Interest in continuous psychophysical approaches as a means of collecting data quickly under natural conditions is growing. Such approaches require stimuli to be changed randomly on a continuous basis so that participants can not guess future stimulus states. Participants are generally tasked with responding continuously using a continuum of response options. These features introduce variability in the data that is not present in traditional trial-based experiments. Given the unique weaknesses and strengths of continuous psychophysical approaches, we propose that they are well suited to quickly mapping out relationships between above-threshold stimulus variables such as the perceived direction of a moving target as a function of the direction of the background against which the target is moving. We show that modelling the participant in such a two-variable experiment using a novel “Bayesian Participant” model facilitates the conversion of the noisy continuous data into a less-noisy form that resembles data from an equivalent trial-based experiment. We also show that adaptation can result from longer-than-usual stimulus exposure times during continuous experiments, even to features that the participant is not aware of. Methods for mitigating the effects of adaptation are discussed.

Visuomotor synchrony in time and space induces a sense of embodiment towards virtual bodies experienced in first-person view using Virtual Reality (VR). Here, we investigated whether temporal visuomotor synchrony affects avatar embodiment even when the movements of the virtual arms are spatially altered from those of the user in a non-human-like manner. In a within-subjects design VR experiment, participants performed a reaching task controlling an avatar whose lower arms bent in inversed and biomechanically impossible directions from the elbow joints. They performed the reaching task using this “unnatural avatar” as well as a “natural avatar,” whose arm movements and positions spatially matched the user. The reaching tasks were performed with and without a one second delay between the real and virtual movements. While the senses of body ownership and agency towards the unnatural avatar were significantly lower compared to those towards the natural avatar, temporal visuomotor synchrony did significantly increase the sense of embodiment towards the unnatural avatar as well as the natural avatar. These results suggest that temporal visuomotor synchrony is crucial for inducing embodiment even when the spatial match between the real and virtual limbs is disrupted with movements outside the pre-existing cognitive representations of the human body.

Advances in artificial intelligence (AI) have significantly improved the abilities of machines. Human-unique abilities, such as art creation, are now being challenged by AI. Recent studies have investigated and compared people's attitudes toward human-made and AI-generated artworks. These results suggest that a negative bias may exist toward the latter. However, none of these previous studies has examined the extent of this bias. In this study, we investigate whether a bias against AI art can be found at an implicit level. Viewers' attitudes toward AI art were assessed using eye-tracking measures and subjective aesthetic evaluations. Visual attention and aesthetic judgments were compared between artworks categorized as human-made and AI-made. The results showed that although it was difficult for individuals to identify AI-generated artwork, they exhibited an implicit prejudice against AI art. Participants looked longer at paintings that they thought were made by humans. No significant effect of categorization of paintings was found in subjective evaluations. These findings suggest that although human and AI art may be perceived as having similar aesthetic values, an implicit negative bias toward AI art exists. Although AI can now perform creative tasks, artistic creativity is still considered a human prerogative.

While sunbathing, our skin becomes susceptible to quite remarkable changes in visual appearance, that is, freckles appear or increase in intensity—most obviously on the face. Research on face adaptation repeatedly showed that the inspection of manipulated versions of faces (so-called adaptor faces) leads to robust and sustainable changes in the perception of subsequently presented faces. Therefore, during the adaptation phase of the present study, participants saw faces with either strongly increased or decreased intensities of freckles. After a 5-minute break, during the test phase, participants had to identify the veridical (non-manipulated) face out of two faces (a slightly manipulated face combined with a non-manipulated face). Results showed strong adaptation effects to increased and decreased levels of freckles. We conclude that updating facial representations in memory is relatively fast, and these representation updates seem to sustain over a certain time span (at least 5 minutes). Face-specificity of our effects will be discussed. The results align with our everyday experience that the appearance of freckles in spring is a salient change in a familiar face; however, we seem to not register these changes after a few exposures due to a loss of information quality.

A movie taken from the front window of a running train, with zooming in and out, has been popularly acknowledged as a perceptual illusion such that the train motion is perceived as much slower when zoomed in. This is, however, not a real illusion because the image speed varies as a function of the focal length of the lens. This could be a meta-illusion, that is, an illusory sense of illusion, that might reflect a lack of understanding of how zooming changes the geometrical structure of the image.

Perceptual multistability is well-known and mostly visually demonstrated: Common examples are Necker's cube or Rubin's face-vase that produce qualitatively different percepts continuously oscillating between the solutions despite physically stable stimuli. We lack knowledge about similar phenomena in other domains, for instance in linguistics, where we are faced with homonyms that create multistability of cognitive semantics, differently assigned meanings of identical words. Our participants listened to repeated presentations of homonyms for which two or even three meanings could be assigned, and they reported the dominant meaning perceived at a certain point in time. Results showed that most participants experienced multistability of meaning for homonyms, with semiperiodic changes in dominant meaning similar to multistabity in perception. These findings suggest that multistability is a general property of the brain's neural architecture that resolves ambiguity irrespective of the level of representation.

In recent years, awareness of the influence of different modalities on tasteperception has grown. Although previous research in crossmodal taste perceptionhas touched upon the bipolar distinction between softness/smoothness androughness/angularity, ambiguity largely remains surrounding other crossmodalcorrespondences between taste and other specific textures we regularly use todescribe our food, such as crispy or crunchy. Sweetness has previously beenfound to be associated with soft textures but our current understanding does notexceed the basic distinction made between roughness and smoothness.Specifically, the role of texture in taste perception remains relativelyunderstudied. The current study consisted of two parts. First, because of thelack of clarity concerning specific associations between basic tastes andtextures, an online questionnaire served to assess whether consistentassociations between texture words and taste words exist and how these ariseintuitively. The second part consisted of a taste experiment with factorialcombinations of four tastes and four textures. The results of the questionnairestudy showed that consistent associations are made between soft and sweet andbetween crispy and salty at the conceptual level. The results of the tasteexperiment largely showed evidence in support of these findings at theperceptual level. In addition, the experiment allowed for a closer look into thecomplexity found regarding the association between sour and crunchy, and bitterand sandy.

Rapid evolution of artificial intelligence (AI) based on deep neural networks hasresulted in artificial systems such as generative pre-trained transformer 3(GPT-3), which can generate human-like language. Such a system may provide anovel platform for studying how human perception is related to knowledge and theability of language generation. We compared the frequency distribution of basiccolor terms in the answers of human subjects and GPT-3 when both were askedsimilar questions regarding color names associated with the letters of thealphabet. We found that GPT-3 generated basic color terms at a frequency verysimilar to that of human non-synaesthetes. A similar frequency was observed whencolor names associated with numerals were tested indicating that simpleco-occurrence of alphabet and color word in the trained dataset cannot explainthe results. We suggest that the proposed experimental framework using thelatest AI models has the potential to explore the mechanisms of humanperception.

People tend to associate abstract visual features with basic taste qualities. This narrative historical review critically evaluates the literature on these associations, often referred to as crossmodal correspondences, between basic tastes and visual design features such as color hue and shape curvilinearity. The patterns, discrepancies, and evolution in the development of the research are highlighted while the mappings that have been reported to date are summarized. The review also reflects on issues of cross-cultural validity and deviations in the matching patterns that are observed when correspondences are assessed with actual tastants versus with verbal stimuli. The various theories that have been proposed to account for different classes of crossmodal correspondence are discussed, among which the statistical and affective (or emotional-mediation) accounts currently appear most promising. Several critical research questions for the future are presented to address the gaps that have been identified in the literature and help validate the popular theories on the origin and operations of visual-taste correspondences.

Integrating mobile eye tracking and optoelectronic motion capture enables point of gazeto be expressed within the laboratory co-ordinate system and presents a method notcommonly applied during research examining dynamic behaviors, such as locomotion. Thispaper examines the quality of gaze data collected through the integration. Based onresearch suggesting increased viewing distances are associated with reduced data quality;the accuracy and precision of gaze data as participants (N = 11) viewedfloor-based targets at distances of 1–6 m was investigated. A mean accuracy of2.55 ± 1.12° was identified, however, accuracy and precision measures (relative totargets) were significantly (p < .05) reduced at greater viewingdistances. We then consider if signal processing techniques may improve accuracy andprecision, and overcome issues associated with missing data. A 4th-order Butterworthlowpass filter with cut-off frequencies determined via autocorrelation did notsignificantly improve data quality, however, interpolation via Quintic spline wassufficient to overcome gaps of up to 0.1 s. We conclude the integration of gaze and motioncapture presents a viable methodology in the study of human behavior and presentsadvantages for data collection, treatment, and analysis. We provide considerations for thecollection, analysis, and treatment of gaze data that may help inform futuremethodological decisions.