Effects of arm crossing on spatial perspective-taking

Seeing through the cat's eyes: evidence of a spontaneous perspective taking process using a non-human avatar

In many daily face-to-face interactions, people are able to take the perspective of others, for example, coding right and left based on point-of-view of others. In the present study, we investigated whether observers are able to take the perspective of a non-human figure such as a cat, observing the same effects obtained with human or robot avatars. In both experiments, we used a centrally presented stimulus (i.e. a cat), with its tail lateralized to the left or to the right. Participants had to respond to the side of the tail with a lateralized keypress. In Experiment 1 (spatial perspective taking task), participants were required to explicitly adopt the cat's perspective to respond, whereas in Experiment 2 (SR compatibility task), this was not explicitly required. In both experiments, faster RTs are obtained when the cat is presented back, with a greater difference between front and back views when the tail is on the right; furthermore, there is no temporal modulation of the back-front effect. These common results between the two experiments are interpreted on the basis of the spatial perspective taking processes, elicited voluntarily (Experiment 1) or spontaneously (Experiment 2).

Selective attention to real-world objects drives their emotional appraisal

Attentional manipulations have been shown to influence subsequent evaluations of objects and images. For example, images used as distractors in a visual search task are subsequently rated more negatively than are target images. One powerful manipulation of attention occurs when we plan and execute movements toward objects in our environment. Here, in two experiments, we show that selective attention to real-world objects subsequently improves emotional appraisal of those objects-an effect we term "target appreciation." Participants were presented with abstract images on three-dimensional objects, and were cued to either reach and grasp one of the two objects, or to respond to the cued object with a keyboard. Images presented on target objects were appraised more positively when compared with novel images. In contrast, images associated with obstacles or distractor objects were not appraised differently than novel images, despite the attentional suppression thought to be required to successfully avoid or ignore these objects. We speculate that this automatic appreciation of the objects of selective attention may be adaptive for organisms acting in complex environments.

Imitation of meaningless gestures in normal aging

While imitation of meaningless gestures is a gold standard in the assessment of apraxia in patients with either stroke or neurodegenerative diseases, little is known about potential age-related effects on this measure. A significant body of literature has indicated that different mechanisms (i.e., executive functioning, visuospatial skills, sensory integration, body knowledge, categorical apprehension) may underlie the performance depending on imitation conditions (i.e., finger/hand, uni-/bimanual, symmetric/asymmetric, crossed/uncrossed configurations). However, neither the effects of these conditions on performance, nor the contribution of the abovementioned mechanisms to imitation have been explored in normal aging. The aim of the present study was to fill this gap. To do so, healthy adults (n = 103) aged 50 to 89 were asked to imitate 45 meaningless gestures. The authors controlled for general cognitive function, motor function, visual-spatial skills, executive function, sensory integration, body knowledge, and mechanical problem-solving skills. The results showed that asymmetry, body-midline crossing and, to a lesser extent, bimanual activity added an additional layer of difficulty to imitation tasks. After controlling for motor speed and cognitive function, age had an effect on imitation skills after 70 years old. This may reflect a decline in body knowledge, sensory integration, and executive functions. In contrast, the visuospatial and mechanical problem-solving hypotheses were ruled out. An additional motor simulation hypothesis is proposed. These findings may prove useful for clinicians working in memory clinics by providing insights on how to interpret imitation deficits. Lower performance after 70 years old should not be considered abnormal in a systematic manner.

Cognitive processes in spatial mapping: Evidence from a developmental spatial deficit

We report a case study of an adolescent girl (N.K.Y.) with a developmental deficit affecting spatial processing. In a simple spatial mapping task, N.K.Y. shows a striking dissociation: She succeeds in one variant of the experiment in which the stimuli are objects, but struggles in a structurally identical task with people as stimuli. We present evidence that this dissociation stems from a tendency to automatically adopt the spatial perspective of other people, but not objects-a phenomenon also observed in neurotypical individuals. When adopting another person's perspective, N.K.Y. imagines herself in the other's position, representing the other's left and right as if it were her own. N.K.Y.'s deficit in relating left-right information to her own body then disrupts her performance. Our results shed light on the nature of N.K.Y.'s deficit as well as the cognitive operations involved in spatial perspective taking.

Dissociating contributions of head and torso to spatial reference frames: The misalignment paradigm

When we represent someone's view of a scene as egocentrically structured, where do we represent the origin of the reference frame? By analysing responses in a spatial perspective-taking task as a function of spatial location with respect to both head and torso, we isolated the respective contribution of each part to spatial judgments. Both the head and the torso contributed to judgements, though with greater contributions from the torso. A second experiment manipulating visual contrast of the torso showed that this does not reflect low-level differences in visual salience between body parts. Our results demonstrate that spatial perspective-taking relies on a weighted combination of reference frames centred on different parts of the body.

When Far Becomes Near

On many occasions, people spontaneously or deliberately take the perspective of a person facing them rather than their own perspective. How is this done? Using a spatial perspective task in which participants were asked to identify objects at specific locations, we found that self-perspective judgments were faster for objects presented to the right, rather than the left, and for objects presented closer to the participants’ own bodies. Strikingly, taking the opposing perspective of another person led to a reversal (i.e., remapping) of these effects, with reference to the other person’s position (Experiment 1). A remapping of spatial relations was also observed when an empty chair replaced the other person (Experiment 2), but not when access to the other viewpoint was blocked (Experiment 3). Thus, when the spatial scene allows a physically feasible but opposing point of view, people respond as if their own bodies were in that place. Imagination can thus overcome perception.

Embodied perspective-taking indicated by selective disruption from aberrant self motion

Spatial perspective-taking that involves imagined changes in one's spatial orientation is facilitated by vestibular stimulation inducing a congruent sensation of self-motion. We examined further the role of vestibular resources in perspective-taking by evaluating whether aberrant and conflicting vestibular stimulation impaired perspective-taking performance. Participants (N = 39) undertook either an "own body transformation" (OBT) task, requiring speeded spatial judgments made from the perspective of a schematic figure, or a control task requiring reconfiguration of spatial mappings from one's own visuo-spatial perspective. These tasks were performed both without and with vestibular stimulation by whole-body Coriolis motion, according to a repeated measures design, balanced for order. Vestibular stimulation was found to impair performance during the first minute post stimulus relative to the stationary condition. This disruption was task-specific, affecting only the OBT task and not the control task, and dissipated by the second minute post-stimulus. Our experiment thus demonstrates selective temporary impairment of perspective-taking from aberrant vestibular stimulation, implying that uncompromised vestibular resources are necessary for efficient perspective-taking. This finding provides evidence for an embodied mechanism for perspective-taking whereby vestibular input contributes to multisensory processing underlying bodily and social cognition. Ultimately, this knowledge may contribute to the design of interventions that help patients suffering sudden vertigo adapt to the cognitive difficulties caused by aberrant vestibular stimulation.