The impact of aging on spatial frequency processing in naturalistic scenes and its relation to oculomotor behavior

Natural scene perception relies on processing both low spatial frequencies (LSF), which provide coarse global information, and high spatial frequencies (HSF), which convey fine details. Older adults exhibit reduced sensitivity mainly to HSF and impaired categorization of briefly presented HSF-filtered scenes, likely reflecting age-related changes in occipito-temporal regions and the parvocellular pathway. Yet, previous research has largely relied on simple stimuli (e.g., Gabor patches) under fixated conditions, rather than during naturalistic free-viewing of complex scenes. The aim of this study is to examine whether age-related HSF processing decline observed with simple stimuli extends to natural scenes, and whether and how these declines impact oculomotor behaviour and recognition performance. We will compare younger and older adults across three tasks: (1) an orientation discrimination task to establish contrast thresholds for LSF and HSF simple Gabor stimuli; (2) free-viewing of grayscale natural scenes (non-filtered, LSF, or HSF) with concurrent eye-tracking, followed immediately by an indoor/outdoor categorization judgment for each trial; and (3) a subsequent 2AFC old/new recognition memory test.