Heaviness-brightness correspondence and stimulus-response compatibility

Abstract

Cross-sensory correspondences can reflect crosstalk between aligned conceptual feature dimensions, though uncertainty remains regarding the identities of all the dimensions involved. It is unclear, for example, if heaviness contributes to correspondences separately from size. Taking steps to dissociate variations in heaviness from variations in size, the question was asked if a heaviness-brightness correspondence will induce a congruity effect during the speeded brightness classification of simple visual stimuli. Participants classified the stimuli according to whether they were brighter or darker than the mid-gray background against which they appeared. They registered their speeded decisions by manipulating (e.g., tapping) the object they were holding in either their left or right hand (e.g., left for bright, right for dark). With these two otherwise identical objects contrasting in their weight, stimuli were classified more quickly when the relative heaviness of the object needing to be manipulated corresponded with the brightness of the stimulus being classified (e.g., the heavier object for a darker stimulus). This novel congruity effect, in the guise of a stimulus-response (S-R) compatibility effect, was induced when heaviness was isolated as an enduring feature of the object needing to be manipulated. It was also undiminished when participants completed a concurrent verbal memory load task, countering claims that the heaviness-brightness correspondence is verbally mediated. Heaviness, alongside size, appears to contribute to cross-sensory correspondences in its own right and in a manner confirming the far-reaching influence of correspondences, extending here to the fluency with which people communicate simple ideas by manipulating a hand-held object.

Keywords: Brightness; Cross-sensory correspondences; Heaviness; Stimulus-response compatibility.

Fig. 1.

Illustration of the size and weight of each object in the set of nine objects created by crossing weight against size. The objects are labelled to facilitate discussion here, but were not labelled in the experiment. The three alternative values for weight were chosen on the basis that they are a set of values that could arise when objects at the three different sizes are made from the same material (i.e., the same density). Therefore, objects A, E, and I are very close to forming a natural set of objects whose weights indicate they are formed from the same material. From Walker, Scallon, and Francis (2016)

Fig. 2.

Experiments 1– - 3: Mean correct response speed, with 95% confidence intervals, according to the categorical brightness of the visual test stimulus and the heaviness (and size also in Experiment 1) of the response key needing to be manipulated. In the case of Experiment 3, the results are shown separately for the without and with concurrent memory load task conditions. Note the different range for response speed for Experiment 3

Fig. 3.

Different ways in which modality-specific features from different domains can be associated with each other, with a potential role for mediating features also being illustrated. (A) The notion of cross-sensory correspondences adopted in the present study regards them as reflecting relatively direct associations across aligned feature dimensions (illustrated here with the dimensions of visual brightness and auditory pitch). The individual associations thereby established reflect the context-sensitive and relative mapping of feature values based on them sharing similar ordinal positions within their respective feature sets (i.e., the highest pitch sound in the currently pertinent set of sounds will also be the brightest sound and on this basis will correspond with the brightest visual stimulus in the currently pertinent set). (B) Where the different values for a particular feature do not themselves lie along a single dimension, illustrated here with hue, then the mapping of these values onto the values for another feature (here auditory pitch), that do lie on a dimension, can be mediated by mapping both features onto some other dimension, such as valence. In this way, valence can act as a mediator through which the individual values in the two other feature sets become associated. (C) A dimension such as valence can serve equally well as a mediator between two sets of features for neither of which do the feature values lie on a dimension (here illustrated with hue and flavour). (D) Illustrating how the alphabetic order of a sample of different wines and a sample of different perfumes could, in principle, serve to associate individual wines with individual perfumes