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https://www.readbyqxmd.com/read/28223931/a-computational-model-for-spatial-navigation-based-on-reference-frames-in-the-hippocampus-retrosplenial-cortex-and-posterior-parietal-cortex
#1
Timo Oess, Jeffrey L Krichmar, Florian Röhrbein
Behavioral studies for humans, monkeys, and rats have shown that, while traversing an environment, these mammals tend to use different frames of reference and frequently switch between them. These frames represent allocentric, egocentric, or route-centric views of the environment. However, combinations of either of them are often deployed. Neurophysiological studies on rats have indicated that the hippocampus, the retrosplenial cortex, and the posterior parietal cortex contribute to the formation of these frames and mediate the transformation between those...
2017: Frontiers in Neurorobotics
https://www.readbyqxmd.com/read/28221082/partial-lesion-of-the-nigrostriatal-dopamine-pathway-in-rats-impairs-egocentric-learning-but-not-spatial-learning-or-behavioral-flexibility
#2
Katharine M Seip-Cammack, James J Young, Megan E Young, Matthew L Shapiro
Degeneration of the nigrostriatal dopaminergic system in Parkinson's disease (PD) causes motor dysfunction and cognitive impairment, but the etiology of the cognitive deficits remains unclear. The present study investigated the behavioral effects of partial lesions of the nigrostriatal dopamine (DA) pathway. Rats received bilateral infusions of either 6-hydroxydopamine (6-OHDA) or vehicle into the dorsolateral striatum and were tested in spatial and procedural learning tasks. Compared with intact rats, DA-depleted rats were impaired when the first task they learned required egocentric responses...
February 20, 2017: Behavioral Neuroscience
https://www.readbyqxmd.com/read/28190682/perception-of-active-head-rotation-in-patients-with-severe-left-unilateral-spatial-neglect
#3
Shinobu Kaibe, Manabu Okita, Hideto Kaba
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...
February 9, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/28188853/drifting-while-stepping-in-place-in-old-adults-association-of-self-motion-perception-with-reference-frame-reliance-and-ground-optic-flow-sensitivity
#4
Catherine P Agathos, Delphine Bernardin, Konogan Baranton, Christine Assaiante, Brice Isableu
Optic flow provides visual self-motion information and is shown to modulate gait and provoke postural reactions. We have previously reported an increased reliance on the visual, as opposed to the somatosensory-based, egocentric frame of reference (FoR) for spatial orientation with age. In this study, we evaluated FoR reliance for self-motion perception with respect to the ground surface. We examined how effects of ground optic flow direction on posture may be enhanced by an intermittent podal contact with the ground, and reliance on the visual FoR and aging...
February 7, 2017: Neuroscience
https://www.readbyqxmd.com/read/28185328/where-is-the-subjective-straight-ahead-in-williams-syndrome
#5
A Saj, J Heiz, K Barisnikov
BACKGROUND: Individuals with Williams Syndrome (WS) are known to have particular difficulties when performing visuo-spatial tasks, which could be related to their difficulties in using a specific reference system to determine spatial relations. The aim of the present study was to assess the internal representation of the body's sagittal plane, which is an important benchmark for an egocentric frame of reference. METHOD: The results of 18 WS individuals (mean age = 20...
February 10, 2017: Journal of Intellectual Disability Research: JIDR
https://www.readbyqxmd.com/read/28168112/what-has-been-missed-for-predicting-human-attention-in-viewing-driving-clips
#6
Jiawei Xu, Shigang Yue, Federica Menchinelli, Kun Guo
Recent research progress on the topic of human visual attention allocation in scene perception and its simulation is based mainly on studies with static images. However, natural vision requires us to extract visual information that constantly changes due to egocentric movements or dynamics of the world. It is unclear to what extent spatio-temporal regularity, an inherent regularity in dynamic vision, affects human gaze distribution and saliency computation in visual attention models. In this free-viewing eye-tracking study we manipulated the spatio-temporal regularity of traffic videos by presenting them in normal video sequence, reversed video sequence, normal frame sequence, and randomised frame sequence...
2017: PeerJ
https://www.readbyqxmd.com/read/28166888/how-much-time-do-drivers-need-to-obtain-situation-awareness-a-laboratory-based-study-of-automated-driving
#7
Zhenji Lu, Xander Coster, Joost de Winter
Drivers of automated cars may occasionally need to take back manual control after a period of inattentiveness. At present, it is unknown how long it takes to build up situation awareness of a traffic situation. In this study, 34 participants were presented with animated video clips of traffic situations on a three-lane road, from an egocentric viewpoint on a monitor equipped with eye tracker. Each participant viewed 24 videos of different durations (1, 3, 7, 9, 12, or 20 s). After each video, participants reproduced the end of the video by placing cars in a top-down view, and indicated the relative speeds of the placed cars with respect to the ego-vehicle...
April 2017: Applied Ergonomics
https://www.readbyqxmd.com/read/28162167/-change-of-white-matter-neuronal-integrity-associated-with-spatial-navigation-impairment-in-mild-cognitive-impairment
#8
W P Li, F F Wang, J M Lu, S C Wu, W B Wu, R Y Liu, X Zhang, M Li, H Zhao, B Zhu, Y Xu, B Zhang
Objective: To analyze the correlation between white matter integrity and spatial navigation impairment in patients with mild cognitive impairment (MCI). Methods: A total of 27 MCI subjects and 24 healthy controls were enrolled from the Affiliated Drum Tower Hospital of Nanjing University Medical School from May 2015 to February 2016, who underwent 3.0 T MRI scan and 2D-computer version spatial navigation test.DTI preprocessing and tract-based spatial statistics (TBSS) were performed by PANDA.Two sample t-test and partial correlation coefficients were performed to investigate the correlation of white matter impairments and spatial navigation decline...
January 17, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28154968/unilateral-lesions-of-the-dorsocentral-striatum-dcs-disrupt-spatial-and-temporal-characteristics-of-food-protection-behavior
#9
Philip A Blankenship, Joseph L Cheatwood, Douglas G Wallace
Spatial and temporal information processing provide a foundation for higher cognitive functions. The survival of animals depends on integrating spatial and temporal information to organize behavior. In general, previous research has focused on only one source of information processing; however, there is evidence to support a convergence in the processing of egocentric-spatial and temporal information within a cortico-striatal system of structures. The current study evaluated the contributions of the dorsocentral striatum (DCS) to egocentric-spatial and temporal (within the seconds-to-minutes range) processing of information using a food protection task...
February 3, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28129074/egocentric-reciprocity-and-the-role-of-friendship-and-anger
#10
Xiaoping Chen, Marion Eberly, Daniel G Bachrach, Keke Wu, Quing Qu
In this research we examine the phenomenon of egocentric reciprocity, where individuals protect self-interest by adopting an eye-for-an-eye strategy in negatively imbalanced exchanges, and by taking advantage of overly generous treatment in positively imbalanced exchanges. We conducted two experiments using a modified ultimatum game examining attitudinal and behavioral responses to imbalanced exchanges. The experiments allowed us to explore the moderating role of relational closeness (i.e., whether the game partner was a friend or a stranger) and the mediating role of anger and indebtedness in these moderated relationships...
January 27, 2017: Journal of Social Psychology
https://www.readbyqxmd.com/read/28129062/-nonspatial-attentional-deficits-interact-with-spatial-position-in-neglect
#11
Dongyun Li, Christopher Rorden, Hans-Otto Karnath
A widely debated question concerns whether or not spatial and nonspatial components of visual attention interact in attentional performance. Spatial neglect is a common consequence of brain injury where individuals fail to respond to stimuli presented on their contralesional side. It has been argued that, beyond the spatial bias, these individuals also tend to exhibit nonspatial perceptual deficits. Here we demonstrate that the "nonspatial" deficits affecting the temporal dynamics of attentional deployment are in fact modulated by spatial position...
January 27, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28114481/asymmetric-representations-of-upper-and-lower-visual-fields-in-egocentric-and-allocentric-references
#12
Yang Zhou, Gongchen Yu, Xuefei Yu, Si Wu, Mingsha Zhang
Two spatial reference systems, i.e., the observer-centered (egocentric) and object-centered (allocentric) references, are most commonly used to locate the position of the external objects in space. Although we sense the world as a unified entity, visual processing is asymmetric between upper and lower visual fields (VFs). For example, the goal-directed reaching responses are more efficient in the lower VF. Such asymmetry suggests that the visual space might be composed of different realms regarding perception and action...
January 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28114045/interaction-detection-in-egocentric-video-towards-a-novel-outcome-measure-for-upper-extremity-function
#13
Jirapat Likitlersuang, Jose Zariffa
In order to develop effective interventions for restoring upper extremity function after cervical spinal cord injury, tools are needed to accurately measure hand function throughout the rehabilitation process. However, there is currently no suitable method to collect information about hand function in the community, when patients are not under direct observation of a clinician. We propose a wearable system that can monitor functional hand use using computer vision techniques applied to egocentric camera videos...
December 7, 2016: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28111152/how-ants-use-vision-when-homing-backward
#14
Sebastian Schwarz, Michael Mangan, Jochen Zeil, Barbara Webb, Antoine Wystrach
Ants can navigate over long distances between their nest and food sites using visual cues [1, 2]. Recent studies show that this capacity is undiminished when walking backward while dragging a heavy food item [3-5]. This challenges the idea that ants use egocentric visual memories of the scene for guidance [1, 2, 6]. Can ants use their visual memories of the terrestrial cues when going backward? Our results suggest that ants do not adjust their direction of travel based on the perceived scene while going backward...
February 6, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28100028/perirhinal-cortex-involvement-in-allocentric-spatial-learning-in-the-rat-evidence-from-doubly-marked-tasks
#15
Juan M J Ramos
It has recently been suggested that the different cortices of the medial temporal lobe support a mixture of object and spatial processing functions, challenging the anterior model that emphasized a strict functional differentiation between regions. However, for some structures, the perirhinal cortex (Prh) for example, a number of studies using lesion methods have shown a profound deficit exclusively in tasks involving object learning but not allocentric spatial learning. It may be that the learning paradigms used in previous studies have not been sensitive enough to detect a possible allocentric deficit in Prh-lesioned animals...
January 18, 2017: Hippocampus
https://www.readbyqxmd.com/read/28089516/environmental-geometry-aligns-the-hippocampal-map-during-spatial-reorientation
#16
Alex T Keinath, Joshua B Julian, Russell A Epstein, Isabel A Muzzio
When a navigator's internal sense of direction is disrupted, she must rely on external cues to regain her bearings, a process termed spatial reorientation. Extensive research has demonstrated that the geometric shape of the environment exerts powerful control over reorientation behavior, but the neural and cognitive mechanisms underlying this phenomenon are not well understood. Whereas some theories claim that geometry controls behavior through an allocentric mechanism potentially tied to the hippocampus, others postulate that disoriented navigators reach their goals by using an egocentric view-matching strategy...
February 6, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28057536/transcranial-alternating-current-stimulation-to-the-inferior-parietal-lobe-decreases-mu-suppression-to-egocentric-but-not-allocentric-hand-movements
#17
Monica B Berntsen, Nicholas R Cooper, Vincenzo Romei
Egocentric vs. allocentric perspective during observation of hand movements has been related to self-other differentiation such that movements observed from an egocentric viewpoint have been considered as self-related while movements observed from an allocentric viewpoint have been considered as belonging to someone else. Correlational studies have generally found that egocentric perspective induces greater neurophysiological responses and larger behavioral effects compared to an allocentric perspective. However, recent studies question previous findings by reporting greater (μ) suppression and greater transcranial magnetic stimulation (TMS)-induced motor-evoked potentials (MEPs) during observation of allocentric compared to egocentric movements...
March 6, 2017: Neuroscience
https://www.readbyqxmd.com/read/28054740/common-and-specific-neural-correlates-underlying-the-spatial-congruency-effect-induced-by-the-egocentric-and-allocentric-reference-frame
#18
Nan Liu, Hui Li, Wen Su, Qi Chen
The spatial location of an object can be represented in two frames of reference: egocentric (relative to the observer's body or body parts) and allocentric (relative to another object independent of the observer). The object positions relative to the two frames can be either congruent (e.g., both left or both right) or incongruent (e.g., one left and one right). Most of the previous studies, however, did not discriminate between the two types of spatial conflicts. To investigate the common and specific neural mechanisms underlying the spatial congruency effect induced by the two reference frames, we adopted a 3 (type of task: allocentric, egocentric, and color) × 2 (spatial congruency: congruent vs...
January 5, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28039765/exploring-the-contribution-of-spatial-navigation-to-cognitive-functioning-in-older-adults
#19
Jan Laczó, Ross Andel, Zuzana Nedelska, Martin Vyhnalek, Kamil Vlcek, Sebastian Crutch, John Harrison, Jakub Hort
Spatial navigation (SN) impairment is present early in Alzheimer's disease (AD). We tested whether SN performance, self-centered (egocentric) and world-centered (allocentric), was distinguishable from performance on established cognitive functions-verbal and nonverbal memory, executive and visuospatial function, attention/working memory, and language function. 108 older adults (53 cognitively normal [CN] and 55 with amnestic mild cognitive impairment [aMCI]) underwent neuropsychological examination and real-space navigation testing...
March 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28032476/conflict-processing-among-multiple-frames-of-reference
#20
Weizhi Nan, Qi Li, Yanlong Sun, Hongbin Wang, Xun Liu
People rely on multiple frames of reference (FORs) to represent and update spatial relationships of different objects in a complex environment. According to the "Frame of Reference-based Map of Salience" theory (FORMS), FORs with high salience are processed in priority, and human performance is determined by the interaction of all relevant FOR-based representations. We conducted a modified two-cannon task manipulating conflicts among FORs (e.g., egocentric [FOR-EFOR], intrinsic [FOR-IFOR]) in order to explore how FORs interact with each other...
December 2016: PsyCh Journal
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