Brief periods of repetitive stimulation (click trains) presented either contiguous or simultaneous to an interval have been previously shown to impact on its perceived duration. In the current investigation we asked whether the perception of temporal order can be altered in a similar way. Participants completed a dichotic spectral temporal order judgement task with the stimuli titrated to their individual thresholds. Immediately prior to the judgement, participants were presented with five seconds of click trains, white noise or silence. We extended previous work on this topic by using each participant’s accuracy and response time data to estimate diffusion model parameters so that the cognitive mechanisms underlying any effect of click trains on the response could be disentangled. There was no effect of stimulation condition on participant’s accuracy, or diffusion model parameters (drift rate, boundary separation or non-decision time). The present findings therefore suggest that click trains do not influence temporal order perception. Additionally, the previous suggestion that click trains induce an increase in the rate of information processing was not supported for this temporal order task. Further work probing the limits and conditions of the click train effect will help to constrain and extend theoretical accounts of subjective timing.
Illusory contours (ICs) are borders that are perceived in the absence of contrast gradients. Until recently, IC processes were considered exclusively visual in nature and presumed to be unaffected by information from other senses. Electrophysiological data in humans indicates that sounds can enhance IC processes. Despite cross-modal enhancement being observed at the neurophysiological level, to date there is no evidence of direct amplification of behavioural performance in IC processing by sounds. We addressed this knowledge gap. Healthy adults () discriminated instances when inducers were arranged to form an IC from instances when no IC was formed (NC). Inducers were low-constrast and masked, and there was continuous background acoustic noise throughout a block of trials. On half of the trials, i.e., independently of IC vs NC, a 1000-Hz tone was presented synchronously with the inducer stimuli. Sound presence improved the accuracy of indicating when an IC was presented, but had no impact on performance with NC stimuli (significant IC presence/absence × Sound presence/absence interaction). There was no evidence that this was due to general alerting or to a speed–accuracy trade-off (no main effect of sound presence on accuracy rates and no comparable significant interaction on reaction times). Moreover, sound presence increased sensitivity and reduced bias on the IC vs NC discrimination task. These results demonstrate that multisensory processes augment mid-level visual functions, exemplified by IC processes. Aside from the impact on neurobiological and computational models of vision, our findings may prove clinically beneficial for low-vision or sight-restored patients.
To create art means to be creative, but how creativity is gained, how we can induce and train creativity and how we can validly measure creative potential is a matter of still unsolved research. In our exploratory study, 49 participants had to create figures by using a double set of Tangram puzzles — so to say: to create something with an infinite degree of freedoms but that is still based on just a few defined and simple basic elements. In total, participants created 708 different figures. Creativity and complexity of these creations were then assessed in a subsequent study by five further raters in two randomly ordered blocks. We observed a strong correlation between the ratings of creativity and complexity on basis of average as well as individual data level. Interestingly, highly productive people, sometimes misinterpreted as ‘creatives’ due to their sheer quantitative output, actually produced simpler scenes that were also evaluated as less creative. We could also reveal that the level of creativity in the produced items remained very similar over the course of the test, pointing to relatively stable creativity traits (at least during the study phase). Our approach could lead to a deeper and more differentiated understanding of the concept of creativity and creative potential, specifically by combining it with qualitative analyses of the complexity of the created figures.
Multisensory integration (MSI) of emotion has been increasingly recognized as an essential element of schizophrenic patients’ impairments, leading to the breakdown of their interpersonal functioning. The present review provides an updated synopsis of schizophrenics’ MSI abilities in emotion processing by examining relevant behavioral and neurological research. Existing behavioral studies have adopted well-established experimental paradigms to investigate how participants understand multisensory emotion stimuli, and interpret their reciprocal interactions. Yet it remains controversial with regard to congruence-induced facilitation effects, modality dominance effects, and generalized vs specific impairment hypotheses. Such inconsistencies are likely due to differences and variations in experimental manipulations, participants’ clinical symptomatology, and cognitive abilities. Recent electrophysiological and neuroimaging research has revealed aberrant indices in event-related potential (ERP) and brain activation patterns, further suggesting impaired temporal processing and dysfunctional brain regions, connectivity and circuities at different stages of MSI in emotion processing. The limitations of existing studies and implications for future MSI work are discussed in light of research designs and techniques, study samples and stimuli, and clinical applications.
The failure of e-books to take over from the traditional print format, as was so confidently predicted would happen only a few years ago, highlights how there is more to reading than merely the content of what we see. In fact, like any other object, the experience of interacting with a book, especially an old or historic volume, offers the reader the potential for a multisensory encounter. One that involves not only what the book looks and feels like, both the weight of the volume and the feel of the pages, but also the distinctive smell. In fact, one might also want to consider the particular sound made by the pages as they are turned over. However, it is the smell of older, and seemingly more olfactorily-redolent, works that appears to be especially effective at triggering nostalgic associations amongst readers. It is therefore only by understanding the multisensory nature of handling books, as stressed by this review, that one can really hope to fully appreciate the enduring appeal of the traditional format in the modern digital era. Several recent exhibitions that have attempted to engage their visitors by means of exploring the multisensory appeal of historic books or manuscripts in their collections are briefly discussed. While the multisensory mental imagery that is typically evoked by reading is unlikely to differ much between the print and e-book formats, there is nevertheless still some evidence to suggest that physical books can occasionally convey information more effectively than their digital counterparts.
Our timing estimates are often prone to distortions from non-temporal attributes such as the direction of motion. Motion direction has been reported to lead to interval dilation when the movement is toward (i.e., looming) as compared to away from the viewer (i.e., receding). This perceptual asymmetry has been interpreted based on the contextual salience and prioritization of looming stimuli that allows for timely reactions to approaching objects. This asymmetry has mainly been studied through abstract stimulation with minimal social relevance. Focusing on the latter, we utilized naturalistic displays of biological motion and examined the aforementioned perceptual asymmetry in the temporal domain. In Experiment 1, we tested visual looming and receding human movement at various intervals in a reproduction task and found no differences in the participants’ timing estimates as a function of motion direction. Given the superiority of audition in timing, in Experiment 2, we combined the looming and receding visual stimulation with sound stimulation of congruent, incongruent, or no direction information. The analysis showed an overestimation of the looming as compared to the receding visual stimulation when the sound presented was of congruent or no direction, while no such difference was noted for the incongruent condition. Both looming and receding conditions (congruent and control) led to underestimations as compared to the physical durations tested. Thus, the asymmetry obtained could be attributed to the potential perceptual negligibility of the receding stimuli instead of the often-reported salience of looming motion. The results are also discussed in terms of the optimality of sound in the temporal domain.
Crossmodal correspondences (CMC) systematically associate perceptual dimensions in different sensory modalities (e.g., auditory pitch and visual brightness), and affect perception, cognition, and action. While previous work typically investigated associations between basic perceptual dimensions, here we present a new type of CMC, involving a high-level, quasi-syntactic schema: music tonality. Tonality governs most Western music and regulates stability and tension in melodic and harmonic progressions. Musicians have long associated tonal stability with non-auditory domains, yet such correspondences have hardly been investigated empirically. Here, we investigated CMC between tonal stability and visual brightness, in musicians and in non-musicians, using explicit and implicit measures. On the explicit test, participants heard a tonality-establishing context followed by a probe tone, and matched each probe to one of several circles, varying in brightness. On the implicit test, we applied the Implicit Association Test to auditory (tonally stable or unstable sequences) and visual (bright or dark circles) stimuli. The findings indicate that tonal stability is associated with visual brightness both explicitly and implicitly. They further suggest that this correspondence depends only partially on conceptual musical knowledge, as it also operates through fast, unintentional, and arguably automatic processes in musicians and non-musicians alike. By showing that abstract musical structure can establish concrete connotations to a non-auditory perceptual domain, our results open a hitherto unexplored avenue for research, associating syntactical structure with connotative meaning.
I conducted three experiments to investigate haptic working memory capacity using a haptic change detection task with 2D stimuli. I adopted a single-task paradigm comprising haptic single-feature (orientation or texture) and haptic multifeature (orientation and texture) conditions in Experiment 1 and a dual-task paradigm with a primary haptic orientation or texture change detection task and a concurrent secondary visual shape or colour change detection task in Experiments 2–3. I observed that in the single-task paradigm, haptic change detection capacity was higher for single features than it was for multiple features. In haptic working memory, unlike in visual working memory, features of two different dimensions within an object cannot be integrated. In the dual-task paradigm, interference was observed when the concurrent visual shape change detection task was combined with the haptic orientation change detection task although interference was not observed when the concurrent visual colour change detection task was combined with it. In addition, the concurrent visual shape or colour change detection task did not interfere with the capacity for haptic texture memory, which was higher than that for haptic orientation memory. These findings demonstrate that geometric properties perhaps retained a common storage system shared between haptic working memory and visual working memory; however, haptic texture might be retained in an independent stable storage system that is haptic-specific.