Processing bimodal stimuli: integrality/separability of color and orientation

Abstract

We examined how two distinct stimulus features, orientation and color, interact as contributions to global stimulus dissimilarity. Five subjects rated dissimilarity between pairs of bars (N = 30) varying in color (four cardinal hues, plus white) and orientation (six angles at 30° intervals). An exploratory analysis with individual-differences multidimensional scaling (MDS) resulted in a 5D solution, with two dimensions required to accommodate the circular sequence of the angular attribute, and red-green, blue-yellow and achromatic axes for the color attribute. Weights of the orientation subspace relative to the color subspace varied among the subjects, from a 0.32:0.61 ratio to 0.53:0.44, emphasis shifting between color and orientation. In addition to Euclidean metric, we modeled the interaction of color and orientation using Minkowski power metrics across a range of Minkowski exponents p, including the city-block (p = 1), Euclidean (p = 2) and Dominance metric (p → ∞) as special cases. For averaged data, p ~ 1.3 provided the best fit, i.e., intermediate between separable and integral features. For individual subjects, however, the metric exponent varied significantly from p = 0.7 to p = 3.1, indicating a subject-specific rule for combining color and orientation, as in Tversky and Gati's variable-weights model. No relationship was apparent between dimensional weights and individual p exponents. Factors affecting dimensional integrality are discussed, including possible underlying neural mechanisms where the interaction of the low-level vision attributes orientation and color might shift between uncorrelated (p = 1) or correlated (p ≥ 2) forms.

The role of attention in retaining the binding of integral features in working memory

“…Here we consider that this alternative does not hold. Particularly, we used a thin line (1 pixel thick, 0.03°) to convey the value of width and height, which is a common and well-accepted manner in the research of length perception (e.g., Avery & Day, 1969;Brosvic & Cohen, 1988;Charras & Lupiáñez, 2009;Charras & Lupiáñez, 2010;Lipshits & McIntyre, 1999). Moreover, our post hoc interview suggested that no participants subjectively treated these lines as rectangles (see footnote 2).…”

“…Stimuli composed of separable features have feature structures that are directly perceived; in other words, the feature structure itself determines the similarity between stimuli (a linear summation of the absolute differences each of the features in isolation; cf. Bimler, Izmailov, & Paramei, 2013). In contrast, integral dimensions are those that can be manipulated independently but not attended to and processed independently of each other, such as width and height, brightness and saturation, and hue and color saturation.…”

Distributed processing of color and form in the visual cortex

“…Likewise, performance in contour integration was similar from either color or luminance local elements ( McIlhagga and Mullen, 1996 ; Rentzeperis and Kiper, 2010 ). Furthermore, recent rating experiments on the similarity of two bars varying in both orientation and color have been inconclusive on how separable color and orientation are ( Bimler et al, 2013 ). This evidence suggests the possibility of color and orientation mechanisms interacting at an early stage of visual processing.…”

Content, Context, and Complexity in Personality Trait Perceptions

“…We computed, separately for each target type, simple Euclidean distances between each pair of the 44 BFI items with reverse-scored items for each trait keyed in the proper direction. A Euclidean distance measure conforms to the assumption that perceivers cognitively integrate the information from a series of Likert scale judgments into a coherent perception of a target (Bimler et al, 2013) and is frequently used in MDS studies in which objects are described by a series of rating scales (e.g., Hart et al, 1995; Hartwell & Kaplan, 2018; Kressel et al., 2012; Tiliopoulos et al., 2009; van Tilburg et al., 2018).…”