scholarly journals A Semantic Representation of Time Intervals in OWL 2

2017 ◽  
Author(s):  
Noura Herradi ◽  
Fayçal Hamdi ◽  
Elisabeth Métais
Keyword(s):  
Semantic Representation ◽  
Time Intervals ◽  
Representation Of Time

Representation of time intervals in the right posterior parietal cortex: Implications for a mental time line

NeuroImage ◽  
2009 ◽  
Vol 46 (4) ◽  
pp. 1173-1179 ◽  
Author(s):  
Massimiliano Oliveri ◽  
Giacomo Koch ◽  
Silvia Salerno ◽  
Sara Torriero ◽  
Emanuele Lo Gerfo ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Time Intervals ◽  
Time Line ◽  
Mental Time Line ◽  
Posterior Parietal ◽  
The Right ◽  
Representation Of Time

scholarly journals Locally distributed abstraction of temporal distance in human parietal cortex

2018 ◽  
Author(s):  
Qun Ye ◽  
Yi Hu ◽  
Yixuan Ku ◽  
Kofi Appiah ◽  
Sze Chai Kwok
Keyword(s):  
Memory Retrieval ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Temporal Structure ◽  
Neural Mechanism ◽  
Temporal Distance ◽  
Time Intervals ◽  
Episodic Event ◽  
Memory Network ◽  
The Brain ◽  
Representation Of Time

AbstractAn enduring puzzle in the neuroscience of memory is how the brain parsimoniously situates past events by their order in relation to time. By combining functional MRI, and representational similarity analysis, we reveal a multivoxel representation of time intervals separating pairs of episodic event-moments in the posterior medial memory system, especially when the events were experienced within a similar temporal context. We further show such multivoxel representations to be vulnerable to disruption through targeted repetitive transcranial magnetic stimulation and that perturbation to the mnemonic abstraction alters the neural—behavior relationship across the wider parietal memory network. Our findings establish a mnemonic “pattern-based” code of temporal distances in the human brain, a fundamental neural mechanism for supporting the temporal structure of past events, assigning the precuneus as a locus of flexibly effecting the manipulation of physical time during episodic memory retrieval.

scholarly journals Spatial attention and representation of time intervals in childhood

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Barbara Magnani ◽  
Alessandro Musetti ◽  
Francesca Frassinetti
Keyword(s):  
Spatial Attention ◽  
Auditory Stimuli ◽  
Time Intervals ◽  
Attentional Shift ◽  
Time Representation ◽  
Before And After ◽  
Bilateral Effects ◽  
Temporal Bisection Task ◽  
Prismatic Adaptation ◽  
Representation Of Time

Abstract Spatial attention and spatial representation of time are strictly linked in the human brain. In young adults, a leftward shift of spatial attention by prismatic adaptation (PA), is associated with an underestimation whereas a rightward shift is associated with an overestimation of time both for visual and auditory stimuli. These results suggest a supra-modal representation of time left-to-right oriented that is modulated by a bilateral attentional shift. However, there is evidence of unilateral, instead of bilateral, effects of PA on time in elderly adults suggesting an influence of age on these effects. Here we studied the effects of spatial attention on time representation focusing on childhood. Fifty-four children aged from 5 to 11 years-old performed a temporal bisection task with visual and auditory stimuli before and after PA inducing a leftward or a rightward attentional shift. Results showed that children underestimated time after a leftward attentional shift either for visual or auditory stimuli, whereas a rightward attentional shift had null effect on time. Our results are discussed as a partial maturation of the link between spatial attention and time representation in childhood, due to immaturity of interhemispheric interactions or of executive functions necessary for the attentional complete influence on time representation.

scholarly journals Scalable representation of time in the hippocampus

2021 ◽  
Vol 7 (6) ◽  
pp. eabd7013 ◽  
Author(s):  
Akihiro Shimbo ◽  
Ei-Ichi Izawa ◽  
Shigeyoshi Fujisawa
Keyword(s):  
Time Estimation ◽  
Time Intervals ◽  
Elapsed Time ◽  
Temporal Representation ◽  
Temporal Relationships ◽  
Phase Precession ◽  
Temporal Structures ◽  
Theta Phase ◽  
Theta Phase Precession ◽  
Representation Of Time

Hippocampal “time cells” encode specific moments of temporally organized experiences that may support hippocampal functions for episodic memory. However, little is known about the reorganization of the temporal representation of time cells during changes in temporal structures of episodes. We investigated CA1 neuronal activity during temporal bisection tasks, in which the sets of time intervals to be discriminated were designed to be extended or contracted across the blocks of trials. Assemblies of neurons encoded elapsed time during the interval, and the representation was scaled when the set of interval times was varied. Theta phase precession and theta sequences of time cells were also scalable, and the fine temporal relationships were preserved between pairs in theta cycles. Moreover, theta sequences reflected the rats’ decisions on the basis of their time estimation. These findings demonstrate that scalable features of time cells may support the capability of flexible temporal representation for memory formation.

Prismatic Lenses Shift Time Perception

2009 ◽  
Vol 20 (8) ◽  
pp. 949-954 ◽  
Author(s):  
Francesca Frassinetti ◽  
Barbara Magnani ◽  
Massimiliano Oliveri
Keyword(s):  
Spatial Attention ◽  
Spatial Modulation ◽  
Spatial Coding ◽  
Time Intervals ◽  
Reproduction Task ◽  
Time Reproduction ◽  
Before And After ◽  
Temporal Intervals ◽  
Prismatic Adaptation ◽  
Representation Of Time

Previous studies have demonstrated the involvement of spatial codes in the representation of time and numbers. We took advantage of a well-known spatial modulation (prismatic adaptation) to test the hypothesis that the representation of time is spatially oriented from left to right, with smaller time intervals being represented to the left of larger time intervals. Healthy subjects performed a time-reproduction task and a time-bisection task, before and after leftward and rightward prismatic adaptation. Results showed that prismatic adaptation inducing a rightward orientation of spatial attention produced an overestimation of time intervals, whereas prismatic adaptation inducing a leftward shift of spatial attention produced an underestimation of time intervals. These findings not only confirm that temporal intervals are represented as horizontally arranged in space, but also reveal that spatial modulation of time processing most likely occurs via cuing of spatial attention, and that spatial attention can influence the spatial coding of quantity in different dimensions.

The role of posterior parietal cortices on prismatic adaptation effects on the representation of time intervals

2013 ◽  
Vol 51 (13) ◽  
pp. 2825-2832 ◽  
Author(s):  
Barbara Magnani ◽  
Giuseppa Renata Mangano ◽  
Francesca Frassinetti ◽  
Massimiliano Oliveri
Keyword(s):  
Time Intervals ◽  
Posterior Parietal ◽  
Parietal Cortices ◽  
Prismatic Adaptation ◽  
Representation Of Time ◽  
Adaptation Effects

Representation of time intervals in a double bisection task: Relative or absolute?

2009 ◽  
Vol 81 (2) ◽  
pp. 280-285 ◽  
Author(s):  
Susana Maia ◽  
Armando Machado
Keyword(s):  
Time Intervals ◽  
Bisection Task ◽  
Representation Of Time

Rotational Characteristics of the Green Solar Corona: 1947-1991

1994 ◽  
Vol 144 ◽  
pp. 139-141 ◽  
Author(s):  
J. Rybák ◽  
V. Rušin ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
World Wide ◽  
Rotation Period ◽  
Original Data ◽  
Coronal Emission ◽  
Time Intervals ◽  
Data Set ◽  
The World ◽  
Coronal Emission Line ◽  
Homogeneous Data

AbstractFe XIV 530.3 nm coronal emission line observations have been used for the estimation of the green solar corona rotation. A homogeneous data set, created from measurements of the world-wide coronagraphic network, has been examined with a help of correlation analysis to reveal the averaged synodic rotation period as a function of latitude and time over the epoch from 1947 to 1991.The values of the synodic rotation period obtained for this epoch for the whole range of latitudes and a latitude band ±30° are 27.52±0.12 days and 26.95±0.21 days, resp. A differential rotation of green solar corona, with local period maxima around ±60° and minimum of the rotation period at the equator, was confirmed. No clear cyclic variation of the rotation has been found for examinated epoch but some monotonic trends for some time intervals are presented.A detailed investigation of the original data and their correlation functions has shown that an existence of sufficiently reliable tracers is not evident for the whole set of examinated data. This should be taken into account in future more precise estimations of the green corona rotation period.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Ultrastructure of Lymphatic Capillaries in the Transport of Colloidal Particles

1967 ◽  
Vol 25 ◽  
pp. 186-187
Author(s):  
L. V. Leak ◽  
J. F. Burke
Keyword(s):  
Connective Tissue ◽  
Colloidal Particles ◽  
Ultrastructural Level ◽  
Vital Role ◽  
Time Intervals ◽  
Thorium Dioxide ◽  
Lymphatic Capillary ◽  
Tissue Area ◽  
Rapid Removal ◽  
Tissue Fluids

The vital role played by the lymphatic capillaries in the transfer of tissue fluids and particulate materials from the connective tissue area can be demonstrated by the rapid removal of injected vital dyes into the tissue areas. In order to ascertain the mechanisms involved in the transfer of substances from the connective tissue area at the ultrastructural level, we have injected colloidal particles of varying sizes which range from 80 A up to 900-mμ. These colloidal particles (colloidal ferritin 80-100A, thorium dioxide 100-200 A, biological carbon 200-300 and latex spheres 900-mμ) are injected directly into the interstitial spaces of the connective tissue with glass micro-needles mounted in a modified Chambers micromanipulator. The progress of the particles from the interstitial space into the lymphatic capillary lumen is followed by observing tissues from animals (skin of the guinea pig ear) that were injected at various time intervals ranging from 5 minutes up to 6 months.

Sign in / Sign up

Export Citation Format

Share Document