title: Are the visual transients from microsaccades helpful? Measuring the influences of small saccades on contrast sensitivity.
abstract: Like all saccades, microsaccades cause both spatial and temporal changes in the input to the retina. In space, recent studies have shown that these small shifts precisely relocate a narrow (smaller than the foveola) high-acuity retinal locus on the stimulus. However, it has long been questioned whether the temporal modulations resulting from microsaccades are also beneficial for vision. To address this question, we combined spectral analysis of the visual input to the retina with measurements of contrast sensitivity in humans. Estimation of how different types of eye movements redistribute the power of an otherwise stationary stimulus shows that small saccades contribute more temporal power than ocular drift in the low-frequency range, suggesting a specific role for these movements in the encoding of low spatial frequencies. However, an influence on contrast sensitivity was only found for saccades with amplitudes larger than 30'. Contrast thresholds remained highly similar in the presence and absence of smaller saccades. Furthermore, saccades of all amplitudes, including microsaccades, were strongly suppressed during exposure to the stimulus. These findings do not support an important function of the visual transients caused by microsaccades.
authors: Department of Psychological and Brain Sciences, Boston University, United States.
authors: Naghmeh
authors: N
authors: Mostofi
authors: Department of Psychological and Brain Sciences, Boston University, United States.
authors: Marco
authors: M
authors: Boi
authors: Department of Psychological and Brain Sciences, Boston University, United States; Graduate Program in Neuroscience, Boston University, United States.
authors: Michele
authors: M
authors: Rucci
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D010775:Photic Stimulation / Q000379:methods; D012438:Saccades / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*; D055815:Young Adult
keywords: Contrast sensitivity; Eye movements; Microsaccade; Ocular drift; Saccade; Saccadic suppression