In recent years, numerous studies demonstrating the crossmodal correspondences between individual olfactory stimuli and both auditory and visual stimuli have been published. However, most commercial perfumes are more complex (both chemically and perceptually) than individual olfactory stimuli, incorporating designated top, middle, and base notes. What is more, it is unlikely that it will be possible to discriminate effectively at a population level between hedonic responses to, and rated intensity of, most commercial perfumes (given that they are deliberately created to be pleasant and to provide an intense and long-lasting scent). Perfumes, unlike other classes of olfactory stimuli, also tend to be strongly gendered (masculine, feminine, or occasionally unisex). As such, the matching of music to fine fragrance faces different challenges than when matching music to the aromas and flavours of food and drink (a much more common application domain for crossmodal correspondences research currently). In this review, we examine the emerging literature on crossmodal correspondences to assess whether empirical findings can provide any actionable insights when it comes to assisting those wishing to design music and soundscapes that, in any meaningful sense, translate a perfume into its auditory equivalent.

The tritone paradox is a bistable auditory phenomenon where two Shepard tones can be interpreted as either ascending or descending. Previous studies have demonstrated that preceding auditory context can bias the direction of tritone perception. Here, we systematically manipulated both the quantity (anywhere between 1 and 10) and types (higher, lower, same as first target tone, or silent) of context tones before presenting a target tritone pair. We found that the contextual biasing effect can emerge with as few as 1–2 context tones, and plateaus quickly within this small window. Notably, low-frequency context tones produced a more pronounced and immediate bias than high-frequency tones. Together, this study demonstrates a narrow window of the auditory context effect, where minimal contextual cues are sufficient to guide perceptual interpretation of ambiguous auditory stimuli. The findings pave the way for more detailed investigations into the cognitive mechanisms of auditory perception, emphasizing the swift influence of immediate auditory contexts on perceptual outcomes.

We report a novel visual illusion, where a 2 × 2 two-colored checkerboard square rotating against an identical background appears to morph into a circle with a size change. This illusion can be categorized as a subtype of the breathing illusion (BI) based on its phenomenological characteristics. However, it also exhibits intriguing features that may offer new insights into BI's underlying mechanisms, not fully captured by existing displays.

Happy and sad moods promote global and local visual processing, respectively. However, it is unclear whether mood also affects the processing level in haptics. Here, we used classical music to induce happy and sad moods in blindfolded participants before they scanned printed, flat 2D embossed configurations with their fingers. We also included a neutral group that did not listen to any music. Global shapes were triangles, circles, or squares (33 mm) composed of smaller local relief shapes (3 mm): either triangles, circles, or squares. Participants explored a probe stimulus with identical local and global shapes, and two comparison stimuli, matching the probe in local or global shape. They reported which comparison stimulus appeared more similar to the probe. In the “sad” group, participants chose the locally matching comparison more frequently than in the “happy” and “neutral” groups, suggesting that unpleasant mood can influence spatial preferences in haptic shape matching. Overall, participants tended to prefer global matches, indicating that under these specific conditions, global-level information may be relatively more prominent in touch.

The human visual system is sensitive to statistical regularities in natural images. This includes general properties like the characteristic 1/f power-spectrum fall-off coefficient observed across diverse natural scenes and category-specific properties like the bias favoring horizontal contrast energy for face recognition. Here, we examined the sensitivity of face pareidolia in adult observers to these image properties using fractal noise images and an unconstrained pareidolic face detection task. We presented participants in separate experiments with (Experiment 1) noise patterns with varying spectral fall-off coefficients and (Experiment 2) noise patterns with bandpass orientation filtering such that either horizontal or vertical contrast energy was limited. In both experiments, we found that face pareidolia rates were sensitive to these manipulations. In Experiment 1, we found that fractal noise patterns with steeper fall-off coefficients (favoring coarser appearance) led to lower rates of pareidolic face detection. In Experiment 2, we found that despite the clear bias favoring horizontal contrast energy in a wide range of face recognition tasks, both horizontal and vertical orientation bandpass filtering reduced rates of face pareidolia relative to isotropic images. We suggest that these results indicate that detecting pareidolic faces depends on the availability of face-like information across many low-level channels rather than a favored scale or orientation that is face-specific.

This study investigates how the method used by participants to assess the beauty of pictures influences their preference for the compositional rules of symmetry, balance, and proximity. The hypothesis that production methods (actively arranging picture elements) prompt a local perspective, favoring proximity, while evaluation tasks (rating precomposed pictures) elicit a global perspective, favoring symmetry and balance, was tested in two experiments. Experiment 1 demonstrated that (positional) symmetry was preferred over balance, and balance over proximity, when participants rated precomposed pictures. Experiment 2, employing a production method with movable elements, showed a frequent use of proximity, yet also a tendency toward (positional) symmetry. The combined results indicate that assessment methods substantially impact the preferred composition rules.

This paper introduces the Mainz-Linez Illusion (MLI), a novel dynamic display in which rectilinearly moving targets appear to deviate from their true physical paths and instead give the impression of following the curves of static background elements. We attempt to relate the MLI to previously known effects and discuss possible mechanisms. We particularly focus on the possible role of negative afterimages, and speculate how their emergence and interaction with physical contours might contribute to some of the unique characteristics of the MLI. We also provide an online demo where readers can experience the effect and manipulate relevant parameters for themselves.

Earlier research has shown that seven-month-old infants prefer to look at real objects over their referents. Which visual cues determine that preference? Motivated by research on adult observers highlighting the significance of motion parallax over other depth cues contributing to a sense of presence and place, we tested the hypothesis that motion parallax alone is sufficient to cause preferential looking to real objects in infants. We presented pairs of displays of toys in different formats: (a) The real three-dimensional toy; (b) a realistic image of that toy presented on screen; (c) the same image, but with added depth-from-motion-parallax. Infants preferred (a) over (b) (57% vs. 43%, p < .01) and (c) over (b) (52% vs. 48%, p < .05), but showed no significant preference between (a) and (c) (51% vs. 49%, n.s.). This supports the hypothesis that motion parallax alone can induce a looking preference comparable to that observed for real objects.

We discovered a new type of assimilative color induction. An achromatic target with a white background was placed in the center of a concentric chromatic gradient that caused the glare effect. The target frequently appears to be in the same hue as the gradient. We discussed lower-level factors such as lateral inhibition and spatial summation functions, and higher-level factors such as illumination estimation.