Different Spatial Frames Of Reference Research Articles

Effect of Hindi, Sanskrit and Urdu medium schooling on spatial language and encoding

Spatial cognition refers to the process through which people acquire knowledge of the location of objects in their surrounding environment. Studies suggest that people use different spatial frames of reference to describe the location of objects in space. The present study examines the frames of reference used by 10–15-year-old students attending Hindi, Sanskrit and Urdu medium schools at Varanasi in performing spatial cognitive tasks. Traditional schools, such as Sanskrit and Urdu medium schools, provide substantial experience and training in the use of a geocentric frame of reference based on cardinal directions (i.e., north, south, east and west). In view of this, it was expected that children attending these schools would use a geocentric frame of reference more than those attending Hindi medium school. Using a variety of procedures, the spatial frames of reference used in description and encoding of objects by students in Hindi, Sanskrit and Urdu medium schools were assessed. The results indicated that traditional Sanskrit and Urdu medium school students used more geocentric language for description of spatial objects and they also engaged in greater geocentric encoding of those objects than the students of Hindi medium schools.

The spatial representation of numbers and time follow distinct developmental trajectories: A study in 6- and 10-year-old children

Space-number and space-time associations have been a timely topic in the cognitive sciences for years, but evidence from developmental populations is still scarce. In particular, it remains to be established whether space-number and space-time mappings are anchored onto the same spatial frame of reference across development. To explore this issue, we manipulated visual and proprioceptive feedback in a Number Comparison task (Experiment 1) and a Time Comparison task (Expriment 2), in which 6- and 10-year-old children had to classify numerical and temporal words by means of a lateralised response with or without a blindfold (visual manipulation), and with hands uncrossed or crossed over the body midline (proprioceptive manipulation). Results revealed that 10-year-old children were more efficient in associating smaller numbers and past events with the left key, and larger numbers and future events with the right key, irrespective of the visual and proprioceptive manipulations. On the contrary, younger children did so only in the Time Comparison task, but not in the Number Comparison task. In the latter task, 6-year-olds associated small/large numbers with the left/right side of space only in the presence of visual feedback, but not when blindfolded. Taken together, our findings unveil that in school-aged children the spatial representation of number and time develop on different spatial frames of reference: while space-time associations exclusively rely on external coordinates at age 6, space-number associations shift from mixed internal and external coordinates at age 6 to more adult-like external coordinates by age 10.

Integrating multisensory information across external and motor-based frames of reference

In the mirror box illusion, participants often report that their hand is located where they see it, even when the position of the reflected hand differs from the actual position of their hand. This illusory shift (an index of multisensory integration) is stronger when the two hands engage in synchronous bimanual movement, in which visual and proprioceptive information is congruent in both motor-based (i.e. coordinate centered on the effector) and external (i.e. coordinates centered on elements external to the effector) frames of reference. To investigate the separate contributions of external and motor-based congruence in multisensory integration, we instructed participants to make synchronous or asynchronous tapping movements in either the same (i.e. both hands palms up) or opposing (palm up, palm down) postures. When in opposing postures, externally congruent movements were incongruent in a motor-based frame of reference, and vice versa. Across three experiments, participants reported more illusory shift and stronger ownership of the viewed hand in the mirror for external versus motor-based congruence trials regardless of motor outflow or motor effort, indicating that information from an externally-based representation is more strongly weighted in multisensory integration. These findings provide evidence that not only information across sensory modalities, but also information regarding crossmodal congruence represented in different spatial frames of reference, is differentially weighted in multisensory integration. We discuss how our findings can be incorporated into current computational models on multisensory integration.

Visual and proprioceptive feedback differently modulate the spatial representation of number and time in children

There has been compelling evidence favoring the idea that human adults similarly represent number and time along a horizontal mental number line (MNL) and mental time line (MTL), respectively. Yet, analogies drawn between the MNL and MTL have been challenged by recent studies suggesting that adults’ representations of number and time arise from different spatial frames of reference; whereas the MNL relies on both hand-centered and object-centered coordinates, the MTL appears to be exclusively anchored on object-centered coordinates. To directly test this possibility, here we explored the extent to which visual feedback and proprioceptive feedback affect children’s performance in a Number Comparison task (Experiment 1) and a Time Comparison task (Experiment 2), in which participants needed to associate a lateralized key with numerical and temporal words, respectively. Children (5- and 6-year-olds) performed the task with their hands either uncrossed or crossed over the body midline (i.e., manipulation of proprioceptive feedback) and with either visual control over their hands allowed or precluded under blindfolds (i.e., manipulation of visual feedback). Results showed that children were facilitated in associating smaller/larger numbers with the left/right side of the external space, but only when hands were uncrossed and visual feedback was available. On the contrary, blindfolding and crossing their hands over the midline did not affect spatial time mapping, with 6-year-olds showing facilitation in associating words referring to the past/future with the left/right side of the external space irrespective of visual and proprioceptive feedback. This same effect was also present in 5-year-olds despite their difficulty in performing the Time Comparison task. Together, these findings show, for the first time, that—just like adults—young children (a) map temporal events onto space in a rightward direction as they do for numbers and (b) anchor their spatial representation of time and numbers to different spatial frames of reference.

Applying embodied cognition: from useful interventions and their theoretical underpinnings to practical applications

Embodied trainings allowing children to move their whole body in space have recently been shown to foster the acquisition of basic numerical competencies (e.g. magnitude understanding, addition performance). Following a brief summary of recent embodied training studies, we integrate the different results into a unified model framework to elucidate the working mechanisms of embodied trainings: Mapping processes, interaction between different regions of personal space, and the integration of different spatial frames of reference are addressed as potential factors underlying the effectiveness of embodied numerical trainings. In the concluding section, we elaborate on the practical applications of embodied numerical trainings in educational setting. We discuss under which circumstances embodied trainings work best, that is, for which age group and/or which numerical content embodied trainings should be most beneficial and which aspects need to be considered when aiming at applying embodied numerical trainings in formal educational settings like kindergartens or schools.

Seeing One's Own Painful Hand Positioned in the Contralateral Space Reduces Subjective Reports of Pain and Modulates Laser Evoked Potentials

Studies report that viewing the body or keeping one's arms crossed while receiving painful stimuli may have an analgesic effect. Interestingly, changes in ratings of pain are accompanied by a reduction of brain metabolism or of laser evoked potentials amplitude. What remains unknown is the link between visual analgesia and crossed-arms related analgesia. Here, we investigated pain perception and laser evoked potentials in 3 visual contexts while participants kept their arms in a crossed or uncrossed position during vision of 1) one's own hand, 2) a neutral object in the same spatial location, and 3) a fixation cross placed in front of the participant. We found that having vision of the affected body part in the crossed-arms position was associated with a significant reduction in pain reports. However, no analgesic effect of having vision of the hand in an uncrossed position or of crossing the arms alone was found. The increase of the late vertex laser evoked potential P2 amplitude indexed a general effect of vision of the hand. Our results hint at a complex interaction between cross-modal input and body representation in different spatial frames of reference and at the same time question the effect of visual analgesia and crossed-arms analgesia alone. PerspectiveWe found that nociceptive stimuli delivered to the hand in a crossed-arms position evoke less pain than in a canonical anatomic position. Yet we report no significant analgesic effect of vision or crossing the arms on their own. These findings foster the integration of visuospatial and proprioceptive information in rehabilitation protocols.

Development of different spatial frames of reference for orientation in small-scale environments.

Previous studies show that there is a developmental transition in the frames of reference children use to orientate from a body-centered to an allocentric strategy. However, there is no agreement concerning the age at which they begin to integrate and flexibly use both strategies in small-scale environments. 6-10-year-old children and adults were trained to locate a hidden object in an arm-maze placed within a small-scale model, which maintained stable relationships with the frames of reference provided by the experimental room and by the subject (Experiment 1), and in a situation of inconsistency between the frame provided by the small-scale model and the other two (Experiment 2). When the frames of reference provided by the room and by the subject conflict with that of the manipulative space, the performance deteriorates compared to the situation when multiple frames of reference can be used cooperatively to locate the goal. The flexible use of the information provided by the model (i.e., the cues surrounding the maze and the geometrical features) emerged at 10 years. Through development, children acquire new spatial abilities and increasing flexibility in the conjoint use of egocentric and allocentric frames of reference in small-scale environments.

Visual experience differentially impacts the egocentric and allocentric coding of touch and motor sequence

Touch processing and motor execution both rely on two different spatial frames of reference: a representation built upon egocentric coordinates and a goal-directed representation built upon allocentric coordinates. If early visual deprivation impairs the use of an external frame of reference for touch, the question arises as to whether visual experience also affects the allocentric representation of space in the motor field. To examine this issue, early blind (EB) and sighted control participants (SC) took part in two experiments. In the first, targeting touch processing, participants were required to determine, either with their hands in parallel or crossed over the body midline, the temporal order of two tactile stimuli, one applied to each hand. Crossing the hands led to a significant decrement in performance in SC but did not affect EB, as also demonstrated by Roder and collaborators (2004), suggesting an absence of automatic external remapping of touch in this population. In the second experiment, participants were trained to perform a sequence of five fingers movements. After the training session, participants were tested on their ability to produce, with the same hand, but with the keypad turned upside down, the learned (egocentric condition) or the mirror sequence (allocentric condition). In this task, EB and SC both experienced significant transfer of motor sequence knowledge irrespective of whether the representation of the sequence was allocentric or egocentric. These results therefore demonstrate that early visual experience differentially impacts the egocentric and allocentric coding of touch and motor sequence.

Selective role of lingual/parahippocampal gyrus and retrosplenial complex in spatial memory across viewpoint changes relative to the environmental reference frame

Remembering object locations across different views is a fundamental competence for keeping oriented in large-scale space. Here we investigated such ability by comparing encoding and retrieval of locations across viewpoint changes relative to different spatial frames of reference. We acquired functional magnetic resonance images while subjects detected target displacements across consecutive views of a familiar virtual room, reporting changes in the target absolute position in the room (stable environmental frame), changes in its position relative to a set of movable objects (unstable object-based frame), and changes relative to their point of view (control viewer-centered frame). Behavioral costs were higher for the stable environmental frame, and a cortical network including the lingual/parahippocampal gyrus (LPHG) and the retrosplenial complex (RSC) selectively encoded spatial locations relative to this frame. Several regions, including the dorsal fronto-parietal cortex and the LPHG, were modulated by the amount of experienced viewpoint change, but only the RSC was selectively modulated by the amount of viewpoint change relative to the environmental frame, thus showing a special role in coding one's own position and heading in familiar environments.

Hippocampal Neurons Keep Track of Two Things—One Moving, One Not—Simultaneously

​AnimalsAnimals move, and because they do, they must be masters of multiple frames of reference. As the monkey vaults himself through the air, his eye must be on the stationary branch looming into view; as the child circles on the merry-go-round, her eye must track the brass ring just around the curve. Cognitive control of distinct streams of information is at the core of understanding how we think, but how the electrical activity of neurons mediates cognitive control is unknown. Each frame provides its own stream of spatial information—the moving limb, the fixed target—and processing both streams, while keeping the two separate, is the key to successful behavior in a complex world. This ability, called cognitive control, is clearly essential, but the neural mechanisms underlying it are not well understood. One tool used in cognitive control is believed to be “dynamic grouping,” in which a single set of neurons fires in different patterns, each representing a different information stream, and each pattern alternates in quick succession to allow the brain to process each stream without mashing up the information each contains. While some studies have suggested the hippocampus—a center not only of memory creation but also of spatial positioning—engages in dynamic grouping, the evidence has been conflicting. In a study in this issue, Eduard Kelemen and Andre Fenton show that the hippocampus does indeed use dynamic grouping to process dual (and dueling) spatial information streams. To present a rat with two different spatial frames of reference simultaneously, the authors placed the rat within a rotating “arena,” in which it could scurry around to pick up food rewards. The arena's floor was marked with two wedge-shaped zones, each of which would deliver a shock if the rat stepped on it. One wedge was stationary with respect to the room, and so as the arena rotated and the rat was carried around the circle, it would be swept into the shock zone unless it moved away. Here, the stationary frame of reference of the room (which the rat could see beyond the arena's walls) was most relevant for avoiding the shock. The other wedge moved with the arena, and for avoiding that shock as it navigated the arena, smells and marks on the arena from a moving frame of reference were most useful. The rat quickly learned to avoid both shocks as it negotiated this diabolical merry-go-round—the average rat improved its performance 15-fold within 5 training sessions, confirming the ability to use the two spatial frames of reference concurrently. The hippocampus was crucial for this skill; when the authors temporarily blocked one side of the hippocampus with a toxin, the rat could no longer avoid the shock zones when one was in motion. Within the rat hippocampus, “place cells” process the spatial information that allows the rat to know where it is and to navigate its environment. To investigate the role of hippocampal neuronal ensembles in the rat's behavior, the authors recorded the firings of multiple neurons in the hippocampus while the rat navigated the rotating arena. Based on their previous work correlating discharge patterns with the positional information contained within them, the authors classified individual neuronal discharges at any moment as being stationary frame-specific (meaning the neuron was involved in processing spatial information regarding the stationary frame), or rotational frame-specific. They found that most of the cells they recorded fired in response to one frame or another, about equally divided between the two frames. Cells that fired close together tended to be firing in response to the same frame, linking them into a frame-specific ensemble. Any individual cell could be part of either ensemble, and many were in fact part of both—they fired when either ensemble was active. In keeping with the need to process both streams of information simultaneously, the room-specific ensemble and the arena-specific ensemble alternated their firing. Preference for each ensemble was greatest when the rat was closest to the relevant shock wedge—that is, the room-specific ensemble activated most when the rat was closest to the stationary wedge, versus the arena-specific ensemble when closest to the moving wedge. Taken together, these results indicate that neuronal ensembles encoding spatial information alternate in their activity in synchrony with the relevance of the information, thus using dynamic grouping in the process of cognitive control. These results are valuable not only for understanding the hippocampus, but likely other brain regions as well, since the same challenges, and likely similar solutions, occur elsewhere in the brain. They may also provide some insight into schizophrenia, a central aspect of which is difficulty with processing multiple streams of information simultaneously. Kelemen E, Fenton AA (2010) Dynamic Grouping of Hippocampal Neural Activity during Cognitive Control of Two Spatial Frames. doi:10.1371/journal.pbio.1000403

Equivalence of cognitive processes in brain imaging and behavioral studies: evidence from task switching

A growing number of studies on the higher-order cognitive functions of the human brain use brain-imaging techniques, such as functional magnetic resonance imaging (fMRI). For the validity and generality of fMRI results, it is important that the relevant cognitive processes are equivalent to those functioning in typical settings used in behavioral research. This equivalence could be, for example, endangered by different spatial frames of reference when lying in the scanner. In the present study, we tested whether the cognitive processes, as reflected in behavioral data in brain-imaging settings, are indeed functionally equivalent to those reflected in “purely” behavioral settings. To this end, we used a task-switching paradigm with a spatial component, increasing the likelihood to find effects of experimental setting. We compared the data of three different groups that only differed in testing environments (real, operating fMRI vs simulated fMRI vs standard behavioral with upright position of participants) but used otherwise strictly equivalent experimental conditions. Of importance for our validation purposes, unlike previous studies, we included a group with a behavioral setting, and we tested whether we would replicate a nontrivial, complex three-way interaction across all three groups. We replicated the predicted complex data pattern in all groups, suggesting functional equivalence of the underlying cognitive processes. We also found strongly increased reaction time (RT) levels in the two fMRI groups. We attribute this increase to unspecific distracting factors affecting late motor processes and discuss potential methodological implications of this increased baseline RT in the scanner.

Intrinsic Reference Systems in Map Displays

Within the area of navigation displays, the distinction between track-up display and fixed-orientation displays ( north-up) has received a lot of attention. Theoretically, this distinction has been linked to different spatial frames of reference. Using alignment effects, recent studies on the role of different reference systems in human spatial memory have identified the important role of environmental and intrinsic reference systems for the cognitive organization of spatial information. In the first experiment of its kind, we tested the effects of alignment of an observer with the visible, local environment and the global, large-scale environment depicted in a You-are-Here type of map display while holding the usually emphasized relation between map orientation and observer orientation constant. Our results show that both alignments have a strong and additive effect on memory performance, suggesting a new and important dimension for the design of spatial information displays such as maps.

Route knowledge in different spatial frames of reference

Orienting oneself in space requires establishing a correspondence between various spatial frames of reference (SFR) in which the same information about the environment can be encoded in different ways and formats. In this encoding process, one key point is the alignment of the SFRs, which may require additional operations such as a mental or real rotation. Three experiments were conducted to investigate the process of spatial orientation under aligned and misaligned conditions. Subjects were shown animated sequences of decision points perceived along a route (Experiments 1 and 2) or verbal route instructions (Experiment 3) to which they had to attribute a path on a map. The results showed that when the orientations of the map and the route were different (misalignment) both total time and errors increased. The route length (Experiment 1), and the need to reverse the direction of the path (reverse response condition in Experiments 2 and 3) also led to a decline in performance. In Experiment 3, the map-rotation strategy was found to be pertinent for solving misaligned spatial problems.

A Model for the Interaction of Migration and Commuting

This paper presents a simultaneous equations model for the interaction of migration with changes in commuting, employment and housing stocks, and applies the model to census data for Greater London. Different spatial frames of reference are used: intra-metropolitan, intra-regional, and national. The results suggest an interdependence of migration and commuting with the decentralisation of employment within Greater London. Migration is influenced by tenure structure and turnover in the existing housing stock as well as by the availability of new housing.