Visual attention and memory under central vision loss [article]

Franziska Geringswald, Universitäts- Und Landesbibliothek Sachsen-Anhalt, Martin-Luther Universität, Stefan Pollmann
2020
Efficient goal-directed interaction with our environment depends on attentional selection. In normal viewing attentive stimulus processing is carried out with high-resolution foveal vision and attentional selection is closely tied to eye movements. Does the loss of central vision impair higher-level visual memory functions that depend on the efficient deployment of attention? This research question is highly relevant to patients with age-related macular degeneration (AMD) who are forced to rely
more » ... on extrafoveal vision for all processes typically carried out in foveal vision. The experiments presented in this thesis were designed to examine whether encoding of objects into visual long-term memory (VLTM) or efficient attentional guidance by acquired contextual memory suffers when central vision is impaired. Experiments were performed by patients with AMD and normal-sighted younger observers under sco-toma simulation. Patients were tested monocularly with their worse eye and under binocular vision. Recording of eye movements allowed for the additional analysis of exploration behavior. Performance and gaze parameters were compared to respectively matched unimpaired control groups. The first set of experiments examined encoding of natural objects into visual long-term memory, a process that crucially depends on attentive foveation. Change detection sensitivity was measured af-ter free scene exploration. A highly salient cue capturing attention to a non-target location in half of the trials ensured that change detection relied on memory. In Experiment 1, patients' monocular and binocular change detection sensitivity was preserved, not significantly correlated with visual impair-ment, and went along with normal fixation parameters. A simulated gaze-contingent central scotoma in Experiment 2 complicated visual exploration and impaired memory performance in unexperienced observers. Attentive encoding of objects into VLTM thus depends on attentive foveal vision as long as saccadic rereferencing to an extrafoveal retinal location as a [...]
doi:10.25673/35146 fatcat:a3pfifsueffx3f7tgrhyxnkxlu