Temporal aspects of visual perception: what can we learn from clinical populations?

• Applicant: Professor Dr. Michael Hoffmann
• Subject Area: Human Cognitive and Systems Neuroscience ; Ophthalmology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 561039026

Our capacity to process changes over time is fundamental for our daily living activities. Temporal vision is crucial for tracking movement, detecting changes in light, and adapting to dynamic environments. A critical question is, how the underlying processing deals with the ubiquitous changes of the timing at which visual the information reaches the different processing stages (i) at the short term, e.g. due to luminance changes, (ii) at the long term, e.g. due to visual decline in diseases. In patients with visual system disorders these challenges can be extreme, which renders them powerful models to study the adaptive and plastic nature of the temporal visual system. We aim to explore how the visual system copes with slowed input and processing in order to characterize long- and short-term adaptive plasticity in the temporal visual domain. We will study two patient cohorts, achromatopsia associated with congenital cone-dysfunction (ACHM, with and without gene-therapy treatment) and optic neuritis (ON). Both share disruptions in temporal vision while their underlying causes and extent of damage differ. In addition, ACHM affects temporal processing from birth, while ON involves acquired damage to visual pathways. This offers a unique opportunity to explore adaptation and recovery across these complementary models in order to address three key questions: How does the visual system respond to congenital binocularly slowed visual input? How does the visual system respond to acquired monocular slowed visual input? How does the visual system respond to late-life treatment of congenitally slowed input? To address these questions, we will investigate visual neuro-plasticity and adaptivity in the temporal domain with a combined approach of functional MRI (3T and 7T magnetic field strength), non-invasive electrophysiology (ERG/VEP), and psychophysics. Specifically, we will assess response timing, motion detection, contrast sensitivity, and differential processing of temporal frequency along the visual pathway. Taken together, we will be investigating retinal, post-retinal, and cortical processing stages in three different contexts, i.e. physiologically normal (luminance reductions including rod vision), congenital (achromatopsia [ACHM]), acquired (optic neuritis [ON]) forms of slowed input. The proposed project strongly builds on the applicants' history in patient studies, relevant methods, and mutual previous collaborations. From our combined multimodal investigation of temporal vision in healthy controls and the patient groups ACHM and ON, we expect profound insights into the key mechanisms of visual perception, which will be of help to identify valid biomarkers to assess the success of ongoing and upcoming therapies.

• DFG Programme: Research Grants
• International Connection: Israel
• Partner Organisation: The Israel Science Foundation
• Cooperation Partner: Professorin Dr. Netta Levin, Ph.D.