Reflexive Shifts of Covert Attention Operate in an Egocentric Coordinate Frame

Perception ◽  
10.1068/p3165 ◽  
2001 ◽  
Vol 30 (9) ◽  
pp. 1083-1091 ◽  
Author(s):  
Doug J K Barrett ◽  
Mark F Bradshaw ◽  
David Rose ◽  
John Everatt ◽  
Peter J Simpson
Keyword(s):  
Spatial Representation ◽  
Spatial Relationship ◽  
Empirical Support ◽  
Region Of Interest ◽  
Frame Of Reference ◽  
Covert Attention ◽  
Coordinate Frame ◽  
Correct Identification ◽  
Current Experiment ◽  
Object Based

Covert shifts of attention have been shown to improve detection and discrimination thresholds for a range of visual stimuli. Although there is some evidence to suggest that the allocation of attention to a particular region of interest occurs in a retinotopic frame of reference, the importance of an allocentric, or object-based, framework has gained widespread empirical support. The current experiment investigates the nature of the spatial representation in which covert shifts of attention occur in response to a reflexive prime. Primes and targets were presented in four conditions designed to vary systematically the validity of the spatial relationship between the prime and target in egocentric or allocentric coordinate frameworks. A significant advantage, in terms of reaction time and correct identification, was found for targets located in positions previously primed in an egocentric (but not allocentric) framework whereas there was no advantage for locations primed in an allocentric (but not egocentric) framework. These results suggest that the allocation of covert spatial attention within an egocentric framework may be more important than previously thought.

Verbal and Math Self-Concepts: An Internal/External Frame of Reference Model

1986 ◽  
Vol 23 (1) ◽  
pp. 129-149 ◽  
Author(s):  
Herbert W. Marsh
Keyword(s):  
Math Achievement ◽  
Reference Model ◽  
Empirical Support ◽  
Frame Of Reference ◽  
Self Concept ◽  
Math Skills ◽  
Verbal Skills ◽  
External Process ◽  
External Frame ◽  
Verbal Achievement

The purpose of this investigation is to examine empirical support for the internal/external (I/E) frame of reference model that describes the relation between Verbal and Math self-concepts, and between these academic self-concepts and verbal and math achievement. The empirical tests are based on all studies (n = 6,010; age range = 7–35+ years) that have employed the Self Description Questionnaire (SDQ), SDQII, or SDQ III self-concept instruments. The I/E model posits, for example, that a high Math self-concept is more likely when math skills are good relative to those of peers (an external comparison) and when math skills are better than verbal skills (an internal comparison). Consistent with the model and empirical findings, (a) Verbal and Math self-concepts are nearly uncorrelated with each other even though verbal and math achievement indicators are substantially correlated with each other and with the matching areas of self-concept; (b) the direct effects of math achievement on Verbal self-concept, and of verbal achievement on Math self-concept, are both negative. For inferred self-concepts based on the ratings of external observers, the external process seems to operate, but not the internal process. The findings demonstrate that academic self-concepts are affected by different processes than are the academic achievement areas they reflect and the inferred self-concepts offered by external observers.

scholarly journals Covert Visual Attention Modulates Face-Specific Activity in the Human Fusiform Gyrus: fMRI Study

1998 ◽  
Vol 79 (3) ◽  
pp. 1574-1578 ◽  
Author(s):  
Ewa Wojciulik ◽  
Nancy Kanwisher ◽  
Jon Driver
Keyword(s):  
Visual Attention ◽  
Specific Activity ◽  
Region Of Interest ◽  
Fusiform Gyrus ◽  
Covert Attention ◽  
Matching Task ◽  
Voluntary Attention ◽  
Retinal Stimulation ◽  
Covert Visual Attention ◽  
Fmri Study

Wojciulik, Ewa, Nancy Kanwisher, and Jon Driver. Covert visual attention modulates face-specific activity in the human fusiform gyrus: an fMRI study. J. Neurophysiol. 79: 1574–1578, 1998. Several lines of evidence demonstrate that faces undergo specialized processing within the primate visual system. It has been claimed that dedicated modules for such biologically significant stimuli operate in a mandatory fashion whenever their triggering input is presented. However, the possible role of covert attention to the activating stimulus has never been examined for such cases. We used functional magnetic resonance imaging to test whether face-specific activity in the human fusiform face area (FFA) is modulated by covert attention. The FFA was first identified individually in each subject as the ventral occipitotemporal region that responded more strongly to visually presented faces than to other visual objects under passive central viewing. This then served as the region of interest within which attentional modulation was tested independently, using active tasks and a very different stimulus set. Subjects viewed brief displays each comprising two peripheral faces and two peripheral houses (all presented simultaneously). They performed a matching task on either the two faces or the two houses, while maintaining central fixation to equate retinal stimulation across tasks. Signal intensity was reliably stronger during face-matching than house matching in both right- and left-hemisphere predefined FFAs. These results show that face-specific fusiform activity is reduced when stimuli appear outside (vs. inside) the focus of attention. Despite the modular nature of the FFA (i.e., its functional specificity and anatomic localization), face processing in this region nonetheless depends on voluntary attention.

scholarly journals Flood Mapping in Vegetated Areas Using an Unsupervised Clustering Approach on Sentinel-1 and -2 Imagery

2020 ◽  
Vol 12 (21) ◽  
pp. 3611
Author(s):  
Lisa Landuyt ◽  
Niko E. C. Verhoest ◽  
Frieke M. B. Van Coillie
Keyword(s):  
Optimal Parameter ◽  
Complex Mixture ◽  
Region Of Interest ◽  
Region Growing ◽  
Feature Space ◽  
Flood Mapping ◽  
Dry Land ◽  
Object Based ◽  
Forested Areas ◽  
Sar Imagery

The European Space Agency’s Sentinel-1 constellation provides timely and freely available dual-polarized C-band Synthetic Aperture Radar (SAR) imagery. The launch of these and other SAR sensors has boosted the field of SAR-based flood mapping. However, flood mapping in vegetated areas remains a topic under investigation, as backscatter is the result of a complex mixture of backscattering mechanisms and strongly depends on the wave and vegetation characteristics. In this paper, we present an unsupervised object-based clustering framework capable of mapping flooding in the presence and absence of flooded vegetation based on freely and globally available data only. Based on a SAR image pair, the region of interest is segmented into objects, which are converted to a SAR-optical feature space and clustered using K-means. These clusters are then classified based on automatically determined thresholds, and the resulting classification is refined by means of several region growing post-processing steps. The final outcome discriminates between dry land, permanent water, open flooding, and flooded vegetation. Forested areas, which might hide flooding, are indicated as well. The framework is presented based on four case studies, of which two contain flooded vegetation. For the optimal parameter combination, three-class F1 scores between 0.76 and 0.91 are obtained depending on the case, and the pixel- and object-based thresholding benchmarks are outperformed. Furthermore, this framework allows an easy integration of additional data sources when these become available.

Object-Centered Neglect in Patients with Unilateral Neglect: Effects of Left-Right Coordinates of Objects

1994 ◽  
Vol 6 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Marlene Behrmann ◽  
Morris Moscovitch
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Frame Of Reference ◽  
The Other ◽  
Unilateral Neglect ◽  
Independent Measure ◽  
Object Based ◽  
Spatial Coordinates ◽  
Left And Right

When patients with right-sided hemispheric lesions neglect information on the left side, with respect to what set of spatial coordinates is left defined? Two potential reference frames were examined in this study, one where left and right are defined with respect to the midline of the viewer and/or environment (viewer/env-centered) and the other where left and right are defined with respect to the midline of the object (object-centered). By rotating the stimulus 90° clockwise or counterclockwise, and instructing patients with neglect to report the colors appearing around the border of a stimulus, an independent measure was obtained for the number of colors reported from the left and right of the viewer/env- and from the object-based reference frame. Whereas significant object-centered neglect was observed only for upper case asymmetrical letters but not for symmetrical letters nor for drawings of familiar animals or objects, significant viewer/env-based neglect was observed with all the stimulus types. We present an account of the coexistence of neglect in more than one frame of reference and the presence of object-centered neglect under a restricted set of conditions.

Focused Ultrasound Thalamotomy Sensory Side Effects Follow the Thalamic Structural Homonculus

2020 ◽  
pp. 10.1212/CPJ.0000000000001013
Author(s):  
Michelle Paff ◽  
Alexandre Boutet ◽  
Jürgen Germann ◽  
Gavin J. B. Elias ◽  
Clement T. Chow ◽  
...  
Keyword(s):  
Side Effects ◽  
Functional Connectivity ◽  
Adverse Effects ◽  
Focused Ultrasound ◽  
Univariate Analysis ◽  
Spatial Relationship ◽  
Significant Risk ◽  
Region Of Interest ◽  
Medial Lemniscus ◽  
Sensory Nucleus

AbstractIntroduction:Focused ultrasound thalamotomy is an effective treatment for tremor, however, side effects may occur. The purpose of the present study was to investigate the spatial relationship between thalamotomies and specific sensory side effects as well as their functional connectivity with somatosensory cortex and relationship to the medial lemniscus (ML).Methods:Sensory adverse effects were categorized into four groups based on the location of the disturbance: face/mouth/tongue numbness/paresthesia, hand-only paresthesia, hemi-body/limb paresthesia, and dysgeusia. Then, areas of significant risk (ASR) for each category were defined using voxel-wise mass univariate analysis and overlaid on corresponding odds ratio maps. The ASR area associated with the maximum risk was used as a region-of-interest in a normative functional connectome to determine side-effect specific functional connectivity. Finally, each ASR was overlaid on the medial lemniscus derived from normative template.Results:Of 103 patients, 17 developed sensory side effects after thalamotomy persisting 3 months after the procedures. Lesions producing sensory side effects extended posteriorly into the principle sensory nucleus of the thalamus or below the thalamus in the ML. The topography of sensory adverse effects followed the know somatotopy of the ML and the sensory nucleus. Functional connectivity patterns between each sensory-specific thalamic seed and the primary somatosensory areas supported the role of the middle insula in processing of gustatory information and in multisensory integration.Discussion:Distinct regions in the sensory thalamus and its afferent connections rise to specific sensory disturbances. These findings demonstrate the relationship between the sensory thalamus, ML, and bilateral sensory cortical areas.

A Moving Zonal Method in the Time-Domain Simulation for Acoustic Propagation

2010 ◽  
Author(s):  
Z. Charlie Zheng ◽  
Guoyi Ke
Keyword(s):  
Long Range ◽  
Time Domain ◽  
Region Of Interest ◽  
Acoustic Propagation ◽  
Coordinate Frame ◽  
Computational Domain ◽  
Perfectly Matched Layers ◽  
Zonal Method ◽  
Moving Domain ◽  
The Time Domain

Conventional time-domain schemes have limited capability in modeling long-range acoustic propagation because of the vast computer resources needed to cover the entire region of interest with a computational domain. Many of the long-range acoustic propagation problems need to consider propagation distances of hundreds or thousands of meters. It is thus very difficult to maintain adequate grid resolution for such a large computational domain, even with the state-of-the-art capacity in computer memory and computing speed. In order to overcome this barrier, a moving zonal-domain approach is developed. This concept uses a moving computational domain that follows an acoustic wave. The size and interval of motion of the domain are problem dependent. In this paper, an Euler-type moving domain in a stationary coordinate frame is first tested. Size effects and boundary conditions for the moving domain are considered. The results are compared and verified with both analytical solutions and results from the non-zonal domain. Issues of using the moving zonal-domain with perfectly-matched layers for the free-space boundary are also discussed.

scholarly journals Investigating the Performance of Generative Adversarial Networks for Prostate Tissue Detection and Segmentation

2020 ◽  
Vol 6 (9) ◽  
pp. 83 ◽  
Author(s):  
Ufuk Cem Birbiri ◽  
Azam Hamidinekoo ◽  
Amélie Grall ◽  
Paul Malcolm ◽  
Reyer Zwiggelaar
Keyword(s):  
Region Of Interest ◽  
Training Data ◽  
Prostate Tissue ◽  
Generative Adversarial Networks ◽  
Correct Identification ◽  
Adversarial Networks ◽  
Training Samples ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri ◽  
Public Datasets

The manual delineation of region of interest (RoI) in 3D magnetic resonance imaging (MRI) of the prostate is time-consuming and subjective. Correct identification of prostate tissue is helpful to define a precise RoI to be used in CAD systems in clinical practice during diagnostic imaging, radiotherapy and monitoring the progress of disease. Conditional GAN (cGAN), cycleGAN and U-Net models and their performances were studied for the detection and segmentation of prostate tissue in 3D multi-parametric MRI scans. These models were trained and evaluated on MRI data from 40 patients with biopsy-proven prostate cancer. Due to the limited amount of available training data, three augmentation schemes were proposed to artificially increase the training samples. These models were tested on a clinical dataset annotated for this study and on a public dataset (PROMISE12). The cGAN model outperformed the U-Net and cycleGAN predictions owing to the inclusion of paired image supervision. Based on our quantitative results, cGAN gained a Dice score of 0.78 and 0.75 on the private and the PROMISE12 public datasets, respectively.

scholarly journals Targeted Memory Reactivation During Sleep Improves Next-Day Problem Solving

2019 ◽  
Vol 30 (11) ◽  
pp. 1616-1624 ◽  
Author(s):  
Kristin E. G. Sanders ◽  
Samuel Osburn ◽  
Ken A. Paller ◽  
Mark Beeman
Keyword(s):  
Information Processing ◽  
Problem Solving ◽  
Empirical Support ◽  
Memory Studies ◽  
Difficult Problem ◽  
New Technique ◽  
Current Experiment ◽  
Memory Reactivation ◽  
Puzzle Solving ◽  
A New Technique

Many people have claimed that sleep has helped them solve a difficult problem, but empirical support for this assertion remains tentative. The current experiment tested whether manipulating information processing during sleep impacts problem incubation and solving. In memory studies, delivering learning-associated sound cues during sleep can reactivate memories. We therefore predicted that reactivating previously unsolved problems could help people solve them. In the evening, we presented 57 participants with puzzles, each arbitrarily associated with a different sound. While participants slept overnight, half of the sounds associated with the puzzles they had not solved were surreptitiously presented. The next morning, participants solved 31.7% of cued puzzles, compared with 20.5% of uncued puzzles (a 55% improvement). Moreover, cued-puzzle solving correlated with cued-puzzle memory. Overall, these results demonstrate that cuing puzzle information during sleep can facilitate solving, thus supporting sleep’s role in problem incubation and establishing a new technique to advance understanding of problem solving and sleep cognition.

Integrating STARE with relational databases

2021 ◽  
Author(s):  
Niklas Griessbaum ◽  
Mike Rilee ◽  
James Frew ◽  
Kwo-Sen Kuo
Keyword(s):  
Remote Sensing ◽  
Relational Databases ◽  
Infrared Imaging ◽  
Spatial Relationship ◽  
Region Of Interest ◽  
Remote Sensing Data ◽  
Search Problem ◽  
Common Path ◽  
Elegant Method ◽  
Geographical Regions

<p>When working with ungridded remote sensing data, such as swath surface reflectance like Moderate Resolution Imaging Spectroradiometer (MODIS) MOD09 or Visible Infrared Imaging Radiometer Suite (VIIRS) VNP09, extracting targeted information of interest from a collection of granules can be a challenging exercise. Given a region of interest (ROI), it is tedious both to determine the subset of granules that intersect the ROI, as well as identifying, within the granules, the individual instantaneous field of views (IFOVs) contained by the ROI.</p><p>The SpatioTemporal Adaptive-Resolution Encoding (STARE) is an indexing scheme that recursively divides the Earth's surface into quadtree hierarchies, allowing triangular elements ("trixels") of varying sizes (resolutions) to be identified with unique index values. STARE is also a software library that operates on STARE indices. It can efficiently determine the spatial relationship between two trixels, by evaluating their index values, if the trixels share a common path in the STARE tree structure. By representing geographical regions as the sets of trixels with adaptive resolutions that tesselating them, STARE provides an elegant method to determine geospatial coincidence of arbitrarily shaped geographic regions, with accuracy up to ~7-8 cm in length. </p><p>In this presentation, we introduce <em>STARELite</em>, a SQLite STARE extension and its use for cataloguing volumes of remote sensing granules that researchers often possess in their local storage. In this application, STARELite is used to determine subsets of granules intersecting arbitrary ROIs. Further, STARELite can be used for the inverse search problem: Determining all spatially coincident granules of an individual granule. STARELite leverages other components of the STARE ecosystem; namely <em>STARE sidecars</em>, which hold the trixel index values of each iFOV and a set of trixels representing the cover of each granule; <em>STAREMaster</em>, which is used to generate STARE sidecar files; and <em>STARPandas</em>, a Python Pandas extension used to bootstrap STARELite databases.</p><p>Given the limitations of SQLite, STARELite is to be understood as a proof of concept for the integration of STARE into relational databases in general. </p>

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