Spatial reference frames (RFs) play a key role in spatial cognition, especially in perception, spatial memory, and navigation. There are two main types of RFs: egocentric (self-centered) and allocentric (object-centered). Although many fMRI studies examined the neural correlates of egocentric and allocentric RFs, they could not sample the fast temporal dynamics of the underlying cognitive processes. Therefore, the interaction and timing between these two RFs remain unclear. Taking advantage of the high temporal resolution of intracranial EEG (iEEG), we aimed to determine the timing of egocentric and allocentric information processing and describe the brain areas involved. We recorded iEEG and analyzed broad gamma activity (50-150 Hz) in 37 epilepsy patients performing a spatial judgment task in a three-dimensional circular virtual arena. We found overlapping activation for egocentric and allocentric RFs in many brain regions, with several additional egocentric- and allocentric-selective areas. In contrast to the egocentric responses, the allocentric responses peaked later than the control ones in frontal regions with overlapping selectivity. Also, across several egocentric or allocentric selective areas, the egocentric selectivity appeared earlier than the allocentric one. We identified the maximum number of egocentric-selective channels in the medial occipito-temporal region and allocentric-selective channels around the intraparietal sulcus in the parietal cortex. Our findings favor the hypothesis that egocentric spatial coding is a more primary process, and allocentric representations may be derived from egocentric ones. They also broaden the dominant view of the dorsal and ventral streams supporting egocentric and allocentric space coding, respectively.

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.

This study explores the interpersonal space (IPS) and peripersonal space (PPS) of Chinese people and evaluates the relationship between the two spaces for different directions and genders. Seventy-one participants were recruited for this study. Participants were required to determine their IPS in eight directions (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) when approached by male or female confederates in the comfort distance task. Each participant was also asked to judge their PPS in five directions (0°, 45°, 90°, 270°, 315°) following the same procedure. Results showed that their IPS was significantly influenced by direction (p < 0.05), with the largest distance in the front (0°) and the closest distance in the rear (135°, 180°, 225°), indicating non-circular IPS among Chinese subjects. Moreover, the PPS on the right side (90°) was larger than in other directions (0°, 45°, 270°, 315°). Participants maintained larger IPS than PPS in the front, but the IPS was closer than PPS on the right and left sides. When facing a female confederate, larger IPS was preferred than PPS, whereas the opposite held true when facing a male confederate. Comparison of participants\' arm length and PPS showed that the reachability distance was overestimated in the front but underestimated laterally. The findings of this study can be applied to environmental design, space utilization, and social interaction.

These data provide coordinates generated from a large healthy adult lifespan sample undergoing functional Magnetic Resonance Imaging (fMRI) while completing a spatial judgment task with varying levels of difficulty, as well as a control categorical condition. The data presented here include the average blood-oxygen-dependent (BOLD) response to the spatial judgment vs. the control task, as well as the BOLD response to incremental increasing difficulty; see also \"Age-related Reduction of BOLD Modulation to Cognitive Difficulty Predicts Poorer Task Accuracy and Poorer Fluid Reasoning Ability\" (Rieck et al., 2017) [1].

Our actions are influenced by the social context in which they are performed, specifically it has been shown that observing others\' actions influences the execution of the same action. In the present study, we examined whether and to what extent observers are influenced by the presence and performance of another person in a visual spatial task, using a line bisection paradigm in which two participants performed the task in turns while sitting in front of each other. Thirty pairs of participants took part in the experiment, which was divided into a non-social and a social session. In the latter, each participant was alternately an agent (performing the task) and an observer (evaluating covertly the other\'s performance). Results show that the leftward bias (pseudoneglect) in the line bisection task was significantly reduced when the task was performed in the social session, although the bias (both in the non-social and in the social session) was observed only when the left hand was used. Moreover, a dissociation between performance and perception was observed: the judgment given to the other\'s performance (which visually deviated in the direction opposite to one\'s own bias due to the spatial arrangement of participants and their facing vantage points) was significantly in disagreement with one\'s own performance. Overall, our results demonstrate that the other\'s presence influences our own action during a line bisection task and that spatial judgments on other\'s performance can modulate our own performance, even when coordination between participants is not required. Results are discussed in relation to social influence and perspective taking in the general framework of interpersonal resonance.

Findings for heat pain have shown consistent pain attenuation through concurrent cognitive task completion; but only a minimal amount of studies have explored that for cold pain. This study investigated the direct impact of two well-established cognitive tasks on cold pain tolerance. In a within-subject design, 36 female Hong Kong locals were required to complete a baseline pain tolerance measurement, induced by the well-established Cold Pressor Test. This was followed by the counterbalanced presentation of the Colour Stroop or the Judgment of Line Orientation task with and without concurrent pain administration. As suggested by the Limited Capacity, Multiple Resource, and Cognitive-Affective Models, participants were expected to tolerate pain for significantly longer durations when they perform either concurrent Colour Stroop or concurrent Judgment of Line Orientation tasks compared to baseline measures with no concurrent task. The findings clearly indicated increased pain tolerance times during task completion compared with baseline measures, providing support for the a-priori hypothesis. The results contribute to existing literature by confirming increased cold pain tolerance during selective attention to cognitive tasks and extending this finding to tasks previously established in heat pain but not for cold pain research.

The default network is a system of brain areas that are engaged when the mind is not involved in goal-directed activity. Most previous studies of age-related changes in default mode processing have used verbal tasks. We studied non-verbal spatial tasks that vary in difficulty. We presented old and young participants with two spatial judgment tasks: an easy categorical judgment and a more demanding coordinate judgment. We report that (a) Older adults show markedly less default network modulation than young on the demanding spatial task, but there is age equivalence on the easy task; (b) This Age x Task interaction is restricted to the default network: Brain areas that are deactivated by the tasks, but that are outside the default network, show no interaction; (c) Young adults exhibit significantly stronger functional connectivity among posterior regions of the default network compared with older adults, whereas older adults exhibit stronger connectivity between medial prefrontal cortex and other sites; and (d) The relationship of default activity to reaction time performance on the spatial tasks is mediated by age: in old adults, those who deactivate the default network most also perform best, whereas the opposite is true in younger adults. These results extend the findings of age-related changes in default mode processing and connectivity to visuo-spatial tasks and demonstrate that the results are specific to the default network.