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45 result(s) for "allocentric frame of reference"
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Effects of Mindfulness Meditation on Self-Transcendent States: Perceived Body Boundaries and Spatial Frames of Reference
Objectives 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) allocentric spatial frame 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 that 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 that 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.
What is the role of spatial processing in the decline of episodic memory in Alzheimer's disease? The \mental frame syncing\ hypothesis
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.
Learning a Path from Real Navigation: The Advantage of Initial View, Cardinal North and Visuo-Spatial Ability
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. Method: 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.
Tool use in Goffin’s cockatoos: Shape/frame matching
Nonhuman tool use is no longer questioned; the issues now are whether such use is mostly inflexible and innately specified or involves experience, innovation, adaptation, and cognitive planning, and how many species qualify. Habl and Auersperg ( PLoS One, 12 (11):e0186859, 2017 ) have shown that some Goffin’s cockatoos ( Cacatua goffiniana ) respond in novel ways to a tool-use task that nonhuman primates and young children find somewhat challenging.
Cognitive load in switching between egocentric and allocentric spatial frames of reference: a pupillometry study
Every day we combine and switch between body-centered (egocentric) and object-centered (allocentric) spatial representations. Several studies so far have reported a greater difficulty to switch from an allocentric reference frame to an egocentric one than vice-versa. To clarify this effect, the present work measured the cognitive load underlying switching vs. non-switching processes between reference frames through cognitive pupillometry. Participants performed a custom-designed visuo-spatial memory task, while pupil dilation variations were measured with eye-tracking. After memorizing triads of objects, participants provided judgments of relative distance in non-switching (only-egocentric, only-allocentric) and switching (from-ego-to-allo, from-allo-to-ego) conditions. The results showed a larger pupil dilation in switching judgments from-allocentric-to-egocentric reference frames than from-egocentric-to-allocentric ones. Moreover, pupil evoked-responses were also larger in allocentric- than egocentric-based non-switching conditions. Overall, the results showed that, for both non-switching and switching visuo-spatial processes, starting from an allocentric-based representation elicits a higher cognitive load than starting from an egocentric-based one. Thus, the disproportional effort in visuo-spatial switching processes seems to be determined by the first reference frame adopted that, in turn, contaminates also the following one.
No Gender Differences in Egocentric and Allocentric Environmental Transformation After Compensating for Male Advantage by Manipulating Familiarity
The present study has two-fold aims: to investigate whether gender differences persist even when more time is given to acquire spatial information; to assess the gender effect when the retrieval phase requires recalling the pathway from the same or a different reference perspective (egocentric or allocentric). Specifically, we analyse the performance of men and women while learning a path from a map or by observing an experimenter in a real environment. We then asked them to reproduce the learned path using the same reference system (map learning vs. map retrieval or real environment learning vs. real environment retrieval) or using a different reference system (map learning vs. real environment retrieval or vice versa). The results showed that gender differences were not present in the retrieval phase when women have the necessary time to acquire spatial information. Moreover, using the egocentric coordinates (both in the learning and retrieval phase) proved easier than the other conditions, whereas learning through allocentric coordinates and then retrieving the environmental information using egocentric coordinates proved to be the most difficult. Results showed that by manipulating familiarity, gender differences disappear, or are attenuated in all conditions.
Frames of reference and categorical/coordinate spatial relations in a “what was where” task
The aim of this study was to explore how people use egocentric (i.e., with respect to their body) and allocentric (i.e., with respect to another element in the environment) references in combination with coordinate (metric) or categorical (abstract) spatial information to identify a target element. Participants were asked to memorize triads of 3D objects or 2D figures, and immediately or after a delay of 5 s, they had to verbally indicate what was the object/figure: (1) closest/farthest to them ( egocentric coordinate task ); (2) on their right/left ( egocentric categorical task ); (3) closest/farthest to another object/figure ( allocentric coordinate task ); (4) on the right/left of another object/figure ( allocentric categorical task ). Results showed that the use of 2D figures favored categorical judgments over the coordinate ones with either an egocentric or an allocentric reference frame, whereas the use of 3D objects specifically favored egocentric coordinate judgments rather than the allocentric ones. Furthermore, egocentric judgments were more accurate than allocentric judgments when the response was Immediate rather than delayed and 3D objects rather than 2D figures were used. This pattern of results is discussed in the light of the functional roles attributed to the frames of reference and spatial relations by relevant theories of visuospatial processing.
From aMCI to AD: The Role of Visuo-Spatial Memory Span and Executive Functions in Egocentric and Allocentric Spatial Impairments
A difficulty in encoding spatial information in an egocentric (i.e., body-to-object) and especially allocentric (i.e., object-to-object) manner, and impairments in executive function (EF) are typical in amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD). Since executive functions are involved in spatial encodings, it is important to understand the extent of their reciprocal or selective impairment. To this end, AD patients, aMCI and healthy elderly people had to provide egocentric (What object was closest to you?) and allocentric (What object was closest to object X?) judgments about memorized objects. Participants’ frontal functions, attentional resources and visual-spatial memory were assessed with the Frontal Assessment Battery (FAB), the Trail Making Test (TMT) and the Corsi Block Tapping Test (forward/backward). Results showed that ADs performed worse than all others in all tasks but did not differ from aMCIs in allocentric judgments and Corsi forward. Regression analyses showed, although to different degrees in the three groups, a link between attentional resources, visuo-spatial memory and egocentric performance, and between frontal resources and allocentric performance. Therefore, visuo-spatial memory, especially when it involves allocentric frames and requires demanding active processing, should be carefully assessed to reveal early signs of conversion from aMCI to AD.
Human spatial navigation: Neural representations of spatial scales and reference frames obtained from an ALE meta-analysis
•Spatial navigation system involves the MTL, PPA, RSC, OPA, and PFC.•Navigation in vista and environmental spaces evoked the PPA, RSC, and OPA.•Navigation in environmental space evoked more brain areas than in vista space.•Both allocentric and egocentric frames evoked the bilateral PPA and right RSC.•Allocentric frame evoked three more areas, right culmen, left MFG, and LING than egocentric frame. Humans use different spatial reference frames (allocentric or egocentric) to navigate successfully toward their destination in different spatial scale spaces (environmental or vista). However, it remains unclear how the brain represents different spatial scales and different spatial reference frames. Thus, we conducted an activation likelihood estimation (ALE) meta-analysis of 47 fMRI articles involving human spatial navigation. We found that both the environmental and vista spaces activated the parahippocampal place area (PPA), retrosplenial complex (RSC), and occipital place area in the right hemisphere. The environmental space showed stronger activation than the vista space in the occipital and frontal regions. No brain region exhibited stronger activation for the vista than the environmental space. The allocentric and egocentric reference frames activated the bilateral PPA and right RSC. The allocentric frame showed more stronger activations than the egocentric frame in the right culmen, left middle frontal gyrus, and precuneus. No brain region displayed stronger activation for the egocentric than the allocentric navigation. Our findings suggest that navigation in different spatial scale spaces can evoke specific and common brain regions, and that the brain regions representing spatial reference frames are not absolutely separated.