Cross-cultural color-odor associations

Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e., an inherent mapping between color and odor), statistical reasons (i.e., covariance in experience), and/or semantically-mediated reasons (i.e., stemming from language). The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents), using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience

Odor-color associations differ with verbal descriptors for odors : A comparison of three linguistically diverse groups

People appear to have systematic associations between odors and colors. Previous research has emphasized the perceptual nature of these associations, but little attention has been paid to what role language might play. It is possible odor-color associations arise through a process of labeling; that is, participants select a descriptor for an odor and then choose a color accordingly (e.g., banana odor → "banana" label → yellow). If correct, this would predict odor-color associations would differ as odor descriptions differ. We compared speakers of Dutch (who overwhelmingly describe odors by referring to the source; e.g., smells like banana) with speakers of Maniq and Thai (who also describe odors with dedicated, abstract smell vocabulary; e.g., musty), and tested whether the type of descriptor mattered for odor-color associations. Participants were asked to select a color that they associated with an odor on two separate occasions (to test for consistency), and finally to label the odors. We found the hunter-gatherer Maniq showed few, if any, consistent or accurate odor-color associations. More importantly, we found the types of descriptors used to name the smells were related to the odor-color associations. When people used abstract smell terms to describe odors, they were less likely to choose a color match, but when they described an odor with a source-based term, their color choices more accurately reflected the odor source, particularly when the odor source was named correctly (e.g., banana odor → yellow). This suggests language is an important factor in odor-color cross-modal associations

Tactual perception: a review of experimental variables and procedures

This paper reviews literature on tactual perception. Throughout this review we will highlight some of the most relevant variables in touch literature: interaction between touch and other senses; type of stimuli, from abstract stimuli such as vibrations, to two- and three-dimensional stimuli, also considering concrete stimuli such as the relation between familiar and unfamiliar stimuli or the haptic perception of faces; type of participants, separating studies with blind participants, studies with children and adults, and an analysis of sex differences in performance; and finally, type of tactile exploration, considering conditions of active and passive touch, the relevance of movement in touch and the relation between exploration and time. This review intends to present an organised overview of the main variables in touch experiments, attending to the main findings described in literature, to guide the design of future works on tactual perception and memory.This work was funded by the Portuguese “Foundation for Science and Technology” through PhD scholarship SFRH/BD/35918/2007

Olfactory discrimination: when vision matters?

Many previous studies have attempted to investigate the effect of visual cues on olfactory perception in humans. The majority of this research has only looked at the modulatory effect of color, which has typically been explained in terms of multisensory perceptual interactions. However, such crossmodal effects may equally well relate to interactions taking place at a higher level of information processing as well. In fact, it is well-known that semantic knowledge can have a substantial effect on people's olfactory perception. In the present study, we therefore investigated the influence of visual cues, consisting of color patches and/or shapes, on people's olfactory discrimination performance. Participants had to make speeded odor discrimination responses (lemon vs. strawberry) while viewing a red or yellow color patch, an outline drawing of a strawberry or lemon, or a combination of these color and shape cues. Even though participants were instructed to ignore the visual stimuli, our results demonstrate that the accuracy of their odor discrimination responses was influenced by visual distractors. This result shows that both color and shape information are taken into account during speeded olfactory discrimination, even when such information is completely task irrelevant, hinting at the automaticity of such higher level visual-olfactory crossmodal interactions

Cross-modal interactions between olfaction and touch.

We report two experiments designed to investigate the nature of any cross-modal interactions between olfactory and tactile information processing. In Experiment 1, we assessed the influence of olfactory cues on the tactile perception of fabric softness using computer-controlled stimulus presentation. The results showed that participants rated fabric swatches as feeling significantly softer when presented with a lemon odor than when presented with an animal-like odor, demonstrating that olfactory cues can modulate tactile perception. In Experiment 2, we assessed whether this modulatory effect varied as a function of the particular odors being used and/or of the spatial coincidence between the olfactory and tactile stimuli. The results replicated those reported in Experiment 1 thus further supporting the claim that people's rating of tactile stimuli can be modulated by the presence of an odor. Taken together, the results of the two experiments reported here support the existence of a cross-modal interaction between olfaction and touch

Individual variability in the awareness of odors: demographic parameters and odor identification ability

Human chemosensation can be strongly influenced by how much attention people pay to chemosensory stimuli (e.g., Marks and Wheeler in Chem Senses 23:19–29, 1998; Prescott et al. in Chem Senses 29:331–340, 2004). In a recent study, a scale has been devised (i.e., the Odor Awareness Scale; OAS; see Smeets et al. in Chem Senses 33:725–734, 2008) to investigate the level of awareness people have of the available odorants in the environment. Here, we explored whether a variant (Italian version) of the OAS could be used to discriminate between different groups of participants in terms of olfactory abilities (i.e., performance in an odor identification task) and/or personal/demographic characteristics (e.g., gender, age, etc.). Ninety-eight participants underwent this study that was composed of a personal detail questionnaire, the OAS, and a deep investigation of odor identification ability based on a large variety of odor stimuli. During 6 testing sessions, a total of 72 odor stimuli were evaluated: 36 aromas in vapor phase presented in vials and 36 chemical compounds in hydroalcoholic solutions. The results did not indicate any relationships between the participants’ declared awareness of odors and the real performance in the identification test. However, differences in the awareness of odors were found as a function of a number of personal factors such as, for example, gender (with females showing higher scores than males) or age (with younger collecting lower scores than older participants). In conclusion, we could not predict from modified OAS scores the participants’ specific ability to identify odors. Nevertheless, we could extend the scale’s characterization by highlighting different connections between OAS scores and individual parameters