The Contribution of Visual Area V5 to the Perception of Implied Motion in Art and Its Appreciation

Does V5, a brain region involved in the perception of movement, contribute to the aesthetic appreciation of artworks that depict movement? In the study under discussion, the authors asked participants to view abstract and representational artworks depicting motion. While they judged the sense of motion conveyed by the artworks and how much they liked them, the authors delivered transcranial magnetic stimulation (TMS) over V5. They found that TMS over V5 reduced the sense of motion participants perceived and reduced how much participants liked the abstract paintings. These results show, first, that V5 is involved in extracting implied motion information even when the object whose motion is implied is not real. Second, they show that V5 is involved in extracting implied motion information even in the absence of any object, as in the abstract paintings. Finally, they show that activity in V5 plays a causal role in the appreciation of abstract art.

Pupil responses to implied motion in figurative and abstract paintings

Motion can be perceived in static images, such as photos and figurative paintings, representing realistic subjects in motion, with or without directional information (e.g., motion blur or speed lines). Motion impression can be achieved even in non-realistic static images such as motion illusions and abstract paintings. It has been shown that visual motion processing affects the diameter of the pupil, responding differently to real, illusory, and implied motion in photographs (IM). It has been suggested that these different effects might be due to top-down modulations from different cortical areas underlying their processing. It is worthwhile to investigate pupillary response to figurative paintings, since they require an even higher level of interpretation than photos representing the same kind of subjects, given the complexity of cognitive processes involved in the aesthetic experience. Also, pupil responses to abstract paintings allows to study the effect of IM perception in representations devoid of real-life motion cues. We measured pupil responses to IM in figurative and abstract artworks depicting static and dynamic scenes, as rated by a large group of individuals not participating in the following experiment. Since the pupillary response is modulated by the subjective image interpretation, a motion rating test has been used to correct individual pupil data according to whether participants actually perceived the presence of motion in the paintings. Pupil responses to movies showing figurative and abstract subjects, and to motion illusions were also measured, to compare real and illusory motion with painted IM. Movies, both figurative and abstract, elicit the largest pupillary dilation of all static stimuli, whereas motion illusions cause the smallest pupil size, as previously shown. Interestingly, pupil responses to IM depend on the paintings’ style. Figurative paintings depicting moving subjects cause more dilation than those representing static figures, and pupil size increases with the strength of IM, as already found with realistic photos. The opposite effect is obtained with abstract artworks. Abstract paintings depicting motion produce less dilation than those depicting stillness. In any case, these results reflect the individual subjective perception of dynamism, as the very same paintings can induce opposite responses in observer which interpreted it as static or dynamic. Overall, our data show that pupil size depends on high-level interpretation of motion in paintings, even when they do not represent real-world scenes. Our findings further suggest that the pupil is modulated by multiple top-down cortical mechanisms, involving the processing of motion, attention, memory, imagination, and other cognitive functions necessary for enjoying a complete aesthetic experience.

Food on the Move: The Impact of Implied Motion in Pictures on Food Perceptions through Anticipated Pleasure of Consumption

To tackle obesity, upgrading the image of healthy food is increasingly relevant. Rather than focusing on long-term benefits, an effective way to promote healthy food consumption through visual advertising is to increase its pleasure perception. We investigate whether implied motion, a popular trend in food pictures, affects food perceptions through anticipated consumption pleasure. Prior research shows that motion affects food perceptions, but these studies focused on limited food categories, using experiments with a single food stimulus, and mainly showing unhealthy food effects. Therefore, we aim to (1) replicate prior findings on the effects of food in motion on appeal, tastiness, healthiness, and freshness perceptions; (2) examine whether these effects differ for healthy and unhealthy food; and (3) investigate whether anticipated pleasure of consumption drives the effects of implied motion on food perceptions. Three between-subjects experiments (N = 626) reveal no evidence for the effectiveness of motion (vs. no motion) across a large variety of food products. We further show no differential effects for healthy versus unhealthy foods. Moreover, implied motion does not increase appeal or taste perceptions through anticipated pleasure. Considering the current replication crisis, these findings provide more nuanced insights into the effectiveness of motion in visual food advertising.

The implied motion aftereffect changes decisions, but not confidence

Viewing static images depicting movement can result in a motion aftereffect: people tend to categorise direction signals as moving in the opposite direction relative to the implied motion in still photographs. This finding could indicate that inferred motion direction can penetrate sensory processing and change perception. Equally possible, however, is that inferred motion changes decision processes, but not perception. Here we test these two possibilities. Since both categorical decisions and subjective confidence are informed by sensory information, confidence can be informative about whether an aftereffect probably results from changes to perceptual or decision processes. We therefore used subjective confidence as an additional measure of the implied motion aftereffect. In Experiment 1 (implied motion), we find support for decision-level changes only, with no change in subjective confidence. In Experiment 2 (real motion), we find equal changes to decisions and confidence. Our results suggest the implied motion aftereffect produces a bias in decision-making, but leaves perceptual processing unchanged.

Pupillary response to real, illusory, and implied motion

The perception of moving objects (real motion) is a critical function for interacting with a dynamic environment. Motion perception can be also induced by particular structural features of static images (illusory motion) or by photographic images of subjects in motion (implied motion, IM). Many cortical areas are involved in motion processing, particularly the medial temporal cortical area (MT), dedicated to the processing of real, illusory, and implied motion. Recently, there has been a growing interest in the influence of high-level visual processes on pupillary responses. However, just a few studies have measured the effect of motion processing on the pupil, and not always with consistent results. Here we systematically investigate the effects of real, illusory, and implied motion on the pupil diameter for the first time, by showing different types of stimuli (movies, illusions, and photos) with the same average luminance to the same observers. We find different pupillary responses depending on the nature of motion. Real motion elicits a larger pupillary dilation than IM, which in turn induces more dilation than control photos representing static subjects (No-IM). The pupil response is sensitive even to the strength of IM, as photos with enhanced IM (blur, motion streaks, speed lines) induce larger dilation than simple freezed IM (subjects captured in the instant they are moving). Also, the subject represented in the stimulus matters: human figures are interpreted as more dynamic and induce larger dilation than objects/animals. Interestingly, illusory motion induces much less dilation than all the other motion categories, despite being seen as moving. Overall, pupil responses depend on the individual perception of dynamicity, confirming that the pupil is modulated by the subjective interpretation of complex stimuli. We argue that the different pupillary responses to real, illusory, and implied motion reflect the top-down modulations of different cortical areas involved in their processing.

Bara_implied_motion

Although there is growing interest in the neural foundations of aesthetic experience, it remains unclear how particular mental sub-systems (e.g., perceptual, affective, cognitive) are involved in different types of aesthetic judgments. Here we use fMRI to investigate the involvement of different neural networks during aesthetic judgments of visual artworks with implied motion cues. First, a behavioural experiment (N=45) confirmed a preference for paintings with implied motion over static cues. Subsequently, in a pre-registered fMRI experiment (N=27), participants made aesthetic and motion judgments towards paintings representing human bodies in dynamic and static postures. Using functional region-of-interest and Bayesian multilevel modelling approaches, we show clear functional differences in the way motion, body-image and affective processing systems contribute to aesthetic judgments. Visual motion and body-selective regions were sensitive to implied motion cues, but only body-selective regions showed sensitivity to aesthetic judgments. In contrast, within the affective network, bilateral anterior cingulate cortex showed more sensitivity to the aesthetic than control task. In addition, we show suggestive evidence that motion and body-selective systems may integrate signals via functional connections with a separate neural network in dorsal parietal cortex, which may act as a relay or integration site. Our findings clarify the roles of basic visual and affective brain circuitry in evaluating a central aesthetic feature – implied motion – whilst also pointing towards promising future research directions, which involve modelling aesthetic preferences as hierarchical interplay between visual and affective circuits and integration processes in frontoparietal cortex.

The Varying Coherences of Implied Motion Modulates the Subjective Time Perception

Previous research has demonstrated that duration of implied motion (IM) was dilated, whereas hMT+ activity related to perceptual processes on IM stimuli could be modulated by their motion coherence. Based on these findings, the present study aimed to examine whether subjective time perception of IM stimuli would be influenced by varying coherence levels. A temporal bisection task was used to measure the subjective experience of time, in which photographic stimuli showing a human moving in four directions (left, right, toward, or away from the viewer) were presented as probe stimuli. The varying coherence of these IM stimuli was manipulated by changing the percentage of pictures implying movement in one direction. Participants were required to judge whether the duration of probe stimulus was more similar to the long or short pre-presented standard duration. As predicted, the point of subjective equality was significantly modulated by the varying coherence of the IM stimuli, but not for no-IM stimuli. This finding suggests that coherence level might be a key mediating factor for perceived duration of IM images, and top-down perceptual stream from inferred motion could influence subjective experience of time perception.