The role of competing stimuli in feature-based attention

AbstractIn this work, we investigated the effects of the vacuum pumping on both the loading efficiencies and the release kinetics of halloysite nanotubes filled with drug molecules dissolved in ethanol. As model drugs, salicylic acid and sodium diclofenac were selected. For comparison, the loading of the drug molecules was conducted on platy kaolinite to explore the key role of the hollow tubular morphology on the filling mechanism of halloysite. The effects of the pressure conditions used in the loading protocol were interpreted and discussed on the basis of the thermodynamic results provided by Knudsen thermogravimetry, which demonstrated the ethanol confinement inside the halloysite cavity. Several techniques (TEM, FTIR spectroscopy, DLS and $$\zeta$$ ζ -potential experiments) were employed to characterize the drug filled nanoclays. Besides, release kinetics of the drugs were studied and interpreted according to the loading mechanism. This work represents a further step for the development of nanotubular carriers with tunable release feature based on the loading protocol and drug localization into the carrier. Graphic abstract The filling efficiency of halloysite nanotubes is enhanced by the reduction of the pressure conditions used in the loading protocol.

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The Role of Alpha Activity in Spatial and Feature-Based Attention

eNeuro ◽

10.1523/eneuro.0204-16.2016 ◽

2016 ◽

Vol 3 (5) ◽

pp. ENEURO.0204-16.2016 ◽

Cited By ~ 34

Author(s):

Rosanne M. van Diepen ◽

Lee M. Miller ◽

Ali Mazaheri ◽

Joy J. Geng

Keyword(s):

Alpha Activity ◽

Feature Based

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Understanding location- and feature-based processing along the human intraparietal sulcus

Journal of Neurophysiology ◽

10.1152/jn.00404.2016 ◽

2016 ◽

Vol 116 (3) ◽

pp. 1488-1497 ◽

Cited By ~ 12

Author(s):

Katherine C. Bettencourt ◽

Yaoda Xu

Keyword(s):

Short Term Memory ◽

Visual Cognition ◽

Cognitive Tasks ◽

Intraparietal Sulcus ◽

Short Term ◽

Object Individuation ◽

Visual Short Term Memory ◽

Feature Based ◽

Partial Overlap

Based on different cognitive tasks and mapping methods, the human intraparietal sulcus (IPS) has been subdivided according to multiple different organizational schemes. The presence of topographically organized regions throughout IPS indicates a strong location-based processing in this brain region. However, visual short-term memory (VSTM) studies have shown that while a region in the inferior IPS region (inferior IPS) is involved in object individuation and selection based on location, a region in the superior IPS (superior IPS) primarily encodes and stores object featural information. Here, we determined the localization of these two VSTM IPS regions with respect to the topographic IPS regions in individual participants and the role of different IPS regions in location- and feature-based processing. Anatomically, inferior IPS showed an 85.2% overlap with topographic IPS regions, with the greatest overlap seen in V3A and V3B, and superior IPS showed a 73.6% overall overlap, with the greatest overlap seen in IPS0-2. Functionally, there appeared to be a partial overlap between IPS regions involved in location- and feature-based processing, with more inferior and medial regions showing a stronger location-based processing and more superior and lateral regions showing a stronger feature-based processing. Together, these results suggest that understanding the multiplex nature of IPS in visual cognition may not be reduced to examining the functions of the different IPS topographic regions, but rather, it can only be accomplished by understanding how regions identified by different tasks and methods may colocalize with each other.

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The role of lightness, hue and saturation in feature-based visual attention

Vision Research ◽

10.1016/j.visres.2013.12.013 ◽

2014 ◽

Vol 96 ◽

pp. 25-32 ◽

Cited By ~ 2

Author(s):

Geoffrey W. Stuart ◽

Wendy N. Barsdell ◽

Ross H. Day

Keyword(s):

Visual Attention ◽

Feature Based

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ROLE OF TIE-POINTS DISTRIBUTION IN AERIAL PHOTOGRAPHY

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xl-3-w4-41-2016 ◽

2016 ◽

Vol XL-3/W4 ◽

pp. 41-44

Author(s):

S. Kerner ◽

I. Kaufman ◽

Y. Raizman

Keyword(s):

Feature Extraction ◽

Spatial Distribution ◽

Aerial Photography ◽

Image Matching ◽

Feature Matching ◽

Real Data ◽

Matching Process ◽

Feature Based ◽

Extraction Stage

Automatic image matching algorithms, and especially feature-based methods, profoundly changed our understanding and requirements of tie points. The number of tie points has increased by orders of magnitude, yet the notions of accuracy and reliability of tie points remain equally important. The spatial distribution of tie points is less predictable, and is subject only to limited control. Feature-based methods also highlighted a conceptual division of the matching process into two separate stages – feature extraction and feature matching. <br><br> In this paper we discuss whether spatial distribution requirements, such as Von Gruber positions, are still relevant to modern matching methods. We argue that forcing such patterns might no longer be required in the feature extraction stage. However, we claim spatial distribution is important in the feature matching stage. <br><br> We will focus on terrains that are notorious for difficult matching, such as water bodies, with real data obtained by users of VisionMap’s A3 Edge camera and LightSpeed photogrammetric suite.

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Ocular tracking responses to background motion gated by feature-based attention

Journal of Neurophysiology ◽

10.1152/jn.00810.2013 ◽

2014 ◽

Vol 112 (5) ◽

pp. 1074-1081 ◽

Cited By ~ 3

Author(s):

David Souto ◽

Dirk Kerzel

Keyword(s):

Peak Velocity ◽

Horizontal Direction ◽

Motion Onset ◽

Motion Direction ◽

Ocular Tracking ◽

Feature Based ◽

Background Motion ◽

Ocular Following Response ◽

Tracking Response

Involuntary ocular tracking responses to background motion offer a window on the dynamics of motion computations. In contrast to spatial attention, we know little about the role of feature-based attention in determining this ocular response. To probe feature-based effects of background motion on involuntary eye movements, we presented human observers with a balanced background perturbation. Two clouds of dots moved in opposite vertical directions while observers tracked a target moving in horizontal direction. Additionally, they had to discriminate a change in the direction of motion (±10° from vertical) of one of the clouds. A vertical ocular following response occurred in response to the motion of the attended cloud. When motion selection was based on motion direction and color of the dots, the peak velocity of the tracking response was 30% of the tracking response elicited in a single task with only one direction of background motion. In two other experiments, we tested the effect of the perturbation when motion selection was based on color, by having motion direction vary unpredictably, or on motion direction alone. Although the gain of pursuit in the horizontal direction was significantly reduced in all experiments, indicating a trade-off between perceptual and oculomotor tasks, ocular responses to perturbations were only observed when selection was based on both motion direction and color. It appears that selection by motion direction can only be effective for driving ocular tracking when the relevant elements can be segregated before motion onset.

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