Corinne Jola

Towards a sensorimotor aesthetics of performing art

The field of neuroaesthetics attempts to identify the brain processes underlying aesthetic experience, including but not limited to beauty. Previous neuroaesthetic studies have focussed largely on paintings and music, while performing arts such as dance have been less studied. Nevertheless, increasing knowledge of the neural mechanisms that represent the bodies and actions of others, and which contribute to empathy, make a neuroaesthetics of dance timely. Here, we present the first neuroscientific study of aesthetic perception in the context of the performing arts. We investigated brain areas whose activity during passive viewing of dance stimuli was related to later, independent aesthetic evaluation of the same stimuli. Brain activity of six naïve male subjects was measured using fMRI, while they watched 24 dance movements, and performed an irrelevant task. In a later session, participants rated each movement along a set of established aesthetic dimensions. The ratings were used to identify brain regions that were more active when viewing moves that received high average ratings than moves that received low average ratings. This contrast revealed bilateral activity in the occipital cortices and in right premotor cortex. Our results suggest a possible role of visual and sensorimotor brain areas in an automatic aesthetic response to dance. This sensorimotor response may explain why dance is widely appreciated in so many human cultures.

Segmenting the body into parts: evidence from biases in tactile perception.

How do we individuate body parts? Here, we investigated the effect of body segmentation between hand and arm in tactile and visual perception. In a first experiment, we showed that two tactile stimuli felt farther away when they were applied across the wrist than when they were applied within a single body part (palm or forearm), indicating a “category boundary effect”. In the following experiments, we excluded two hypotheses, which attributed tactile segmentation to other, nontactile factors. In Experiment 2, we showed that the boundary effect does not arise from motor cues. The effect was reduced during a motor task involving flexion and extension movements of the wrist joint. Action brings body parts together into functional units, instead of pulling them apart. In Experiments 3 and 4, we showed that the effect does not arise from perceptual cues of visual discontinuities. We did not find any segmentation effect for the visual percept of the body in Experiment 3, nor for a neutral shape in Experiment 4. We suggest that the mental representation of the body is structured in categorical body parts delineated by joints, and that this categorical representation modulates tactile spatial perception.

Mental object rotation and egocentric body transformation: two dissociable processes?

An important question in studies on mental rotation is whether the mental object rotation and the egocentric body transformation rely on dissociable mechanisms. We tested non-dancers and professional dancers as experts in the mental object rotation task (MORT, 3D-cubes used by Shepard & Metzler, 1971) and the mental body transformation task (MBRT, line drawings of human bodies similar to those used by Parsons, 1987). The cubes and body figures were presented in exactly the same rotation conditions; in the picture plane, 0 degree, 45 degrees, 90 degrees, 135 degrees, and 180 degrees, and in combination with a rotation in depth, 0 degree (the stimuli are rotated in the picture plane only) and 180 degrees. We could replicate the linear increase in RT with increasing angle for the cubes whereas the RT for rotated body figures increased for not depth-rotated bodies only (back view). Though, the RTs for inverted body figures were faster when they were rotated in depth (front view) compared to when they were rotated in the picture plane only (back view). This finding suggests that participants use different strategies depending on the perceived orientation of the stimulus. The results indicate impaired performance in the MORT for the experts.

Proprioceptive integration and body representation: insights into dancers' expertise.

The experience of the body as a single coherent whole is based on multiple local sensory signals, integrated across different sensory modalities. We investigated how local information is integrated to form a single body representation and also compared the contribution of proprioceptive and visual information both in expert dancers and non-dancer controls. A number of previous studies have focused on individual differences in proprioceptive acuity at single joints and reported inconsistent findings. We used the established endpoint position matching task to measure absolute and directional errors in matching the position of one hand with the other. The matching performance was tested in three different conditions, which involved different information about the target position: only proprioceptive information from a ‘target’ hand which could be either the left or the right, only visual information, or both proprioceptive and visual information. Differences in matching errors between these sensory conditions suggested that dancers show better integration of local proprioceptive signals than non-dancers. The dancers also relied more on proprioception when both proprioceptive and visual information about hand position were present.

The psychological validity of qualitative spatial reasoning in one dimension

One of the central questions of spatial reasoning research is whether the underlying processes are inherently visual, spatial, or logical. We applied the dual task interference paradigm to spatial reasoning problems in one dimension, using Allens interval calculus, in order to make progress towards resolving this argument. Our results indicate that spatial reasoning with interval relations is largely based on the construction and inspection of qualitative spatial representations, or mental models, while no evidence for logical proofs of derivations or the involvement of visual representations and processes was found.

In the here and now: enhanced motor corticospinal excitability in novices when watching live compared to video recorded dance

Enhanced motor corticospinal excitability (MCE) in passive action observation is thought to signify covert motor resonance with the actions seen. Actions performed by others are an important social stimulus and thus, motor resonance is prevalent during social interaction. However, most studies employ simple/short snippets of recorded movements devoid of any real-life social context, which has recently been criticized for lacking ecological validity. Here, we investigated whether the co-presence of the actor and the spectator has an impact on motor resonance by comparing novices’ MCE for the finger (FDI) and the arm (ECR) with single-pulse transcranial magnetic stimulation when watching five-minute solos of ballet dance, Bharatanatyam (Indian dance) and an acting control condition either live or on video. We found that (1) MCE measured in the arm muscle was significantly enhanced in the live compared to the video condition, (2) differences across performances were only evident in the live condition, and (3) our novices reported enjoying the live presentations significantly more. We suggest that novice spectators’ MCE is susceptible to the performers’ live presence.

Spatial Reasoning: No Need for Visual Information

One of the central questions of spatial reasoning research is whether the underlying processes are inherently visual or spatial. The article reports a dual-task experiment that was conducted to explore the visual and/or spatial nature of human spatial reasoning. The main tasks were inferences based on a spatial version of the interval calculus introduced by Allen (1983). The secondary tasks were presented visually or acoustically, and were either spatial or non-spatial. The results indicate that spatial reasoning is mainly based on the construction and inspection of spatial layouts, whereas no evidence of the involvement of visual representations and processes was found.

Motor imagery training improves precision of an upper limb movement in patients with hemiparesis

BACKGROUND In healthy participants, beneficial effects of motor imagery training on movement execution have been shown for precision, strength, and speed. In the clinical context, it is still debated whether motor imagery provides an effective rehabilitation technique in patients with motor deficits. OBJECTIVE To compare the effectiveness of two different types of movement training: motor imagery vs. motor execution. METHODS Twenty-five patients with hemiparesis were assigned to one of two training groups: the imagery or the execution-training group. Both groups completed a baseline test before they received six training sessions, each of which was followed by a test session. Using a novel and precisely quantifiable test, we assessed how accurately patients performed an upper limb movement. RESULTS Both training groups improved performance over the six test sessions but the improvement was significantly larger in the imagery group. That is, the imagery group was able to perform more precise movements than the execution group after the sixth training session while there was no difference at the beginning of the training. CONCLUSIONS The results provide evidence for the benefit of motor imagery training in patients with hemiparesis and thus suggest the integration of cognitive training in conventional physiotherapy practice.

Differences in fMRI intersubject correlation while viewing unedited and edited videos of dance performance

Intersubject correlation (ISC) analysis of functional magnetic resonance imaging (fMRI) data provides insight into how continuous streams of sensory stimulation are processed by groups of observers. Although edited movies are frequently used as stimuli in ISC studies, there has been little direct examination of the effect of edits on the resulting ISC maps. In this study we showed 16 observers two audiovisual movie versions of the same dance. In one experimental condition there was a continuous view from a single camera (Unedited condition) and in the other condition there were views from different cameras (Edited condition) that provided close up views of the feet or face and upper body. We computed ISC maps for each condition, as well as created a map that showed the difference between the conditions. The results from the Unedited and Edited maps largely overlapped in the occipital and temporal cortices, although more voxels were found for the Edited map. The difference map revealed greater ISC for the Edited condition in the Postcentral Gyrus, Lingual Gyrus, Precentral Gyrus and Medial Frontal Gyrus, while the Unedited condition showed greater ISC in only the Superior Temporal Gyrus. These findings suggest that the visual changes associated with editing provide a source of correlation in maps obtained from edited film, and highlight the utility of using maps to evaluate the difference in ISC between conditions.

Reference amounts utilised in front of package nutrition labelling; impact on product healthfulness evaluations

Background/Objectives:The research question addressed in this paper is how different reference amounts utilised in front of package nutrition labelling influence evaluation of product healthfulness.Subjects/Methods:A total of 13 117 participants from six European countries (Germany, UK, Spain, France, Poland and Sweden) were recruited via online panels. A mixed between/within-subject factorial design was employed with food (biscuits, sandwiches, yogurts), healthfulness and presence of Guideline Daily Amounts as within-subjects factors and reference amount (‘per 100 g’, ‘typical portion’, ‘half portion’) and country as between-subjects factors.Results:Overall, people correctly ranked foods according to their objective healthfulness as defined by risk nutrients alone, and could distinguish between more and less healthful variants of foods. General healthfulness associations with the three product categories do not appear to have had a strong influence on product ratings. This study shows that where the reference amount of ‘per 100 g’ is very different from the ‘typical’ portion size, as was the case for biscuits, products with a ‘per 100 g’ label are rated significantly less healthful than the ‘typical’ or ‘half typical’ portions.Conclusion:The results indicate that across the three food categories, consumers do factor the reference amount, that is, the quantity of food for which the nutritional information is being presented, into their judgements of healthfulness. Therefore, appropriate reference amounts are also of importance for the effective presentation of nutritional information.