When lying inside a MRI scanner and even in the absence of any motion, the static magnetic field of MRI scanners induces a magneto-hydrodynamic stimulation of subjects\' vestibular organ (MVS). MVS thereby not only causes a horizontal vestibular nystagmus but also induces a horizontal bias in spatial attention. In this study, we aimed to determine the time course of MVS-induced biases in both VOR and spatial attention inside a 3 T MRI-scanner as well as their respective aftereffects after participants left the scanner. Eye movements and overt spatial attention in a visual search task were assessed in healthy volunteers before, during, and after a one-hour MVS period. All participants exhibited a VOR inside the scanner, which declined over time but never vanished completely. Importantly, there was also an MVS-induced horizontal bias in spatial attention and exploration, which persisted throughout the entire hour within the scanner. Upon exiting the scanner, we observed aftereffects in the opposite direction manifested in both the VOR and in spatial attention, which were statistically no longer detectable after 7 min. Sustained MVS effects on spatial attention have important implications for the design and interpretation of fMRI-studies and for the development of therapeutic interventions counteracting spatial neglect.

The uniqueness of neural processes between allocentric and egocentric spatial coding has been controversial. The distinctive paradigms used in previous studies for manipulating spatial coding could have attributed for the inconsistent results. This study was aimed to generate converging evidence from previous functional brain imaging experiments for collating neural substrates associated with these two types of spatial coding. An additional aim was to test whether test-taking processes would have influenced the results. We obtained coordinate-based functional neuroimaging data for 447 subjects and performed activation likelihood estimation (ALE) meta-analysis. Among the 28 experiments, the results indicate two common clusters of convergence. They were the right precuneus and the right superior frontal gyrus as parts of the parieto-frontal circuit. Between-type differences were in the parieto-occipital circuit, with allocentric showing convergence in the superior occipital gyrus (SOG) cluster compared with egocentric showing convergence in the middle occipital gyrus (MOG) cluster. Task-specific influences were only found in allocentric spatial coding. Spatial judgment-oriented tasks seem to increase the demands on manipulating spatial relationships among the visual objects, while spatial navigation tasks seem to increase the demands on maintaining object representations. Our findings address the theoretical controversies on spatial coding that both the allocentric and egocentric types are common in their processes mediated by the parieto-frontal network, while unique and additional processes in the allocentric type are mediated by the parieto-occipital network. The positive results on possible task-specific confound offer insights into the future design of spatial tasks for eliciting spatial coding processes.

OBJECTIVE: Mindfulness training is believed to encourage self-transcendent states, but little research has examined this hypothesis. This study examined the effects of mindfulness training on two phenomenological features of self-transcendence: 1) perceived body boundary dissolution, and 2) more allocentric spatial frames of reference.
METHODS: A sample of healthy, young adults (n=45) were randomized to five sessions of mindfulness training or an active listening control condition.
RESULTS: Results indicated mindfulness training decreased perceived body boundaries (F 4,172=6.010, p<.001, η 2=.12) and encouraged more allocentric frames of reference (F 4,168=2.586, p=.039, η 2=.06). The expected inverse relationship was observed between perceived body boundaries and allocentric frames of reference ((β=-.58, p=.001)), and path analysis revealed the effect of mindfulness training on allocentric frames of reference was mediated by decreased perceived body boundaries (β=.24, se=.17, CI: 0.11 to 0.78).
CONCLUSIONS: Taken together, study results suggest that mindfulness training alters practitioners\' experience of self, relaxing the boundaries of the self and extending the spatial frame of reference further beyond the physical body. Future studies are needed to explore the psychophysiological changes that co-occur with phenomenological reports of self-transcendence and the behavioral consequences following self-transcendent experiences.

BACKGROUND: Spatial cognition research strives to maximize conditions favoring environment representation. This study examined how initial (egocentric) navigation headings interact with allocentric references in terms of world-based information (such as cardinal points) in forming environment representations. The role of individual visuo-spatial factors was also examined.
METHODS: Ninety-one undergraduates took an unfamiliar path in two learning conditions, 46 walked from cardinal south to north (SN learning), and 45 walked from cardinal north to south (NS learning). Path recall was tested with SN and NS pointing tasks. Perspective-taking ability and self-reported sense of direction were also assessed.
RESULTS: Linear models showed a better performance for SN learning and SN pointing than for NS learning and NS pointing. The learning condition x pointing interaction proved SN pointing more accurate than NS pointing after SN learning, while SN and NS pointing accuracy was similar after NS learning. Perspective-taking ability supported pointing accuracy.
CONCLUSIONS: These results indicate that initial heading aligned with cardinal north prompt a north-oriented representation. No clear orientation of the representation emerges when the initial heading is aligned with cardinal south. Environment representations are supported by individual perspective-taking ability. These findings offer new insight on the environmental and individual factors facilitating environment representations acquired from navigation.

Different reference frames are used in daily life in order to structure the environment. The two-choice Simon task setting has been used to investigate how task-irrelevant spatial information influences human cognitive control. In recent studies, a Go/NoGo Simon task setting was used in order to divide the Simon task between a pair of participants. Yet, not only a human co-actor, but also even an attention-grabbing object can provide sufficient reference in order to reintroduce a Simon effect (SE) indicating cognitive conflict in Go/NoGo task settings. Interestingly, the SE could only occur when a reference point outside of the stimulus setup was available. The current studies exploited the dependency between different spatial reference frames (egocentric and allocentric) offered by the stimulus setup itself and the task setup (individual vs. joint Go/NoGot task setting). Two studies (Experiments 1 and 2) were carried out along with a human co-actor. Experiment 3 used an attention-grabbing object instead. The egocentric and allocentric SEs triggered by different features of the stimulus setup (global vs. local) were modulated by the task setup. When interacting with a human co-actor, an egocentric SE was found for global features of the stimulus setup (i.e., stimulus position on the screen). In contrast, an allocentric SE was yielded in the individual task setup illustrating the relevance of more local features of the stimulus setup (i.e., the manikin\'s ball position). Results point toward salience shifts between different spatial reference frames depending on the nature of the task setup.

Unilateral spatial neglect is a common neurological syndrome following predominantly right hemisphere damage, and is characterized by a failure to perceive and report stimuli in the contralesional side of space. To test the reference shift hypothesis that contralesional spatial neglect in right-brain-damaged patients is attributed to a rightward deviation of the egocentric reference frame, we measured the final angular position to which controls and left-side neglect patients actively turned their head toward the left in response to a verbal instruction given from each of three locations-right, left, and front-in two conditions, with and without visual feedback. When neglect patients were asked to \"look straight ahead\", they deviated about 30° toward the right in the eyes-open condition. However, the rightward deviation was markedly reduced in the eyes-closed condition. Regardless of visual feedback, there was no significant difference between controls and neglect patients in the final angular position of active head rotation when the verbal instruction came from the subject\'s left or front side; however, the final angular position was significantly smaller in the neglect patients than in the controls when the verbal instruction was given from the right. These results support the contention that cervico-vestibular stimulation during active head rotation restores spatial remapping and sensori-motor correlations and so improves neglect without affecting the position of the egocentric reference; however, once left-side neglect patients respond to verbal instruction from the right side, they are unable to disengage attention from the hemispace, and the performance of head rotation is disturbed.

[This corrects the article on p. 64 in vol. 7, PMID: 26903893.].

Knowing who we are, and where we are, are two fundamental aspects of our physical and mental experience. Although the domains of spatial and social cognition are often studied independently, a few recent areas of scholarship have explored the interactions of place and self. This fits in with increasing evidence for embodied theories of cognition, where mental processes are grounded in action and perception. Who we are might be integrated with where we are, and impact how we move through space. Individuals vary in personality, navigational strategies, and numerous cognitive and social competencies. Here we review the relation between social and spatial spheres of existence in the realms of philosophical considerations, neural and psychological representations, and evolutionary context, and how we might use the built environment to suit who we are, or how it creates who we are. In particular we investigate how two spatial reference frames, egocentric and allocentric, might transcend into the social realm. We then speculate on how environments may interact with spatial cognition. Finally, we suggest how a framework encompassing spatial and social cognition might be taken in consideration by architects and urban planners.

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The current theories on episodic memory suggest a crucial role of spatial processing for an effective retrieval. For a successful episodic recall, the long-term allocentric scene has to be translated into an egocentric scene. Here, we argue that a crucial role for an episodic retrieval is played by a \"mental frame syncing\" between two kinds of allocentric representations. This neurocognitive process allows an effective retrieval of our past experiences by synchronizing the allocentric view-point independent representation with the allocentric view-point dependent representation. If the \"mental frame syncing\" stops, even momentarily, it is difficult to reconstruct a coherent spatial scaffold upon which to effectively retrieve our previous events within an egocentric perspective. This is what apparently happens in Alzheimer\'s disease: a break in the \"mental frame syncing\" between these two kinds of allocentric representations, underpinned by damage to the hippocampus, may contribute significantly to the early deficit in episodic memory.