Different Measures of Structural Similarity Tap Different Aspects of Visual Object Processing

Abstract

The structural similarity of objects has been an important variable in explaining why some objects are easier to categorize at a superordinate level than to individuate, and also why some patients with brain injury have more difficulties in recognizing natural (structurally similar) objects than artifacts (structurally distinct objects). In spite of its merits as an explanatory variable, structural similarity is not a unitary construct, and it has been operationalized in different ways. Furthermore, even though measures of structural similarity have been successful in explaining task and category-effects, this has been based more on implication than on direct empirical demonstrations. Here, the direct influence of two different measures of structural similarity, contour overlap and within-item structural diversity, on object individuation (object decision) and superordinate categorization performance is examined. Both measures can account for performance differences across objects, but in different conditions. It is argued that this reflects differences between the measures in whether they tap: (i) global or local shape characteristics, and (ii) between- or within-category structural similarity.

Patterns of perceptual performance in developmental prosopagnosia: An in-depth case series

“…Indeed, the idea of top-down processing can be traced back to the work of Heinrich Lissauer (1890), who also drew the distinction between apperception (shape configuration) and association (access to VLTM). What PACE offers is a framework where these assumptions are combined and related to object properties such as visual similarity and visual complexity (Gerlach, 2017a(Gerlach, , 2017b.…”

“…Likewise, while dogs may be similar to other animals, dogs are probably less similar to other animals than any particular face is compared with other faces. Because it is well-known that category-effects are modulated by both visual similarity and the degree of perceptual differentiation required (Gerlach, 2017a;Gerlach, Zhu, & Joseph, 2015), it is important to examine if these variables may contribute to, or even account for, the poorer performance with faces than with objects observed in DP.…”

Navon’s classical paradigm concerning local and global processing relates systematically to visual object classification performance

“… 28 , for example, found that difficult object decision was associated with greater activation of posterior and ventral brain regions than categorization; areas associated with structural processing. Likewise, superordinate categorizations can be performed a lot faster than difficult object decisions 29 – 31 .…”

Naming in Older Adults: Complementary Auditory and Visual Assessment

“…Additionally, semantic and perceptual features can influence object recognition and naming. Although beyond the scope of this study, future investigations could assess the clinical significance of features, including category crowding (Gerlach, 2017), semantic and structural similarity (Dickerson & Humphreys;Lloyd-Jones & Humphreys, 1997), and visual features (Humphreys et al, 1988) of test items. Finally, we note that the ANT and VNT, like other verbal measures, are culturally bound, and therefore, intended for use with individuals raised and educated in the US.…”