Spontaneous perspective-taking and its relation to schizotypy.

INTRODUCTION: Patients with schizophrenia differ from healthy controls in the extent that they spontaneously take another's perspective. For such effects, it is difficult to separate the influence of schizophrenia from multiple potential confounders. Here, for the first time, associations between spontaneous perspective-taking and schizotypy were investigated in a nonclinical population. METHODS: Adult participants completed both a Schizotypal Personality Questionnaire (SPQ-BRU) and a novel online adaptation of a visual perspective-taking task that required participants to make judgements both from their own perspective and that of a human avatar. RESULTS: Response times were elevated when the avatar's perspective was inconsistent with that of the participant, providing evidence of spontaneous perspective-taking. This demonstrates that the visual perspective-taking task can be successfully implemented in an online format. However, schizotypy did not predict these spontaneous perspective-taking effects. CONCLUSIONS: Unlike explicit mentalising, this form of implicit mentalising is not affected by nonclinical manifestations of schizotypy traits. This implies that impairment of general neurocognitive function contributes to altered spontaneous perspective-taking in schizophrenia. A novel account based on the cognitive control processes involved in perspective selection and the role of attention in perspective calculation reconciles apparently contradictory findings of earlier studies comparing patients with schizophrenia and healthy controls.

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.

Water consumption, not expectancies about water consumption, affects cognitive performance in adults.

Research has shown that water supplementation positively affects cognitive performance in children and adults. The present study considered whether this could be a result of expectancies that individuals have about the effects of water on cognition. Forty-seven participants were recruited and told the study was examining the effects of repeated testing on cognitive performance. They were assigned either to a condition in which positive expectancies about the effects of drinking water were induced, or a control condition in which no expectancies were induced. Within these groups, approximately half were given a drink of water, while the remainder were not. Performance on a thirst scale, letter cancellation, digit span forwards and backwards and a simple reaction time task was assessed at baseline (before the drink) and 20 min and 40 min after water consumption. Effects of water, but not expectancy, were found on subjective thirst ratings and letter cancellation task performance, but not on digit span or reaction time. This suggests that water consumption effects on letter cancellation are due to the physiological effects of water, rather than expectancies about the effects of drinking water.

Empathic and non-empathic routes to visuospatial perspective-taking.

The present study examined whether strategy moderated the relationship between visuospatial perspective-taking and empathy. Participants (N=96) undertook both a perspective-taking task requiring speeded spatial judgements made from the perspective of an observed figure and the Empathy Quotient questionnaire, a measure of trait empathy. Perspective-taking performance was found to be related to empathy in that more empathic individuals showed facilitated performance particularly for figures sharing their own spatial orientation. This relationship was restricted to participants that reported perspective-taking by mentally transforming their spatial orientation to align with that of the figure; it was absent in those adopting an alternative strategy of transposing left and right whenever confronted with a front-view figure. Our finding that strategy moderates the relationship between empathy and visuospatial perspective-taking enables a reconciliation of the apparently inconclusive findings of previous studies and provides evidence for functionally dissociable empathic and non-empathic routes to visuospatial perspective-taking.

Hand dominance influences the processing of observed bodies.

In motor tasks, subgroups of lefthanders have been shown to differ in the distribution of attention about their own bodies. The present experiment examined whether similar attentional biases also apply when processing observed bodies. Sixteen right handers (RHs), 22 consistent left handers (CLHs) and 11 relatively ambidextrous inconsistent left handers (ILHs) performed an own body transformation task in which they were instructed to make speeded left-right judgements about a schematic human figure. Attentional biases associated with handedness were found to extend to observed bodies: CLHs' judgements were faster to the figure's left side, while ILHs, like RHs, showed facilitated performance to the figure's right side. These results demonstrate a novel embodiment effect whereby the processing of a static schematic human figure is modulated by an individual's personal motor capabilities. This finding suggests that motor simulation may contribute to whole body perception in the absence of actual or implied actions.

Implicit Mentalising during Level-1 Visual Perspective-Taking Indicated by Dissociation with Attention Orienting.

Experiments demonstrating level-1 visual perspective-taking have been interpreted as providing important evidence for 'implicit mentalising'-the ability to track simple mental states in a fast and efficient manner. However, this interpretation has been contested by a rival 'submentalising' account that proposes that these experiments can be explained by the general purpose mechanisms responsible for attentional orienting. Here, we aim to discriminate between these competing accounts by examining whether a gaze aversion manipulation expected to enhance attention orienting would have similar effects on both perspective-taking and attention orienting tasks. Gaze aversion was operationalised by manipulating head position relative to torso of the avatar figures employed in two experiments (gaze-averted vs. gaze-maintained). Experiment 1 used a Posner cueing task to establish that gaze aversion enhanced attention orienting cued by these avatars. Using the avatar task, Experiment 2 revealed level-1 visual perspective-taking effects of equivalent magnitude for gaze-averted and gaze-maintained conditions. These results indicate that gaze aversion moderated attention orienting but not perspective-taking. This dissociation in performance favours implicit mentalising by casting doubt on the submentalising account. It further constrains theorising by implying that attention orienting is not integral to the system permitting the relatively automatic tracking of mental states.

'Spontaneous' visual perspective-taking mediated by attention orienting that is voluntary and not reflexive.

Experiments revealing 'spontaneous' visual perspective-taking are conventionally interpreted as demonstrating that adults have the capacity to track simple mental states in a fast and efficient manner ('implicit mentalising'). A rival account suggests that these experiments can be explained by the general purpose mechanisms responsible for reflexive attentional orienting. Here, we report two experiments designed to distinguish between these competing accounts. In Experiment 1, we assessed whether reflexive attention orienting was sufficient to yield findings interpreted as spontaneous perspective-taking in the 'avatar task' when the protocol was adapted so that participants were unaware that they were taking part in a perspective-taking experiment. Results revealed no evidence for perspective-taking. In Experiment 2, we employed a Posner paradigm to investigate the attentional orienting properties of the avatar stimuli. This revealed cue-validity effects only for longer stimulus onset asynchronies, which indicates a voluntary rather than reflexive shift in spatial attention. Taken together, these findings suggest that attentional orienting does indeed contribute to performance in the Samson et al. avatar task. However, attention orienting appears to be voluntary rather than reflexive, indicating that the perspective-taking phenomenon measured may be less spontaneous than first reported.

Observed bodies generate object-based spatial codes.

Contemporary studies of spatial and social cognition frequently use human figures as stimuli. The interpretation of such studies may be complicated by spatial compatibility effects that emerge when researchers employ spatial responses, and participants spontaneously code spatial relationships about an observed body. Yet, the nature of these spatial codes - whether they are location- or object-based, and coded from the perspective of the observer or the figure - has not been determined. Here, we investigated this issue by exploring spatial compatibility effects arising for objects held by a visually presented whole-bodied schematic human figure. In three experiments, participants responded to the colour of the object held in the figure's left or right hand, using left or right key presses. Left-right compatibility effects were found relative to the participant's egocentric perspective, rather than the figure's. These effects occurred even when the figure was rotated by 90° to the left or to the right, and the coloured objects were aligned with the participant's midline. These findings are consistent with spontaneous spatial coding from the participant's perspective and relative to the normal upright orientation of the body. This evidence for object-based spatial coding implies that the domain general cognitive mechanisms that result in spatial compatibility effects may contribute to certain spatial perspective-taking and social cognition phenomena.

Subjective thirst moderates changes in speed of responding associated with water consumption.

Participants (N = 34) undertook a CANTAB battery on two separate occasions after fasting and abstaining from fluid intake since the previous evening. On one occasion they were offered 500 ml water shortly before testing, and on the other occasion no water was consumed prior to testing. Reaction times, as measured by Simple Reaction Time (SRT), were faster on the occasion on which they consumed water. Furthermore, subjective thirst was found to moderate the effect of water consumption on speed of responding. Response latencies in the SRT task were greater under the "no water" condition than under the "water" condition, but only for those participants with relatively high subjective thirst after abstaining from fluid intake overnight. For those participants with relatively low subjective thirst, latencies were unaffected by water consumption, and were similarly fast as those recorded for thirsty participants who had consumed water. These results reveal the novel finding that subjective thirst moderates the positive effect of fluid consumption on speed of responding. The results also showed evidence that practice also affected task performance. These results imply that, for speed of responding at least, the positive effects of water supplementation may result from an attenuation of the central processing resources consumed by the subjective sensation of thirst that otherwise impair the execution of speeded cognitive processes.

Strategy modulates spatial perspective-taking: evidence for dissociable disembodied and embodied routes.

Previous research provides evidence for a dissociable embodied route to spatial perspective-taking that is under strategic control. The present experiment investigated further the influence of strategy on spatial perspective-taking by assessing whether participants may also elect to employ a separable "disembodied" route loading on inhibitory control mechanisms. Participants (N = 92) undertook both the "own body transformation" (OBT) perspective-taking task, requiring speeded spatial judgments made from the perspective of an observed figure, and a control task measuring ability to inhibit spatially compatible responses in the absence of a figure. Perspective-taking performance was found to be related to performance on the response inhibition control task, in that participants who tended to take longer to adopt a new perspective also tended to show a greater elevation in response times when inhibiting spatially compatible responses. This relationship was restricted to those participants reporting that they adopted the perspective of another by reversing left and right whenever confronted with a front-view figure; it was absent in those participants who reported perspective-taking by mentally transforming their spatial orientation to align with that of the figure. Combined with previously published results, these findings complete a double dissociation between embodied and disembodied routes to spatial perspective-taking, implying that spatial perspective-taking is subject to modulation by strategy, and suggesting that embodied routes to perspective-taking may place minimal demands on domain general executive functions.

Sex differences in components of imagined perspective transformation.

Little research to date has examined whether sex differences in spatial ability extend to the mental self rotation involved in taking on a third party perspective. This question was addressed in the present study by assessing components of imagined perspective transformations in twenty men and twenty women. Participants made speeded left-right judgements about the hand in which an object was held by front- and back- facing schematic human figures in an "own body transformation task." Response times were longer when the figure did not share the same spatial orientation as the participant, and were substantially longer than those made for a control task requiring left-right judgements about the same stimuli from the participant's own point of view. A sex difference in imagined perspective transformation favouring males was found to be restricted to the speed of imagined self rotation, and was not observed for components indexing readiness to take a third party point of view, nor in left-right confusion. These findings indicate that the range of spatial abilities for which a sex difference has been established should be extended to include imagined perspective transformations. They also suggest that imagined perspective transformations may not draw upon those empathic social-emotional perspective taking processes for which females show an advantage.

Domain general mechanisms account for imagined transformations of whole body perspective.

Three experiments investigated the contribution of domain general processes to imagined transformations of whole body perspective. In a task where participants make left-right judgements about a schematic human figure, reaction times made from the point of view of the figure are longer when the figure does not share the same spatial orientation as the participant and are substantially longer than those made from the participant's own point of view. These phenomena have been attributed to a specialised mechanism for imagined perspective transformations. In the present experiments, the effect of orientation on performance was influenced by factors that affect spatial stimulus-response (S-R) compatibility; it was attenuated with reduced dimensional overlap and reversed by crossed S-R mappings. Performance in a control experiment in which no figure was present suggests that processes moderating S-R mappings may account for the effect of adopting another's point of view. Our findings demonstrate a role for domain general processes in imagined transformations of whole body perspective, imply that egocentric codes for spatial relationships within visually presented bodies are automatically generated, and undermine evidence for a specialised mechanism for imagined perspective transformations.