Abstract
In developmental studies, either identification or detection paradigms can be used to assess various types of visual functioning. We suggest that detection paradigms may be more suited for assessing the perceptual abilities of the very young (i.e., three-year-olds) and atypical development children, given their less-developed communicative and cognitive capabilities. The objective of the present study was to systematically assess and contrast identification and detection paradigms in order to determine whether paradigm-contingent differences exist at the perceptual level as a function of development. Typically-developing participants were placed in one of 5 age groups (5–6, 7–8, 9–10, 11–12 and 18+ years). For each participant, sensitivity to static and dynamic gratings defined by either luminance-contrast (with and without noise) or texture-contrast (noise) was measured using both identification (i.e, vertical/horizontal or left/right) and detection paradigm. For the latter, participants were asked to indicate which of two spatial locations contained the grating (versus noise or uniform background), regardless of its orientation or direction. An adaptive staircase procedure was used to obtain thresholds. In addition, the developmental level of each participant, as defined by verbal mental ability, was assessed using the Peabody Picture Vocabulary Test (PPVT) for all participants. For all three experimental conditions, no significant differences in sensitivity were found between the detection and identification paradigms as a function of age. These results suggest that at least within the context of the tasks assessed, a paradigm-contingent difference in sensitivity does not exist at a perceptual level from the ages of 5 years through adulthood. We therefore argue that when working with either very young or atypically developing participants presenting with impairments in attention, working memory and/or developmental delay, using a spatial 2AFC detection paradigm may be a more appropriate paradigm for assessing visual function.