot study. PloS One, 11, e0157825.

Eisenbarth, W. ., Pado, U. ., Schriever, S. ., Schötschel, D. ., Feucht, N. ., & Mackeben, M. . (2016). Lokalisation von Skotomen mittels Lesetest bei AMD – Localization of scotomas in AMD by reading test. Der Ophthalmologe, 113, 754–762.

Eisenbarth, W. ., Richert, J. ., & Mackeben, M. . (2016). Testing macular letter recognition-reliability and influence of refraction errors. Clinical and Experimental Optometry, 99, 322–327.

Parafoveal contributions to retinal function during ranibizumab therapy for age-related macular degeneration. (2015).

Random Word Recognition Chart Helps Scotoma Assessment in Low Vision. (2015).

Fletcher, D. C., & Mackeben, M. . (2013). Everyday use of modern microperimetry in a low-vision service. Canadian Journal of Ophthalmology Journal Canadien d’ophtalmologie, 5, e99–e101.

Mackeben, M. ., & Fletcher, D. C. (2011). Target search and identification performance in low vision patients. Investigative Ophthalmology & Visual Science, 52, 7603–7609.

Behrens, F. ., Mackeben, M. ., & Schröder-Preikschat, W. . (2010). An improved algorithm for automatic detection of saccades in eye movement data and for calculating saccade parameters. Behavior Research Methods, 42, 701–708.

Li, R. W., Mackeben, M. ., Chat, S. W., Kumar, M. ., Ngo, C. ., & Levi, D. M. (2010). Aging and visual counting. PLoS ONE 5(10): E13434.

Hahn, G. A., Messias, A. ., Mackeben, M. ., Dietz, K. ., Horwath, K. ., Hyvärinen, L. ., … Trauzettel-Klosinski, S. . (2009). Parafoveal letter recognition at reduced contrast in normal aging and in patients with risk factors for AMD. Graefe’s Archive for Clinical and Experimental Ophthalmology, 247, 43–51.

Projects

  • Haptic Kinematics of Two-Handed Braille Reading in Blind Adults
    Active
    Haptic Kinematics of Two-Handed Braille Reading in Blind Adults

    This page (currently under construction) accompanies a work-in-progress poster at the 2020 Eurohaptics meeting.

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  • Inactive
    The Kinematics of Braille Reading

    [Under construction]

    When blind persons read braille, a system of raised dots for tactile reading and writing, how is the information processed? How do a few indentations on the fingerpads translate to linguistic information, and how does the text, in turn, influence the motions of the hands reading it? Our work on braille addresses these processes on several levels.

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  • Regressions in Braille Reading
    Completed
    Regressions in Braille Reading

    This project explores regressions (movements to re-read text) in braille reading. The image on the right plots the braille reading finger movements in blue and regressions in black.

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  • Reading Random Word Sequences (The SKread Test)
    Inactive
    Reading Random Word Sequences (The SKread Test)

    This vision test shows random word sequences that prevent the prediction of upcoming words by linguistic criteria and is simple to score in a clinical setting.

    It combines the standardized format of the MNread test with sequences of random words and letters, like in the Pepper test. We have used this test on hundreds of patients with maculopathies and on healthy subjects to measure their reading speed and register errors.

    Reading speed was always higher for continuous text than for random word sequences, even in normally sighted subjects. The number of errors made was always higher than for…

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  • Micro-Perimetry by Scanning Laser Ophthalmoscope
    Completed
    Micro-Perimetry by Scanning Laser Ophthalmoscope

    We developed software to make the retinal placement of stimuli during micro-perimetry by a scanning laser ophthalmoscope (SLO) independent of involuntary fixational eye movements. This greatly increases the accuracy of the measurement and enhances the ability to reliably repeat a measurement on the same patient, as well as making comparisons between patients.

     

    Reference

    MacKeben M & Gofen A. (2007) Gaze-contingent display for retinal function testing by scanning laser ophthalmoscope. J Opt Soc America A, vol. 24/5, May, pp. 1402-1410 (feature issue on “Retinal Imaging”)

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  • Completed
    Motion as a Cue for Attention

    We investigated whether relative motion can serve as a cue for sustained attention. We found that relative motion perception has a long latency and that it can indeed attract attention to improve discrimination performance.

     

    Reference

    Poggel DA, Strasburger H, MacKeben M. (2007) Cueing attention by relative motion in the periphery of the visual field. Perception 36(7) 955 – 970. (pubmed )

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  • Completed
    Focal Attention and Letter Recognition

    We studied letter recognition in 8 deg eccentricity from the fovea after attracting sustained focal attention to the stimulated location by a cue. Young and elderly healthy subjects, as well as patients with central vision loss participated. We found that the ability to utilize focal attention has an irregular topographic component in some subjects. The experiments in patients indicated that locations with high attentional potential are more likely to be used as preferred retinal loci after central vision loss.

     

    References

    MacKeben, M. (1999) Sustained Focal Attention and Peripheral Letter…

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  • Completed
    Reading with the Retinal Periphery

    Typographical features of letters were manipulated in such a way that frequently occurring letter confusions in eccentric viewing happened less frequently. This demonstrated that a combination of psychophysics and goal-directed modification of typographic features is a viable experimental strategy.

     

    Reference

    MacKeben M. (2000) Enhancement of peripheral letter recognition by typographical features. Visual Impairment Research 2, (2) 95 -103. (link to VIR)

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  • Completed
    Dyslexia Project

    We studied the ability of dyslexic young teenagers to fluently name pictograms (shapes of objects). We found that some dyslexics are very good at this task, some were even better than the control subjects.

     

    We also investigated whether dyslexics make instantaneous automatic adjustments of reading saccades depending on word length. We found evidence that dyslexics have the mechanisms to make such adjustments, but that they are quantitatively impaired.

    References

    Trauzettel-Klosinski S, MacKeben M, Reinhard J, Feucht A, Dürrwächter U & Klosinski G (2002) Pictogram naming in dyslexics and normal…

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Collaborators

External Collaborators

Trainees