Determining the energetic and informational components of speech-on-speech masking

PubMed Central

Kidd, Gerald; Mason, Christine R.; Swaminathan, Jayaganesh; Roverud, Elin; Clayton, Kameron K.; Best, Virginia

2016-01-01

Identification of target speech was studied under masked conditions consisting of two or four independent speech maskers. In the reference conditions, the maskers were colocated with the target, the masker talkers were the same sex as the target, and the masker speech was intelligible. The comparison conditions, intended to provide release from masking, included different-sex target and masker talkers, time-reversal of the masker speech, and spatial separation of the maskers from the target. Significant release from masking was found for all comparison conditions. To determine whether these reductions in masking could be attributed to differences in energetic masking, ideal time-frequency segregation (ITFS) processing was applied so that the time-frequency units where the masker energy dominated the target energy were removed. The remaining target-dominated “glimpses” were reassembled as the stimulus. Speech reception thresholds measured using these resynthesized ITFS-processed stimuli were the same for the reference and comparison conditions supporting the conclusion that the amount of energetic masking across conditions was the same. These results indicated that the large release from masking found under all comparison conditions was due primarily to a reduction in informational masking. Furthermore, the large individual differences observed generally were correlated across the three masking release conditions. PMID:27475139

How Does Target Duration Affect Object Substitution Masking?

ERIC Educational Resources Information Center

Gellatly, Angus; Pilling, Michael; Carter, Wakefield; Guest, Duncan

2010-01-01

Object substitution masking (OSM) is typically studied using a brief search display. The target item may be indicated by a cue/mask surrounding but not overlapping it. Report of the target is reduced when mask offset trails target offset rather than being simultaneous with it. We report 5 experiments investigating whether OSM can be obtained if…

Different effects of the two types of spatial pre-cueing: what precisely is "attention" in Di Lollo's and Enns' substitution masking theory?

PubMed

Luiga, I; Bachmann, T

2007-11-01

Enns and Di Lollo [Psychological Science, 8 (2), 135-139, 1997] have introduced the object substitution theory of visual masking. Object substitution masking occurs when focusing attention on the target is delayed. However, Posner (Quarterly Journal of Experimental Psychology, 32, 3-25, 1980) has already shown that attention can be directed to a target at least in two ways: intentionally (endogenously) and automatically (exogenously). We conducted two experiments to explore the effects of endogenous and exogenous cues on substitution masking. The results showed that when attention was shifted to the target location automatically (using a local peripheral pre-cue), masking was attenuated. A decrease in target identification dependent on a delay of mask offset, typical to substitution masking, was not observed. However, strong substitution masking occurred when the target location was not pre-cued or when attention was directed to the target location intentionally (using a symbolic pre-cue displayed centrally). The hypothesis of two different mechanisms of attentional control in substitution masking was confirmed.

Neuroimaging somatosensory perception and masking.

PubMed

Meador, Kimford J; Revill, Kathleen Pirog; Epstein, Charles M; Sathian, K; Loring, David W; Rorden, Chris

2017-01-08

The specific cortical and subcortical regions involved in conscious perception and masking are uncertain. This study sought to identify brain areas involved in conscious perception of somatosensory stimuli during a masking task using functional magnetic resonance (fMRI) to contrast perceived vs. non-perceived targets. Electrical trains were delivered to the right index finger for targets and to the left index finger for masks. Target intensities were adjusted to compensate for threshold drift. Sham target trials were given in ~10% of the trials, and target stimuli without masks were delivered in one of the five runs (68 trials/run). When healthy dextral adult volunteers (n=15) perceived right hand targets, greater left- than right-cerebral activations were seen with similar patterns across the parietal cortex, thalamus, insula, claustrum, and midbrain. When targets were not perceived, left/right cerebral activations were similar overall. Directly comparing perceived vs. non-perceived stimuli with similar intensities in the masking task revealed predominate activations contralateral to masks. In contrast, activations were greater contralateral to perceived targets if no masks were given or if masks were given but target stimulus intensities were greater for perceived than non-perceived targets. The novel aspects of this study include: 1) imaging of cortical and subcortical activations in healthy humans related to somatosensory perception during a masking task, 2) activations in the human thalamus and midbrain related to perception of stimuli compared to matched non-perceived stimuli, and 3) similar left/right cerebral activation patterns across cortical, thalamic and midbrain structures suggesting interactions across all three levels during conscious perception in humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Secret shared multiple-image encryption based on row scanning compressive ghost imaging and phase retrieval in the Fresnel domain

NASA Astrophysics Data System (ADS)

Li, Xianye; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Yin, Yongkai; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

2017-09-01

A multiple-image encryption method is proposed that is based on row scanning compressive ghost imaging, (t, n) threshold secret sharing, and phase retrieval in the Fresnel domain. In the encryption process, after wavelet transform and Arnold transform of the target image, the ciphertext matrix can be first detected using a bucket detector. Based on a (t, n) threshold secret sharing algorithm, the measurement key used in the row scanning compressive ghost imaging can be decomposed and shared into two pairs of sub-keys, which are then reconstructed using two phase-only mask (POM) keys with fixed pixel values, placed in the input plane and transform plane 2 of the phase retrieval scheme, respectively; and the other POM key in the transform plane 1 can be generated and updated by the iterative encoding of each plaintext image. In each iteration, the target image acts as the input amplitude constraint in the input plane. During decryption, each plaintext image possessing all the correct keys can be successfully decrypted by measurement key regeneration, compression algorithm reconstruction, inverse wavelet transformation, and Fresnel transformation. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method.

Spatial release from masking based on binaural processing for up to six maskers

PubMed Central

Yost, William A.

2017-01-01

Spatial Release from Masking (SRM) was measured for identification of a female target word spoken in the presence of male masker words. Target words from a single loudspeaker located at midline were presented when two, four, or six masker words were presented either from the same source as the target or from spatially separated masker sources. All masker words were presented from loudspeakers located symmetrically around the centered target source in the front azimuth hemifield. Three masking conditions were employed: speech-in-speech masking (involving both informational and energetic masking), speech-in-noise masking (involving energetic masking), and filtered speech-in-filtered speech masking (involving informational masking). Psychophysical results were summarized as three-point psychometric functions relating proportion of correct word identification to target-to-masker ratio (in decibels) for both the co-located and spatially separated target and masker sources cases. SRM was then calculated by comparing the slopes and intercepts of these functions. SRM decreased as the number of symmetrically placed masker sources increased from two to six. This decrease was independent of the type of masking, with almost no SRM measured for six masker sources. These results suggest that when SRM is dependent primarily on binaural processing, SRM is effectively limited to fewer than six sound sources. PMID:28372135

Gestalt grouping and common onset masking.

PubMed

Kahan, Todd A; Mathis, Katherine M

2002-11-01

A four-dot mask that surrounds and is presented simultaneously with a briefly presented target will reduce a person's ability to identity that target if the mask persists beyond target offset and attention is divided (Enns & Di Lollo, 1997, 2000). This masking effect, referred to as common onset masking, reflects reentrant processing in the visual system and can best be explained with a theory of object substitution (Di Lollo, Enns, & Rensink, 2000). In the present experiments, we investigated whether Gestalt grouping variables would influence the strength of common onset masking. The results indicated that (1) masking was impervious to grouping by form, similarity of color, position, luminance polarity, and common region and (2) masking increased with the number of elements in the masking display.

Visual Masking During Pursuit Eye Movements

ERIC Educational Resources Information Center

White, Charles W.

1976-01-01

Visual masking occurs when one stimulus interferes with the perception of another stimulus. Investigates which matters more for visual masking--that the target and masking stimuli are flashed on the same part of the retina, or, that the target and mask appear in the same place. (Author/RK)

Asymmetry in Object Substitution Masking Occurs Relative to the Direction of Spatial Attention Shift

ERIC Educational Resources Information Center

Hirose, Nobuyuki; Osaka, Naoyuki

2010-01-01

A sparse mask that persists beyond the duration of a target can reduce its visibility, a phenomenon called "object substitution masking". Y. Jiang and M. M. Chun (2001a) found an asymmetric pattern of substitution masking such that a mask on the peripheral side of the target caused stronger substitution masking than on the central side.…

Effects of Temporal Integration on the Shape of Visual Backward Masking Functions

ERIC Educational Resources Information Center

Francis, Gregory; Cho, Yang Seok

2008-01-01

Many studies of cognition and perception use a visual mask to explore the dynamics of information processing of a target. Especially important in these applications is the time between the target and mask stimuli. A plot of some measure of target visibility against stimulus onset asynchrony is called a masking function, which can sometimes be…

Competing for Consciousness: Prolonged Mask Exposure Reduces Object Substitution Masking

ERIC Educational Resources Information Center

Goodhew, Stephanie C.; Visser, Troy A. W.; Lipp, Ottmar V.; Dux, Paul E.

2011-01-01

In object substitution masking (OSM) a sparse, temporally trailing 4-dot mask impairs target identification, even though it has different contours from, and does not spatially overlap with the target. Here, we demonstrate a previously unknown characteristic of OSM: Observers show reduced masking at prolonged (e.g., 640 ms) relative to intermediate…

Research on infrared ship detection method in sea-sky background

NASA Astrophysics Data System (ADS)

Tang, Da; Sun, Gang; Wang, Ding-he; Niu, Zhao-dong; Chen, Zeng-ping

2013-09-01

An approach to infrared ship detection based on sea-sky-line(SSL) detection, ROI extraction and feature recognition is proposed in this paper. Firstly, considering that far ships are expected to be adjacent to the SSL, SSL is detected to find potential target areas. Radon transform is performed on gradient image to choose candidate SSLs, and detection result is given by fuzzy synthetic evaluation values. Secondly, in view of recognizable condition that there should be enough differences between target and background in infrared image, two gradient masks have been created and improved as practical guidelines in eliminating false alarm. Thirdly, extract ROI near the SSL by using multi-grade segmentation and fusion method after image sharpening, and unsuitable candidates are screened out according to the gradient masks and ROI shape. Finally, we segment the rest of ROIs by two-stage modified OTSU, and calculate target confidence as a standard measuring the facticity of target. Compared with other ship detection methods, proposed method is suitable for bipolar targets, which offers a good practicability and accuracy, and achieves a satisfying detection speed. Detection experiments with 200 thousand frames show that the proposed method is widely applicable, powerful in resistance to interferences and noises with a detection rate of above 95%, which satisfies the engineering needs commendably.

Image masking using polygon fills and morphological transformations

NASA Technical Reports Server (NTRS)

Simpson, James J.

1992-01-01

Polygon-fill operations and morphological transformations are effective computational tools for the land-masking and coastline-correction preprocessing operations often applied to AVHRR data prior to oceanographic applications. These masking operations, in conjunction with cloud-screening techniques, can be used on such other oceanographically significant remote-sensing data as those of the Coastal Zone Color Scanner, GOES, and Landsat. The sensitivity of the methods to regional variations in atmospheric conditions and land-ocean temperature gradients is assessed for tropical, midlatitude, and high latitude regions.

Summation versus suppression in metacontrast masking: On the potential pitfalls of using metacontrast masking to assess perceptual-motor dissociation.

PubMed

Cardoso-Leite, Pedro; Waszak, Florian

2014-07-01

A briefly flashed target stimulus can become "invisible" when immediately followed by a mask-a phenomenon known as backward masking, which constitutes a major tool in the cognitive sciences. One form of backward masking is termed metacontrast masking. It is generally assumed that in metacontrast masking, the mask suppresses activity on which the conscious perception of the target relies. This assumption biases conclusions when masking is used as a tool-for example, to study the independence between perceptual detection and motor reaction. This is because other models can account for reduced perceptual performance without requiring suppression mechanisms. In this study, we used signal detection theory to test the suppression model against an alternative view of metacontrast masking, referred to as the summation model. This model claims that target- and mask-related activations fuse and that the difficulty in detecting the target results from the difficulty to discriminate this fused response from the response produced by the mask alone. Our data support this alternative view. This study is not a thorough investigation of metacontrast masking. Instead, we wanted to point out that when a different model is used to account for the reduced perceptual performance in metacontrast masking, there is no need to postulate a dissociation between perceptual and motor responses to account for the data. Metacontrast masking, as implemented in the Fehrer-Raab situation, therefore is not a valid method to assess perceptual-motor dissociations.

Reduced OSM for Long Duration Targets: Individuation or Items Loaded into VSTM?

ERIC Educational Resources Information Center

Guest, Duncan; Gellatly, Angus; Pilling, Michael

2012-01-01

Typical studies of object substitution masking (OSM) employ a briefly presented search array. The target item is indicated by a cue/mask that surrounds but does not overlap the target and, compared to a common offset control condition, report of the target is reduced when the mask remains present after target offset. Given how little observers are…

Orientation tuning of contrast masking caused by motion streaks.

PubMed

Apthorp, Deborah; Cass, John; Alais, David

2010-08-01

We investigated whether the oriented trails of blur left by fast-moving dots (i.e., "motion streaks") effectively mask grating targets. Using a classic overlay masking paradigm, we varied mask contrast and target orientation to reveal underlying tuning. Fast-moving Gaussian blob arrays elevated thresholds for detection of static gratings, both monoptically and dichoptically. Monoptic masking at high mask (i.e., streak) contrasts is tuned for orientation and exhibits a similar bandwidth to masking functions obtained with grating stimuli (∼30 degrees). Dichoptic masking fails to show reliable orientation-tuned masking, but dichoptic masks at very low contrast produce a narrowly tuned facilitation (∼17 degrees). For iso-oriented streak masks and grating targets, we also explored masking as a function of mask contrast. Interestingly, dichoptic masking shows a classic "dipper"-like TVC function, whereas monoptic masking shows no dip and a steeper "handle". There is a very strong unoriented component to the masking, which we attribute to transiently biased temporal frequency masking. Fourier analysis of "motion streak" images shows interesting differences between dichoptic and monoptic functions and the information in the stimulus. Our data add weight to the growing body of evidence that the oriented blur of motion streaks contributes to the processing of fast motion signals.

What's in a mask? Information masking with forward and backward visual masks.

PubMed

Davis, Chris; Kim, Jeesun

2011-10-01

Three experiments tested how the physical format and information content of forward and backward masks affected the extent of visual pattern masking. This involved using different types of forward and backward masks with target discrimination measured by percentage correct in the first experiment (with a fixed target duration) and by an adaptive threshold procedure in the last two. The rationale behind the manipulation of the content of the masks stemmed from masking theories emphasizing attentional and/or conceptual factors rather than visual ones. Experiment 1 used word masks and showed that masking was reduced (a masking reduction effect) when the forward and backward masks were the same word (although in different case) compared to when the masks were different words. Experiment 2 tested the extent to which a reduction in masking might occur due to the physical similarity between the forward and backward masks by comparing the effect of the same content of the masks in the same versus different case. The result showed a significant reduction in masking for same content masks but no significant effect of case. The last experiment examined whether the reduction in masking effect would be observed with nonword masks--that is, having no high-level representation. No reduction in masking was found from same compared to different nonword masks (Experiment 3). These results support the view that the conscious perception of a rapidly displayed target stimulus is in part determined by high-level perceptual/cognitive factors concerned with masking stimulus grouping and attention.

Simultaneous masking additivity for short Gaussian-shaped tones: spectral effects.

PubMed

Laback, Bernhard; Necciari, Thibaud; Balazs, Peter; Savel, Sophie; Ystad, Sølvi

2013-08-01

Laback et al. [(2011). J. Acoust. Soc. Am. 129, 888-897] investigated the additivity of nonsimultaneous masking using short Gaussian-shaped tones as maskers and target. The present study involved Gaussian stimuli to measure the additivity of simultaneous masking for combinations of up to four spectrally separated maskers. According to most basilar membrane measurements, the maskers should be processed linearly at the characteristic frequency (CF) of the target. Assuming also compression of the target, all masker combinations should produce excess masking (exceeding linear additivity). The results for a pair of maskers flanking the target indeed showed excess masking. The amount of excess masking could be predicted by a model assuming summation of masker-evoked excitations in intensity units at the target CF and compression of the target, using compressive input/output functions derived from the nonsimultaneous masking study. However, the combinations of lower-frequency maskers showed much less excess masking than predicted by the model. This cannot easily be attributed to factors like off-frequency listening, combination tone perception, or between-masker suppression. It was better predicted, however, by assuming weighted intensity summation of masker excitations. The optimum weights for the lower-frequency maskers were smaller than one, consistent with partial masker compression as indicated by recent psychoacoustic data.

Temporal masking of multidimensional tactual stimuli

NASA Astrophysics Data System (ADS)

Tan, Hong Z.; Reed, Charlotte M.; Delhorne, Lorraine A.; Durlach, Nathaniel I.; Wan, Natasha

2003-12-01

Experiments were performed to examine the temporal masking properties of multidimensional tactual stimulation patterns delivered to the left index finger. The stimuli consisted of fixed-frequency sinusoidal motions in the kinesthetic (2 or 4 Hz), midfrequency (30 Hz), and cutaneous (300 Hz) frequency ranges. Seven stimuli composed of one, two, or three spectral components were constructed at each of two signal durations (125 or 250 ms). Subjects identified target signals under three different masking paradigms: forward masking, backward masking, and sandwiched masking (in which the target is presented between two maskers). Target identification was studied as a function of interstimulus interval (ISI) in the range 0 to 640 ms. For both signal durations, percent-correct scores increased with ISI for each of the three masking paradigms. Scores with forward and backward masking were similar and significantly higher than scores obtained with sandwiched masking. Analyses of error trials revealed that subjects showed a tendency to respond, more often than chance, with the masker, the composite of the masker and target, or the combination of the target and a component of the masker. The current results are compared to those obtained in previous studies of tactual recognition masking with brief cutaneous spatial patterns. The results are also discussed in terms of estimates of information transfer (IT) and IT rate, are compared to previous studies with multidimensional tactual signals, and are related to research on the development of tactual aids for the deaf.

Differential effect of visual masking in perceptual categorization.

PubMed

Hélie, Sébastien; Cousineau, Denis

2015-06-01

This article explores the visual information used to categorize stimuli drawn from a common stimulus space into verbal and nonverbal categories using 2 experiments. Experiment 1 explores the effect of target duration on verbal and nonverbal categorization using backward masking to interrupt visual processing. With categories equated for difficulty for long and short target durations, intermediate target duration shows an advantage for verbal categorization over nonverbal categorization. Experiment 2 tests whether the results of Experiment 1 can be explained by shorter target duration resulting in a smaller signal-to-noise ratio of the categorization stimulus. To test for this possibility, Experiment 2 used integration masking with the same stimuli, categories, and masks as Experiment 1 with a varying level of mask opacity. As predicted, low mask opacity yielded similar results to long target duration while high mask opacity yielded similar results to short target duration. Importantly, intermediate mask opacity produced an advantage for verbal categorization over nonverbal categorization, similar to intermediate target duration. These results suggest that verbal and nonverbal categorization are affected differently by manipulations affecting the signal-to-noise ratio of the stimulus, consistent with multiple-system theories of categorizations. The results further suggest that verbal categorization may be more digital (and more robust to low signal-to-noise ratio) while the information used in nonverbal categorization may be more analog (and less robust to lower signal-to-noise ratio). This article concludes with a discussion of how these new results affect the use of masking in perceptual categorization and multiple-system theories of perceptual category learning. (c) 2015 APA, all rights reserved).

Microlens array processor with programmable weight mask and direct optical input

NASA Astrophysics Data System (ADS)

Schmid, Volker R.; Lueder, Ernst H.; Bader, Gerhard; Maier, Gert; Siegordner, Jochen

1999-03-01

We present an optical feature extraction system with a microlens array processor. The system is suitable for online implementation of a variety of transforms such as the Walsh transform and DCT. Operating with incoherent light, our processor accepts direct optical input. Employing a sandwich- like architecture, we obtain a very compact design of the optical system. The key elements of the microlens array processor are a square array of 15 X 15 spherical microlenses on acrylic substrate and a spatial light modulator as transmissive mask. The light distribution behind the mask is imaged onto the pixels of a customized a-Si image sensor with adjustable gain. We obtain one output sample for each microlens image and its corresponding weight mask area as summation of the transmitted intensity within one sensor pixel. The resulting architecture is very compact and robust like a conventional camera lens while incorporating a high degree of parallelism. We successfully demonstrate a Walsh transform into the spatial frequency domain as well as the implementation of a discrete cosine transform with digitized gray values. We provide results showing the transformation performance for both synthetic image patterns and images of natural texture samples. The extracted frequency features are suitable for neural classification of the input image. Other transforms and correlations can be implemented in real-time allowing adaptive optical signal processing.

Relationship of extinction to perceptual thresholds for single stimuli.

PubMed

Meador, K J; Ray, P G; Day, L J; Loring, D W

2001-04-24

To demonstrate the effects of target stimulus intensity on extinction to double simultaneous stimuli. Attentional deficits contribute to extinction in patients with brain lesions, but extinction (i.e., masking) can also be produced in healthy subjects. The relationship of extinction to perceptual thresholds for single stimuli remains uncertain. Brief electrical pulses were applied simultaneously to the left and right index fingers of 16 healthy volunteers (8 young and 8 elderly adults) and 4 patients with right brain stroke (RBS). The stimulus to be perceived (i.e., target stimulus) was given at the lowest perceptual threshold to perceive any single stimulus (i.e., Minimal) and at the threshold to perceive 100% of single stimuli. The mask stimulus (i.e., stimulus given to block the target) was applied to the contralateral hand at intensities just below discomfort. Extinction was less for target stimuli at 100% than Minimal threshold for healthy subjects. Extinction of left targets was greater in patients with RBS than elderly control subjects. Left targets were extinguished less than right in healthy subjects. In contrast, the majority of left targets were extinguished in patients with RBS even when right mask intensity was reduced below right 100% threshold for single stimuli. RBS patients had less extinction for right targets despite having greater left mask - threshold difference than control subjects. In patients with RBS, right "targets" at 100% threshold extinguished left "masks" (20%) almost as frequently as left masks extinguished right targets (32%). Subtle changes in target intensity affect extinction in healthy adults. Asymmetries in mask and target intensities (relative to single-stimulus perceptual thresholds) affect extinction in RBS patients less for left targets but more for right targets as compared with control subjects.

[Recognition of visual objects under forward masking. Effects of cathegorial similarity of test and masking stimuli].

PubMed

Gerasimenko, N Iu; Slavutskaia, A V; Kalinin, S A; Kulikov, M A; Mikhaĭlova, E S

2013-01-01

In 38 healthy subjects accuracy and response time were examined during recognition of two categories of images--animals andnonliving objects--under forward masking. We revealed new data that masking effects depended of categorical similarity of target and masking stimuli. The recognition accuracy was the lowest and the response time was the most slow, when the target and masking stimuli belongs to the same category, that was combined with high dispersion of response times. The revealed effects were more clear in the task of animal recognition in comparison with the recognition of nonliving objects. We supposed that the revealed effects connected with interference between cortical representations of the target and masking stimuli and discussed our results in context of cortical interference and negative priming.

Direct Measures of Character Mislocalizations with Masked/Unmasked Exposures.

ERIC Educational Resources Information Center

Chastain, Garvin; And Others

Butler (1980) compared errors representing intrusions and mislocalizations on 3x3 letter displays under pattern-mask versus no-mask conditions and found that pattern masking increased character mislocalization errors (naming a character in the display but not in the target position as being the target) over intrusion errors (naming a character not…

Titanium dioxide fine structures by RF magnetron sputter method deposited on an electron-beam resist mask

NASA Astrophysics Data System (ADS)

Hashiba, Hideomi; Miyazaki, Yuta; Matsushita, Sachiko

2013-09-01

Titanium dioxide (TiO2) has been draw attention for wide range of applications from photonic crystals for visible light range by its catalytic characteristics to tera-hertz range by its high refractive index. We present an experimental study of fabrication of fine structures of TiO2 with a ZEP electron beam resist mask followed by Ti sputter deposition techniques. A TiO2 thin layer of 150 nm thick was grown on an FTO glass substrate with a fine patterned ZEP resist mask by a conventional RF magnetron sputter method with Ti target. The deposition was carried out with argon-oxygen gases at a pressure of 5.0 x 10 -1 Pa in a chamber. During the deposition, ratio of Ar-O2 gas was kept to the ratio of 2:1 and the deposition ratio was around 0.5 Å/s to ensure enough oxygen to form TiO2 and low temperature to avoid deformation of fine pattern of the ZPU resist mask. Deposited TiO2 layers are white-transparent, amorphous, and those roughnesses are around 7 nm. Fabricated TiO2 PCs have wider TiO2 slabs of 112 nm width leaving periodic 410 x 410 nm2 air gaps. We also studied transformation of TiO2 layers and TiO2 fine structures by baking at 500 °C. XRD measurement for TiO2 shows that the amorphous TiO2 transforms to rutile and anatase forms by the baking while keeping the same profile of the fine structures. Our fabrication method can be one of a promising technique to optic devices on researches and industrial area.

Masking interrupts figure-ground signals in V1.

PubMed

Lamme, Victor A F; Zipser, Karl; Spekreijse, Henk

2002-10-01

In a backward masking paradigm, a target stimulus is rapidly (<100 msec) followed by a second stimulus. This typically results in a dramatic decrease in the visibility of the target stimulus. It has been shown that masking reduces responses in V1. It is not known, however, which process in V1 is affected by the mask. In the past, we have shown that in V1, modulations of neural activity that are specifically related to figure-ground segregation can be recorded. Here, we recorded from awake macaque monkeys, engaged in a task where they had to detect figures from background in a pattern backward masking paradigm. We show that the V1 figure-ground signals are selectively and fully suppressed at target-mask intervals that psychophysically result in the target being invisible. Initial response transients, signalling the features that make up the scene, are not affected. As figure-ground modulations depend on feedback from extrastriate areas, these results suggest that masking selectively interrupts the recurrent interactions between V1 and higher visual areas.

Brightness masking is modulated by disparity structure.

PubMed

Pelekanos, Vassilis; Ban, Hiroshi; Welchman, Andrew E

2015-05-01

The luminance contrast at the borders of a surface strongly influences surface's apparent brightness, as demonstrated by a number of classic visual illusions. Such phenomena are compatible with a propagation mechanism believed to spread contrast information from borders to the interior. This process is disrupted by masking, where the perceived brightness of a target is reduced by the brief presentation of a mask (Paradiso & Nakayama, 1991), but the exact visual stage that this happens remains unclear. In the present study, we examined whether brightness masking occurs at a monocular-, or a binocular-level of the visual hierarchy. We used backward masking, whereby a briefly presented target stimulus is disrupted by a mask coming soon afterwards, to show that brightness masking is affected by binocular stages of the visual processing. We manipulated the 3-D configurations (slant direction) of the target and mask and measured the differential disruption that masking causes on brightness estimation. We found that the masking effect was weaker when stimuli had a different slant. We suggest that brightness masking is partly mediated by mid-level neuronal mechanisms, at a stage where binocular disparity edge structure has been extracted. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Chronometry of Mental Ability: An Event-Related Potential Analysis of an Auditory Oddball Discrimination Task

ERIC Educational Resources Information Center

Beauchamp, Chris M.; Stelmack, Robert M.

2006-01-01

The relation between intelligence and speed of auditory discrimination was investigated during an auditory oddball task with backward masking. In target discrimination conditions that varied in the interval between the target and the masking stimuli and in the tonal frequency of the target and masking stimuli, higher ability participants (HA)…

Exploiting Small Leakages in Masks to Turn a Second-Order Attack into a First-Order Attack and Improved Rotating Substitution Box Masking with Linear Code Cosets.

PubMed

DeTrano, Alexander; Karimi, Naghmeh; Karri, Ramesh; Guo, Xiaofei; Carlet, Claude; Guilley, Sylvain

2015-01-01

Masking countermeasures, used to thwart side-channel attacks, have been shown to be vulnerable to mask-extraction attacks. State-of-the-art mask-extraction attacks on the Advanced Encryption Standard (AES) algorithm target S-Box recomputation schemes but have not been applied to scenarios where S-Boxes are precomputed offline. We propose an attack targeting precomputed S-Boxes stored in nonvolatile memory. Our attack targets AES implemented in software protected by a low entropy masking scheme and recovers the masks with 91% success rate. Recovering the secret key requires fewer power traces (in fact, by at least two orders of magnitude) compared to a classical second-order attack. Moreover, we show that this attack remains viable in a noisy environment or with a reduced number of leakage points. Eventually, we specify a method to enhance the countermeasure by selecting a suitable coset of the masks set.

Exploiting Small Leakages in Masks to Turn a Second-Order Attack into a First-Order Attack and Improved Rotating Substitution Box Masking with Linear Code Cosets

PubMed Central

DeTrano, Alexander; Karimi, Naghmeh; Karri, Ramesh; Guo, Xiaofei; Carlet, Claude; Guilley, Sylvain

2015-01-01

Masking countermeasures, used to thwart side-channel attacks, have been shown to be vulnerable to mask-extraction attacks. State-of-the-art mask-extraction attacks on the Advanced Encryption Standard (AES) algorithm target S-Box recomputation schemes but have not been applied to scenarios where S-Boxes are precomputed offline. We propose an attack targeting precomputed S-Boxes stored in nonvolatile memory. Our attack targets AES implemented in software protected by a low entropy masking scheme and recovers the masks with 91% success rate. Recovering the secret key requires fewer power traces (in fact, by at least two orders of magnitude) compared to a classical second-order attack. Moreover, we show that this attack remains viable in a noisy environment or with a reduced number of leakage points. Eventually, we specify a method to enhance the countermeasure by selecting a suitable coset of the masks set. PMID:26491717

Video encryption using chaotic masks in joint transform correlator

NASA Astrophysics Data System (ADS)

Saini, Nirmala; Sinha, Aloka

2015-03-01

A real-time optical video encryption technique using a chaotic map has been reported. In the proposed technique, each frame of video is encrypted using two different chaotic random phase masks in the joint transform correlator architecture. The different chaotic random phase masks can be obtained either by using different iteration levels or by using different seed values of the chaotic map. The use of different chaotic random phase masks makes the decryption process very complex for an unauthorized person. Optical, as well as digital, methods can be used for video encryption but the decryption is possible only digitally. To further enhance the security of the system, the key parameters of the chaotic map are encoded using RSA (Rivest-Shamir-Adleman) public key encryption. Numerical simulations are carried out to validate the proposed technique.

Metacontrast masking and attention do not interact.

PubMed

Agaoglu, Sevda; Breitmeyer, Bruno; Ogmen, Haluk

2016-07-01

Visual masking and attention have been known to control the transfer of information from sensory memory to visual short-term memory. A natural question is whether these processes operate independently or interact. Recent evidence suggests that studies that reported interactions between masking and attention suffered from ceiling and/or floor effects. The objective of the present study was to investigate whether metacontrast masking and attention interact by using an experimental design in which saturation effects are avoided. We asked observers to report the orientation of a target bar randomly selected from a display containing either two or six bars. The mask was a ring that surrounded the target bar. Attentional load was controlled by set-size and masking strength by the stimulus onset asynchrony between the target bar and the mask ring. We investigated interactions between masking and attention by analyzing two different aspects of performance: (i) the mean absolute response errors and (ii) the distribution of signed response errors. Our results show that attention affects observers' performance without interacting with masking. Statistical modeling of response errors suggests that attention and metacontrast masking exert their effects by independently modulating the probability of "guessing" behavior. Implications of our findings for models of attention are discussed.

Individual differences in metacontrast masking regarding sensitivity and response bias.

PubMed

Albrecht, Thorsten; Mattler, Uwe

2012-09-01

In metacontrast masking target visibility is modulated by the time until a masking stimulus appears. The effect of this temporal delay differs across participants in such a way that individual human observers' performance shows distinguishable types of masking functions which remain largely unchanged for months. Here we examined whether individual differences in masking functions depend on different response criteria in addition to differences in discrimination sensitivity. To this end we reanalyzed previously published data and conducted a new experiment for further data analyses. Our analyses demonstrate that a distinction of masking functions based on the type of masking stimulus is superior to a distinction based on the target-mask congruency. Individually different masking functions are based on individual differences in discrimination sensitivities and in response criteria. Results suggest that individual differences in metacontrast masking result from individually different criterion contents. Copyright © 2012 Elsevier Inc. All rights reserved.

Masking of Figure-Ground Texture and Single Targets by Surround Inhibition: A Computational Spiking Model

PubMed Central

Supèr, Hans; Romeo, August

2012-01-01

A visual stimulus can be made invisible, i.e. masked, by the presentation of a second stimulus. In the sensory cortex, neural responses to a masked stimulus are suppressed, yet how this suppression comes about is still debated. Inhibitory models explain masking by asserting that the mask exerts an inhibitory influence on the responses of a neuron evoked by the target. However, other models argue that the masking interferes with recurrent or reentrant processing. Using computer modeling, we show that surround inhibition evoked by ON and OFF responses to the mask suppresses the responses to a briefly presented stimulus in forward and backward masking paradigms. Our model results resemble several previously described psychophysical and neurophysiological findings in perceptual masking experiments and are in line with earlier theoretical descriptions of masking. We suggest that precise spatiotemporal influence of surround inhibition is relevant for visual detection. PMID:22393370

Reward-associated features capture attention in the absence of awareness: Evidence from object-substitution masking.

PubMed

Harris, Joseph A; Donohue, Sarah E; Schoenfeld, Mircea A; Hopf, Jens-Max; Heinze, Hans-Jochen; Woldorff, Marty G

2016-08-15

Reward-associated visual features have been shown to capture visual attention, evidenced in faster and more accurate behavioral performance, as well as in neural responses reflecting lateralized shifts of visual attention to those features. Specifically, the contralateral N2pc event-related-potential (ERP) component that reflects attentional shifting exhibits increased amplitude in response to task-relevant targets containing a reward-associated feature. In the present study, we examined the automaticity of such reward-association effects using object-substitution masking (OSM) in conjunction with MEG measures of visual attentional shifts. In OSM, a visual-search array is presented, with the target item to be detected indicated by a surrounding mask (here, four surrounding squares). Delaying the offset of the target-surrounding four-dot mask relative to the offset of the rest of the target/distracter array disrupts the viewer's awareness of the target (masked condition), whereas simultaneous offsets do not (unmasked condition). Here we manipulated whether the color of the OSM target was or was not of a previously reward-associated color. By tracking reward-associated enhancements of behavior and the N2pc in response to masked targets containing a previously rewarded or unrewarded feature, the automaticity of attentional capture by reward could be probed. We found an enhanced N2pc response to targets containing a previously reward-associated color feature. Moreover, this enhancement of the N2pc by reward did not differ between masking conditions, nor did it differ as a function of the apparent visibility of the target within the masked condition. Overall, these results underscore the automaticity of attentional capture by reward-associated features, and demonstrate the ability of feature-based reward associations to shape attentional capture and allocation outside of perceptual awareness. Copyright © 2016 Elsevier Inc. All rights reserved.

Recovery of a crowded object by masking the flankers: Determining the locus of feature integration

PubMed Central

Chakravarthi, Ramakrishna; Cavanagh, Patrick

2009-01-01

Object recognition is a central function of the visual system. As a first step, the features of an object are registered; these independently encoded features are then bound together to form a single representation. Here we investigate the locus of this “feature integration” by examining crowding, a striking breakdown of this process. Crowding, an inability to identify a peripheral target surrounded by flankers, results from “excessive integration” of target and flanker features. We presented a standard crowding display with a target C flanked by four flanker C's in the periphery. We then masked only the flankers (but not the target) with one of three kinds of masks—noise, metacontrast, and object substitution—each of which interferes at progressively higher levels of visual processing. With noise and metacontrast masks (low-level masking), the crowded target was recovered, whereas with object substitution masks (high-level masking), it was not. This places a clear upper bound on the locus of interference in crowding suggesting that crowding is not a low-level phenomenon. We conclude that feature integration, which underlies crowding, occurs prior to the locus of object substitution masking. Further, our results indicate that the integrity of the flankers, but not their identification, is crucial for crowding to occur. PMID:19810785

Optical image encryption using multilevel Arnold transform and noninterferometric imaging

NASA Astrophysics Data System (ADS)

Chen, Wen; Chen, Xudong

2011-11-01

Information security has attracted much current attention due to the rapid development of modern technologies, such as computer and internet. We propose a novel method for optical image encryption using multilevel Arnold transform and rotatable-phase-mask noninterferometric imaging. An optical image encryption scheme is developed in the gyrator transform domain, and one phase-only mask (i.e., phase grating) is rotated and updated during image encryption. For the decryption, an iterative retrieval algorithm is proposed to extract high-quality plaintexts. Conventional encoding methods (such as digital holography) have been proven vulnerably to the attacks, and the proposed optical encoding scheme can effectively eliminate security deficiency and significantly enhance cryptosystem security. The proposed strategy based on the rotatable phase-only mask can provide a new alternative for data/image encryption in the noninterferometric imaging.

Effect of random phase mask on input plane in photorefractive authentic memory with two-wave encryption method

NASA Astrophysics Data System (ADS)

Mita, Akifumi; Okamoto, Atsushi; Funakoshi, Hisatoshi

2004-06-01

We have proposed an all-optical authentic memory with the two-wave encryption method. In the recording process, the image data are encrypted to a white noise by the random phase masks added on the input beam with the image data and the reference beam. Only reading beam with the phase-conjugated distribution of the reference beam can decrypt the encrypted data. If the encrypted data are read out with an incorrect phase distribution, the output data are transformed into a white noise. Moreover, during read out, reconstructions of the encrypted data interfere destructively resulting in zero intensity. Therefore our memory has a merit that we can detect unlawful accesses easily by measuring the output beam intensity. In our encryption method, the random phase mask on the input plane plays important roles in transforming the input image into a white noise and prohibiting to decrypt a white noise to the input image by the blind deconvolution method. Without this mask, when unauthorized users observe the output beam by using CCD in the readout with the plane wave, the completely same intensity distribution as that of Fourier transform of the input image is obtained. Therefore the encrypted image will be decrypted easily by using the blind deconvolution method. However in using this mask, even if unauthorized users observe the output beam using the same method, the encrypted image cannot be decrypted because the observed intensity distribution is dispersed at random by this mask. Thus it can be said the robustness is increased by this mask. In this report, we compare two correlation coefficients, which represents the degree of a white noise of the output image, between the output image and the input image in using this mask or not. We show that the robustness of this encryption method is increased as the correlation coefficient is improved from 0.3 to 0.1 by using this mask.

Reentrant processing mediates object substitution masking: comment on Põder (2013).

PubMed

Di Lollo, Vincent

2014-01-01

Object-substitution masking (OSM) occurs when a target stimulus and a surrounding mask are displayed briefly together, and the display then continues with the mask alone. Target identification is accurate when the stimuli co-terminate but is progressively impaired as the duration of the trailing mask is increased. In reentrant accounts, OSM is said to arise from iterative exchanges between brain regions connected by two-way pathways. In an alternative account, OSM is explained on the basis of exclusively feed-forward processes, without recourse to reentry. Here I show that the feed-forward account runs afoul of the extant phenomenological, behavioral, brain-imaging, and electrophysiological evidence. Further, the feed-forward assumption that masking occurs when attention finds a degraded target is shown to be entirely ad hoc. In contrast, the evidence is uniformly consistent with a reentrant-processing account of OSM.

"Slit Mask Design for the Giant Magellan Telescope Multi-object Astronomical and Cosmological Spectrograph"

NASA Astrophysics Data System (ADS)

Williams, Darius; Marshall, Jennifer L.; Schmidt, Luke M.; Prochaska, Travis; DePoy, Darren L.

2018-01-01

The Giant Magellan Telescope Multi-object Astronomical and Cosmological Spectrograph (GMACS) is currently in development for the Giant Magellan Telescope (GMT). GMACS will employ slit masks with a usable diameter of approximately 0.450 m for the purpose of multi-slit spectroscopy. Of significant importance are the design constraints and parameters of the multi-object slit masks themselves as well as the means for mapping astronomical targets to physical mask locations. Analytical methods are utilized to quantify deformation effects on a potential slit mask due to thermal expansion and vignetting of target light cones. Finite element analysis (FEA) is utilized to simulate mask flexure in changing gravity vectors. The alpha version of the mask creation program for GMACS, GMACS Mask Simulator (GMS), a derivative of the OSMOS Mask Simulator (OMS), is introduced.

Cryptosystem for Securing Image Encryption Using Structured Phase Masks in Fresnel Wavelet Transform Domain

NASA Astrophysics Data System (ADS)

Singh, Hukum

2016-12-01

A cryptosystem for securing image encryption is considered by using double random phase encoding in Fresnel wavelet transform (FWT) domain. Random phase masks (RPMs) and structured phase masks (SPMs) based on devil's vortex toroidal lens (DVTL) are used in spatial as well as in Fourier planes. The images to be encrypted are first Fresnel transformed and then single-level discrete wavelet transform (DWT) is apply to decompose LL,HL, LH and HH matrices. The resulting matrices from the DWT are multiplied by additional RPMs and the resultants are subjected to inverse DWT for the encrypted images. The scheme is more secure because of many parameters used in the construction of SPM. The original images are recovered by using the correct parameters of FWT and SPM. Phase mask SPM based on DVTL increases security that enlarges the key space for encryption and decryption. The proposed encryption scheme is a lens-less optical system and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The computed value of mean-squared-error between the retrieved and the input images shows the efficacy of scheme. The sensitivity to encryption parameters, robustness against occlusion, entropy and multiplicative Gaussian noise attacks have been analysed.

NOTE: Calculating diffraction patterns

NASA Astrophysics Data System (ADS)

Rioux, Frank

2003-05-01

Following Marcella's approach to the double-slit experiment (Marcella T V 2002 Eur. J. Phys. 23 615-21), diffraction patterns for two-dimensional masks are calculated by Fourier transform of the Mask geometry into momentum space.

[Micro Hadamard transform near-infrared spectrometer].

PubMed

Zhang, Zhi-hai; Muo, Xiang-xia; Guo, Yuan-jun; Wang, Wei

2011-07-01

A new type micro Hadamard transform (HT) near-infrared (NIR) spectrometer is proposed in the present paper. It has a MOEMS (Micro-Opto-Electro-Mechanical Systems) blazed grating HT mask. It has merits of compactness, agility of dynamic mask generation and high scan speed. The structure and theory of this spectrometer are analyzed. The 63-order Hadamard-S matrix and mask are designed. The mask is dynamically generated by program of MOEMS blazed gratings. The spectrum is in agreement with that measured by Shimadzu spectrometer in experiments. It has a wavelength range between 900 and 1 700 nm, spectral resolution of 19 nm, single scan time of 2.4 s, SNR of 44.67:1, optical path of 70 mm x 130 mm, and weight under 1 kg. It can meet the requirement of real time detection and portable application.

Cross-orientation suppression in human visual cortex

PubMed Central

Heeger, David J.

2011-01-01

Cross-orientation suppression was measured in human primary visual cortex (V1) to test the normalization model. Subjects viewed vertical target gratings (of varying contrasts) with or without a superimposed horizontal mask grating (fixed contrast). We used functional magnetic resonance imaging (fMRI) to measure the activity in each of several hypothetical channels (corresponding to subpopulations of neurons) with different orientation tunings and fit these orientation-selective responses with the normalization model. For the V1 channel maximally tuned to the target orientation, responses increased with target contrast but were suppressed when the horizontal mask was added, evident as a shift in the contrast gain of this channel's responses. For the channel maximally tuned to the mask orientation, a constant baseline response was evoked for all target contrasts when the mask was absent; responses decreased with increasing target contrast when the mask was present. The normalization model provided a good fit to the contrast-response functions with and without the mask. In a control experiment, the target and mask presentations were temporally interleaved, and we found no shift in contrast gain, i.e., no evidence for suppression. We conclude that the normalization model can explain cross-orientation suppression in human visual cortex. The approach adopted here can be applied broadly to infer, simultaneously, the responses of several subpopulations of neurons in the human brain that span particular stimulus or feature spaces, and characterize their interactions. In addition, it allows us to investigate how stimuli are represented by the inferred activity of entire neural populations. PMID:21775720

A diffusion model account of masked vs. unmasked priming: Are they qualitatively different?

PubMed Central

Gomez, Pablo; Perea, Manuel; Ratcliff, Roger

2017-01-01

In the past decades, hundreds of articles have explored the mechanisms underlying priming. Most researchers assume that masked and unmasked priming are qualitatively different. For masked priming, the effects are often assumed to reflect savings in the encoding of the target stimulus, whereas for unmasked priming, it has been suggested that the effects reflect the familiarity of the prime-target compound cue. In contrast, other researchers have claimed that masked and unmasked priming reflect essentially the same core processes. In this article, we use the diffusion model (Ratcliff, 1978) to account for the effects of masked and unmasked priming for identity and associatively related primes. The fits of the model lead us to the following conclusion: masked related primes give a head start to the processing of the target compared to unrelated primes, while unmasked priming affects primarily the quality of the lexical information. PMID:23647337

System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

DOEpatents

Senroy, Nilanjan [New Delhi, IN; Suryanarayanan, Siddharth [Littleton, CO

2011-03-15

A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

Applying Triple-Matrix Masking for Privacy Preserving Data Collection and Sharing in HIV Studies.

PubMed

Pei, Qinglin; Chen, Shigang; Xiao, Yao; Wu, Samuel S

2016-01-01

Many HIV research projects are plagued by the high missing rate of selfreported information during data collection. Also, due to the sensitive nature of the HIV research data, privacy protection is always a concern for data sharing in HIV studies. This paper applies a data masking approach, called triple-matrix masking [1], to the context of HIV research for ensuring privacy protection during the process of data collection and data sharing. Using a set of generated HIV patient data, we show step by step how the data are randomly transformed (masked) before leaving the patients' individual data collection device (which ensures that nobody sees the actual data) and how the masked data are further transformed by a masking service provider and a data collector. We demonstrate that the masked data retain statistical utility of the original data, yielding the exactly same inference results in the planned logistic regression on the effect of age on the adherence to antiretroviral therapy and in the Cox proportional hazard model for the age effect on time to viral load suppression. Privacy-preserving data collection method may help resolve the privacy protection issue in HIV research. The individual sensitive data can be completely hidden while the same inference results can still be obtained from the masked data, with the use of common statistical analysis methods.

Cerebral Asymmetries in Early Orthographic and Phonological Reading Processes: Evidence from Backward Masking

ERIC Educational Resources Information Center

Halderman, Laura K.; Chiarello, Christine

2005-01-01

A lateralized backward masking paradigm was used to examine hemisphere differences in orthographic and phonological processes at an early time course of word recognition. Targets (e.g., bowl) were presented and backward masked by either pseudohomophones of the target word (orthographically and phonologically similar, e.g., BOAL), orthographically…

Attentional capture by masked colour singletons.

PubMed

Ansorge, Ulrich; Horstmann, Gernot; Worschech, Franziska

2010-09-15

We tested under which conditions a colour singleton of which an observer is unaware captures attention. To prevent visual awareness of the colour singleton, we used backward masking. We find that a masked colour singleton cue captures attention if it matches the observer's goal to search for target colours but not if it is task-irrelevant. This is also reflected in event-related potentials to the visible target: the masked goal-matching cue elicits an attentional potential (N2pc) in a target search task. By contrast, a non-matching but equally strong masked colour singleton cue failed to elicit a capture effect and an N2pc. Results are discussed with regard to currently pertaining conceptions of attentional capture by colour singletons. Copyright 2010 Elsevier Ltd. All rights reserved.

Real-Time Implementation of Nonlinear Processing Functions.

DTIC Science & Technology

1981-08-01

crystal devices and then to use them in a coherent optical data- processing apparatus using halftone masks custom designed at the University oi Southern...California. With the halftone mask technique, we have demonstrated logarithmic nonlinear transformation, allowing us to separate multiplicative images...improved.,_ This device allowed nonlinear functions to be implemented directly wit - out the need for specially made halftone masks. Besides

Asymmetric multiple-image encryption based on the cascaded fractional Fourier transform

NASA Astrophysics Data System (ADS)

Li, Yanbin; Zhang, Feng; Li, Yuanchao; Tao, Ran

2015-09-01

A multiple-image cryptosystem is proposed based on the cascaded fractional Fourier transform. During an encryption procedure, each of the original images is directly separated into two phase masks. A portion of the masks is subsequently modulated into an interim mask, which is encrypted into the ciphertext image; the others are used as the encryption keys. Using phase truncation in the fractional Fourier domain, one can use an asymmetric cryptosystem to produce a real-valued noise-like ciphertext, while a legal user can reconstruct all of the original images using a different group of phase masks. The encryption key is an indivisible part of the corresponding original image and is still useful during decryption. The proposed system has high resistance to various potential attacks, including the chosen-plaintext attack. Numerical simulations also demonstrate the security and feasibility of the proposed scheme.

Object Substitution Masking Induced by Illusory Masks: Evidence for Higher Object-Level Locus of Interference

ERIC Educational Resources Information Center

Hirose, Nobuyuki; Osaka, Naoyuki

2009-01-01

A briefly presented target can be rendered invisible by a lingering sparse mask that does not even touch it. This form of visual backward masking, called object substitution masking, is thought to occur at the object level of processing. However, it remains unclear whether object-level interference alone produces substitution masking because…

The Crossmodal Facilitation of Visual Object Representations by Sound: Evidence from the Backward Masking Paradigm

ERIC Educational Resources Information Center

Chen, Yi-Chuan; Spence, Charles

2011-01-01

We report a series of experiments designed to demonstrate that the presentation of a sound can facilitate the identification of a concomitantly presented visual target letter in the backward masking paradigm. Two visual letters, serving as the target and its mask, were presented successively at various interstimulus intervals (ISIs). The results…

Analysis method to determine and characterize the mask mean-to-target and uniformity specification

NASA Astrophysics Data System (ADS)

Lee, Sung-Woo; Leunissen, Leonardus H. A.; Van de Kerkhove, Jeroen; Philipsen, Vicky; Jonckheere, Rik; Lee, Suk-Joo; Woo, Sang-Gyun; Cho, Han-Ku; Moon, Joo-Tae

2006-06-01

The specification of the mask mean-to-target (MTT) and uniformity is related to functions as: mask error enhancement factor, dose sensitivity and critical dimension (CD) tolerances. The mask MTT shows a trade-off relationship with the uniformity. Simulations for the mask MTT and uniformity (M-U) are performed for LOGIC devices of 45 and 37 nm nodes according to mask type, illumination condition and illuminator polarization state. CD tolerances and after develop inspection (ADI) target CD's in the simulation are taken from the 2004 ITRS roadmap. The simulation results allow for much smaller tolerances in the uniformity and larger offsets in the MTT than the values as given in the ITRS table. Using the parameters in the ITRS table, the mask uniformity contributes to nearly 95% of total CDU budget for the 45 nm node, and is even larger than the CDU specification of the ITRS for the 37 nm node. We also compared the simulation requirements with the current mask making capabilities. The current mask manufacturing status of the mask uniformity is barely acceptable for the 45 nm node, but requires process improvements towards future nodes. In particular, for the 37 nm node, polarized illumination is necessary to meet the ITRS requirements. The current mask linearity deviates for pitches smaller than 300 nm, which is not acceptable even for the 45 nm node. More efforts on the proximity correction method are required to improve the linearity behavior.

Categorical information influences conscious perception: An interaction between object-substitution masking and repetition blindness.

PubMed

Goodhew, Stephanie C; Greenwood, John A; Edwards, Mark

2016-05-01

The visual system is constantly bombarded with dynamic input. In this context, the creation of enduring object representations presents a particular challenge. We used object-substitution masking (OSM) as a tool to probe these processes. In particular, we examined the effect of target-like stimulus repetitions on OSM. In visual crowding, the presentation of a physically identical stimulus to the target reduces crowding and improves target perception, whereas in spatial repetition blindness, the presentation of a stimulus that belongs to the same category (type) as the target impairs perception. Across two experiments, we found an interaction between spatial repetition blindness and OSM, such that repeating a same-type stimulus as the target increased masking magnitude relative to presentation of a different-type stimulus. These results are discussed in the context of the formation of object files. Moreover, the fact that the inducer only had to belong to the same "type" as the target in order to exacerbate masking, without necessarily being physically identical to the target, has important implications for our understanding of OSM per se. That is, our results show the target is processed to a categorical level in OSM despite effective masking and, strikingly, demonstrate that this category-level content directly influences whether or not the target is perceived, not just performance on another task (as in priming).

Schizophrenia alters intra-network functional connectivity in the caudate for detecting speech under informational speech masking conditions.

PubMed

Zheng, Yingjun; Wu, Chao; Li, Juanhua; Li, Ruikeng; Peng, Hongjun; She, Shenglin; Ning, Yuping; Li, Liang

2018-04-04

Speech recognition under noisy "cocktail-party" environments involves multiple perceptual/cognitive processes, including target detection, selective attention, irrelevant signal inhibition, sensory/working memory, and speech production. Compared to health listeners, people with schizophrenia are more vulnerable to masking stimuli and perform worse in speech recognition under speech-on-speech masking conditions. Although the schizophrenia-related speech-recognition impairment under "cocktail-party" conditions is associated with deficits of various perceptual/cognitive processes, it is crucial to know whether the brain substrates critically underlying speech detection against informational speech masking are impaired in people with schizophrenia. Using functional magnetic resonance imaging (fMRI), this study investigated differences between people with schizophrenia (n = 19, mean age = 33 ± 10 years) and their matched healthy controls (n = 15, mean age = 30 ± 9 years) in intra-network functional connectivity (FC) specifically associated with target-speech detection under speech-on-speech-masking conditions. The target-speech detection performance under the speech-on-speech-masking condition in participants with schizophrenia was significantly worse than that in matched healthy participants (healthy controls). Moreover, in healthy controls, but not participants with schizophrenia, the strength of intra-network FC within the bilateral caudate was positively correlated with the speech-detection performance under the speech-masking conditions. Compared to controls, patients showed altered spatial activity pattern and decreased intra-network FC in the caudate. In people with schizophrenia, the declined speech-detection performance under speech-on-speech masking conditions is associated with reduced intra-caudate functional connectivity, which normally contributes to detecting target speech against speech masking via its functions of suppressing masking-speech signals.

Effect of target-masker similarity on across-ear interference in a dichotic cocktail-party listening task.

PubMed

Brungart, Douglas S; Simpson, Brian D

2007-09-01

Similarity between the target and masking voices is known to have a strong influence on performance in monaural and binaural selective attention tasks, but little is known about the role it might play in dichotic listening tasks with a target signal and one masking voice in the one ear and a second independent masking voice in the opposite ear. This experiment examined performance in a dichotic listening task with a target talker in one ear and same-talker, same-sex, or different-sex maskers in both the target and the unattended ears. The results indicate that listeners were most susceptible to across-ear interference with a different-sex within-ear masker and least susceptible with a same-talker within-ear masker, suggesting that the amount of across-ear interference cannot be predicted from the difficulty of selectively attending to the within-ear masking voice. The results also show that the amount of across-ear interference consistently increases when the across-ear masking voice is more similar to the target speech than the within-ear masking voice is, but that no corresponding decline in across-ear interference occurs when the across-ear voice is less similar to the target than the within-ear voice. These results are consistent with an "integrated strategy" model of speech perception where the listener chooses a segregation strategy based on the characteristics of the masker present in the target ear and the amount of across-ear interference is determined by the extent to which this strategy can also effectively be used to suppress the masker in the unattended ear.

On the effectiveness of noise masks: naturalistic vs. un-naturalistic image statistics.

PubMed

Hansen, Bruce C; Hess, Robert F

2012-05-01

It has been argued that the human visual system is optimized for identification of broadband objects embedded in stimuli possessing orientation averaged power spectra fall-offs that obey the 1/f(β) relationship typically observed in natural scene imagery (i.e., β=2.0 on logarithmic axes). Here, we were interested in whether individual spatial channels leading to recognition are functionally optimized for narrowband targets when masked by noise possessing naturalistic image statistics (β=2.0). The current study therefore explores the impact of variable β noise masks on the identification of narrowband target stimuli ranging in spatial complexity, while simultaneously controlling for physical or perceived differences between the masks. The results show that β=2.0 noise masks produce the largest identification thresholds regardless of target complexity, and thus do not seem to yield functionally optimized channel processing. The differential masking effects are discussed in the context of contrast gain control. Copyright © 2012 Elsevier Ltd. All rights reserved.

Inverse Target- and Cue-Priming Effects of Masked Stimuli

ERIC Educational Resources Information Center

Mattler, Uwe

2007-01-01

The processing of a visual target that follows a briefly presented prime stimulus can be facilitated if prime and target stimuli are similar. In contrast to these positive priming effects, inverse priming effects (or negative compatibility effects) have been found when a mask follows prime stimuli before the target stimulus is presented: Responses…

The detrimental effects of atypical nonverbal behavior on older adults' first impressions of individuals with Parkinson's disease.

PubMed

Hemmesch, Amanda R

2014-09-01

After viewing short video clips of individuals with Parkinson's disease (PD) who varied in the symptoms of facial masking (reduced expressivity) and abnormal bodily movement (ABM: including tremor and related movement disorders), older adult observers provided their first impressions of targets' social positivity. Impressions of targets with higher masking or ABM were more negative than impressions of targets with lower masking or ABM. Furthermore, masking was more detrimental for impressions of women and when observers considered emotional relationship goals, whereas ABM was more detrimental for instrumental relationship goals. This study demonstrated the stigmatizing effects of both reduced and excessive movement. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Devil's vortex Fresnel lens phase masks on an asymmetric cryptosystem based on phase-truncation in gyrator wavelet transform domain

NASA Astrophysics Data System (ADS)

Singh, Hukum

2016-06-01

An asymmetric scheme has been proposed for optical double images encryption in the gyrator wavelet transform (GWT) domain. Grayscale and binary images are encrypted separately using double random phase encoding (DRPE) in the GWT domain. Phase masks based on devil's vortex Fresnel Lens (DVFLs) and random phase masks (RPMs) are jointly used in spatial as well as in the Fourier plane. The images to be encrypted are first gyrator transformed and then single-level discrete wavelet transformed (DWT) to decompose LL , HL , LH and HH matrices of approximation, horizontal, vertical and diagonal coefficients. The resulting coefficients from the DWT are multiplied by other RPMs and the results are applied to inverse discrete wavelet transform (IDWT) for obtaining the encrypted images. The images are recovered from their corresponding encrypted images by using the correct parameters of the GWT, DVFL and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The mother wavelet family, DVFL and gyrator transform orders associated with the GWT are extra keys that cause difficulty to an attacker. Thus, the scheme is more secure as compared to conventional techniques. The efficacy of the proposed scheme is verified by computing mean-squared-error (MSE) between recovered and the original images. The sensitivity of the proposed scheme is verified with encryption parameters and noise attacks.

Collinear masking effect in visual search is independent of perceptual salience.

PubMed

Jingling, Li; Lu, Yi-Hui; Cheng, Miao; Tseng, Chia-Huei

2017-07-01

Searching for a target in a salient region should be easier than looking for one in a nonsalient region. However, we previously discovered a contradictory phenomenon in which a local target in a salient structure was more difficult to find than one in the background. The salient structure was constructed of orientation singletons aligned to each other to form a collinear structure. In the present study, we undertake to determine whether such a masking effect was a result of salience competition between a global structure and the local target. In the first 3 experiments, we increased the salience value of the local target with the hope of adding to its competitive advantage and eventually eliminating the masking effect; nevertheless, the masking effect persisted. In an additional 2 experiments, we reduced salience of the global collinear structure by altering the orientation of the background bars and the masking effect still emerged. Our salience manipulations were validated by a controlled condition in which the global structure was grouped noncollinearly. In this case, local target salience increase (e.g., onset) or global distractor salience reduction (e.g., randomized flanking orientations) effectively removed the facilitation effect of the noncollinear structure. Our data suggest that salience competition is unlikely to explain the collinear masking effect, and other mechanisms such as contour integration, border formation, or the crowding effect may be prospective candidates for further investigation.

Double image encryption in Fresnel domain using wavelet transform, gyrator transform and spiral phase masks

NASA Astrophysics Data System (ADS)

Kumar, Ravi; Bhaduri, Basanta

2017-06-01

In this paper, we propose a new technique for double image encryption in the Fresnel domain using wavelet transform (WT), gyrator transform (GT) and spiral phase masks (SPMs). The two input mages are first phase encoded and each of them are then multiplied with SPMs and Fresnel propagated with distances d1 and d2, respectively. The single-level discrete WT is applied to Fresnel propagated complex images to decompose each into sub-band matrices i.e. LL, HL, LH and HH. Further, the sub-band matrices of two complex images are interchanged after modulation with random phase masks (RPMs) and subjected to inverse discrete WT. The resulting images are then both added and subtracted to get intermediate images which are further Fresnel propagated with distances d3 and d4, respectively. These outputs are finally gyrator transformed with the same angle α to get the encrypted images. The proposed technique provides enhanced security in terms of a large set of security keys. The sensitivity of security keys such as SPM parameters, GT angle α, Fresnel propagation distances are investigated. The robustness of the proposed techniques against noise and occlusion attacks are also analysed. The numerical simulation results are shown in support of the validity and effectiveness of the proposed technique.

Is masked priming modulated by memory load? A test of the automaticity of masked identity priming in lexical decision.

PubMed

Perea, Manuel; Marcet, Ana; Lozano, Mario; Gomez, Pablo

2018-05-29

One of the key assumptions of the masked priming lexical decision task (LDT) is that primes are processed without requiring attentional resources. Here, we tested this assumption by presenting a dual-task manipulation to increase memory load and measure the change in masked identity priming on the targets in the LDT. If masked priming does not require attentional resources, increased memory load should have no influence on the magnitude of the observed identity priming effects. We conducted two LDT experiments, using a within-subjects design, to investigate the effect of memory load (via a concurrent matching task Experiment 1 and a concurrent search task in Experiment 2) on masked identity priming. Results showed that the magnitude of masked identity priming on word targets was remarkably similar under high and low memory load. Thus, these experiments provide empirical evidence for the automaticity assumption of masked identity priming in the LDT.

Seeing for speaking: Semantic and lexical information provided by briefly presented, naturalistic action scenes

PubMed Central

Bölte, Jens; Hofmann, Reinhild; Meier, Claudine C.; Dobel, Christian

2018-01-01

At the interface between scene perception and speech production, we investigated how rapidly action scenes can activate semantic and lexical information. Experiment 1 examined how complex action-scene primes, presented for 150 ms, 100 ms, or 50 ms and subsequently masked, influenced the speed with which immediately following action-picture targets are named. Prime and target actions were either identical, showed the same action with different actors and environments, or were unrelated. Relative to unrelated primes, identical and same-action primes facilitated naming the target action, even when presented for 50 ms. In Experiment 2, neutral primes assessed the direction of effects. Identical and same-action scenes induced facilitation but unrelated actions induced interference. In Experiment 3, written verbs were used as targets for naming, preceded by action primes. When target verbs denoted the prime action, clear facilitation was obtained. In contrast, interference was observed when target verbs were phonologically similar, but otherwise unrelated, to the names of prime actions. This is clear evidence for word-form activation by masked action scenes. Masked action pictures thus provide conceptual information that is detailed enough to facilitate apprehension and naming of immediately following scenes. Masked actions even activate their word-form information–as is evident when targets are words. We thus show how language production can be primed with briefly flashed masked action scenes, in answer to long-standing questions in scene processing. PMID:29652939

Concept of a photon-counting camera based on a diffraction-addressed Gray-code mask

NASA Astrophysics Data System (ADS)

Morel, Sébastien

2004-09-01

A new concept of photon counting camera for fast and low-light-level imaging applications is introduced. The possible spectrum covered by this camera ranges from visible light to gamma rays, depending on the device used to transform an incoming photon into a burst of visible photons (photo-event spot) localized in an (x,y) image plane. It is actually an evolution of the existing "PAPA" (Precision Analog Photon Address) Camera that was designed for visible photons. This improvement comes from a simplified optics. The new camera transforms, by diffraction, each photo-event spot from an image intensifier or a scintillator into a cross-shaped pattern, which is projected onto a specific Gray code mask. The photo-event position is then extracted from the signal given by an array of avalanche photodiodes (or photomultiplier tubes, alternatively) downstream of the mask. After a detailed explanation of this camera concept that we have called "DIAMICON" (DIffraction Addressed Mask ICONographer), we briefly discuss about technical solutions to build such a camera.

Does "Darkness" Lead to "Happiness"? Masked Suffix Priming Effects

ERIC Educational Resources Information Center

Dunabeitia, Jon Andoni; Perea, Manuel; Carreiras, Manuel

2008-01-01

Masked affix priming effects have usually been obtained for words sharing the initial affix (e.g., "reaction"-"REFORM"). However, prior evidence on masked suffix priming effects (e.g., "baker"-"WALKER") is inconclusive. In the present series of masked priming lexical decision experiments, a target word was…

The contribution of forward masking to saccadic inhibition of return.

PubMed

Souto, David; Born, Sabine; Kerzel, Dirk

2018-03-08

Inhibition of return is the name typically given to the prolonged latency of motor responses directed to a previously cued target location. There is intense debate about the origins of this effect and its function, but most take for granted (despite lack of evidence) that it depends little on forward masking. Therefore, we re-examined the role of forward masking in inhibition of return. Forward masking was indexed by slower saccadic reaction times (SRTs) when the target orientation repeated the cue orientation at the same location. We confirmed effects of orientation repetition in the absence of an attentional bias when cues were presented on both sides of fixation (bilateral presentation). The effect of orientation repetition was reduced with high target contrast, consistent with a low-level origin such as contrast gain control in early visual areas. When presenting cues on only one side of fixation (unilateral presentation), we obtained inhibition of return with longer cue-target intervals and facilitation with targets presented shortly after the cue. The effect of orientation repetition was reduced when facilitation was observed, but was as strong as with bilateral cues when inhibition of return was observed. Therefore, forward masking may contribute to the inhibition of return effect by delaying reaction times to repeated features at the same location, but is not a principal cause of inhibition of return; in agreement with previous views. The saccadic inhibition of return effect is a reaction-time cost when responding to a pre-cued location. Additional object updating costs are typically invoked to explain reaction-time costs observed when cue and target have the same shape. Yet, lower-level, forward masking of the target by the cue can not be ruled out. Importantly, we show an effect of orientation repetition that is consistent with low-level forward masking rather than object updating costs and that does not interact with inhibition of return.

Targets Mask U-Net for Wind Turbines Detection in Remote Sensing Images

NASA Astrophysics Data System (ADS)

Han, M.; Wang, H.; Wang, G.; Liu, Y.

2018-04-01

To detect wind turbines precisely and quickly in very high resolution remote sensing images (VHRRSI) we propose target mask U-Net. This convolution neural network (CNN), which is carefully designed to be a wide-field detector, models the pixel class assignment to wind turbines and their context information. The shadow, which is the context information of the target in this study, has been regarded as part of a wind turbine instance. We have trained the target mask U-Net on training dataset, which is composed of down sampled image blocks and instance mask blocks. Some post-processes have been integrated to eliminate wrong spots and produce bounding boxes of wind turbine instances. The evaluation metrics prove the reliability and effectiveness of our method for the average F1-score of our detection method is up to 0.97. The comparison of detection accuracy and time consuming with the weakly supervised targets detection method based on CNN illustrates the superiority of our method.

Cortical dynamics of figure-ground segmentation: shine-through.

PubMed

Francis, Gregory

2009-01-01

The shine-through effect occurs when a brief offset vernier target is followed by a grating of non-offset vernier elements. Rather than mask the target, this stimulus sequence produces a percept of the target vernier occluding the mask elements. We analyzed the dynamics of the 3D LAMINART model of depth perception and found that it explains the appearance of shine-through for these stimuli. The model explanation proposes that shine-through is due to a combination of false binocular disparity matches between the target and the central element of the mask, and a weakening of between disparity competition due to spatial competition and boundary grouping. Simulations of the model demonstrate that its behavior closely matches empirical data on the properties of shine-through. The model is contrasted with an alternative explanation of shine-through, and novel mask conditions are studied that allow for empirical tests of the model hypotheses.

Optical images of visible and invisible percepts in the primary visual cortex of primates

PubMed Central

Macknik, Stephen L.; Haglund, Michael M.

1999-01-01

We optically imaged a visual masking illusion in primary visual cortex (area V-1) of rhesus monkeys to ask whether activity in the early visual system more closely reflects the physical stimulus or the generated percept. Visual illusions can be a powerful way to address this question because they have the benefit of dissociating the stimulus from perception. We used an illusion in which a flickering target (a bar oriented in visual space) is rendered invisible by two counter-phase flickering bars, called masks, which flank and abut the target. The target and masks, when shown separately, each generated correlated activity on the surface of the cortex. During the illusory condition, however, optical signals generated in the cortex by the target disappeared although the image of the masks persisted. The optical image thus was correlated with perception but not with the physical stimulus. PMID:10611363

Model-based assist feature insertion for sub-40nm memory device

NASA Astrophysics Data System (ADS)

Suh, Sungsoo; Lee, Suk-joo; Choi, Seong-woon; Lee, Sung-Woo; Park, Chan-hoon

2009-04-01

Many issues need to be resolved for a production-worthy model based assist feature insertion flow for single and double exposure patterning process to extend low k1 process at 193 nm immersion technology. Model based assist feature insertion is not trivial to implement either for single and double exposure patterning compared to rule based methods. As shown in Fig. 1, pixel based mask inversion technology in itself has difficulties in mask writing and inspection although it presents as one of key technology to extend single exposure for contact layer. Thus far, inversion technology is tried as a cooptimization of target mask to simultaneously generate optimized main and sub-resolution assists features for a desired process window. Alternatively, its technology can also be used to optimize for a target feature after an assist feature types are inserted in order to simplify the mask complexity. Simplification of inversion mask is one of major issue with applying inversion technology to device development even if a smaller mask feature can be fabricated since the mask writing time is also a major factor. As shown in Figure 2, mask writing time may be a limiting factor in determining whether or not an inversion solution is viable. It can be reasoned that increased number of shot counts relates to increase in margin for inversion methodology. On the other hand, there is a limit on how complex a mask can be in order to be production worthy. There is also source and mask co-optimization which influences the final mask patterns and assist feature sizes and positions for a given target. In this study, we will discuss assist feature insertion methods for sub 40-nm technology.

Enhancement of security using structured phase masked in optical image encryption on Fresnel transform domain

NASA Astrophysics Data System (ADS)

Yadav, Poonam Lata; Singh, Hukum

2018-05-01

To enhance the security in optical image encryption system and to protect it from the attackers, this paper proposes new digital spiral phase mask based on Fresnel Transform. In this cryptosystem the Spiral Phase Mask (SPM) used is a hybrid of Fresnel Zone Plate (FZP) and Radial Hilbert Mask (RHM) which makes the key strong and enhances the security. The different keys used for encryption and decryption purposed make the system much more secure. Proposed scheme uses various structured phase mask which increases the key space also it increases the number of parameters which makes it difficult for the attackers to exactly find the key to recover the original image. We have also used different keys for encryption and decryption purpose to make the system much more secure. The strength of the proposed cryptosystem has been analyzed by simulating on MATLAB 7.9.0(R2008a). Mean Square Errors (MSE) and Peak Signal to Noise Ratio (PSNR) are calculated for the proposed algorithm. The experimental results are provided to highlight the effectiveness and sustainability of proposed cryptosystem and to prove that the cryptosystem is secure for usage.

Reading a standing wave: figure-ground-alternation masking of primes in evaluative priming.

PubMed

Bermeitinger, Christina; Kuhlmann, Michael; Wentura, Dirk

2012-09-01

We propose a new masking technique for masking word stimuli. Drawing on the phenomena of metacontrast and paracontrast, we alternately presented two prime displays of the same word with the background color in one display matching the font color in the other display and vice versa. The sequence of twenty alterations (spanning approx. 267 ms) was sandwich-masked by structure masks. Using this masking technique, we conducted evaluative priming experiments with positive and negative target and prime words. Significant priming effects were found - for primes and targets drawn from the same as well as from different word sets. Priming effects were independent of prime discrimination performance in direct tests and they were still significant after the sample was restricted to those participants who showed random responding in the direct test. Copyright © 2012 Elsevier Inc. All rights reserved.

Information verification and encryption based on phase retrieval with sparsity constraints and optical inference

NASA Astrophysics Data System (ADS)

Zhong, Shenlu; Li, Mengjiao; Tang, Xiajie; He, Weiqing; Wang, Xiaogang

2017-01-01

A novel optical information verification and encryption method is proposed based on inference principle and phase retrieval with sparsity constraints. In this method, a target image is encrypted into two phase-only masks (POMs), which comprise sparse phase data used for verification. Both of the two POMs need to be authenticated before being applied for decrypting. The target image can be optically reconstructed when the two authenticated POMs are Fourier transformed and convolved by the correct decryption key, which is also generated in encryption process. No holographic scheme is involved in the proposed optical verification and encryption system and there is also no problem of information disclosure in the two authenticable POMs. Numerical simulation results demonstrate the validity and good performance of this new proposed method.

Auditory Masking Patterns in Bottlenose Dolphins from Anthropogenic and Natural Sound Sources

DTIC Science & Technology

2011-09-30

in Comparative Psychoacoustics, Birkhäuser Verlag Basel, Switzerland. pp. 307-318. Erbe C. (2008) Critical ratios of beluga whales ( Delphinapterus ... leucas ) and masked signal duration. Journal of the Acoustical Society of America 124:2216-2223. Levitt H. (1971) Transformed up-down methods in

What Is Being Masked in Object Substitution Masking?

ERIC Educational Resources Information Center

Gellatly, Angus; Pilling, Michael; Cole, Geoff; Skarratt, Paul

2006-01-01

Object substitution masking (OSM) is said to occur when a perceptual object is hypothesized that is mismatched by subsequent sensory evidence, leading to a new hypothesized object being substituted for the first. For example, when a brief target is accompanied by a longer lasting display of nonoverlapping mask elements, reporting of target…

Masked response priming in expert typists.

PubMed

Heinemann, Alexander; Kiesel, Andrea; Pohl, Carsten; Kunde, Wilfried

2010-03-01

In masked priming tasks responses are usually faster when prime and target require identical rather than different responses. Previous research has extensively manipulated the nature and number of response-affording stimuli. However, little is known about the constraints of masked priming regarding the nature and number of response alternatives. The present study explored the limits of masked priming in a six-choice reaction time task, where responses from different fingers of both hands were required. We studied participants that were either experts for the type of response (skilled typists) or novices. Masked primes facilitated responding to targets that required the same response, responses with a different finger of the same hand, and with a homologous finger of the other hand. These effects were modulated by expertise. The results show that masked primes facilitate responding especially for experts in the S-R mapping and with increasing similarity of primed and required response.

Transforming Leadership Identity in a Virtual Environment: Learning about the Leading Self

ERIC Educational Resources Information Center

Rusch, Edith A.; Brunner, C. Cryss

2013-01-01

Schein contends that "unless leaders become learners themselves … acknowledg[ing] vulnerabilities and uncertainties--then transformational learning will never take that lead to transformative learning, the authors engaged educational leadership doctoral students in an 'Experimental Simulation', using masked identities in a virtual…

Phonological and Orthographic Overlap Effects in Fast and Masked Priming

PubMed Central

Frisson, Steven; Bélanger, Nathalie N.; Rayner, Keith

2014-01-01

We investigated how orthographic and phonological information is activated during reading, using a fast priming task, and during single word recognition, using masked priming. Specifically, different types of overlap between prime and target were contrasted: high orthographic and high phonological overlap (track-crack), high orthographic and low phonological overlap (bear-gear), or low orthographic and high phonological overlap (fruit-chute). In addition, we examined whether (orthographic) beginning overlap (swoop-swoon) yielded the same priming pattern as end (rhyme) overlap (track-crack). Prime durations were 32 and 50ms in the fast priming version, and 50ms in the masked priming version, and mode of presentation (prime and target in lower case) was identical. The fast priming experiment showed facilitatory priming effects when both orthography and phonology overlapped, with no apparent differences between beginning and end overlap pairs. Facilitation was also found when prime and target only overlapped orthographically. In contrast, the masked priming experiment showed inhibition for both types of end overlap pairs (with and without phonological overlap), and no difference for begin overlap items. When prime and target only shared principally phonological information, facilitation was only found with a long prime duration in the fast priming experiment, while no differences were found in the masked priming version. These contrasting results suggest that fast priming and masked priming do not necessarily tap into the same type of processing. PMID:24365065

Understanding response proclivity and the limits of sensory capability: What do we hear and what can we hear?

NASA Astrophysics Data System (ADS)

Leek, Marjorie R.; Neff, Donna L.

2004-05-01

Charles Watson's studies of informational masking and the effects of stimulus uncertainty on auditory perception have had a profound impact on auditory research. His series of seminal studies in the mid-1970s on the detection and discrimination of target sounds in sequences of brief tones with uncertain properties addresses the fundamental problem of extracting target signals from background sounds. As conceptualized by Chuck and others, informational masking results from more central (even ``cogneetive'') processes as a consequence of stimulus uncertainty, and can be distinguished from ``energetic'' masking, which primarily arises from the auditory periphery. Informational masking techniques are now in common use to study the detection, discrimination, and recognition of complex sounds, the capacity of auditory memory and aspects of auditory selective attention, the often large effects of training to reduce detrimental effects of uncertainty, and the perceptual segregation of target sounds from irrelevant context sounds. This paper will present an overview of past and current research on informational masking, and show how Chuck's work has been expanded in several directions by other scientists to include the effects of informational masking on speech perception and on perception by listeners with hearing impairment. [Work supported by NIDCD.

Modeling of intense pulsed ion beam heated masked targets for extreme materials characterization

DOE PAGES

Barnard, John J.; Schenkel, Thomas

2017-11-15

Intense, pulsed ion beams locally heat materials and deliver dense electronic excitations that can induce material modifications and phase transitions. Material properties can potentially be stabilized by rapid quenching. Pulsed ion beams with pulse lengths of order ns have recently become available for materials processing. Here, we optimize mask geometries for local modification of materials by intense ion pulses. The goal is to rapidly excite targets volumetrically to the point where a phase transition or local lattice reconstruction is induced followed by rapid cooling that stabilizes desired material's properties fast enough before the target is altered or damaged by, e.g.,more » hydrodynamic expansion. By using a mask, the longitudinal dimension can be large compared to the transverse dimension, allowing the possibility of rapid transverse cooling. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of silicon targets with micro-structured masks and compare these to a simple analytical model. In conclusion, the model gives scaling laws that can guide the design of targets over a wide range of pulsed ion beam parameters.« less

Modeling of intense pulsed ion beam heated masked targets for extreme materials characterization

NASA Astrophysics Data System (ADS)

Barnard, John J.; Schenkel, Thomas

2017-11-01

Intense, pulsed ion beams locally heat materials and deliver dense electronic excitations that can induce material modifications and phase transitions. Material properties can potentially be stabilized by rapid quenching. Pulsed ion beams with pulse lengths of order ns have recently become available for materials processing. Here, we optimize mask geometries for local modification of materials by intense ion pulses. The goal is to rapidly excite targets volumetrically to the point where a phase transition or local lattice reconstruction is induced followed by rapid cooling that stabilizes desired material's properties fast enough before the target is altered or damaged by, e.g., hydrodynamic expansion. By using a mask, the longitudinal dimension can be large compared to the transverse dimension, allowing the possibility of rapid transverse cooling. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of silicon targets with micro-structured masks and compare these to a simple analytical model. The model gives scaling laws that can guide the design of targets over a wide range of pulsed ion beam parameters.

Interactions between concentric form-from-structure and face perception revealed by visual masking but not adaptation

PubMed Central

Feczko, Eric; Shulman, Gordon L.; Petersen, Steven E.; Pruett, John R.

2014-01-01

Findings from diverse subfields of vision research suggest a potential link between high-level aspects of face perception and concentric form-from-structure perception. To explore this relationship, typical adults performed two adaptation experiments and two masking experiments to test whether concentric, but not nonconcentric, Glass patterns (a type of form-from-structure stimulus) utilize a processing mechanism shared by face perception. For the adaptation experiments, subjects were presented with an adaptor for 5 or 20 s, prior to discriminating a target. In the masking experiments, subjects saw a mask, then a target, and then a second mask. Measures of discriminability and bias were derived and repeated measures analysis of variance tested for pattern-specific masking and adaptation effects. Results from Experiment 1 show no Glass pattern-specific effect of adaptation to faces; results from Experiment 2 show concentric Glass pattern masking, but not adaptation, may impair upright/inverted face discrimination; results from Experiment 3 show concentric and radial Glass pattern masking impaired subsequent upright/inverted face discrimination more than translational Glass pattern masking; and results from Experiment 4 show concentric and radial Glass pattern masking impaired subsequent face gender discrimination more than translational Glass pattern masking. Taken together, these findings demonstrate interactions between concentric form-from-structure and face processing, suggesting a possible common processing pathway. PMID:24563526

Interaural level differences do not suffice for restoring spatial release from masking in simulated cochlear implant listening.

PubMed

Ihlefeld, Antje; Litovsky, Ruth Y

2012-01-01

Spatial release from masking refers to a benefit for speech understanding. It occurs when a target talker and a masker talker are spatially separated. In those cases, speech intelligibility for target speech is typically higher than when both talkers are at the same location. In cochlear implant listeners, spatial release from masking is much reduced or absent compared with normal hearing listeners. Perhaps this reduced spatial release occurs because cochlear implant listeners cannot effectively attend to spatial cues. Three experiments examined factors that may interfere with deploying spatial attention to a target talker masked by another talker. To simulate cochlear implant listening, stimuli were vocoded with two unique features. First, we used 50-Hz low-pass filtered speech envelopes and noise carriers, strongly reducing the possibility of temporal pitch cues; second, co-modulation was imposed on target and masker utterances to enhance perceptual fusion between the two sources. Stimuli were presented over headphones. Experiments 1 and 2 presented high-fidelity spatial cues with unprocessed and vocoded speech. Experiment 3 maintained faithful long-term average interaural level differences but presented scrambled interaural time differences with vocoded speech. Results show a robust spatial release from masking in Experiments 1 and 2, and a greatly reduced spatial release in Experiment 3. Faithful long-term average interaural level differences were insufficient for producing spatial release from masking. This suggests that appropriate interaural time differences are necessary for restoring spatial release from masking, at least for a situation where there are few viable alternative segregation cues.

Pre-saccadic perception: Separate time courses for enhancement and spatial pooling at the saccade target

PubMed Central

Buonocore, Antimo; Fracasso, Alessio; Melcher, David

2017-01-01

We interact with complex scenes using eye movements to select targets of interest. Studies have shown that the future target of a saccadic eye movement is processed differently by the visual system. A number of effects have been reported, including a benefit for perceptual performance at the target (“enhancement”), reduced influences of backward masking (“un-masking”), reduced crowding (“un-crowding”) and spatial compression towards the saccade target. We investigated the time course of these effects by measuring orientation discrimination for targets that were spatially crowded or temporally masked. In four experiments, we varied the target-flanker distance, the presence of forward/backward masks, the orientation of the flankers and whether participants made a saccade. Masking and randomizing flanker orientation reduced performance in both fixation and saccade trials. We found a small improvement in performance on saccade trials, compared to fixation trials, with a time course that was consistent with a general enhancement at the saccade target. In addition, a decrement in performance (reporting the average flanker orientation, rather than the target) was found in the time bins nearest saccade onset when random oriented flankers were used, consistent with spatial pooling around the saccade target. We did not find strong evidence for un-crowding. Overall, our pattern of results was consistent with both an early, general enhancement at the saccade target and a later, peri-saccadic compression/pooling towards the saccade target. PMID:28614367

Advanced stable lipid-based formulations for a patient-centric product design.

PubMed

Becker, Karin; Saurugger, Eva-Maria; Kienberger, Diana; Lopes, Diogo; Haack, Detlev; Köberle, Martin; Stehr, Michael; Lochmann, Dirk; Zimmer, Andreas; Salar-Behzadi, Sharareh

2016-01-30

Multiparticulate dosage forms are a recent strategy to meet the special needs of children, elderly people and patients suffering from dysphagia. Our study presents a novel and cost-efficient approach for the manufacturing of a taste-masked multiparticulate system with a stable immediate release profile by applying lipid-based excipients in a solvent-free hot melt coating process. The thermosensitive N-acetylcysteine (N-ac) was used as model drug and hot-melt coated with a mixture of tripalmitin and polysorbate 65. A predictive in vitro method for the evaluation of the taste masking efficiency was developed based on the deprotonation of the carboxyl group of N-ac and the decline of pH, responsible for the unpleasant sour taste of the compound. The method was confirmed using in vivo studies. Differential scanning calorimetry and X-ray scattering experiments revealed polymorphic transformation and its dependency on transformation time, temperature and emulsifier concentration. During the process, the coating was transformed almost completely into the stable β-polymorph, leading to an unaltered dissolution profile during storage. A statistical design was conducted that revealed the critical process parameters affecting the taste masking efficiency and drug release. This study shows the successful application of solvent-free hot-melt coating in the development of a taste-masked and stable formulation. Copyright © 2015 Elsevier B.V. All rights reserved.

[Affine transformation-based automatic registration for peripheral digital subtraction angiography (DSA)].

PubMed

Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min

2008-07-01

In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.

Comparison of arterial spin labeling registration strategies in the multi-center GENetic frontotemporal dementia initiative (GENFI).

PubMed

Mutsaerts, Henri J M M; Petr, Jan; Thomas, David L; De Vita, Enrico; Cash, David M; van Osch, Matthias J P; Golay, Xavier; Groot, Paul F C; Ourselin, Sebastien; van Swieten, John; Laforce, Robert; Tagliavini, Fabrizio; Borroni, Barbara; Galimberti, Daniela; Rowe, James B; Graff, Caroline; Pizzini, Francesca B; Finger, Elizabeth; Sorbi, Sandro; Castelo Branco, Miguel; Rohrer, Jonathan D; Masellis, Mario; MacIntosh, Bradley J

2018-01-01

To compare registration strategies to align arterial spin labeling (ASL) with 3D T1-weighted (T1w) images, with the goal of reducing the between-subject variability of cerebral blood flow (CBF) images. Multi-center 3T ASL data were collected at eight sites with four different sequences in the multi-center GENetic Frontotemporal dementia Initiative (GENFI) study. In a total of 48 healthy controls, we compared the following image registration options: (I) which images to use for registration (perfusion-weighted images [PWI] to the segmented gray matter (GM) probability map (pGM) (CBF-pGM) or M0 to T1w (M0-T1w); (II) which transformation to use (rigid-body or non-rigid); and (III) whether to mask or not (no masking, M0-based FMRIB software library Brain Extraction Tool [BET] masking). In addition to visual comparison, we quantified image similarity using the Pearson correlation coefficient (CC), and used the Mann-Whitney U rank sum test. CBF-pGM outperformed M0-T1w (CC improvement 47.2% ± 22.0%; P < 0.001), and the non-rigid transformation outperformed rigid-body (20.6% ± 5.3%; P < 0.001). Masking only improved the M0-T1w rigid-body registration (14.5% ± 15.5%; P = 0.007). The choice of image registration strategy impacts ASL group analyses. The non-rigid transformation is promising but requires validation. CBF-pGM rigid-body registration without masking can be used as a default strategy. In patients with expansive perfusion deficits, M0-T1w may outperform CBF-pGM in sequences with high effective spatial resolution. BET-masking only improves M0-T1w registration when the M0 image has sufficient contrast. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:131-140. © 2017 International Society for Magnetic Resonance in Medicine.

Contribution of Binaural Masking Release to Improved Speech Intelligibility for different Masker types.

PubMed

Sutojo, Sarinah; van de Par, Steven; Schoenmaker, Esther

2018-06-01

In situations with competing talkers or in the presence of masking noise, speech intelligibility can be improved by spatially separating the target speaker from the interferers. This advantage is generally referred to as spatial release from masking (SRM) and different mechanisms have been suggested to explain it. One proposed mechanism to benefit from spatial cues is the binaural masking release, which is purely stimulus driven. According to this mechanism, the spatial benefit results from differences in the binaural cues of target and masker, which need to appear simultaneously in time and frequency to improve the signal detection. In an alternative proposed mechanism, the differences in the interaural cues improve the segregation of auditory streams, a process, which involves top-down processing rather than being purely stimulus driven. Other than the cues that produce binaural masking release, the interaural cue differences between target and interferer required to improve stream segregation do not have to appear simultaneously in time and frequency. This study is concerned with the contribution of binaural masking release to SRM for three masker types that differ with respect to the amount of energetic masking they exert. Speech intelligibility was measured, employing a stimulus manipulation that inhibits binaural masking release, and analyzed with a metric to account for the number of better-ear glimpses. Results indicate that the contribution of the stimulus-driven binaural masking release plays a minor role while binaural stream segregation and the availability of glimpses in the better ear had a stronger influence on improving the speech intelligibility. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Interocular suppression in normal and amblyopic vision: spatio-temporal properties.

PubMed

Huang, Pi-Chun; Baker, Daniel H; Hess, Robert F

2012-10-31

We measured the properties of interocular suppression in strabismic amblyopes and compared these to dichoptic masking in binocularly normal observers. We used a dichoptic version of the well-established probed-sinewave paradigm that measured sensitivity to a brief target stimulus (one of four letters to be discriminated) in the amblyopic eye at different times relative to a suppression-inducing mask in the fixing eye. This was done using both sinusoidal steady state and transient approaches. The suppression-inducing masks were either modulations of luminance or contrast (full field, just overlaying the target, or just surrounding the target). Our results were interpreted using a descriptive model that included contrast gain control and spatio-temporal filtering prior to excitatory binocular combination. The suppression we measured, other than in magnitude, was not fundamentally different from normal dichoptic masking: lowpass spatio-temporal properties with similar contributions from both surround and overlay suppression.

Additivity of nonsimultaneous masking for short Gaussian-shaped sinusoids.

PubMed

Laback, Bernhard; Balazs, Peter; Necciari, Thibaud; Savel, Sophie; Ystad, Solvi; Meunier, Sabine; Kronland-Martinet, Richard

2011-02-01

The additivity of nonsimultaneous masking was studied using Gaussian-shaped tone pulses (referred to as Gaussians) as masker and target stimuli. Combinations of up to four temporally separated Gaussian maskers with an equivalent rectangular bandwidth of 600 Hz and an equivalent rectangular duration of 1.7 ms were tested. Each masker was level-adjusted to produce approximately 8 dB of masking. Excess masking (exceeding linear additivity) was generally stronger than reported in the literature for longer maskers and comparable target levels. A model incorporating a compressive input/output function, followed by a linear summation stage, underestimated excess masking when using an input/output function derived from literature data for longer maskers and comparable target levels. The data could be predicted with a more compressive input/output function. Stronger compression may be explained by assuming that the Gaussian stimuli were too short to evoke the medial olivocochlear reflex (MOCR), whereas for longer maskers tested previously the MOCR caused reduced compression. Overall, the interpretation of the data suggests strong basilar membrane compression for very short stimuli.

Formulation design of taste-masked particles, including famotidine, for an oral fast-disintegrating dosage form.

PubMed

Mizumoto, Takao; Tamura, Tetsuya; Kawai, Hitoshi; Kajiyama, Atsushi; Itai, Shigeru

2008-04-01

In this study, the taste-masking of famotidine, which could apply to any fast-disintegrating tablet, was investigated using the spray-dry method. The target characteristics of taste-masked particles were set as follows: the dissolution rate is not to be more than 30% at 1 min and not less than 85% at 15 min, and the particle size is not to be more than 150 microm in diameter to avoid a gritty feeling in the mouth. The target dissolution profiles of spray-dried particles consisting of Aquacoat ECD30 and Eudragit NE30D or triacetin was accomplished by the screening of formulas and the appropriate lab-scale manufacturing conditions. Lab-scale testing produced taste-masked particles that met the formulation targets. On the pilot scale, spray-dried particles with attributes, such as dissolution rate and particle size, of the same quality were produced, and reproducibility was also confirmed. This confirmed that the spray-dry method produced the most appropriate taste-masked particles for fast-disintegrating dosage forms.

Contextual influence on orientation discrimination of humans and responses of neurons in V1 of alert monkeys.

PubMed

Li, W; Thier, P; Wehrhahn, C

2000-02-01

We studied the effects of various patterns as contextual stimuli on human orientation discrimination, and on responses of neurons in V1 of alert monkeys. When a target line is presented along with various contextual stimuli (masks), human orientation discrimination is impaired. For most V1 neurons, responses elicited by a line in the receptive field (RF) center are suppressed by these contextual patterns. Orientation discrimination thresholds of human observers are elevated slightly when the target line is surrounded by orthogonal lines. For randomly oriented lines, thresholds are elevated further and even more so for lines parallel to the target. Correspondingly, responses of most V1 neurons to a line are suppressed. Although contextual lines inhibit the amplitude of orientation tuning functions of most V1 neurons, they do not systematically alter the tuning width. Elevation of human orientation discrimination thresholds decreases with increasing curvature of masking lines, so does the inhibition of V1 neuronal responses. A mask made of straight lines yields the strongest interference with human orientation discrimination and produces the strongest suppression of neuronal responses. Elevation of human orientation discrimination thresholds is highest when a mask covers only the immediate vicinity of the target line. Increasing the masking area results in less interference. On the contrary, suppression of neuronal responses in V1 increases with increasing mask size. Our data imply that contextual interference observed in human orientation discrimination is in part directly related to contextual inhibition of neuronal activity in V1. However, the finding that interference with orientation discrimination is weaker for larger masks suggests a figure-ground segregation process that is not located in V1.

Masking with faces in central visual field under a variety of temporal schedules.

PubMed

Daar, Marwan; Wilson, Hugh R

2015-11-01

With a few exceptions, previous studies have explored masking using either a backward mask or a common onset trailing mask, but not both. In a series of experiments, we demonstrate the use of faces in central visual field as a viable method to study the relationship between these two types of mask schedule. We tested observers in a two alternative forced choice face identification task, where both target and mask comprised synthetic faces, and show that a simple model can successfully predict masking across a variety of masking schedules ranging from a backward mask to a common onset trailing mask and a number of intermediate variations. Our data are well accounted for by a window of sensitivity to mask interference that is centered at around 100 ms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Posthypnotic suggestion alters conscious color perception in an automatic manner.

PubMed

Kallio, Sakari; Koivisto, Mika

2013-01-01

The authors studied whether a posthypnotic suggestion to see a brief, masked target as gray can change the color experience of a hypnotic virtuoso. The visibility of the target was manipulated by varying the delay between the target and the mask that followed it. The virtuoso's subjective reports indicated that her conscious color experience was altered already at short delays between the target and the subsequent mask. The virtuoso's objectively measured pattern of responding under posthypnotic suggestion could not be mimicked either by control participants nor the virtuoso herself. Due to posthypnotic amnesia, the virtuoso was unaware of suggestions given during hypnosis. Importantly, the virtuoso could not alter her color perception without a hypnotic suggestion. These results suggest that hypnosis can affect even a highly automatic process such as color perception.

Informational masking of speech in children: Effects of ipsilateral and contralateral distracters

NASA Astrophysics Data System (ADS)

Wightman, Frederic L.; Kistler, Doris J.

2005-11-01

Using a closed-set speech recognition paradigm thought to be heavily influenced by informational masking, auditory selective attention was measured in 38 children (ages 4-16 years) and 8 adults (ages 20-30 years). The task required attention to a monaural target speech message that was presented with a time-synchronized distracter message in the same ear. In some conditions a second distracter message or a speech-shaped noise was presented to the other ear. Compared to adults, children required higher target/distracter ratios to reach comparable performance levels, reflecting more informational masking in these listeners. Informational masking in most conditions was confirmed by the fact that a large proportion of the errors made by the listeners were contained in the distracter message(s). There was a monotonic age effect, such that even the children in the oldest age group (13.6-16 years) demonstrated poorer performance than adults. For both children and adults, presentation of an additional distracter in the contralateral ear significantly reduced performance, even when the distracter messages were produced by a talker of different sex than the target talker. The results are consistent with earlier reports from pure-tone masking studies that informational masking effects are much larger in children than in adults.

Backward masked fearful faces enhance contralateral occipital cortical activity for visual targets within the spotlight of attention

PubMed Central

Reinke, Karen S.; LaMontagne, Pamela J.; Habib, Reza

2011-01-01

Spatial attention has been argued to be adaptive by enhancing the processing of visual stimuli within the ‘spotlight of attention’. We previously reported that crude threat cues (backward masked fearful faces) facilitate spatial attention through a network of brain regions consisting of the amygdala, anterior cingulate and contralateral visual cortex. However, results from previous functional magnetic resonance imaging (fMRI) dot-probe studies have been inconclusive regarding a fearful face-elicited contralateral modulation of visual targets. Here, we tested the hypothesis that the capture of spatial attention by crude threat cues would facilitate processing of subsequently presented visual stimuli within the masked fearful face-elicited ‘spotlight of attention’ in the contralateral visual cortex. Participants performed a backward masked fearful face dot-probe task while brain activity was measured with fMRI. Masked fearful face left visual field trials enhanced activity for spatially congruent targets in the right superior occipital gyrus, fusiform gyrus and lateral occipital complex, while masked fearful face right visual field trials enhanced activity in the left middle occipital gyrus. These data indicate that crude threat elicited spatial attention enhances the processing of subsequent visual stimuli in contralateral occipital cortex, which may occur by lowering neural activation thresholds in this retinotopic location. PMID:20702500

Recovery from Object Substitution Masking Induced by Transient Suppression of Visual Motion Processing: A Repetitive Transcranial Magnetic Stimulation Study

ERIC Educational Resources Information Center

Hirose, Nobuyuki; Kihara, Ken; Mima, Tatsuya; Ueki, Yoshino; Fukuyama, Hidenao; Osaka, Naoyuki

2007-01-01

Object substitution masking is a form of visual backward masking in which a briefly presented target is rendered invisible by a lingering mask that is too sparse to produce lower image-level interference. Recent studies suggested the importance of an updating process in a higher object-level representation, which should rely on the processing of…

Detection of visual events along the apparent motion trace in patients with paranoid schizophrenia.

PubMed

Sanders, Lia Lira Olivier; Muckli, Lars; de Millas, Walter; Lautenschlager, Marion; Heinz, Andreas; Kathmann, Norbert; Sterzer, Philipp

2012-07-30

Dysfunctional prediction in sensory processing has been suggested as a possible causal mechanism in the development of delusions in patients with schizophrenia. Previous studies in healthy subjects have shown that while the perception of apparent motion can mask visual events along the illusory motion trace, such motion masking is reduced when events are spatio-temporally compatible with the illusion, and, therefore, predictable. Here we tested the hypothesis that this specific detection advantage for predictable target stimuli on the apparent motion trace is reduced in patients with paranoid schizophrenia. Our data show that, although target detection along the illusory motion trace is generally impaired, both patients and healthy control participants detect predictable targets more often than unpredictable targets. Patients had a stronger motion masking effect when compared to controls. However, patients showed the same advantage in the detection of predictable targets as healthy control subjects. Our findings reveal stronger motion masking but intact prediction of visual events along the apparent motion trace in patients with paranoid schizophrenia and suggest that the sensory prediction mechanism underlying apparent motion is not impaired in paranoid schizophrenia. Copyright © 2012. Published by Elsevier Ireland Ltd.

Linguistic contributions to speech-on-speech masking for native and non-native listeners: language familiarity and semantic content.

PubMed

Brouwer, Susanne; Van Engen, Kristin J; Calandruccio, Lauren; Bradlow, Ann R

2012-02-01

This study examined whether speech-on-speech masking is sensitive to variation in the degree of similarity between the target and the masker speech. Three experiments investigated whether speech-in-speech recognition varies across different background speech languages (English vs Dutch) for both English and Dutch targets, as well as across variation in the semantic content of the background speech (meaningful vs semantically anomalous sentences), and across variation in listener status vis-à-vis the target and masker languages (native, non-native, or unfamiliar). The results showed that the more similar the target speech is to the masker speech (e.g., same vs different language, same vs different levels of semantic content), the greater the interference on speech recognition accuracy. Moreover, the listener's knowledge of the target and the background language modulate the size of the release from masking. These factors had an especially strong effect on masking effectiveness in highly unfavorable listening conditions. Overall this research provided evidence that that the degree of target-masker similarity plays a significant role in speech-in-speech recognition. The results also give insight into how listeners assign their resources differently depending on whether they are listening to their first or second language. © 2012 Acoustical Society of America

Focal Suppression of Distractor Sounds by Selective Attention in Auditory Cortex.

PubMed

Schwartz, Zachary P; David, Stephen V

2018-01-01

Auditory selective attention is required for parsing crowded acoustic environments, but cortical systems mediating the influence of behavioral state on auditory perception are not well characterized. Previous neurophysiological studies suggest that attention produces a general enhancement of neural responses to important target sounds versus irrelevant distractors. However, behavioral studies suggest that in the presence of masking noise, attention provides a focal suppression of distractors that compete with targets. Here, we compared effects of attention on cortical responses to masking versus non-masking distractors, controlling for effects of listening effort and general task engagement. We recorded single-unit activity from primary auditory cortex (A1) of ferrets during behavior and found that selective attention decreased responses to distractors masking targets in the same spectral band, compared with spectrally distinct distractors. This suppression enhanced neural target detection thresholds, suggesting that limited attention resources serve to focally suppress responses to distractors that interfere with target detection. Changing effort by manipulating target salience consistently modulated spontaneous but not evoked activity. Task engagement and changing effort tended to affect the same neurons, while attention affected an independent population, suggesting that distinct feedback circuits mediate effects of attention and effort in A1. © The Author 2017. Published by Oxford University Press.

Linguistic contributions to speech-on-speech masking for native and non-native listeners: Language familiarity and semantic content

PubMed Central

Brouwer, Susanne; Van Engen, Kristin J.; Calandruccio, Lauren; Bradlow, Ann R.

2012-01-01

This study examined whether speech-on-speech masking is sensitive to variation in the degree of similarity between the target and the masker speech. Three experiments investigated whether speech-in-speech recognition varies across different background speech languages (English vs Dutch) for both English and Dutch targets, as well as across variation in the semantic content of the background speech (meaningful vs semantically anomalous sentences), and across variation in listener status vis-à-vis the target and masker languages (native, non-native, or unfamiliar). The results showed that the more similar the target speech is to the masker speech (e.g., same vs different language, same vs different levels of semantic content), the greater the interference on speech recognition accuracy. Moreover, the listener’s knowledge of the target and the background language modulate the size of the release from masking. These factors had an especially strong effect on masking effectiveness in highly unfavorable listening conditions. Overall this research provided evidence that that the degree of target-masker similarity plays a significant role in speech-in-speech recognition. The results also give insight into how listeners assign their resources differently depending on whether they are listening to their first or second language. PMID:22352516

Pattern transfer with stabilized nanoparticle etch masks

NASA Astrophysics Data System (ADS)

Hogg, Charles R.; Picard, Yoosuf N.; Narasimhan, Amrit; Bain, James A.; Majetich, Sara A.

2013-03-01

Self-assembled nanoparticle monolayer arrays are used as an etch mask for pattern transfer into Si and SiOx substrates. Crack formation within the array is prevented by electron beam curing to fix the nanoparticles to the substrate, followed by a brief oxygen plasma to remove excess carbon. This leaves a dot array of nanoparticle cores with a minimum gap of 2 nm. Deposition and liftoff can transform the dot array mask into an antidot mask, where the gap is determined by the nanoparticle core diameter. Reactive ion etching is used to transfer the dot and antidot patterns into the substrate. The effect of the gap size on the etching rate is modeled and compared with the experimental results.

Effectiveness of Two-Talker Maskers That Differ in Talker Congruity and Perceptual Similarity to the Target Speech

PubMed Central

Buss, Emily; Bowdrie, Kristina

2017-01-01

Previous work has shown that masked-sentence recognition is particularly poor when the masker is composed of two competing talkers, a finding that is attributed to informational masking. Informational masking tends to be largest when the target and masker talkers are perceptually similar. Reductions in masking have been observed for a wide range of target and masker differences, including language: Performance is better when the target and masker talkers speak in different languages, compared with the same language. The present study evaluated normal-hearing adults’ sentence recognition in a two-talker masker as a function of the perceptual similarity between the target and each of the two masker streams. The target was English, and the maskers were composed of English, time-reversed English, or Dutch. These three masker types are known to vary in the informational masking they exert. The two talkers within the two-talker maskers were either congruent (e.g., both English) or incongruent (e.g., one English, one Dutch). As predicted, mean performance was worse for the congruent English masker than the congruent time-reversed English or congruent Dutch maskers. Incongruent two-talker maskers, with just one English masker stream, were only modestly less effective than the congruent English masker. This result indicates that two-talker masker effectiveness was determined predominantly by the one masker stream that was most perceptually similar to the target. Speech recognition in a single-talker masker differed only marginally between the English, Dutch, and time-reversed English masker types, suggesting that perceptual similarity may be more critical in a two-talker than a one-talker masker. PMID:29169315

In collaboration with mask suppliers for change management enhancement

NASA Astrophysics Data System (ADS)

Deng, Erwin; Lee, Chun Der; Lee, Rachel

2013-06-01

For those wafer fabs that have no their own maskshops, the main target of mask quality department is to gain stable mask quality performance through effective supplier management, and therefore achieves competitive business results. After dealing with lots of mask data preparation (MDP) quality problems with suppliers, we have found that incomplete change management procedures are one of major sources that induce incorrect mask data for writing. This article will share our experience in how to enhance change management flows with mask suppliers together and will also show the utility after a series of flow improvement actions.

Boundary conditions for the influence of unfamiliar non-target primes in unconscious evaluative priming: The moderating role of attentional task sets.

PubMed

Kiefer, Markus; Sim, Eun-Jim; Wentura, Dirk

2015-09-01

Evaluative priming by masked emotional stimuli that are not consciously perceived has been taken as evidence that affective stimulus evaluation can also occur unconsciously. However, as masked priming effects were small and frequently observed only for familiar primes that there also presented as visible targets in an evaluative decision task, priming was thought to reflect primarily response activation based on acquired S-R associations and not evaluative semantic stimulus analysis. The present study therefore assessed across three experiments boundary conditions for the emergence of masked evaluative priming effects with unfamiliar primes in an evaluative decision task and investigated the role of the frequency of target repetition on priming with pictorial and verbal stimuli. While familiar primes elicited robust priming effects in all conditions, priming effects by unfamiliar primes were reliably obtained for low repetition (pictures) or unrepeated targets (words), but not for targets repeated at a high frequency. This suggests that unfamiliar masked stimuli only elicit evaluative priming effects when the task set associated with the visible target involves evaluative semantic analysis and is not based on S-R triggered responding as for high repetition targets. The present results therefore converge with the growing body of evidence demonstrating attentional control influences on unconscious processing. Copyright © 2015 Elsevier Inc. All rights reserved.

Masked Repetition Priming Treatment for Anomia

ERIC Educational Resources Information Center

Silkes, JoAnn P.

2018-01-01

Purpose: Masked priming has been suggested as a way to directly target implicit lexical retrieval processes in aphasia. This study was designed to investigate repeated use of masked repetition priming to improve picture naming in individuals with anomia due to aphasia. Method: A single-subject, multiple-baseline design was used across 6 people…

Masked polycythaemia vera: presenting features, response to treatment and clinical outcomes.

PubMed

Alvarez-Larrán, Alberto; Angona, Anna; Ancochea, Agueda; García-Pallarols, Francesc; Fernández, Concepción; Longarón, Raquel; Bellosillo, Beatriz; Besses, Carlos

2016-01-01

Masked polycythaemia vera (PV) has been proposed as a new entity with poorer outcome than overt PV. In this study, the initial clinical and laboratory characteristics, response to treatment and outcome of masked and overt PV were compared using red cell mass and haemoglobin or haematocrit levels for the distinction between both entities. Sixty-eight of 151 PV patients (45%) were classified as masked PV according to World Health Organisation diagnostic criteria, whereas 16 (11%) were classified as masked PV using the British Committee for Standards in Haematology (BCSH). In comparison with overt PV, a higher platelet count and a lower JAK2V617F allele burden at diagnosis were observed in masked PV. Patients with masked PV needed lower phlebotomies and responded faster to hydroxcarbamide than those with overt PV. Complete haematological response was more frequently achieved in masked than in overt PV (79% vs. 58%, P = 0.001). There were no significant differences in the duration of haematological response, the rate of resistance or intolerance to hydroxycarbamide and the probability of molecular response according to type of PV (masked vs. overt). Overall survival, rate of thrombosis and major bleeding, and probability of transformation was superimposable among patients with masked and overt PV. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Randomly displaced phase distribution design and its advantage in page-data recording of Fourier transform holograms.

PubMed

Emoto, Akira; Fukuda, Takashi

2013-02-20

For Fourier transform holography, an effective random phase distribution with randomly displaced phase segments is proposed for obtaining a smooth finite optical intensity distribution in the Fourier transform plane. Since unitary phase segments are randomly distributed in-plane, the blanks give various spatial frequency components to an image, and thus smooth the spectrum. Moreover, by randomly changing the phase segment size, spike generation from the unitary phase segment size in the spectrum can be reduced significantly. As a result, a smooth spectrum including sidebands can be formed at a relatively narrow extent. The proposed phase distribution sustains the primary functions of a random phase mask for holographic-data recording and reconstruction. Therefore, this distribution is expected to find applications in high-density holographic memory systems, replacing conventional random phase mask patterns.

The role of executive attention in object substitution masking.

PubMed

Filmer, Hannah L; Wells-Peris, Roxanne; Dux, Paul E

2017-05-01

It was long thought that a key characteristic of object substitution masking (OSM) was the requirement for spatial attention to be dispersed for the mask to impact visual sensitivity. However, recent studies have provided evidence questioning whether spatial attention interacts with OSM magnitude, suggesting that the previous reports reflect the impact of performance being at ceiling for the low attention load conditions. Another technique that has been employed to modulate attention in OSM paradigms involves presenting the target stimulus foveally, but with another demanding task shown immediately prior, and thus taxing executive/temporal attention. Under such conditions, when the two tasks occur in close temporal proximity relatively to greater temporal separation, masking is increased. However this effect could also be influenced by performance being at ceiling in some conditions. Here, we manipulated executive attention for a foveated target using a dual-task paradigm. Critically, ceiling performance was avoided by thresholding the target stimulus prior to it being presented under OSM conditions. We found no evidence for an interaction between executive attention load and masking. Collectively, along with the previous findings, our results provide compelling evidence that OSM as a phenomenon occurs independently of attention.

Decomposition into Multiple Morphemes during Lexical Access: A Masked Priming Study of Russian Nouns

ERIC Educational Resources Information Center

Kazanina, Nina; Dukova-Zheleva, Galina; Geber, Dana; Kharlamov, Viktor; Tonciulescu, Keren

2008-01-01

The study reports the results of a masked priming experiment with morphologically complex Russian nouns. Participants performed a lexical decision task to a visual target that differed from its prime in one consonant. Three conditions were included: (1) "transparent," in which the prime was morphologically related to the target and contained the…

Getting the cocktail party started: masking effects in speech perception

PubMed Central

Evans, S; McGettigan, C; Agnew, ZK; Rosen, S; Scott, SK

2016-01-01

Spoken conversations typically take place in noisy environments and different kinds of masking sounds place differing demands on cognitive resources. Previous studies, examining the modulation of neural activity associated with the properties of competing sounds, have shown that additional speech streams engage the superior temporal gyrus. However, the absence of a condition in which target speech was heard without additional masking made it difficult to identify brain networks specific to masking and to ascertain the extent to which competing speech was processed equivalently to target speech. In this study, we scanned young healthy adults with continuous functional Magnetic Resonance Imaging (fMRI), whilst they listened to stories masked by sounds that differed in their similarity to speech. We show that auditory attention and control networks are activated during attentive listening to masked speech in the absence of an overt behavioural task. We demonstrate that competing speech is processed predominantly in the left hemisphere within the same pathway as target speech but is not treated equivalently within that stream, and that individuals who perform better in speech in noise tasks activate the left mid-posterior superior temporal gyrus more. Finally, we identify neural responses associated with the onset of sounds in the auditory environment, activity was found within right lateralised frontal regions consistent with a phasic alerting response. Taken together, these results provide a comprehensive account of the neural processes involved in listening in noise. PMID:26696297

Perception without awareness: further evidence from a Stroop priming task.

PubMed

Daza, M Teresa; Ortells, Juan J; Fox, Elaine

2002-11-01

In the present research, we examined the influence of prime-target stimulus onset asynchrony (SOA) on Stroop-priming effects from masked words. Participants indicated the color of a central target, which was preceded by a 33-msec prime word followed either immediately or after a variable delay by a pattern mask. The prime word was incongruent or congruent with the target color on 75% and 25% of the trials, respectively. The words followed by an immediate mask produced reliable Stroop interference at SOAs of 300 and 400 msec but not at SOAs of 500 and 700 msec. The words followed by a delayed mask produced a reversed (i.e., facilitatory) Stroop effect, which reached significance at an SOA of 400 msec or longer, but never at the shorter 300-msec SOA. Such an differential time course of both types of Stroop priming effects provides further evidence for the existence of qualitative differences between conscious and nonconscious perceptual processes.

The role of low-spatial frequencies in lexical decision and masked priming.

PubMed

Boden, C; Giaschi, D

2009-04-01

Spatial frequency filtering was used to test the hypotheses that low-spatial frequency information in printed text can: (1) lead to a rapid lexical decision or (2) facilitate word recognition. Adult proficient readers made lexical decisions in unprimed and masked repetition priming experiments with unfiltered, low-pass, high-pass and notch filtered letter strings. In the unprimed experiments, a filtered target was presented for 105 or 400 ms followed by a pattern mask. Sensitivity (d') was lowest for the low-pass filtered targets at both durations with a bias towards a 'non-word' response. Sensitivity was higher in the high-pass and notch filter conditions. In the priming experiments, a forward mask was followed by a filtered prime then an unfiltered target. Primed words, but not non-words, were identified faster than unprimed words in both the low-pass and high-pass filtered conditions. These results do not support a unique role for low-spatial frequency information in either facilitating or making rapid lexical decisions.

Decoupling Stimulus Duration from Brightness in Metacontrast Masking: Data and Models

ERIC Educational Resources Information Center

Di Lollo, Vincent; Muhlenen, Adrian von; Enns, James T.; Bridgeman, Bruce

2004-01-01

A brief target that is visible when displayed alone can be rendered invisible by a trailing stimulus (metacontrast masking). It has been difficult to determine the temporal dynamics of masking to date because increments in stimulus duration have been invariably confounded with apparent brightness (Bloch's law). In the research reported here,…

Listeners Experience Linguistic Masking Release in Noise-Vocoded Speech-in-Speech Recognition

ERIC Educational Resources Information Center

Viswanathan, Navin; Kokkinakis, Kostas; Williams, Brittany T.

2018-01-01

Purpose: The purpose of this study was to evaluate whether listeners with normal hearing perceiving noise-vocoded speech-in-speech demonstrate better intelligibility of target speech when the background speech was mismatched in language (linguistic release from masking [LRM]) and/or location (spatial release from masking [SRM]) relative to the…

Programmable masks for optical information processing

NASA Technical Reports Server (NTRS)

Goebel, J. H.; Matsumoto, T.; Mina, C.; Welch, J.

1984-01-01

Research in progress at NASA Ames Research Center on programmable masks is discussed in this paper. One type is a large area format liquid crystal mask intended for binary optical computation problems. To date, an on-off contrast ratio of 500:1 has been achieved at a switching rate of 1 Hz. With a 32 x 32 format, a ratio 10 to the 4th power:1 is desirable. The switching contrast is entirely dependent on the polarized quality; therefore, it is believed that 10 to the 4th power:1 in transmission is possible. Larger format masks are under development. An application to Hadamard transform polarized imagery at wavelengths of 1.0 to 2.0 micrometers, which is competitive with the best monolithic infrared detector arrays, is discussed.

Sample Size Requirements for Studies of Treatment Effects on Beta-Cell Function in Newly Diagnosed Type 1 Diabetes

PubMed Central

Lachin, John M.; McGee, Paula L.; Greenbaum, Carla J.; Palmer, Jerry; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of -cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(), log(+1) and square-root transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8–12 years of age, adolescents (13–17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13–17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(+1) and transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes. PMID:22102862

Sample size requirements for studies of treatment effects on beta-cell function in newly diagnosed type 1 diabetes.

PubMed

Lachin, John M; McGee, Paula L; Greenbaum, Carla J; Palmer, Jerry; Pescovitz, Mark D; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of β-cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(x), log(x+1) and square-root (√x) transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8-12 years of age, adolescents (13-17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13-17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(x+1) and √x transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes.

Simple method for generating adjustable trains of picosecond electron bunches

NASA Astrophysics Data System (ADS)

Muggli, P.; Allen, B.; Yakimenko, V. E.; Park, J.; Babzien, M.; Kusche, K. P.; Kimura, W. D.

2010-05-01

A simple, passive method for producing an adjustable train of picosecond electron bunches is demonstrated. The key component of this method is an electron beam mask consisting of an array of parallel wires that selectively spoils the beam emittance. This mask is positioned in a high magnetic dispersion, low beta-function region of the beam line. The incoming electron beam striking the mask has a time/energy correlation that corresponds to a time/position correlation at the mask location. The mask pattern is transformed into a time pattern or train of bunches when the dispersion is brought back to zero downstream of the mask. Results are presented of a proof-of-principle experiment demonstrating this novel technique that was performed at the Brookhaven National Laboratory Accelerator Test Facility. This technique allows for easy tailoring of the bunch train for a particular application, including varying the bunch width and spacing, and enabling the generation of a trailing witness bunch.

Being forward not backward: lexical limits to masked priming.

PubMed

Davis, Chris; Kim, Jeesun; Forster, Kenneth I

2008-05-01

This study investigated whether masked priming is mediated by existing memory representations by determining whether nonwords targets would show repetition priming. To avoid the potential confound that nonword repetition priming would be obscured by a familiarity response bias, the standard lexical decision and naming tasks were modified to make targets unfamiliar. Participants were required to read a target string from right to left (i.e., "ECAF" should be read as "FACE") and then make a response. To examine if priming was based on lexical representations, repetition primes consisted of words when read forwards or backwards (e.g., "face", "ecaf") and nonwords (e.g., "pame", "emap"). Forward and backward primes were used to test if task instruction affected prime encoding. The lexical decision and naming tasks showed the same pattern of results: priming only occurred for forward primes with word targets (e.g., "face-ECAF"). Additional experiments to test if response priming affected the LDT indicated that the lexical status of the prime per se did not affect target responses. These results showed that the encoding of masked primes was unaffected by the novel task instruction and support the view that masked priming is due to the automatic triggering of pre-established computational processes based on stored information.

Three-dimensional rearrangement of single atoms using actively controlled optical microtraps.

PubMed

Lee, Woojun; Kim, Hyosub; Ahn, Jaewook

2016-05-02

We propose and demonstrate three-dimensional rearrangements of single atoms. In experiments performed with single ⁸⁷Rb atoms in optical microtraps actively controlled by a spatial light modulator, we demonstrate various dynamic rearrangements of up to N = 9 atoms including rotation, 2D vacancy filling, guiding, compactification, and 3D shuffling. With the capability of a phase-only Fourier mask to generate arbitrary shapes of the holographic microtraps, it was possible to place single atoms at arbitrary geometries of a few μm size and even continuously reconfigure them by conveying each atom. For this purpose, we loaded a series of computer-generated phase masks in the full frame rate of 60 Hz of the spatial light modulator, so the animation of phase mask transformed the holographic microtraps in real time, driving each atom along the assigned trajectory. Possible applications of this method of transformation of single atoms include preparation of scalable quantum platforms for quantum computation, quantum simulation, and quantum many-body physics.

Perception as Evidence Accumulation and Bayesian Inference: Insights from Masked Priming

ERIC Educational Resources Information Center

Norris, Dennis; Kinoshita, Sachiko

2008-01-01

The authors argue that perception is Bayesian inference based on accumulation of noisy evidence and that, in masked priming, the perceptual system is tricked into treating the prime and the target as a single object. Of the 2 algorithms considered for formalizing how the evidence sampled from a prime and target is combined, only 1 was shown to be…

Rescuing Stimuli from Invisibility: Inducing a Momentary Release from Visual Masking with Pre-Target Entrainment

ERIC Educational Resources Information Center

Mathewson, Kyle E.; Fabiani, Monica; Gratton, Gabriele; Beck, Diane M.; Lleras, Alejandro

2010-01-01

At near-threshold levels of stimulation, identical stimulus parameters can result in very different phenomenal experiences. Can we manipulate which stimuli reach consciousness? Here we show that consciousness of otherwise masked stimuli can be experimentally induced by sensory entrainment. We preceded a backward-masked stimulus with a series of…

Cross-Language Differences in Informational Masking of Speech by Speech: English versus Mandarin Chinese

ERIC Educational Resources Information Center

Wu, Xihong; Yang, Zhigang; Huang, Ying; Chen, Jing; Li, Liang; Daneman, Meredyth; Schneider, Bruce A.

2011-01-01

Purpose: The purpose of the study was to determine why perceived spatial separation provides a greater release from informational masking in Chinese than English when target sentences in each of the languages are masked by other talkers speaking the same language. Method: Monolingual speakers of English and Mandarin Chinese listened to…

The Role of RT Carry-Over for Congruence Sequence Effects in Masked Priming

ERIC Educational Resources Information Center

Huber-Huber, Christoph; Ansorge, Ulrich

2017-01-01

The present study disentangles 2 sources of the congruence sequence effect with masked primes: congruence and response time of the previous trial (reaction time [RT] carry-over). Using arrows as primes and targets and a metacontrast masking procedure we found congruence as well as congruence sequence effects. In addition, congruence sequence…

Early Morphological Decomposition of Suffixed Words: Masked Priming Evidence with Transposed-Letter Nonword Primes

ERIC Educational Resources Information Center

Beyersmann, Elisabeth; Dunabeitia, Jon Andoni; Carreiras, Manuel; Coltheart, Max; Castles, Anne

2013-01-01

Many studies have previously reported that the recognition of a stem target (e.g., "teach") is facilitated by the prior masked presentation of a prime consisting of a derived form of it (e.g., "teacher"). We conducted two lexical decision experiments to investigate masked morphological priming in Spanish. Experiment 1 showed…

The Effect of Prime Duration in Masked Orthographic Priming Depends on Neighborhood Distribution

ERIC Educational Resources Information Center

Robert, Christelle; Mathey, Stephanie

2012-01-01

A lexical decision task was used with a masked priming procedure to investigate whether and to what extent neighborhood distribution influences the effect of prime duration in masked orthographic priming. French word targets had two higher frequency neighbors that were either distributed over two letter positions (e.g., "LOBE/robe-loge")…

The Role of Polysemy in Masked Semantic and Translation Priming

ERIC Educational Resources Information Center

Finkbeiner, Matthew; Forster, Kenneth; Nicol, Janet; Nakamura, Kumiko

2004-01-01

A well-known asymmetry exists in the bilingual masked priming literature in which lexical decision is used: namely, masked primes in the dominant language (L1) facilitate decision times on targets in the less dominant language (L2), but not vice versa. In semantic categorization, on the other hand, priming is symmetrical. In Experiments 1-3 we…

Development and evaluation of a Hadamard transform imaging spectrometer and a Hadamard transform thermal imager

NASA Technical Reports Server (NTRS)

Harwit, M.; Swift, R.; Wattson, R.; Decker, J.; Paganetti, R.

1976-01-01

A spectrometric imager and a thermal imager, which achieve multiplexing by the use of binary optical encoding masks, were developed. The masks are based on orthogonal, pseudorandom digital codes derived from Hadamard matrices. Spatial and/or spectral data is obtained in the form of a Hadamard transform of the spatial and/or spectral scene; computer algorithms are then used to decode the data and reconstruct images of the original scene. The hardware, algorithms and processing/display facility are described. A number of spatial and spatial/spectral images are presented. The achievement of a signal-to-noise improvement due to the signal multiplexing was also demonstrated. An analysis of the results indicates both the situations for which the multiplex advantage may be gained, and the limitations of the technique. A number of potential applications of the spectrometric imager are discussed.

Aerial image based die-to-model inspections of advanced technology masks

NASA Astrophysics Data System (ADS)

Kim, Jun; Lei, Wei-Guo; McCall, Joan; Zaatri, Suheil; Penn, Michael; Nagpal, Rajesh; Faivishevsky, Lev; Ben-Yishai, Michael; Danino, Udy; Tam, Aviram; Dassa, Oded; Balasubramanian, Vivek; Shah, Tejas H.; Wagner, Mark; Mangan, Shmoolik

2009-10-01

Die-to-Model (D2M) inspection is an innovative approach to running inspection based on a mask design layout data. The D2M concept takes inspection from the traditional domain of mask pattern to the preferred domain of the wafer aerial image. To achieve this, D2M transforms the mask layout database into a resist plane aerial image, which in turn is compared to the aerial image of the mask, captured by the inspection optics. D2M detection algorithms work similarly to an Aerial D2D (die-to-die) inspection, but instead of comparing a die to another die it is compared to the aerial image model. D2M is used whenever D2D inspection is not practical (e.g., single die) or when a validation of mask conformity to design is needed, i.e., for printed pattern fidelity. D2M is of particular importance for inspection of logic single die masks, where no simplifying assumption of pattern periodicity may be done. The application can tailor the sensitivity to meet the needs at different locations, such as device area, scribe lines and periphery. In this paper we present first test results of the D2M mask inspection application at a mask shop. We describe the methodology of using D2M, and review the practical aspects of the D2M mask inspection.

Pan-sharpening algorithm to remove thin cloud via mask dodging and nonsampled shift-invariant shearlet transform

NASA Astrophysics Data System (ADS)

Shi, Cheng; Liu, Fang; Li, Ling-Ling; Hao, Hong-Xia

2014-01-01

The goal of pan-sharpening is to get an image with higher spatial resolution and better spectral information. However, the resolution of the pan-sharpened image is seriously affected by the thin clouds. For a single image, filtering algorithms are widely used to remove clouds. These kinds of methods can remove clouds effectively, but the detail lost in the cloud removal image is also serious. To solve this problem, a pan-sharpening algorithm to remove thin cloud via mask dodging and nonsampled shift-invariant shearlet transform (NSST) is proposed. For the low-resolution multispectral (LR MS) and high-resolution panchromatic images with thin clouds, a mask dodging method is used to remove clouds. For the cloud removal LR MS image, an adaptive principal component analysis transform is proposed to balance the spectral information and spatial resolution in the pan-sharpened image. Since the clouds removal process causes the detail loss problem, a weight matrix is designed to enhance the details of the cloud regions in the pan-sharpening process, but noncloud regions remain unchanged. And the details of the image are obtained by NSST. Experimental results over visible and evaluation metrics demonstrate that the proposed method can keep better spectral information and spatial resolution, especially for the images with thin clouds.

Temporal windows in visual processing: "prestimulus brain state" and "poststimulus phase reset" segregate visual transients on different temporal scales.

PubMed

Wutz, Andreas; Weisz, Nathan; Braun, Christoph; Melcher, David

2014-01-22

Dynamic vision requires both stability of the current perceptual representation and sensitivity to the accumulation of sensory evidence over time. Here we study the electrophysiological signatures of this intricate balance between temporal segregation and integration in vision. Within a forward masking paradigm with short and long stimulus onset asynchronies (SOA), we manipulated the temporal overlap of the visual persistence of two successive transients. Human observers enumerated the items presented in the second target display as a measure of the informational capacity read-out from this partly temporally integrated visual percept. We observed higher β-power immediately before mask display onset in incorrect trials, in which enumeration failed due to stronger integration of mask and target visual information. This effect was timescale specific, distinguishing between segregation and integration of visual transients that were distant in time (long SOA). Conversely, for short SOA trials, mask onset evoked a stronger visual response when mask and targets were correctly segregated in time. Examination of the target-related response profile revealed the importance of an evoked α-phase reset for the segregation of those rapid visual transients. Investigating this precise mapping of the temporal relationships of visual signals onto electrophysiological responses highlights how the stream of visual information is carved up into discrete temporal windows that mediate between segregated and integrated percepts. Fragmenting the stream of visual information provides a means to stabilize perceptual events within one instant in time.

Utilization of optical emission endpoint in photomask dry etch processing

NASA Astrophysics Data System (ADS)

Faure, Thomas B.; Huynh, Cuc; Lercel, Michael J.; Smith, Adam; Wagner, Thomas

2002-03-01

Use of accurate and repeatable endpoint detection during dry etch processing of photomask is very important for obtaining good mask mean-to-target and CD uniformity performance. It was found that the typical laser reflectivity endpoint detecting system used on photomask dry etch systems had several key limitations that caused unnecessary scrap and non-optimum image size performance. Consequently, work to develop and implement use of a more robust optical emission endpoint detection system for chrome dry etch processing of photomask was performed. Initial feasibility studies showed that the emission technique was sensitive enough to monitor pattern loadings on contact and via level masks down to 3 percent pattern coverage. Additional work was performed to further improve this to 1 percent pattern coverage by optimizing the endpoint detection parameters. Comparison studies of mask mean-to-target performance and CD uniformity were performed with the use of optical emission endpoint versus laser endpoint for masks built using TOK IP3600 and ZEP 7000 resist systems. It was found that an improvement in mean-to-target performance and CD uniformity was realized on several types of production masks. In addition, part-to-part endpoint time repeatability was found to be significantly improved with the use of optical emission endpoint.

Model-based MPC enables curvilinear ILT using either VSB or multi-beam mask writers

NASA Astrophysics Data System (ADS)

Pang, Linyong; Takatsukasa, Yutetsu; Hara, Daisuke; Pomerantsev, Michael; Su, Bo; Fujimura, Aki

2017-07-01

Inverse Lithography Technology (ILT) is becoming the choice for Optical Proximity Correction (OPC) of advanced technology nodes in IC design and production. Multi-beam mask writers promise significant mask writing time reduction for complex ILT style masks. Before multi-beam mask writers become the main stream working tools in mask production, VSB writers will continue to be the tool of choice to write both curvilinear ILT and Manhattanized ILT masks. To enable VSB mask writers for complex ILT style masks, model-based mask process correction (MB-MPC) is required to do the following: 1). Make reasonable corrections for complex edges for those features that exhibit relatively large deviations from both curvilinear ILT and Manhattanized ILT designs. 2). Control and manage both Edge Placement Errors (EPE) and shot count. 3. Assist in easing the migration to future multi-beam mask writer and serve as an effective backup solution during the transition. In this paper, a solution meeting all those requirements, MB-MPC with GPU acceleration, will be presented. One model calibration per process allows accurate correction regardless of the target mask writer.

The prevalence effect in lateral masking and its relevance for visual search.

PubMed

Geelen, B P; Wertheim, A H

2015-04-01

In stimulus displays with or without a single target amid 1,644 identical distractors, target prevalence was varied between 20, 50 and 80 %. Maximum gaze deviation was measured to determine the strength of lateral masking in these arrays. The results show that lateral masking was strongest in the 20 % prevalence condition, which differed significantly from both the 50 and 80 % prevalence conditions. No difference was observed between the latter two. This pattern of results corresponds to that found in the literature on the prevalence effect in visual search (stronger lateral masking corresponding to longer search times). The data add to similar findings reported earlier (Wertheim et al. in Exp Brain Res, 170:387-402, 2006), according to which the effects of many well-known factors in visual search correspond to those on lateral masking. These were the effects of set size, disjunctions versus conjunctions, display area, distractor density, the asymmetry effect (Q vs. O's) and viewing distance. The present data, taken together with those earlier findings, may lend credit to a causal hypothesis that lateral masking could be a more important mechanism in visual search than usually assumed.

Orientation masking and cross-orientation suppression (XOS): implications for estimates of filter bandwidth.

PubMed

Meese, Tim S; Holmes, David J

2010-10-01

Most contemporary models of spatial vision include a cross-oriented route to suppression (masking from a broadly tuned inhibitory pool), which is most potent at low spatial and high temporal frequencies (T. S. Meese & D. J. Holmes, 2007). The influence of this pathway can elevate orientation-masking functions without exciting the target mechanism, and because early psychophysical estimates of filter bandwidth did not accommodate this, it is likely that they have been overestimated for this corner of stimulus space. Here we show that a transient 40% contrast mask causes substantial binocular threshold elevation for a transient vertical target, and this declines from a mask orientation of 0° to about 40° (indicating tuning), and then more gently to 90°, where it remains at a factor of ∼4. We also confirm that cross-orientation masking is diminished or abolished at high spatial frequencies and for sustained temporal modulation. We fitted a simple model of pedestal masking and cross-orientation suppression (XOS) to our data and those of G. C. Phillips and H. R. Wilson (1984) and found the dependency of orientation bandwidth on spatial frequency to be much less than previously supposed. An extension of our linear spatial pooling model of contrast gain control and dilution masking (T. S. Meese & R. J. Summers, 2007) is also shown to be consistent with our results using filter bandwidths of ±20°. Both models include tightly and broadly tuned components of divisive suppression. More generally, because XOS and/or dilution masking can affect the shape of orientation-masking curves, we caution that variations in bandwidth estimates might reflect variations in processes that have nothing to do with filter bandwidth.

Advances in low-defect multilayers for EUVL mask blanks

NASA Astrophysics Data System (ADS)

Folta, James A.; Davidson, J. Courtney; Larson, Cindy C.; Walton, Christopher C.; Kearney, Patrick A.

2002-07-01

Low-defect multilayer coatings are required to fabricate mask blanks for Extreme Ultraviolet Lithography (EUVL). The mask blanks consist of high reflectance EUV multilayers on low thermal expansion substrates. A defect density of 0.0025 printable defects/cm2 for both the mask substrate and the multilayer is required to provide a mask blank yield of 60 percent. Current low defect multilayer coating technology allows repeated coating-added defect levels of 0.05/cm2 for defects greater than 90 nm polystyrene latex sphere (PSL) equivalent size for lots of 20 substrates. Extended clean operation of the coating system at levels below 0.08/cm2 for 3 months of operation has also been achieved. Two substrates with zero added defects in the quality area have been fabricated, providing an existence proof that ultra low defect coatings are possible. Increasing the ion source-to-target distance from 410 to 560 mm to reduce undesired coating of the ion source caused the defect density to increase to 0.2/cm2. Deposition and etching diagnostic witness substrates and deposition pinhole cameras showed a much higher level of ion beam spillover (ions missing the sputter target) than expected. Future work will quantify beam spillover, and test designs to reduce spillover, if it is confirmed to be the cause of the increased defect level. The LDD system will also be upgraded to allow clean coating of standard format mask substrates. The upgrade will confirm that the low defect process developed on Si wafers is compatible with the standard mask format 152 mm square substrates, and will provide a clean supply of EUVL mask blanks needed to support development of EUVL mask patterning processes and clean mask handling technologies.

Taming the Wildness of "Trojan-Horse" Peptides by Charge-Guided Masking and Protease-Triggered Demasking for the Controlled Delivery of Antitumor Agents.

PubMed

Shi, Nian-Qiu; Qi, Xian-Rong

2017-03-29

Cell-penetrating peptide (CPP), also called "Trojan Horse" peptide, has become a successful approach to deliver various payloads into cells for achieving the intracellular access. However, the "Trojan Horse" peptide is too wild, not just to "Troy", but rather widely distributed in the body. Thus, there is an urgent need to tame the wildness of "Trojan Horse" peptide for targeted delivery of antineoplastic agents to the tumor site. To achieve this goal, we exploit a masked CPP-doxorubicin conjugate platform for targeted delivery of chemotherapeutic drugs using charge-guided masking and protease-triggered demasking strategies. In this platform, the cell-penetrating function of the positively CPP (d-form nonaarginine) is abrogated by a negatively shielding peptide (masked CPP), and between them is a cleavable substrate peptide by the protease (MMP-2/9). Protease-triggered demasking would occur when the masked CPP reached the MMP-2/9-riched tumor. The CPP-doxorubicin conjugate (CPP-Dox) and the masked CPP-Dox conjugate (mCPP-Dox) were used as models for the evaluation of masking and demasking processes. It was found that exogenous MMP-2/9 could effectively trigger the reversion of CPP-cargo in this conjugate, and this trigger adhered to the Michaelis-Menten kinetics profile. This conjugate was sensitive to the trigger of endogenous MMP-2/9 and could induce enhanced cytotoxicity toward MMP-2/9-rich tumor cells. In vivo antitumor efficacy revealed that this masked conjugate had considerable antitumor activity and could inhibit the tumor growth at a higher level relative to CPP-cargo. Low toxicity in vivo showed the noticeably decreased wildness of this conjugate toward normal tissues and more controllable entry of antitumor agents into "Troy". On the basis of analyses in vitro and in vivo, this mCPP-cargo conjugate delivery system held an improved selectivity toward MMP-2/9-rich tumors and would be a promising strategy for tumor-targeted treatment.

Time-Frequency Masking for Speech Separation and Its Potential for Hearing Aid Design

PubMed Central

Wang, DeLiang

2008-01-01

A new approach to the separation of speech from speech-in-noise mixtures is the use of time-frequency (T-F) masking. Originated in the field of computational auditory scene analysis, T-F masking performs separation in the time-frequency domain. This article introduces the T-F masking concept and reviews T-F masking algorithms that separate target speech from either monaural or binaural mixtures, as well as microphone-array recordings. The review emphasizes techniques that are promising for hearing aid design. This article also surveys recent studies that evaluate the perceptual effects of T-F masking techniques, particularly their effectiveness in improving human speech recognition in noise. An assessment is made of the potential benefits of T-F masking methods for the hearing impaired in light of the processing constraints of hearing aids. Finally, several issues pertinent to T-F masking are discussed. PMID:18974204

Data communications for a collective operation in a parallel active messaging interface of a parallel computer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faraj, Daniel A.

Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and bit masks; receiving in an origin endpoint of the PAMI a collective instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint; constructing a bit mask for the received collective instruction; selecting, from among the associated algorithms and bit masks,more » a data communications algorithm in dependence upon the constructed bit mask; and executing the collective instruction, transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.« less

Data communications for a collective operation in a parallel active messaging interface of a parallel computer

DOEpatents

Faraj, Daniel A

2013-07-16

Algorithm selection for data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including specifications of a client, a context, and a task, endpoints coupled for data communications through the PAMI, including associating in the PAMI data communications algorithms and bit masks; receiving in an origin endpoint of the PAMI a collective instruction, the instruction specifying transmission of a data communications message from the origin endpoint to a target endpoint; constructing a bit mask for the received collective instruction; selecting, from among the associated algorithms and bit masks, a data communications algorithm in dependence upon the constructed bit mask; and executing the collective instruction, transmitting, according to the selected data communications algorithm from the origin endpoint to the target endpoint, the data communications message.

Preprocessed Consortium for Neuropsychiatric Phenomics dataset.

PubMed

Gorgolewski, Krzysztof J; Durnez, Joke; Poldrack, Russell A

2017-01-01

Here we present preprocessed MRI data of 265 participants from the Consortium for Neuropsychiatric Phenomics (CNP) dataset. The preprocessed dataset includes minimally preprocessed data in the native, MNI and surface spaces accompanied with potential confound regressors, tissue probability masks, brain masks and transformations. In addition the preprocessed dataset includes unthresholded group level and single subject statistical maps from all tasks included in the original dataset. We hope that availability of this dataset will greatly accelerate research.

Disentangling the developmental trajectories of letter position and letter identity coding using masked priming.

PubMed

Kezilas, Yvette; McKague, Meredith; Kohnen, Saskia; Badcock, Nicholas A; Castles, Anne

2017-02-01

Masked transposed-letter (TL) priming effects have been used to index letter position processing over the course of reading development. Whereas some studies have reported an increase in TL priming over development, others have reported a decrease. These findings have led to the development of 2 somewhat contradictory accounts of letter position development: the lexical tuning hypothesis and the multiple-route model. One factor that may be contributing to these discrepancies is the use of baseline primes that substitute letters in the target word, which may confound the effect of changes in letter position processing over development with those of letter identity. The present study included an identity prime (e.g., listen-LISTEN), in addition to the standard two-substituted-letter (2SL; e.g., lidfen-LISTEN) and all-letter-different (ALD; e.g., rodfup-LISTEN) baselines, to remove the potential confound between letter position and letter identity information in determining the effect of the TL prime. Priming effects were measured in a lexical decision task administered to children aged 7-12 and a group of university students. Using inverse transformed response times, targets preceded by a TL prime were responded to significantly faster than those preceded by 2SL and ALD primes, and priming remained stable across development. In contrast, targets preceded by a TL prime were responded to significantly slower than those preceded by an ID prime, and this reaction-time cost increased significantly over development, with adults showing the largest cost. These findings are consistent with a lexical tuning account of letter position development, and are inconsistent with the multiple-route model. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Pedestrian Detection Scheme Using a Coherent Phase Difference Method Based on 2D Range-Doppler FMCW Radar

PubMed Central

Hyun, Eugin; Jin, Young-Seok; Lee, Jong-Hun

2016-01-01

For an automotive pedestrian detection radar system, fast-ramp based 2D range-Doppler Frequency Modulated Continuous Wave (FMCW) radar is effective for distinguishing between moving targets and unwanted clutter. However, when a weak moving target such as a pedestrian exists together with strong clutter, the pedestrian may be masked by the side-lobe of the clutter even though they are notably separated in the Doppler dimension. To prevent this problem, one popular solution is the use of a windowing scheme with a weighting function. However, this method leads to a spread spectrum, so the pedestrian with weak signal power and slow Doppler may also be masked by the main-lobe of clutter. With a fast-ramp based FMCW radar, if the target is moving, the complex spectrum of the range- Fast Fourier Transform (FFT) is changed with a constant phase difference over ramps. In contrast, the clutter exhibits constant phase irrespective of the ramps. Based on this fact, in this paper we propose a pedestrian detection for highly cluttered environments using a coherent phase difference method. By detecting the coherent phase difference from the complex spectrum of the range-FFT, we first extract the range profile of the moving pedestrians. Then, through the Doppler FFT, we obtain the 2D range-Doppler map for only the pedestrian. To test the proposed detection scheme, we have developed a real-time data logging system with a 24 GHz FMCW transceiver. In laboratory tests, we verified that the signal processing results from the proposed method were much better than those expected from the conventional 2D FFT-based detection method. PMID:26805835

A Pedestrian Detection Scheme Using a Coherent Phase Difference Method Based on 2D Range-Doppler FMCW Radar.

PubMed

Hyun, Eugin; Jin, Young-Seok; Lee, Jong-Hun

2016-01-20

For an automotive pedestrian detection radar system, fast-ramp based 2D range-Doppler Frequency Modulated Continuous Wave (FMCW) radar is effective for distinguishing between moving targets and unwanted clutter. However, when a weak moving target such as a pedestrian exists together with strong clutter, the pedestrian may be masked by the side-lobe of the clutter even though they are notably separated in the Doppler dimension. To prevent this problem, one popular solution is the use of a windowing scheme with a weighting function. However, this method leads to a spread spectrum, so the pedestrian with weak signal power and slow Doppler may also be masked by the main-lobe of clutter. With a fast-ramp based FMCW radar, if the target is moving, the complex spectrum of the range- Fast Fourier Transform (FFT) is changed with a constant phase difference over ramps. In contrast, the clutter exhibits constant phase irrespective of the ramps. Based on this fact, in this paper we propose a pedestrian detection for highly cluttered environments using a coherent phase difference method. By detecting the coherent phase difference from the complex spectrum of the range-FFT, we first extract the range profile of the moving pedestrians. Then, through the Doppler FFT, we obtain the 2D range-Doppler map for only the pedestrian. To test the proposed detection scheme, we have developed a real-time data logging system with a 24 GHz FMCW transceiver. In laboratory tests, we verified that the signal processing results from the proposed method were much better than those expected from the conventional 2D FFT-based detection method.

Cross-language phonological activation: evidence from masked onset priming and ERPs.

PubMed

Jouravlev, Olessia; Lupker, Stephen J; Jared, Debra

2014-07-01

The goal of the present research was to provide direct evidence for the cross-language interaction of phonologies at the sub-lexical level by using the masked onset priming paradigm. More specifically, we investigated whether there is a cross-language masked onset priming effect (MOPE) with L2 (English) primes and L1 (Russian) targets and whether it is modulated by the orthographic similarity of primes and targets. Primes and targets had onsets that overlapped either only phonologically, only orthographically, both phonologically and orthographically, or did not have any overlap. Phonological overlap, but not orthographic overlap, between primes and targets led to faster naming latencies. In contrast, the ERP data provided evidence for effects of both phonological and orthographic overlap. Finally, the time-course of phonological and orthographic processing for our bilinguals mirrored the time-course previously reported for monolinguals in the ERP data. These results provide evidence for shared representations at the sub-lexical level for a bilingual's two languages. Copyright © 2014 Elsevier Inc. All rights reserved.

Associative and repetition priming with the repeated masked prime technique: no priming found.

PubMed

Avons, S E; Russo, Riccardo; Cinel, Caterina; Verolini, Veronica; Glynn, Kevin; McDonald, Rebecca; Cameron, Marie

2009-01-01

Wentura and Frings (2005) reported evidence of subliminal categorical priming on a lexical decision task, using a new method of visual masking in which the prime string consisted of the prime word flanked by random consonants and random letter masks alternated with the prime string on successive refresh cycles. We investigated associative and repetition priming on lexical decision, using the same method of visual masking. Three experiments failed to show any evidence of associative priming, (1) when the prime string was fixed at 10 characters (three to six flanking letters) and (2) when the number of flanking letters were reduced or absent. In all cases, prime detection was at chance level. Strong associative priming was observed with visible unmasked primes, but the addition of flanking letters restricted priming even though prime detection was still high. With repetition priming, no priming effects were found with the repeated masked technique, and prime detection was poor but just above chance levels. We conclude that with repeated masked primes, there is effective visual masking but that associative priming and repetition priming do not occur with experiment-unique prime-target pairs. Explanations for this apparent discrepancy across priming paradigms are discussed. The priming stimuli and prime-target pairs used in this study may be downloaded as supplemental materials from mc.psychonomic-journals.org/content/supplemental.

A novel thermal face recognition approach using face pattern words

NASA Astrophysics Data System (ADS)

Zheng, Yufeng

2010-04-01

A reliable thermal face recognition system can enhance the national security applications such as prevention against terrorism, surveillance, monitoring and tracking, especially at nighttime. The system can be applied at airports, customs or high-alert facilities (e.g., nuclear power plant) for 24 hours a day. In this paper, we propose a novel face recognition approach utilizing thermal (long wave infrared) face images that can automatically identify a subject at both daytime and nighttime. With a properly acquired thermal image (as a query image) in monitoring zone, the following processes will be employed: normalization and denoising, face detection, face alignment, face masking, Gabor wavelet transform, face pattern words (FPWs) creation, face identification by similarity measure (Hamming distance). If eyeglasses are present on a subject's face, an eyeglasses mask will be automatically extracted from the querying face image, and then masked with all comparing FPWs (no more transforms). A high identification rate (97.44% with Top-1 match) has been achieved upon our preliminary face dataset (of 39 subjects) from the proposed approach regardless operating time and glasses-wearing condition.e

Masked Chimeric Antigen Receptor for Tumor-Specific Activation.

PubMed

Han, Xiaolu; Bryson, Paul D; Zhao, Yifan; Cinay, Gunce E; Li, Si; Guo, Yunfei; Siriwon, Natnaree; Wang, Pin

2017-01-04

Adoptive cellular therapy based on chimeric antigen receptor (CAR)-engineered T (CAR-T) cells is a powerful form of cancer immunotherapy. CAR-T cells can be redirected to specifically recognize tumor-associated antigens (TAAs) and induce high levels of antitumor activity. However, they may also display "on-target off-tumor" toxicities, resulting from low-level expression of TAAs in healthy tissues. These adverse effects have raised considerable safety concerns and limited the clinical application of this otherwise promising therapeutic modality. To minimize such side effects, we have designed an epidermal growth factor receptor (EGFR)-specific masked CAR (mCAR), which consists of a masking peptide that blocks the antigen-binding site and a protease-sensitive linker. Proteases commonly active in the tumor microenvironment can cleave the linker and disengage the masking peptide, thereby enabling CAR-T cells to recognize target antigens only at the tumor site. In vitro mCAR showed dramatically reduced antigen binding and antigen-specific activation in the absence of proteases, but normal levels of binding and activity upon treatment with certain proteases. Masked CAR-T cells also showed antitumor efficacy in vivo comparable to that of unmasked CAR. Our study demonstrates the feasibility of improving the safety profile of conventional CARs and may also inspire future design of CAR molecules targeting broadly expressed TAAs. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Is attention confined to one word at a time? The spatial distribution of parafoveal preview benefits during reading.

PubMed

Wang, Chin-An; Inhoff, Albrecht W; Radach, Ralph

2009-10-01

Eye movements were recorded while participants read declarative sentences. Each sentence contained a critical three-word sequence with a three-letter target word (n), a spatially adjacent post-target word (n+1), and a subsequent nonadjacent post-target word (n+2). The parafoveal previews of words n and n+2 were manipulated so that they were either fully visible or masked until they were fixated. The results revealed longer word n and word n+1 viewing durations when word n had been masked in the parafovea, and this occurred irrespective of whether the target was skipped or fixated. Furthermore, masking of word n diminished the usefulness of the preview of word n+2. These results indicate that the effect of a parafoveally available target preview was not strictly localized. Instead, it influenced target viewing and the viewing of the two subsequent words in the text. These results are difficult to reconcile with the assumption that attention is confined to one word at a time until that word is recognized and that attention is then shifted from the recognized word to the next.

Acoustically Enhanced Electroplating Being Developed

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.

2002-01-01

In cooperation with the NASA Glenn Research Center, Alchemitron Corp. is developing the Acoustically Enhanced Electroplating Process (AEEP), a new technique of employing nonlinear ultrasonics to enhance electroplating. The applications range from electroplating full-panel electronic circuit boards to electroplating microelectronics and microelectromechanical systems (MEMS) devices. In a conventional plating process, the surface area to be plated is separated from the nonplated areas by a temporary mask. The mask may take many forms, from a cured liquid coating to a simple tape. Generally, the mask is discarded when the plating is complete, creating a solid waste product that is often an environmental hazard. The labor and materials involved with the layout, fabrication, and tooling of masks is a primary source of recurring and nonrecurring production costs. The objective of this joint effort, therefore, is to reduce or eliminate the need for masks. AEEP improves selective plating processes by using directed beams of high-intensity acoustic waves to create nonlinear effects that alter the fluid dynamic and thermodynamic behavior of the plating process. It relies on two effects: acoustic streaming and acoustic heating. Acoustic streaming is observed when a high-intensity acoustic beam creates a liquid current within the beam. The liquid current can be directed as the beam is directed and, thus, users can move liquid around as desired without using pumps and nozzles. The current of the electroplating electrolyte, therefore, can be directed at distinct target areas where electroplating is desired. The current delivers fresh electrolyte to the target area while flushing away the spent electrolyte. This dramatically increases the plating rate in the target area. In addition, acoustic heating of both the liquid in the beam and the target surface increases the chemical reaction rate, which further increases the plating rate. The combined effects of acoustic streaming and heating accelerate the deposition of plating in that area and, thus, provide an effect similar to a mask but without the costs of masking. AEEP further improves the plating process by clearing debris and bubbles from the surface by acoustic radiation pressure and acoustic streaming.

Objective measures of binaural masking level differences and comodulation masking release based on late auditory evoked potentials.

PubMed

Epp, Bastian; Yasin, Ifat; Verhey, Jesko L

2013-12-01

The audibility of important sounds is often hampered due to the presence of other masking sounds. The present study investigates if a correlate of the audibility of a tone masked by noise is found in late auditory evoked potentials measured from human listeners. The audibility of the target sound at a fixed physical intensity is varied by introducing auditory cues of (i) interaural target signal phase disparity and (ii) coherent masker level fluctuations in different frequency regions. In agreement with previous studies, psychoacoustical experiments showed that both stimulus manipulations result in a masking release (i: binaural masking level difference; ii: comodulation masking release) compared to a condition where those cues are not present. Late auditory evoked potentials (N1, P2) were recorded for the stimuli at a constant masker level, but different signal levels within the same set of listeners who participated in the psychoacoustical experiment. The data indicate differences in N1 and P2 between stimuli with and without interaural phase disparities. However, differences for stimuli with and without coherent masker modulation were only found for P2, i.e., only P2 is sensitive to the increase in audibility, irrespective of the cue that caused the masking release. The amplitude of P2 is consistent with the psychoacoustical finding of an addition of the masking releases when both cues are present. Even though it cannot be concluded where along the auditory pathway the audibility is represented, the P2 component of auditory evoked potentials is a candidate for an objective measure of audibility in the human auditory system. Copyright © 2013 Elsevier B.V. All rights reserved.

Semantic activation in the absence of perceptual awareness.

PubMed

Ortells, Juan J; Daza, María Teresa; Fox, Elaine

2003-11-01

Participants performed a semantic categorization task on a target that was preceded by a prime word belonging either to the same category (20% of trials) or to a different category (80% of trials). The prime was presented for 33 msec and followed either immediately or after a delay by a pattern mask. With the immediate mask, reaction times (RTs) were shorter on related than on unrelated trials. This facilitatory priming reached significance at prime-target stimulus onset asynchronies (SOAs) of 400 msec or less and remained unaffected by task practice. With the delayed mask, RTs were longer on related than on unrelated trials. This reversed (strategic) semantic priming proved to be significant (1) only at a prime-target SOA of 400 msec or longer and (2) after the participants had some practice with the task. The present findings provide further evidence that perceiving a stimulus with and without phenomenological awareness can lead to qualitatively different behavioral consequences.

Creation of hybrid optoelectronic systems for document identification

NASA Astrophysics Data System (ADS)

Muravsky, Leonid I.; Voronyak, Taras I.; Kulynych, Yaroslav P.; Maksymenko, Olexander P.; Pogan, Ignat Y.

2001-06-01

Use of security devices based on a joint transform correlator (JTC) architecture for identification of credit cards and other products is very promising. The experimental demonstration of the random phase encoding technique for security verification shows that hybrid JTCs can be successfully utilized. The random phase encoding technique provides a very high protection level of products and things to be identified. However, the realization of this technique is connected with overcoming of the certain practical problems. To solve some of these problems and simultaneously to improve the security of documents and other products, we propose to use a transformed phase mask (TPM) as an input object in an optical correlator. This mask is synthesized from a random binary pattern (RBP), which is directly used to fabricate a reference phase mask (RPM). To obtain the TPM, we previously separate the RBP on a several parts (for example, K parts) of an arbitrary shape and further fabricate the TPM from this transformed RBP. The fabricated TPM can be bonded as the optical mark to any product or thing to be identified. If the RPM and the TPM are placed on the optical correlator input, the first diffracted order of the output correlation signal is containing the K narrow autocorrelation peaks. The distances between the peaks and the peak's intensities can be treated as the terms of the identification feature vector (FV) for the TPM identification.

Emotionally conditioning the target-speech voice enhances recognition of the target speech under "cocktail-party" listening conditions.

PubMed

Lu, Lingxi; Bao, Xiaohan; Chen, Jing; Qu, Tianshu; Wu, Xihong; Li, Liang

2018-05-01

Under a noisy "cocktail-party" listening condition with multiple people talking, listeners can use various perceptual/cognitive unmasking cues to improve recognition of the target speech against informational speech-on-speech masking. One potential unmasking cue is the emotion expressed in a speech voice, by means of certain acoustical features. However, it was unclear whether emotionally conditioning a target-speech voice that has none of the typical acoustical features of emotions (i.e., an emotionally neutral voice) can be used by listeners for enhancing target-speech recognition under speech-on-speech masking conditions. In this study we examined the recognition of target speech against a two-talker speech masker both before and after the emotionally neutral target voice was paired with a loud female screaming sound that has a marked negative emotional valence. The results showed that recognition of the target speech (especially the first keyword in a target sentence) was significantly improved by emotionally conditioning the target speaker's voice. Moreover, the emotional unmasking effect was independent of the unmasking effect of the perceived spatial separation between the target speech and the masker. Also, (skin conductance) electrodermal responses became stronger after emotional learning when the target speech and masker were perceptually co-located, suggesting an increase of listening efforts when the target speech was informationally masked. These results indicate that emotionally conditioning the target speaker's voice does not change the acoustical parameters of the target-speech stimuli, but the emotionally conditioned vocal features can be used as cues for unmasking target speech.

Masking release with changing fundamental frequency: Electric acoustic stimulation resembles normal hearing subjects.

PubMed

Auinger, Alice Barbara; Riss, Dominik; Liepins, Rudolfs; Rader, Tobias; Keck, Tilman; Keintzel, Thomas; Kaider, Alexandra; Baumgartner, Wolf-Dieter; Gstoettner, Wolfgang; Arnoldner, Christoph

2017-07-01

It has been shown that patients with electric acoustic stimulation (EAS) perform better in noisy environments than patients with a cochlear implant (CI). One reason for this could be the preserved access to acoustic low-frequency cues including the fundamental frequency (F0). Therefore, our primary aim was to investigate whether users of EAS experience a release from masking with increasing F0 difference between target talker and masking talker. The study comprised 29 patients and consisted of three groups of subjects: EAS users, CI users and normal-hearing listeners (NH). All CI and EAS users were implanted with a MED-EL cochlear implant and had at least 12 months of experience with the implant. Speech perception was assessed with the Oldenburg sentence test (OlSa) using one sentence from the test corpus as speech masker. The F0 in this masking sentence was shifted upwards by 4, 8, or 12 semitones. For each of these masker conditions the speech reception threshold (SRT) was assessed by adaptively varying the masker level while presenting the target sentences at a fixed level. A statistically significant improvement in speech perception was found for increasing difference in F0 between target sentence and masker sentence in EAS users (p = 0.038) and in NH listeners (p = 0.003). In CI users (classic CI or EAS users with electrical stimulation only) speech perception was independent from differences in F0 between target and masker. A release from masking with increasing difference in F0 between target and masking speech was only observed in listeners and configurations in which the low-frequency region was presented acoustically. Thus, the speech information contained in the low frequencies seems to be crucial for allowing listeners to separate multiple sources. By combining acoustic and electric information, EAS users even manage tasks as complicated as segregating the audio streams from multiple talkers. Preserving the natural code, like fine-structure cues in the low-frequency region, seems to be crucial to provide CI users with the best benefit. Copyright © 2017 Elsevier B.V. All rights reserved.

Schizophrenia affects speech-induced functional connectivity of the superior temporal gyrus under cocktail-party listening conditions.

PubMed

Li, Juanhua; Wu, Chao; Zheng, Yingjun; Li, Ruikeng; Li, Xuanzi; She, Shenglin; Wu, Haibo; Peng, Hongjun; Ning, Yuping; Li, Liang

2017-09-17

The superior temporal gyrus (STG) is involved in speech recognition against informational masking under cocktail-party-listening conditions. Compared to healthy listeners, people with schizophrenia perform worse in speech recognition under informational speech-on-speech masking conditions. It is not clear whether the schizophrenia-related vulnerability to informational masking is associated with certain changes in FC of the STG with some critical brain regions. Using sparse-sampling fMRI design, this study investigated the differences between people with schizophrenia and healthy controls in FC of the STG for target-speech listening against informational speech-on-speech masking, when a listening condition with either perceived spatial separation (PSS, with a spatial release of informational masking) or perceived spatial co-location (PSC, without the spatial release) between target speech and masking speech was introduced. The results showed that in healthy participants, but not participants with schizophrenia, the contrast of either the PSS or PSC condition against the masker-only condition induced an enhancement of functional connectivity (FC) of the STG with the left superior parietal lobule and the right precuneus. Compared to healthy participants, participants with schizophrenia showed declined FC of the STG with the bilateral precuneus, right SPL, and right supplementary motor area. Thus, FC of the STG with the parietal areas is normally involved in speech listening against informational masking under either the PSS or PSC conditions, and declined FC of the STG in people with schizophrenia with the parietal areas may be associated with the increased vulnerability to informational masking. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Lenslet array processors.

PubMed

Glaser, I

1982-04-01

By combining a lenslet array with masks it is possible to obtain a noncoherent optical processor capable of computing in parallel generalized 2-D discrete linear transformations. We present here an analysis of such lenslet array processors (LAP). The effect of several errors, including optical aberrations, diffraction, vignetting, and geometrical and mask errors, are calculated, and guidelines to optical design of LAP are derived. Using these results, both ultimate and practical performances of LAP are compared with those of competing techniques.

An analysis of the masking of speech by competing speech using self-report data.

PubMed

Agus, Trevor R; Akeroyd, Michael A; Noble, William; Bhullar, Navjot

2009-01-01

Many of the items in the "Speech, Spatial, and Qualities of Hearing" scale questionnaire [S. Gatehouse and W. Noble, Int. J. Audiol. 43, 85-99 (2004)] are concerned with speech understanding in a variety of backgrounds, both speech and nonspeech. To study if this self-report data reflected informational masking, previously collected data on 414 people were analyzed. The lowest scores (greatest difficulties) were found for the two items in which there were two speech targets, with successively higher scores for competing speech (six items), energetic masking (one item), and no masking (three items). The results suggest significant masking by competing speech in everyday listening situations.

Quantitative evaluation of manufacturability and performance for ILT produced mask shapes using a single-objective function

NASA Astrophysics Data System (ADS)

Choi, Heon; Wang, Wei-long; Kallingal, Chidam

2015-03-01

The continuous scaling of semiconductor devices is quickly outpacing the resolution improvements of lithographic exposure tools and processes. This one-sided progression has pushed optical lithography to its limits, resulting in the use of well-known techniques such as Sub-Resolution Assist Features (SRAF's), Source-Mask Optimization (SMO), and double-patterning, to name a few. These techniques, belonging to a larger category of Resolution Enhancement Techniques (RET), have extended the resolution capabilities of optical lithography at the cost of increasing mask complexity, and therefore cost. One such technique, called Inverse Lithography Technique (ILT), has attracted much attention for its ability to produce the best possible theoretical mask design. ILT treats the mask design process as an inverse problem, where the known transformation from mask to wafer is carried out backwards using a rigorous mathematical approach. One practical problem in the application of ILT is the resulting contour-like mask shapes that must be "Manhattanized" (composed of straight edges and 90-deg corners) in order to produce a manufacturable mask. This conversion process inherently degrades the mask quality as it is a departure from the "optimal mask" represented by the continuously curved shapes produced by ILT. However, simpler masks composed of longer straight edges reduce the mask cost as it lowers the shot count and saves mask writing time during mask fabrication, resulting in a conflict between manufacturability and performance for ILT produced masks1,2. In this study, various commonly used metrics will be combined into an objective function to produce a single number to quantitatively measure a particular ILT solution's ability to balance mask manufacturability and RET performance. Several metrics that relate to mask manufacturing costs (i.e. mask vertex count, ILT computation runtime) are appropriately weighted against metrics that represent RET capability (i.e. process-variation band, edge-placement-error) in order to reflect the desired practical balance. This well-defined scoring system allows direct comparison of several masks with varying degrees of complexities. Using this method, ILT masks produced with increasing mask constraints will be compared, and it will be demonstrated that using the smallest minimum width for mask shapes does not always produce the optimal solution.

Interaction of Object Binding Cues in Binaural Masking Pattern Experiments.

PubMed

Verhey, Jesko L; Lübken, Björn; van de Par, Steven

2016-01-01

Object binding cues such as binaural and across-frequency modulation cues are likely to be used by the auditory system to separate sounds from different sources in complex auditory scenes. The present study investigates the interaction of these cues in a binaural masking pattern paradigm where a sinusoidal target is masked by a narrowband noise. It was hypothesised that beating between signal and masker may contribute to signal detection when signal and masker do not spectrally overlap but that this cue could not be used in combination with interaural cues. To test this hypothesis an additional sinusoidal interferer was added to the noise masker with a lower frequency than the noise whereas the target had a higher frequency than the noise. Thresholds increase when the interferer is added. This effect is largest when the spectral interferer-masker and masker-target distances are equal. The result supports the hypothesis that modulation cues contribute to signal detection in the classical masking paradigm and that these are analysed with modulation bandpass filters. A monaural model including an across-frequency modulation process is presented that account for this effect. Interestingly, the interferer also affects dichotic thresholds indicating that modulation cues also play a role in binaural processing.

Selective spatial attention modulates bottom-up informational masking of speech

PubMed Central

Carlile, Simon; Corkhill, Caitlin

2015-01-01

To hear out a conversation against other talkers listeners overcome energetic and informational masking. Largely attributed to top-down processes, information masking has also been demonstrated using unintelligible speech and amplitude-modulated maskers suggesting bottom-up processes. We examined the role of speech-like amplitude modulations in information masking using a spatial masking release paradigm. Separating a target talker from two masker talkers produced a 20 dB improvement in speech reception threshold; 40% of which was attributed to a release from informational masking. When across frequency temporal modulations in the masker talkers are decorrelated the speech is unintelligible, although the within frequency modulation characteristics remains identical. Used as a masker as above, the information masking accounted for 37% of the spatial unmasking seen with this masker. This unintelligible and highly differentiable masker is unlikely to involve top-down processes. These data provides strong evidence of bottom-up masking involving speech-like, within-frequency modulations and that this, presumably low level process, can be modulated by selective spatial attention. PMID:25727100

Selective spatial attention modulates bottom-up informational masking of speech.

PubMed

Carlile, Simon; Corkhill, Caitlin

2015-03-02

To hear out a conversation against other talkers listeners overcome energetic and informational masking. Largely attributed to top-down processes, information masking has also been demonstrated using unintelligible speech and amplitude-modulated maskers suggesting bottom-up processes. We examined the role of speech-like amplitude modulations in information masking using a spatial masking release paradigm. Separating a target talker from two masker talkers produced a 20 dB improvement in speech reception threshold; 40% of which was attributed to a release from informational masking. When across frequency temporal modulations in the masker talkers are decorrelated the speech is unintelligible, although the within frequency modulation characteristics remains identical. Used as a masker as above, the information masking accounted for 37% of the spatial unmasking seen with this masker. This unintelligible and highly differentiable masker is unlikely to involve top-down processes. These data provides strong evidence of bottom-up masking involving speech-like, within-frequency modulations and that this, presumably low level process, can be modulated by selective spatial attention.

Estimating human cochlear tuning behaviorally via forward masking

NASA Astrophysics Data System (ADS)

Oxenham, Andrew J.; Kreft, Heather A.

2018-05-01

The cochlea is where sound vibrations are transduced into the initial neural code for hearing. Despite the intervening stages of auditory processing, a surprising number of auditory perceptual phenomena can be explained in terms of the cochlea's biomechanical transformations. The quest to relate perception to these transformations has a long and distinguished history. Given its long history, it is perhaps surprising that something as fundamental as the link between frequency tuning in the cochlea and perception remains a controversial and active topic of investigation. Here we review some recent developments in our understanding of the relationship between cochlear frequency tuning and behavioral measures of frequency selectivity in humans. We show that forward masking using the notched-noise technique can produce reliable estimates of tuning that are in line with predictions from stimulus frequency otoacoustic emissions.

Nanofabrication on unconventional substrates using transferred hard masks

DOE PAGES

Li, Luozhou; Bayn, Igal; Lu, Ming; ...

2015-01-15

Here, a major challenge in nanofabrication is to pattern unconventional substrates that cannot be processed for a variety of reasons, such as incompatibility with spin coating, electron beam lithography, optical lithography, or wet chemical steps. Here, we present a versatile nanofabrication method based on re-usable silicon membrane hard masks, patterned using standard lithography and mature silicon processing technology. These masks, transferred precisely onto targeted regions, can be in the millimetre scale. They allow for fabrication on a wide range of substrates, including rough, soft, and non-conductive materials, enabling feature linewidths down to 10 nm. Plasma etching, lift-off, and ion implantationmore » are realized without the need for scanning electron/ion beam processing, UV exposure, or wet etching on target substrates.« less

Effects of set-size and lateral masking in visual search.

PubMed

Põder, Endel

2004-01-01

In the present research, the roles of lateral masking and central processing limitations in visual search were studied. Two search conditions were used: (1) target differed from distractors by presence/absence of a simple feature; (2) target differed by relative position of the same components only. The number of displayed stimuli (set-size) and the distance between neighbouring stimuli were varied as independently as possible in order to measure the effect of both. The effect of distance between stimuli (lateral masking) was found to be similar in both conditions. The effect of set-size was much larger for relative position stimuli. The results support the view that perception of relative position of stimulus components is limited mainly by the capacity of central processing.

Inverse target- and cue-priming effects of masked stimuli.

PubMed

Mattler, Uwe

2007-02-01

The processing of a visual target that follows a briefly presented prime stimulus can be facilitated if prime and target stimuli are similar. In contrast to these positive priming effects, inverse priming effects (or negative compatibility effects) have been found when a mask follows prime stimuli before the target stimulus is presented: Responses are facilitated after dissimilar primes. Previous studies on inverse priming effects examined target-priming effects, which arise when the prime and the target stimuli share features that are critical for the response decision. In contrast, 3 experiments of the present study demonstrate inverse priming effects in a nonmotor cue-priming paradigm. Inverse cue-priming effects exhibited time courses comparable to inverse target-priming effects. Results suggest that inverse priming effects do not arise from specific processes of the response system but follow from operations that are more general.

The attentional blink is not affected by backward masking of T2, T2-mask SOA, or level of T2 impoverishment.

PubMed

Jannati, Ali; Spalek, Thomas M; Lagroix, Hayley E P; Di Lollo, Vincent

2012-02-01

Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). This attentional blink (AB) is thought to arise from a delay in T2 processing during which T2 is vulnerable to masking. Conventional studies have measured T2 accuracy which is constrained by the 100% ceiling. We avoided this problem by using a dynamic threshold-tracking procedure that is inherently free from ceiling constraints. In two experiments we examined how AB magnitude is affected by three masking-related factors: (a) presence/absence of T2 mask, (b) T2-mask stimulus onset asynchrony (SOA), and (c) level of T2 impoverishment (signal-to-noise ratio [SNR]). In Experiment 1, overall accuracy decreased with T2-mask SOA. The magnitude of the AB, however, was invariant with SOA and with mask presence/absence. Experiment 2 further showed that the AB was invariant with T2 SNR. The relationship among mask presence/absence, SOA, and T2 SNR and the AB is encompassed in a qualitative model.

An improved principal component analysis based region matching method for fringe direction estimation

NASA Astrophysics Data System (ADS)

He, A.; Quan, C.

2018-04-01

The principal component analysis (PCA) and region matching combined method is effective for fringe direction estimation. However, its mask construction algorithm for region matching fails in some circumstances, and the algorithm for conversion of orientation to direction in mask areas is computationally-heavy and non-optimized. We propose an improved PCA based region matching method for the fringe direction estimation, which includes an improved and robust mask construction scheme, and a fast and optimized orientation-direction conversion algorithm for the mask areas. Along with the estimated fringe direction map, filtered fringe pattern by automatic selective reconstruction modification and enhanced fast empirical mode decomposition (ASRm-EFEMD) is used for Hilbert spiral transform (HST) to demodulate the phase. Subsequently, windowed Fourier ridge (WFR) method is used for the refinement of the phase. The robustness and effectiveness of proposed method are demonstrated by both simulated and experimental fringe patterns.

Novel Hadamard transform spectrometer realized using a dynamically driven micromirror array as a light modulator

NASA Astrophysics Data System (ADS)

Hanf, Marian; Schaporin, Alexey V.; Hahn, Ramon; Doetzel, Wolfram; Gessner, Thomas

2005-01-01

The paper deals with a novel setup of a Hadamard transform spectrometer (HTS) which encoding mask is realized by a micro mirror array. In contrast to other applications of an HTS the mirrors of the array are not statically switched but dynamically driven to oscillate at the same frequency. The Hadamard transform is obtained by shifting the phase shift of oscillation. The paper gives a brief introduction in the entity of the Hadamard transform technique. The driving and detection circuits are presented and first measurement results are discussed.

Structural colour printing from a reusable generic nanosubstrate masked for the target image

NASA Astrophysics Data System (ADS)

Rezaei, M.; Jiang, H.; Kaminska, B.

2016-02-01

Structural colour printing has advantages over traditional pigment-based colour printing. However, the high fabrication cost has hindered its applications in printing large-area images because each image requires patterning structural pixels in nanoscale resolution. In this work, we present a novel strategy to print structural colour images from a pixelated substrate which is called a nanosubstrate. The nanosubstrate is fabricated only once using nanofabrication tools and can be reused for printing a large quantity of structural colour images. It contains closely packed arrays of nanostructures from which red, green, blue and infrared structural pixels can be imprinted. To print a target colour image, the nanosubstrate is first covered with a mask layer to block all the structural pixels. The mask layer is subsequently patterned according to the target colour image to make apertures of controllable sizes on top of the wanted primary colour pixels. The masked nanosubstrate is then used as a stamp to imprint the colour image onto a separate substrate surface using nanoimprint lithography. Different visual colours are achieved by properly mixing the red, green and blue primary colours into appropriate ratios controlled by the aperture sizes on the patterned mask layer. Such a strategy significantly reduces the cost and complexity of printing a structural colour image from lengthy nanoscale patterning into high throughput micro-patterning and makes it possible to apply structural colour printing in personalized security features and data storage. In this paper, nanocone array grating pixels were used as the structural pixels and the nanosubstrate contains structures to imprint the nanocone arrays. Laser lithography was implemented to pattern the mask layer with submicron resolution. The optical properties of the nanocone array gratings are studied in detail. Multiple printed structural colour images with embedded covert information are demonstrated.

Optical Double Image Hiding in the Fractional Hartley Transform Using Structured Phase Filter and Arnold Transform

NASA Astrophysics Data System (ADS)

Yadav, Poonam Lata; Singh, Hukum

2018-06-01

To maintain the security of the image encryption and to protect the image from intruders, a new asymmetric cryptosystem based on fractional Hartley Transform (FrHT) and the Arnold transform (AT) is proposed. AT is a method of image cropping and edging in which pixels of the image are reorganized. In this cryptosystem we have used AT so as to extent the information content of the two original images onto the encrypted images so as to increase the safety of the encoded images. We have even used Structured Phase Mask (SPM) and Hybrid Mask (HM) as the encryption keys. The original image is first multiplied with the SPM and HM and then transformed with direct and inverse fractional Hartley transform so as to obtain the encrypted image. The fractional orders of the FrHT and the parameters of the AT correspond to the keys of encryption and decryption methods. If both the keys are correctly used only then the original image would be retrieved. Recommended method helps in strengthening the safety of DRPE by growing the key space and the number of parameters and the method is robust against various attacks. By using MATLAB 8.3.0.52 (R2014a) we calculate the strength of the recommended cryptosystem. A set of simulated results shows the power of the proposed asymmetric cryptosystem.

Laser-assisted electrochemical micromachining of mould cavity on the stainless steel surface

NASA Astrophysics Data System (ADS)

Li, Xiaohai; Wang, Shuming; Wang, Dong; Tong, Han

2018-02-01

In order to fabricate the micro mould cavities with complex structures on 304 stainless steel, laser-assisted electrochemical micromachining (EMM) based on surface modification by fiber laser masking was studied,and a new device of laser-assisted EMM was developed. Laser marking on the surface of 304 stainless steel can first be realized by fiber laser heating scanning. Through analysis of X ray diffraction analysis (XRD), metal oxide layer with predefined pattern can be formed by laser marking, and phase transformation can also occur on the 304 stainless steel surface, which produce the laser masking layer with corrosion resistance. The stainless steel surface with laser masking layer is subsequently etched by EMM, the laser masking layer severs as the temporary protective layer without relying on lithography mask, the fabrication of formed electrodes is also avoided, so micro pattern cavities can fast be fabricated. The impacts on machining accuracy during EMM with laser masking were discussed to optimize machining parameters, such as machining voltage, electrolyte concentration, duty cycle of pulse power supply and electrode gap size, the typical mould cavities 23μm deep were fabricated under the optimized parameters.

Masked priming by misspellings: Word frequency moderates the effects of SOA and prime-target similarity.

PubMed

Burt, Jennifer S

2016-02-01

University students made lexical decisions to eight- or nine-letter words preceded by masked primes that were the target, an unrelated word, or a typical misspelling of the target. At a stimulus onset asynchrony (SOA) of 47 ms, primes that were misspellings of the target produced a priming benefit for low-, medium-, and high-frequency words, even when the misspelled primes were changed to differ phonologically from their targets. At a longer SOA of 80 ms, misspelled primes facilitated lexical decisions only to medium- and low-frequency targets, and a phonological change attenuated the benefit for medium-frequency targets. The results indicate that orthographic similarity can be preserved over changes in letter position and word length, and that the priming effect of misspelled words at the shorter SOA is orthographically based. Orthographic-priming effects depend on the quality of the orthographic learning of the target word.

Wafer hot spot identification through advanced photomask characterization techniques

NASA Astrophysics Data System (ADS)

Choi, Yohan; Green, Michael; McMurran, Jeff; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike

2016-10-01

As device manufacturers progress through advanced technology nodes, limitations in standard 1-dimensional (1D) mask Critical Dimension (CD) metrics are becoming apparent. Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that the classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on subresolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. These items are not quantifiable with the 1D metrology techniques of today. Likewise, the mask maker needs advanced characterization methods in order to optimize the mask process to meet the wafer lithographer's needs. These advanced characterization metrics are what is needed to harmonize mask and wafer processes for enhanced wafer hot spot analysis. In this paper, we study advanced mask pattern characterization techniques and their correlation with modeled wafer performance.

An Electrophysiological Investigation of Early Effects of Masked Morphological Priming

ERIC Educational Resources Information Center

Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J.

2008-01-01

This experiment examined event-related responses to targets preceded by semantically transparent morphologically related primes (e.g., farmer-farm), semantically opaque primes with an apparent morphological relation (corner-corn), and orthographically, but not morphologically, related primes (scandal-scan) using the masked priming technique…

A challenging dissociation in masked identity priming with the lexical decision task.

PubMed

Perea, Manuel; Jiménez, María; Gómez, Pablo

2014-05-01

The masked priming technique has been used extensively to explore the early stages of visual-word recognition. One key phenomenon in masked priming lexical decision is that identity priming is robust for words, whereas it is small/unreliable for nonwords. This dissociation has usually been explained on the basis that masked priming effects are lexical in nature, and hence there should not be an identity prime facilitation for nonwords. We present two experiments whose results are at odds with the assumption made by models that postulate that identity priming is purely lexical, and also challenge the assumption that word and nonword responses are based on the same information. Our experiments revealed that for nonwords, but not for words, matched-case identity PRIME-TARGET pairs were responded to faster than mismatched-case identity prime-TARGET pairs, and this phenomenon was not modulated by the lowercase/uppercase feature similarity of the stimuli. Copyright © 2014 Elsevier B.V. All rights reserved.

Attention and positive affect: temporal switching or spatial broadening?

PubMed

Phaf, R Hans

2015-04-01

Evolutionary reasoning and computation suggest that positive affect is associated with higher attentional flexibility than negative affect, even when affectively neutral material is processed. The affective modulation of interference in the Eriksen flanker task seems, however, more readily explained by a spatial broadening of attention due to positive affect. It is argued here that these results should also be interpreted in terms of an increased switching over time between flankers and target (i.e., flexibility). The two hypotheses were contrasted with positive and negative mood inductions in a masked-flanker task. The interval (Stimulus Onset Asynchrony; SOA) with which the masked flankers preceded the target letter was parametrically varied. In contrast to what is found with simultaneous non-masked flanker presentation, masking produced larger interference with negative than with positive moods. In addition, a crossover interaction between mood and SOA emerged. These results seem incompatible with a spatial broadening account and support an affective modulation account in terms of flexibility.

Performance and stability of mask process correction for EBM-7000

NASA Astrophysics Data System (ADS)

Saito, Yasuko; Chen, George; Wang, Jen-Shiang; Bai, Shufeng; Howell, Rafael; Li, Jiangwei; Tao, Jun; VanDenBroeke, Doug; Wiley, Jim; Takigawa, Tadahiro; Ohnishi, Takayuki; Kamikubo, Takashi; Hara, Shigehiro; Anze, Hirohito; Hattori, Yoshiaki; Tamamushi, Shuichi

2010-05-01

In order to support complex optical masks today and EUV masks in the near future, it is critical to correct mask patterning errors with a magnitude of up to 20nm over a range of 2000nm at mask scale caused by short range mask process proximity effects. A new mask process correction technology, MPC+, has been developed to achieve the target requirements for the next generation node. In this paper, the accuracy and throughput performance of MPC+ technology is evaluated using the most advanced mask writing tool, the EBM-70001), and high quality mask metrology . The accuracy of MPC+ is achieved by using a new comprehensive mask model. The results of through-pitch and through-linewidth linearity curves and error statistics for multiple pattern layouts (including both 1D and 2D patterns) are demonstrated and show post-correction accuracy of 2.34nm 3σ for through-pitch/through-linewidth linearity. Implementing faster mask model simulation and more efficient correction recipes; full mask area (100cm2) processing run time is less than 7 hours for 32nm half-pitch technology node. From these results, it can be concluded that MPC+ with its higher precision and speed is a practical technology for the 32nm node and future technology generations, including EUV, when used with advance mask writing processes like the EBM-7000.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnard, John J.; Schenkel, Thomas

Intense, pulsed ion beams locally heat materials and deliver dense electronic excitations that can induce material modifications and phase transitions. Material properties can potentially be stabilized by rapid quenching. Pulsed ion beams with pulse lengths of order ns have recently become available for materials processing. Here, we optimize mask geometries for local modification of materials by intense ion pulses. The goal is to rapidly excite targets volumetrically to the point where a phase transition or local lattice reconstruction is induced followed by rapid cooling that stabilizes desired material's properties fast enough before the target is altered or damaged by, e.g.,more » hydrodynamic expansion. By using a mask, the longitudinal dimension can be large compared to the transverse dimension, allowing the possibility of rapid transverse cooling. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of silicon targets with micro-structured masks and compare these to a simple analytical model. In conclusion, the model gives scaling laws that can guide the design of targets over a wide range of pulsed ion beam parameters.« less

Electrophysiological evidence for size invariance in masked picture repetition priming

PubMed Central

Eddy, Marianna D.; Holcomb, Phillip J.

2009-01-01

This experiment examined invariance in object representations through measuring event-related potentials (ERPs) to pictures in a masked repetition priming paradigm. Pairs of pictures were presented where the prime was either the same size or half the size of the target object and the target was either presented in a normal orientation or was a normal sized mirror reflection of the prime object. Previous masked repetition priming studies have found a cascade of priming effect sensitive to perceptual (N190/P190) and semantic (N400) properties of the stimulus. This experiment found that both early (N190/P190 effects) and later effects (N400) were invariant to size, whereas only the N190/P190 effect was invariant to mirror reflection. The combination of a small prime and a mirror reflected target led to no significant priming effects. Taken together, the results of this set of experiments suggests that object recognition, more specifically, activating an object representation, occurs in a hierarchical fashion where overlapping perceptual information between the prime and target is necessary, although not always sufficient, to activate a higher level semantic representation. PMID:19560248

Neural Correlates of Auditory Perceptual Awareness and Release from Informational Masking Recorded Directly from Human Cortex: A Case Study.

PubMed

Dykstra, Andrew R; Halgren, Eric; Gutschalk, Alexander; Eskandar, Emad N; Cash, Sydney S

2016-01-01

In complex acoustic environments, even salient supra-threshold sounds sometimes go unperceived, a phenomenon known as informational masking. The neural basis of informational masking (and its release) has not been well-characterized, particularly outside auditory cortex. We combined electrocorticography in a neurosurgical patient undergoing invasive epilepsy monitoring with trial-by-trial perceptual reports of isochronous target-tone streams embedded in random multi-tone maskers. Awareness of such masker-embedded target streams was associated with a focal negativity between 100 and 200 ms and high-gamma activity (HGA) between 50 and 250 ms (both in auditory cortex on the posterolateral superior temporal gyrus) as well as a broad P3b-like potential (between ~300 and 600 ms) with generators in ventrolateral frontal and lateral temporal cortex. Unperceived target tones elicited drastically reduced versions of such responses, if at all. While it remains unclear whether these responses reflect conscious perception, itself, as opposed to pre- or post-perceptual processing, the results suggest that conscious perception of target sounds in complex listening environments may engage diverse neural mechanisms in distributed brain areas.

Chosen-plaintext attack on a joint transform correlator encrypting system

NASA Astrophysics Data System (ADS)

Barrera, John Fredy; Vargas, Carlos; Tebaldi, Myrian; Torroba, Roberto

2010-10-01

We demonstrate that optical encryption methods based on the joint transform correlator architecture are vulnerable to chosen-plaintext attack. An unauthorized user, who introduces three chosen plaintexts in the accessible encryption machine, can obtain the security key code mask. In this contribution, we also propose an alternative method to eliminate ambiguities that allows obtaining the right decrypting key.

The serial nature of the masked onset priming effect revisited.

PubMed

Mousikou, Petroula; Coltheart, Max

2014-01-01

Reading aloud is faster when target words/nonwords are preceded by masked prime words/nonwords that share their first sound with the target (e.g., save-SINK) compared to when primes and targets are unrelated to each other (e.g., farm-SINK). This empirical phenomenon is the masked onset priming effect (MOPE) and is known to be due to serial left-to-right processing of the prime by a sublexical reading mechanism. However, the literature in this domain lacks a critical experiment. It is possible that when primes are real words their orthographic/phonological representations are activated in parallel and holistically during prime presentation, so any phoneme overlap between primes and targets (and not just initial-phoneme overlap) could facilitate target reading aloud. This is the prediction made by the only computational models of reading aloud that are able to simulate the MOPE, namely the DRC1.2.1, CDP+, and CDP++ models. We tested this prediction in the present study and found that initial-phoneme overlap (blip-BEST), but not end-phoneme overlap (flat-BEST), facilitated target reading aloud compared to no phoneme overlap (junk-BEST). These results provide support for a reading mechanism that operates serially and from left to right, yet are inconsistent with all existing computational models of single-word reading aloud.

Deep Ensemble Learning for Monaural Speech Separation

DTIC Science & Technology

2015-02-01

cse.ohio- state.edu). typically predict the ideal binary mask (IBM) or ideal ratio mask ( IRM ). For the IBM [21], a T-F unit is assigned 1, if the signal...dominance. For the IRM [17], a T- F unit is assigned some ratio of target energy and mixture energy. Kim et al. [15] used Gaussian mixture models (GMM...significantly outperforms earlier separation methods. Subsequently, Wang et al. [23] examined a number of training targets and suggested that the IRM should be

Exploring EUV and SAQP pattering schemes at 5nm technology node

NASA Astrophysics Data System (ADS)

Hamed Fatehy, Ahmed; Kotb, Rehab; Lafferty, Neal; Jiang, Fan; Word, James

2018-03-01

For years, Moore's law keeps driving the semiconductors industry towards smaller dimensions and higher density chips with more devices. Earlier, the correlation between exposure source's wave length and the smallest resolvable dimension, mandated the usage of Deep Ultra-Violent (DUV) optical lithography system which has been used for decades to sustain Moore's law, especially when immersion lithography was introduced with 193nm ArF laser sources. As dimensions of devices get smaller beyond Deep Ultra-Violent (DUV) optical resolution limits, the need for Extremely Ultra-Violent (EUV) optical lithography systems was a must. However, EUV systems were still under development at that time for the mass-production in semiconductors industry. Theretofore, Multi-Patterning (MP) technologies was introduced to swirl about DUV optical lithography limitations in advanced nodes beyond minimum dimension (CD) of 20nm. MP can be classified into two main categories; the first one is to split the target itself across multiple masks that give the original target patterns when they are printed. This category includes Double, Triple and Quadruple patterning (DP, TP, and QP). The second category is the Self-Aligned Patterning (SAP) where the target is divided into Mandrel patterns and non-Mandrel patterns. The Mandrel patterns get printed first, then a self-aligned sidewalls are grown around these printed patterns drawing the other non-Mandrel targets, afterword, a cut mask(s) is used to define target's line-ends. This approach contains Self-Aligned-Double Pattering (SADP) and Self-Aligned- Quadruple-Pattering (SAQP). DUV and MP along together paved the way for the industry down to 7nm. However, with the start of development at the 5nm node and the readiness of EUV, the differentiation question is aroused again, which pattering approach should be selected, direct printing using EUV or DUV with MP, or a hybrid flow that contains both DUV-MP and EUV. In this work we are comparing two potential pattering techniques for Back End Of Line (BEOL) metal layers in the 5nm technology node, the first technique is Single Exposure EUV (SE-EUV) with a Direct Patterning EUV lithography process, and the second one is Self-Aligned Quadruple Patterning (SAQP) with a hybrid lithography processes, where the drawn metal target layer is decomposed into a Mandrel mask and Blocks/Cut mask, Mandrel mask is printed using DUV 193i lithography process, while Block/Cut Mask is printed using SE-EUV lithography process. The pros and cons of each technique are quantified based on Edge-Placement-Error (EPE) and Process Variation Band (PVBand) measured at 1D and 2D edges. The layout used in this comparison is a candidate layout for Foundries 5nm process node.

The Attentional Blink Is Not Affected by Backward Masking of T2, T2-Mask SOA, or Level of T2 Impoverishment

ERIC Educational Resources Information Center

Jannati, Ali; Spalek, Thomas M.; Lagroix, Hayley E. P.; Di Lollo, Vincent

2012-01-01

Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). This "attentional blink" (AB) is thought to arise from a delay in T2 processing during which T2 is vulnerable to masking. Conventional studies have measured T2 accuracy which is constrained by the 100% ceiling. We avoided this problem by using…

Wafer hot spot identification through advanced photomask characterization techniques: part 2

NASA Astrophysics Data System (ADS)

Choi, Yohan; Green, Michael; Cho, Young; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike

2017-03-01

Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for mask end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on sub-resolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. To overcome the limitation of 1D metrics, there are numerous on-going industry efforts to better define wafer-predictive metrics through both standard mask metrology and aerial CD methods. Even with these improvements, the industry continues to struggle to define useful correlative metrics that link the mask to final device performance. In part 1 of this work, we utilized advanced mask pattern characterization techniques to extract potential hot spots on the mask and link them, theoretically, to issues with final wafer performance. In this paper, part 2, we complete the work by verifying these techniques at wafer level. The test vehicle (TV) that was used for hot spot detection on the mask in part 1 will be used to expose wafers. The results will be used to verify the mask-level predictions. Finally, wafer performance with predicted and verified mask/wafer condition will be shown as the result of advanced mask characterization. The goal is to maximize mask end user yield through mask-wafer technology harmonization. This harmonization will provide the necessary feedback to determine optimum design, mask specifications, and mask-making conditions for optimal wafer process margin.

Asymmetric multiple information cryptosystem based on chaotic spiral phase mask and random spectrum decomposition

NASA Astrophysics Data System (ADS)

Rafiq Abuturab, Muhammad

2018-01-01

A new asymmetric multiple information cryptosystem based on chaotic spiral phase mask (CSPM) and random spectrum decomposition is put forwarded. In the proposed system, each channel of secret color image is first modulated with a CSPM and then gyrator transformed. The gyrator spectrum is randomly divided into two complex-valued masks. The same procedure is applied to multiple secret images to get their corresponding first and second complex-valued masks. Finally, first and second masks of each channel are independently added to produce first and second complex ciphertexts, respectively. The main feature of the proposed method is the different secret images encrypted by different CSPMs using different parameters as the sensitive decryption/private keys which are completely unknown to unauthorized users. Consequently, the proposed system would be resistant to potential attacks. Moreover, the CSPMs are easier to position in the decoding process owing to their own centering mark on axis focal ring. The retrieved secret images are free from cross-talk noise effects. The decryption process can be implemented by optical experiment. Numerical simulation results demonstrate the viability and security of the proposed method.

Spatial Release from Masking in Children: Effects of Simulated Unilateral Hearing Loss

PubMed Central

Corbin, Nicole E.; Buss, Emily; Leibold, Lori J.

2016-01-01

Objectives The purpose of this study was twofold: 1) to determine the effect of an acute simulated unilateral hearing loss on children’s spatial release from masking in two-talker speech and speech-shaped noise, and 2) to develop a procedure to be used in future studies that will assess spatial release from masking in children who have permanent unilateral hearing loss. There were three main predictions. First, spatial release from masking was expected to be larger in two-talker speech than speech-shaped noise. Second, simulated unilateral hearing loss was expected to worsen performance in all listening conditions, but particularly in the spatially separated two-talker speech masker. Third, spatial release from masking was expected to be smaller for children than for adults in the two-talker masker. Design Participants were 12 children (8.7 to 10.9 yrs) and 11 adults (18.5 to 30.4 yrs) with normal bilateral hearing. Thresholds for 50%-correct recognition of Bamford-Kowal-Bench sentences were measured adaptively in continuous two-talker speech or speech-shaped noise. Target sentences were always presented from a loudspeaker at 0° azimuth. The masker stimulus was either co-located with the target or spatially separated to +90° or −90° azimuth. Spatial release from masking was quantified as the difference between thresholds obtained when the target and masker were co-located and thresholds obtained when the masker was presented from +90° or − 90°. Testing was completed both with and without a moderate simulated unilateral hearing loss, created with a foam earplug and supra-aural earmuff. A repeated-measures design was used to compare performance between children and adults, and performance in the no-plug and simulated-unilateral-hearing-loss conditions. Results All listeners benefited from spatial separation of target and masker stimuli on the azimuth plane in the no-plug listening conditions; this benefit was larger in two-talker speech than in speech-shaped noise. In the simulated-unilateral-hearing-loss conditions, a positive spatial release from masking was observed only when the masker was presented ipsilateral to the simulated unilateral hearing loss. In the speech-shaped noise masker, spatial release from masking in the no-plug condition was similar to that obtained when the masker was presented ipsilateral to the simulated unilateral hearing loss. In contrast, in the two-talker speech masker, spatial release from masking in the no-plug condition was much larger than that obtained when the masker was presented ipsilateral to the simulated unilateral hearing loss. When either masker was presented contralateral to the simulated unilateral hearing loss, spatial release from masking was negative. This pattern of results was observed for both children and adults, although children performed more poorly overall. Conclusions Children and adults with normal bilateral hearing experience greater spatial release from masking for a two-talker speech than a speech-shaped noise masker. Testing in a two-talker speech masker revealed listening difficulties in the presence of disrupted binaural input that were not observed in a speech-shaped noise masker. This procedure offers promise for the assessment of spatial release from masking in children with permanent unilateral hearing loss. PMID:27787392

Dynamic mask for producing uniform or graded-thickness thin films

DOEpatents

Folta, James A [Livermore, CA

2006-06-13

A method for producing single layer or multilayer films with high thickness uniformity or thickness gradients. The method utilizes a moving mask which blocks some of the flux from a sputter target or evaporation source before it deposits on a substrate. The velocity and position of the mask is computer controlled to precisely tailor the film thickness distribution. The method is applicable to any type of vapor deposition system, but is particularly useful for ion beam sputter deposition and evaporation deposition; and enables a high degree of uniformity for ion beam deposition, even for near-normal incidence of deposition species, which may be critical for producing low-defect multilayer coatings, such as required for masks for extreme ultraviolet lithography (EUVL). The mask can have a variety of shapes, from a simple solid paddle shape to a larger mask with a shaped hole through which the flux passes. The motion of the mask can be linear or rotational, and the mask can be moved to make single or multiple passes in front of the substrate per layer, and can pass completely or partially across the substrate.

Being Forward Not Backward: Lexical Limits to Masked Priming

ERIC Educational Resources Information Center

Davis, Chris; Kim, Jeesun; Forster, Kenneth I.

2008-01-01

This study investigated whether masked priming is mediated by existing memory representations by determining whether nonwords targets would show repetition priming. To avoid the potential confound that nonword repetition priming would be obscured by a familiarity response bias, the standard lexical decision and naming tasks were modified to make…

Masked Inhibitory Priming in English: Evidence for Lexical Inhibition

ERIC Educational Resources Information Center

Davis, Colin J.; Lupker, Stephen J.

2006-01-01

Predictions derived from the interactive activation (IA) model were tested in 3 experiments using the masked priming technique in the lexical decision task. Experiment 1 showed a strong effect of prime lexicality: Classifications of target words were facilitated by orthographically related nonword primes (relative to unrelated nonword primes) but…

Masked Priming Is Abstract in the Left and Right Visual Fields

ERIC Educational Resources Information Center

Bowers, Jeffrey S.; Turner, Emma L.

2005-01-01

Two experiments assessed masked priming for words presented to the left and right visual fields in a lexical decision task. In both Experiments, the same magnitude and pattern of priming was obtained for visually similar ("kiss"-"KISS") and dissimilar ("read"-"READ") prime-target pairs. These findings…

Matching OPC and masks on 300-mm lithography tools utilizing variable illumination settings

NASA Astrophysics Data System (ADS)

Palitzsch, Katrin; Kubis, Michael; Schroeder, Uwe P.; Schumacher, Karl; Frangen, Andreas

2004-05-01

CD control is crucial to maximize product yields on 300mm wafers. This is particularly true for DRAM frontend lithography layers, like gate level, and deep trench (capacitor) level. In the DRAM process, large areas of the chip are taken up by array structures, which are difficult to structure due to aggressive pitch requirements. Consequently, the lithography process is centered such that the array structures are printed on target. Optical proximity correction is applied to print gate level structures in the periphery circuitry on target. Only slight differences of the different Zernike terms can cause rather large variations of the proximity curves, resulting in a difference of isolated and semi-isolated lines printed on different tools. If the deviations are too large, tool specific OPC is needed. The same is true for deep trench level, where the length to width ratio of elongated contact-like structures is an important parameter to adjust the electrical properties of the chip. Again, masks with specific biases for tools with different Zernikes are needed to optimize product yield. Additionally, mask making contributes to the CD variation of the process. Theoretically, the CD deviation caused by an off-centered mask process can easily eat up the majority of the CD budget of a lithography process. In practice, masks are very often distributed intelligently among production tools, such that lens and mask effects cancel each other. However, only dose adjusting and mask allocation may still result in a high CD variation with large systematical contributions. By adjusting the illumination settings, we have successfully implemented a method to reduce CD variation on our advanced processes. Especially inner and outer sigma for annular illumination, and the numerical aperture, can be optimized to match mask and stepper properties. This process will be shown to overcome slight lens and mask differences effectively. The effects on lithography process windows have to be considered, nonetheless.

Evaluation of setup uncertainties for single-fraction SRS by comparing two different mask-creation methods

NASA Astrophysics Data System (ADS)

Baek, Jong Geun; Jang, Hyun Soo; Oh, Young Kee; Lee, Hyun Jeong; Kim, Eng Chan

2015-07-01

The purpose of this study was to evaluate the setup uncertainties for single-fraction stereotactic radiosurgery (SF-SRS) based on clinical data with two different mask-creation methods using pretreatment con-beam computed tomography imaging guidance. Dedicated frameless fixation Brain- LAB masks for 23 patients were created as a routine mask (R-mask) making method, as explained in the BrainLAB's user manual. Alternative masks (A-masks), which were created by modifying the cover range of the R-masks for the patient's head, were used for 23 patients. The systematic errors including these for each mask and stereotactic target localizer were analyzed, and the errors were calculated as the means ± standard deviations (SD) from the left-right (LR), superior-inferior (SI), anterior-posterior (AP), and yaw setup corrections. In addition, the frequencies of the threedimensional (3D) vector length were analyzed. The values of the mean setup corrections for the R-mask in all directions were < 0.7 mm and < 0.1°, whereas the magnitudes of the SDs were relatively large compared to the mean values. In contrast, the means and SDs of the A-mask were smaller than those for the R-mask with the exception of the SD in the AP direction. The means and SDs in the yaw rotational direction for the R-mask and the A-mask system were comparable. 3D vector shifts of larger magnitude occurred more frequently for the R-mask than the A-mask. The setup uncertainties for each mask with the stereotactic localizing system had an asymmetric offset towards the positive AP direction. The A-mask-creation method, which is capable of covering the top of the patient's head, is superior to that for the R-mask, so the use of the A-mask is encouraged for SF-SRS to reduce the setup uncertainties. Moreover, careful mask-making is required to prevent possible setup uncertainties.

Influence of Temporal Expectations on Response Priming by Subliminal Faces

PubMed Central

Guex, Raphael; Vuilleumier, Patrik

2016-01-01

Unconscious processes are often assumed immune from attention influence. Recent behavioral studies suggest however that the processing of subliminal information can be influenced by temporal attention. To examine the neural mechanisms underlying these effects, we used a stringent masking paradigm together with fMRI to investigate how temporal attention modulates the processing of unseen (masked) faces. Participants performed a gender decision task on a visible neutral target face, preceded by a masked prime face that could vary in gender (same or different than target) and emotion expression (neutral or fearful). We manipulated temporal attention by instructing participants to expect targets to appear either early or late during the stimulus sequence. Orienting temporal attention to subliminal primes influenced response priming by masked faces, even when gender was incongruent. In addition, gender-congruent primes facilitated responses regardless of attention while gender-incongruent primes reduced accuracy when attended. Emotion produced no differential effects. At the neural level, incongruent and temporally unexpected primes increased brain response in regions of the fronto-parietal attention network, reflecting greater recruitment of executive control and reorienting processes. Congruent and expected primes produced higher activations in fusiform cortex, presumably reflecting facilitation of perceptual processing. These results indicate that temporal attention can influence subliminal processing of face features, and thus facilitate information integration according to task-relevance regardless of conscious awareness. They also suggest that task-congruent information between prime and target may facilitate response priming even when temporal attention is not selectively oriented to the prime onset time. PMID:27764124

Influence of Temporal Expectations on Response Priming by Subliminal Faces.

PubMed

Pichon, Swann; Guex, Raphael; Vuilleumier, Patrik

2016-01-01

Unconscious processes are often assumed immune from attention influence. Recent behavioral studies suggest however that the processing of subliminal information can be influenced by temporal attention. To examine the neural mechanisms underlying these effects, we used a stringent masking paradigm together with fMRI to investigate how temporal attention modulates the processing of unseen (masked) faces. Participants performed a gender decision task on a visible neutral target face, preceded by a masked prime face that could vary in gender (same or different than target) and emotion expression (neutral or fearful). We manipulated temporal attention by instructing participants to expect targets to appear either early or late during the stimulus sequence. Orienting temporal attention to subliminal primes influenced response priming by masked faces, even when gender was incongruent. In addition, gender-congruent primes facilitated responses regardless of attention while gender-incongruent primes reduced accuracy when attended. Emotion produced no differential effects. At the neural level, incongruent and temporally unexpected primes increased brain response in regions of the fronto-parietal attention network, reflecting greater recruitment of executive control and reorienting processes. Congruent and expected primes produced higher activations in fusiform cortex, presumably reflecting facilitation of perceptual processing. These results indicate that temporal attention can influence subliminal processing of face features, and thus facilitate information integration according to task-relevance regardless of conscious awareness. They also suggest that task-congruent information between prime and target may facilitate response priming even when temporal attention is not selectively oriented to the prime onset time.

How Orthography Modulates Morphological Priming: Subliminal Kanji Activation in Japanese.

PubMed

Nakano, Yoko; Ikemoto, Yu; Jacob, Gunnar; Clahsen, Harald

2016-01-01

The current study investigates to what extent masked morphological priming is modulated by language-particular properties, specifically by its writing system. We present results from two masked priming experiments investigating the processing of complex Japanese words written in less common (moraic) scripts. In Experiment 1, participants performed lexical decisions on target verbs; these were preceded by primes which were either (i) a past-tense form of the same verb, (ii) a stem-related form with the epenthetic vowel -i, (iii) a semantically-related form, and (iv) a phonologically-related form. Significant priming effects were obtained for prime types (i), (ii), and (iii), but not for (iv). This pattern of results differs from previous findings on languages with alphabetic scripts, which found reliable masked priming effects for morphologically related prime/target pairs of type (i), but not for non-affixal and semantically-related primes of types (ii), and (iii). In Experiment 2, we measured priming effects for prime/target pairs which are neither morphologically, semantically, phonologically nor - as presented in their moraic scripts-orthographically related, but which-in their commonly written form-share the same kanji, which are logograms adopted from Chinese. The results showed a significant priming effect, with faster lexical-decision times for kanji-related prime/target pairs relative to unrelated ones. We conclude that affix-stripping is insufficient to account for masked morphological priming effects across languages, but that language-particular properties (in the case of Japanese, the writing system) affect the processing of (morphologically) complex words.

How Orthography Modulates Morphological Priming: Subliminal Kanji Activation in Japanese

PubMed Central

Nakano, Yoko; Ikemoto, Yu; Jacob, Gunnar; Clahsen, Harald

2016-01-01

The current study investigates to what extent masked morphological priming is modulated by language-particular properties, specifically by its writing system. We present results from two masked priming experiments investigating the processing of complex Japanese words written in less common (moraic) scripts. In Experiment 1, participants performed lexical decisions on target verbs; these were preceded by primes which were either (i) a past-tense form of the same verb, (ii) a stem-related form with the epenthetic vowel -i, (iii) a semantically-related form, and (iv) a phonologically-related form. Significant priming effects were obtained for prime types (i), (ii), and (iii), but not for (iv). This pattern of results differs from previous findings on languages with alphabetic scripts, which found reliable masked priming effects for morphologically related prime/target pairs of type (i), but not for non-affixal and semantically-related primes of types (ii), and (iii). In Experiment 2, we measured priming effects for prime/target pairs which are neither morphologically, semantically, phonologically nor - as presented in their moraic scripts—orthographically related, but which—in their commonly written form—share the same kanji, which are logograms adopted from Chinese. The results showed a significant priming effect, with faster lexical-decision times for kanji-related prime/target pairs relative to unrelated ones. We conclude that affix-stripping is insufficient to account for masked morphological priming effects across languages, but that language-particular properties (in the case of Japanese, the writing system) affect the processing of (morphologically) complex words. PMID:27065895

Multi-atlas-based segmentation of the parotid glands of MR images in patients following head-and-neck cancer radiotherapy

NASA Astrophysics Data System (ADS)

Cheng, Guanghui; Yang, Xiaofeng; Wu, Ning; Xu, Zhijian; Zhao, Hongfu; Wang, Yuefeng; Liu, Tian

2013-02-01

Xerostomia (dry mouth), resulting from radiation damage to the parotid glands, is one of the most common and distressing side effects of head-and-neck cancer radiotherapy. Recent MRI studies have demonstrated that the volume reduction of parotid glands is an important indicator for radiation damage and xerostomia. In the clinic, parotid-volume evaluation is exclusively based on physicians' manual contours. However, manual contouring is time-consuming and prone to inter-observer and intra-observer variability. Here, we report a fully automated multi-atlas-based registration method for parotid-gland delineation in 3D head-and-neck MR images. The multi-atlas segmentation utilizes a hybrid deformable image registration to map the target subject to multiple patients' images, applies the transformation to the corresponding segmented parotid glands, and subsequently uses the multiple patient-specific pairs (head-and-neck MR image and transformed parotid-gland mask) to train support vector machine (SVM) to reach consensus to segment the parotid gland of the target subject. This segmentation algorithm was tested with head-and-neck MRIs of 5 patients following radiotherapy for the nasopharyngeal cancer. The average parotid-gland volume overlapped 85% between the automatic segmentations and the physicians' manual contours. In conclusion, we have demonstrated the feasibility of an automatic multi-atlas based segmentation algorithm to segment parotid glands in head-and-neck MR images.

Motion-Induced Blindness and Troxler Fading: Common and Different Mechanisms

PubMed Central

Bonneh, Yoram S.; Donner, Tobias H.; Cooperman, Alexander; Heeger, David J.; Sagi, Dov

2014-01-01

Extended stabilization of gaze leads to disappearance of dim visual targets presented peripherally. This phenomenon, known as Troxler fading, is thought to result from neuronal adaptation. Intense targets also disappear intermittently when surrounded by a moving pattern (the “mask”), a phenomenon known as motion-induced blindness (MIB). The similar phenomenology and dynamics of these disappearances may suggest that also MIB is, likewise, solely due to adaptation, which may be amplified by the presence of the mask. Here we directly compared the dependence of both phenomena on target contrast. Observers reported the disappearance and reappearance of a target of varying intensity (contrast levels: 8%–80%). MIB was induced by adding a mask that moved at one of various different speeds. The results revealed a lawful effect of contrast in both MIB and Troxler fading, but with opposite trends. Increasing target contrast increased (doubled) the rate of disappearance events for MIB, but decreased the disappearance rate to half in Troxler fading. The target mean invisible period decreased equally strongly with target contrast in MIB and in Troxler fading. The results suggest that both MIB and Troxler are equally affected by contrast adaptation, but that the rate of MIB is governed by an additional mechanism, possibly involving antagonistic processes between neuronal populations processing target and mask. Our results link MIB to other bi-stable visual phenomena that involve neuronal competition (such as binocular rivalry), which exhibit an analogous dependency on the strength of the competing stimulus components. PMID:24658600

Emotion potentiates response activation and inhibition in masked priming

PubMed Central

Bocanegra, Bruno R.; Zeelenberg, René

2012-01-01

Previous studies have shown that emotion can have 2-fold effects on perception. At the object-level, emotional stimuli benefit from a stimulus-specific boost in visual attention at the relative expense of competing stimuli. At the visual feature-level, recent findings indicate that emotion may inhibit the processing of small visual details and facilitate the processing of coarse visual features. In the present study, we investigated whether emotion can boost the activation and inhibition of automatic motor responses that are generated prior to overt perception. To investigate this, we tested whether an emotional cue affects covert motor responses in a masked priming task. We used a masked priming paradigm in which participants responded to target arrows that were preceded by invisible congruent or incongruent prime arrows. In the standard paradigm, participants react faster, and commit fewer errors responding to the directionality of target arrows, when they are preceded by congruent vs. incongruent masked prime arrows (positive congruency effect, PCE). However, as prime-target SOAs increase, this effect reverses (negative congruency effect, NCE). These findings have been explained as evidence for an initial activation and a subsequent inhibition of a partial response elicited by the masked prime arrow. Our results show that the presentation of fearful face cues, compared to neutral face cues, increased the size of both the PCE and NCE, despite the fact that the primes were invisible. This is the first demonstration that emotion prepares an individual's visuomotor system for automatic activation and inhibition of motor responses in the absence of visual awareness. PMID:23162447

Emotion potentiates response activation and inhibition in masked priming.

PubMed

Bocanegra, Bruno R; Zeelenberg, René

2012-01-01

Previous studies have shown that emotion can have 2-fold effects on perception. At the object-level, emotional stimuli benefit from a stimulus-specific boost in visual attention at the relative expense of competing stimuli. At the visual feature-level, recent findings indicate that emotion may inhibit the processing of small visual details and facilitate the processing of coarse visual features. In the present study, we investigated whether emotion can boost the activation and inhibition of automatic motor responses that are generated prior to overt perception. To investigate this, we tested whether an emotional cue affects covert motor responses in a masked priming task. We used a masked priming paradigm in which participants responded to target arrows that were preceded by invisible congruent or incongruent prime arrows. In the standard paradigm, participants react faster, and commit fewer errors responding to the directionality of target arrows, when they are preceded by congruent vs. incongruent masked prime arrows (positive congruency effect, PCE). However, as prime-target SOAs increase, this effect reverses (negative congruency effect, NCE). These findings have been explained as evidence for an initial activation and a subsequent inhibition of a partial response elicited by the masked prime arrow. Our results show that the presentation of fearful face cues, compared to neutral face cues, increased the size of both the PCE and NCE, despite the fact that the primes were invisible. This is the first demonstration that emotion prepares an individual's visuomotor system for automatic activation and inhibition of motor responses in the absence of visual awareness.

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm

NASA Astrophysics Data System (ADS)

Zhang, B.; Sang, Jun; Alam, Mohammad S.

2013-03-01

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm was proposed. Firstly, the original secret image was encrypted into two phase-only masks M1 and M2 via cascaded iterative Fourier transform (CIFT) algorithm. Then, the public-key encryption algorithm RSA was adopted to encrypt M2 into M2' . Finally, a host image was enlarged by extending one pixel into 2×2 pixels and each element in M1 and M2' was multiplied with a superimposition coefficient and added to or subtracted from two different elements in the 2×2 pixels of the enlarged host image. To recover the secret image from the stego-image, the two masks were extracted from the stego-image without the original host image. By applying public-key encryption algorithm, the key distribution was facilitated, and also compared with the image hiding method based on optical interference, the proposed method may reach higher robustness by employing the characteristics of the CIFT algorithm. Computer simulations show that this method has good robustness against image processing.

Bacterial cellulose skin masks-Properties and sensory tests.

PubMed

Pacheco, Guilherme; de Mello, Carolina Véspoli; Chiari-Andréo, Bruna Galdorfini; Isaac, Vera Lucia Borges; Ribeiro, Sidney José Lima; Pecoraro, Édison; Trovatti, Eliane

2017-09-29

Bacterial cellulose (BC) is a versatile material produced by microorganisms in the form of a membranous hydrogel, totally biocompatible, and endowed with high mechanical strength. Its high water-holding capacity based on its highly porous nanofibrillar structure allows BC to incorporate and to release substances very fast, thus being suitable for the preparation of skincare masks. The preparation and characterization of cosmetic masks based on BC membranes and active cosmetics. The masks were prepared by the simple incorporation of the cosmetic actives into BC membranes, used as a swelling matrix. The masks were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), sensory tests, and skin moisture tests on volunteers. The results of sensory tests revealed the good performance of BC, being considered effective by the panel of volunteers, specially for adhesion to the skin (7.7 at the score scale), and improvement of the skin moisture (the hydration effect increased 76% in 75% of the volunteers that used vegetable extract mask formulation [VEM]), or a decrease in skin hydration (80% of the volunteers showed 32.6% decrease on skin hydration using propolis extract formulation [PEM] treatment), indicating the BC nanofiber membranes can be used to skincare applications. The results demonstrate the BC can be used as an alternative support for cosmetic actives for skin treatment. © 2017 Wiley Periodicals, Inc.

The influence of informational masking in reverberant, multi-talker environments.

PubMed

Westermann, Adam; Buchholz, Jörg M

2015-08-01

The relevance of informational masking (IM) in real-world listening is not well understood. In literature, IM effects of up to 10 dB in measured speech reception thresholds (SRTs) are reported. However, these experiments typically employed simplified spatial configurations and speech corpora that magnified confusions. In this study, SRTs were measured with normal hearing subjects in a simulated cafeteria environment. The environment was reproduced by a 41-channel 3D-loudspeaker array. The target talker was 2 m in front of the listener and masking talkers were either spread throughout the room or colocated with the target. Three types of maskers were realized: one with the same talker as the target (maximum IM), one with talkers different from the target, and one with unintelligible, noise-vocoded talkers (minimal IM). Overall, SRTs improved for the spatially distributed conditions compared to the colocated conditions. Within the spatially distributed conditions, there was no significant difference between thresholds with the different- and vocoded-talker maskers. Conditions with the same-talker masker were the only conditions with substantially higher thresholds, especially in the colocated conditions. These results suggest that IM related to target-masker confusions, at least for normal-hearing listeners, is of low relevance in real-life listening.

When orthographic neighbors fail to facilitate.

PubMed

Janack, Tracy; Pastizzo, Matthew J; Beth Feldman, Laurie

2004-01-01

Forward masked word primes that differed from the target in the initial, the final or both the initial and final positions tended to slow target decision latencies and there were no significant differences among prime types. After forward masked nonword primes we observed non significant facilitation when primes differed from the target by one letter in either the initial or final position and significant inhibition when primes differed in both initial and final positions. The patterns did not differ significantly for targets with large and with small neighborhoods. Only in post hoc analyses was there any indication of facilitation after nonword neighbor primes and it appeared only when body neighborhood was small. For slower participants, neighbors tended to facilitate target decision latencies while for relatively fast readers showed neighbors made inhibition that tended to vary with amount of mismatch.

Numerical Generation of Double Star Images for Different Types of Telescopes

NASA Astrophysics Data System (ADS)

Xavier, Ademir

2015-11-01

This paper reviews the modeling of stellar images using diffraction theory applied to different types of telescope masks. The masks are projected by secondary mirror holder vanes (such as the spider type) or holes on the primary mirror which result in different configurations of single stellar images. Using Fast Fourier Transform, the image of binary stars with different magnitudes is calculated. Given the numerical results obtained, a discussion is presented on the best secondary vane configurations and on the effect of obstruction types for the separation of binary pairs with different magnitudes.

Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind braille readers.

PubMed

Bhattacharjee, Arindam; Ye, Amanda J; Lisak, Joy A; Vargas, Maria G; Goldreich, Daniel

2010-10-27

Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at ∼100 ms intervals, and adjacent raised dots within a character at 50 ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25 ms target tap) and amplitude discrimination (compared with 100 μm reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker, 50 Hz, 50 μm; target-masker delays, ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged but that perceptual processing is accelerated in congenitally blind Braille readers.

Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind Braille readers

PubMed Central

Bhattacharjee, Arindam; Ye, Amanda J.; Lisak, Joy A.; Vargas, Maria G.; Goldreich, Daniel

2010-01-01

Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at about 100-ms intervals, and adjacent raised dots within a character at 50-ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25-ms target tap) and amplitude discrimination (compared to 100-micron reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker: 50-Hz, 50-micron; target-masker delays ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged, but that perceptual processing is accelerated in congenitally blind Braille readers. PMID:20980584

Leading, but not trailing, primes influence temporal order perception: further evidence for an attentional account of perceptual latency priming.

PubMed

Scharlau, Ingrid

2002-11-01

Presenting a masked prime leading a target influences the perceived onset of the masking target (perceptual latency priming; Scharlau & Neumann, in press). This priming effect is explained by the asynchronous updating model (Neumann, 1982; Scharlau & Neumann, in press): The prime initiates attentional allocation toward its location, which renders a trailing target at the same place consciously available earlier. In three experiments, this perceptual latency priming by leading primes was examined jointly with the effects of trailing primes in order to compare the explanation of the asynchronous updating model with the onset-averaging and the P-center hypotheses. Experiment 1 showed that an attended, as well as an unattended, prime leads to perceptual latency priming. In addition, a large effect of trailing primes on the onset of a target was found. As Experiment 2 demonstrated, this effect is quite robust, although smaller than that of a leading prime. In Experiment 3, masked primes were used. Under these conditions, no influence of trailing primes could be found, whereas perceptual latency priming persisted. Thus, a nonattentional explanation for the effect of trailing primes seems likely.

Congruence Effect in Semantic Categorization with Masked Primes with Narrow and Broad Categories

ERIC Educational Resources Information Center

Quinn, Wendy Maree; Kinoshita, Sachiko

2008-01-01

In semantic categorization, masked primes that are category-congruent with the target (e.g., "Planets: mars-VENUS") facilitate responses relative to category-incongruent primes (e.g., "tree-VENUS"). The present study investigated why this category congruence effect is more consistently found with narrow categories (e.g., "Numbers larger/smaller…

Rapid modelling of the redshift-space power spectrum multipoles for a masked density field

NASA Astrophysics Data System (ADS)

Wilson, M. J.; Peacock, J. A.; Taylor, A. N.; de la Torre, S.

2017-01-01

In this work, we reformulate the forward modelling of the redshift-space power spectrum multipole moments for a masked density field, as encountered in galaxy redshift surveys. Exploiting the symmetries of the redshift-space correlation function, we provide a masked-field generalization of the Hankel transform relation between the multipole moments in real and Fourier space. Using this result, we detail how a likelihood analysis requiring computation for a broad range of desired P(k) models may be executed 103-104 times faster than with other common approaches, together with significant gains in spectral resolution. We present a concrete application to the complex angular geometry of the VIMOS Public Extragalactic Redshift Survey PDR-1 release and discuss the validity of this technique for finite-angle surveys.

Coherent optical processing using noncoherent light after source masking.

PubMed

Boopathi, V; Vasu, R M

1992-01-10

Coherent optical processing starting with spatially noncoherent illumination is described. Good spatial coherence is introduced in the far field by modulating a noncoherent source when masks with sharp autocorrelation are used. The far-field mutual coherence function of light is measured and it is seen that, for the masks and the source size used here, we get a fairly large area over which the mutual coherence function is high and flat. We demonstrate traditional coherent processing operations such as Fourier transformation and image deblurring when coherent light that is produced in the above fashion is used. A coherence-redundancy merit function is defined for this type of processing system. It is experimentally demonstrated that the processing system introduced here has superior blemish tolerance compared with a traditional processor that uses coherent illumination.

Robust watermark technique using masking and Hermite transform.

PubMed

Coronel, Sandra L Gomez; Ramírez, Boris Escalante; Mosqueda, Marco A Acevedo

2016-01-01

The following paper evaluates a watermark algorithm designed for digital images by using a perceptive mask and a normalization process, thus preventing human eye detection, as well as ensuring its robustness against common processing and geometric attacks. The Hermite transform is employed because it allows a perfect reconstruction of the image, while incorporating human visual system properties; moreover, it is based on the Gaussian functions derivates. The applied watermark represents information of the digital image proprietor. The extraction process is blind, because it does not require the original image. The following techniques were utilized in the evaluation of the algorithm: peak signal-to-noise ratio, the structural similarity index average, the normalized crossed correlation, and bit error rate. Several watermark extraction tests were performed, with against geometric and common processing attacks. It allowed us to identify how many bits in the watermark can be modified for its adequate extraction.

Optical image encryption using fresnel zone plate mask based on fast walsh hadamard transform

NASA Astrophysics Data System (ADS)

Khurana, Mehak; Singh, Hukum

2018-05-01

A new symmetric encryption technique using Fresnel Zone Plate (FZP) based on Fast Walsh Hadamard Transform (FWHT) is proposed for security enhancement. In this technique, bits of plain image is randomized by shuffling the bits randomly. The obtained scrambled image is then masked with FZP using symmetric encryption in FWHT domain to obtain final encrypted image. FWHT has been used in the cryptosystem so as to protect image data from the quantization error and for reconstructing the image perfectly. The FZP used in proposed scheme increases the key space and makes it robust to many traditional attacks. The effectiveness and robustness of the proposed cryptosystem has been analyzed on the basis of various parameters by simulating on MATLAB 8.1.0 (R2012b). The experimental results are provided to highlight suitability of the proposed cryptosystem and prove that the system is secure.

Flat-Sky Pseudo-Cls Analysis for Weak Gravitational Lensing

NASA Astrophysics Data System (ADS)

Asgari, Marika; Taylor, Andy; Joachimi, Benjamin; Kitching, Thomas D.

2018-05-01

We investigate the use of estimators of weak lensing power spectra based on a flat-sky implementation of the 'Pseudo-CI' (PCl) technique, where the masked shear field is transformed without regard for masked regions of sky. This masking mixes power, and 'E'-convergence and 'B'-modes. To study the accuracy of forward-modelling and full-sky power spectrum recovery we consider both large-area survey geometries, and small-scale masking due to stars and a checkerboard model for field-of-view gaps. The power spectrum for the large-area survey geometry is sparsely-sampled and highly oscillatory, which makes modelling problematic. Instead, we derive an overall calibration for large-area mask bias using simulated fields. The effects of small-area star masks can be accurately corrected for, while the checkerboard mask has oscillatory and spiky behaviour which leads to percent biases. Apodisation of the masked fields leads to increased biases and a loss of information. We find that we can construct an unbiased forward-model of the raw PCls, and recover the full-sky convergence power to within a few percent accuracy for both Gaussian and lognormal-distributed shear fields. Propagating this through to cosmological parameters using a Fisher-Matrix formalism, we find we can make unbiased estimates of parameters for surveys up to 1,200 deg2 with 30 galaxies per arcmin2, beyond which the percent biases become larger than the statistical accuracy. This implies a flat-sky PCl analysis is accurate for current surveys but a Euclid-like survey will require higher accuracy.

Joint High-Order Synchrosqueezing Transform and Multi-Taper Empirical Wavelet Transform for Fault Diagnosis of Wind Turbine Planetary Gearbox under Nonstationary Conditions.

PubMed

Hu, Yue; Tu, Xiaotong; Li, Fucai; Meng, Guang

2018-01-07

Wind turbines usually operate under nonstationary conditions, such as wide-range speed fluctuation and time-varying load. Its critical component, the planetary gearbox, is prone to malfunction or failure, which leads to downtime and repair costs. Therefore, fault diagnosis and condition monitoring for the planetary gearbox in wind turbines is a vital research topic. Meanwhile, the signals measured by the vibration sensors mounted in the gearbox exhibit time-varying and nonstationary features. In this study, a novel time-frequency method based on high-order synchrosqueezing transform (SST) and multi-taper empirical wavelet transform (MTEWT) is proposed for the wind turbine planetary gearbox under nonstationary conditions. The high-order SST uses accurate instantaneous frequency approximations to obtain a sharper time-frequency representation (TFR). As the acquired signal consists of many components, like the meshing and rotating components of the gear and bearing, the fault component may be masked by other unrelated components. The MTEWT is used to separate the fault feature from the masking components. A variety of experimental signals of the wind turbine planetary gearbox under nonstationary conditions have been analyzed to demonstrate the effectiveness and robustness of the proposed method. Results show that the proposed method is effective in diagnosing both gear and bearing faults.

Joint High-Order Synchrosqueezing Transform and Multi-Taper Empirical Wavelet Transform for Fault Diagnosis of Wind Turbine Planetary Gearbox under Nonstationary Conditions

PubMed Central

Li, Fucai; Meng, Guang

2018-01-01

Wind turbines usually operate under nonstationary conditions, such as wide-range speed fluctuation and time-varying load. Its critical component, the planetary gearbox, is prone to malfunction or failure, which leads to downtime and repair costs. Therefore, fault diagnosis and condition monitoring for the planetary gearbox in wind turbines is a vital research topic. Meanwhile, the signals measured by the vibration sensors mounted in the gearbox exhibit time-varying and nonstationary features. In this study, a novel time-frequency method based on high-order synchrosqueezing transform (SST) and multi-taper empirical wavelet transform (MTEWT) is proposed for the wind turbine planetary gearbox under nonstationary conditions. The high-order SST uses accurate instantaneous frequency approximations to obtain a sharper time-frequency representation (TFR). As the acquired signal consists of many components, like the meshing and rotating components of the gear and bearing, the fault component may be masked by other unrelated components. The MTEWT is used to separate the fault feature from the masking components. A variety of experimental signals of the wind turbine planetary gearbox under nonstationary conditions have been analyzed to demonstrate the effectiveness and robustness of the proposed method. Results show that the proposed method is effective in diagnosing both gear and bearing faults. PMID:29316668

Mechanical microencapsulation: The best technique in taste masking for the manufacturing scale - Effect of polymer encapsulation on drug targeting.

PubMed

Al-Kasmi, Basheer; Alsirawan, Mhd Bashir; Bashimam, Mais; El-Zein, Hind

2017-08-28

Drug taste masking is a crucial process for the preparation of pediatric and geriatric formulations as well as fast dissolving tablets. Taste masking techniques aim to prevent drug release in saliva and at the same time to obtain the desired release profile in gastrointestinal tract. Several taste masking methods are reported, however this review has focused on a group of promising methods; complexation, encapsulation, and hot melting. The effects of each method on the physicochemical properties of the drug are described in details. Furthermore, a scoring system was established to evaluate each process using recent published data of selected factors. These include, input, process, and output factors that are related to each taste masking method. Input factors include the attributes of the materials used for taste masking. Process factors include equipment type and process parameters. Finally, output factors, include taste masking quality and yield. As a result, Mechanical microencapsulation obtained the highest score (5/8) along with complexation with cyclodextrin suggesting that these methods are the most preferable for drug taste masking. Copyright © 2017 Elsevier B.V. All rights reserved.

A new approach in dry technology for non-degrading optical and EUV mask cleaning

NASA Astrophysics Data System (ADS)

Varghese, Ivin; Smith, Ben; Balooch, Mehdi; Bowers, Chuck

2012-11-01

The Eco-Snow Systems group of RAVE N.P., Inc. has developed a new cleaning technique to target several of the advanced and next generation mask clean challenges. This new technique, especially when combined with Eco-Snow Systems cryogenic CO2 cleaning technology, provides several advantages over existing methods because it: 1) is solely based on dry technique without requiring additional complementary aggressive wet chemistries that degrade the mask, 2) operates at atmospheric pressure and therefore avoids expensive and complicated equipment associated with vacuum systems, 3) generates ultra-clean reactants eliminating possible byproduct adders, 4) can be applied locally for site specific cleaning without exposing the rest of the mask or can be used to clean the entire mask, 5) removes organic as well as inorganic particulates and film contaminations, and 6) complements current techniques utilized for cleaning of advanced masks such as reduced chemistry wet cleans. In this paper, we shall present examples demonstrating the capability of this new technique for removal of pellicle glue residues and for critical removal of carbon contamination on EUV masks.

Perceptual learning for speech in noise after application of binary time-frequency masks

PubMed Central

Ahmadi, Mahnaz; Gross, Vauna L.; Sinex, Donal G.

2013-01-01

Ideal time-frequency (TF) masks can reject noise and improve the recognition of speech-noise mixtures. An ideal TF mask is constructed with prior knowledge of the target speech signal. The intelligibility of a processed speech-noise mixture depends upon the threshold criterion used to define the TF mask. The study reported here assessed the effect of training on the recognition of speech in noise after processing by ideal TF masks that did not restore perfect speech intelligibility. Two groups of listeners with normal hearing listened to speech-noise mixtures processed by TF masks calculated with different threshold criteria. For each group, a threshold criterion that initially produced word recognition scores between 0.56–0.69 was chosen for training. Listeners practiced with one set of TF-masked sentences until their word recognition performance approached asymptote. Perceptual learning was quantified by comparing word-recognition scores in the first and last training sessions. Word recognition scores improved with practice for all listeners with the greatest improvement observed for the same materials used in training. PMID:23464038

Fourier-transform and global contrast interferometer alignment methods

DOEpatents

Goldberg, Kenneth A.

2001-01-01

Interferometric methods are presented to facilitate alignment of image-plane components within an interferometer and for the magnified viewing of interferometer masks in situ. Fourier-transforms are performed on intensity patterns that are detected with the interferometer and are used to calculate pseudo-images of the electric field in the image plane of the test optic where the critical alignment of various components is being performed. Fine alignment is aided by the introduction and optimization of a global contrast parameter that is easily calculated from the Fourier-transform.

Masked mycotoxins: A review

PubMed Central

Berthiller, Franz; Crews, Colin; Dall'Asta, Chiara; Saeger, Sarah De; Haesaert, Geert; Karlovsky, Petr; Oswald, Isabelle P; Seefelder, Walburga; Speijers, Gerrit; Stroka, Joerg

2013-01-01

The aim of this review is to give a comprehensive overview of the current knowledge on plant metabolites of mycotoxins, also called masked mycotoxins. Mycotoxins are secondary fungal metabolites, toxic to human and animals. Toxigenic fungi often grow on edible plants, thus contaminating food and feed. Plants, as living organisms, can alter the chemical structure of mycotoxins as part of their defence against xenobiotics. The extractable conjugated or non-extractable bound mycotoxins formed remain present in the plant tissue but are currently neither routinely screened for in food nor regulated by legislation, thus they may be considered masked. Fusarium mycotoxins (deoxynivalenol, zearalenone, fumonisins, nivalenol, fusarenon-X, T-2 toxin, HT-2 toxin, fusaric acid) are prone to metabolisation or binding by plants, but transformation of other mycotoxins by plants (ochratoxin A, patulin, destruxins) has also been described. Toxicological data are scarce, but several studies highlight the potential threat to consumer safety from these substances. In particular, the possible hydrolysis of masked mycotoxins back to their toxic parents during mammalian digestion raises concerns. Dedicated chapters of this article address plant metabolism as well as the occurrence of masked mycotoxins in food, analytical aspects for their determination, toxicology and their impact on stakeholders. PMID:23047235

Odours reduce the magnitude of object substitution masking for matching visual targets in females.

PubMed

Robinson, Amanda K; Laning, Julia; Reinhard, Judith; Mattingley, Jason B

2016-08-01

Recent evidence suggests that olfactory stimuli can influence early stages of visual processing, but there has been little focus on whether such olfactory-visual interactions convey an advantage in visual object identification. Moreover, despite evidence that some aspects of olfactory perception are superior in females than males, no study to date has examined whether olfactory influences on vision are gender-dependent. We asked whether inhalation of familiar odorants can modulate participants' ability to identify briefly flashed images of matching visual objects under conditions of object substitution masking (OSM). Across two experiments, we had male and female participants (N = 36 in each group) identify masked visual images of odour-related objects (e.g., orange, rose, mint) amongst nonodour-related distracters (e.g., box, watch). In each trial, participants inhaled a single odour that either matched or mismatched the masked, odour-related target. Target detection performance was analysed using a signal detection (d') approach. In females, but not males, matching odours significantly reduced OSM relative to mismatching odours, suggesting that familiar odours can enhance the salience of briefly presented visual objects. We conclude that olfactory cues exert a subtle influence on visual processes by transiently enhancing the salience of matching object representations. The results add to a growing body of literature that points towards consistent gender differences in olfactory perception.

A subliminal inhibitory mechanism for the negative compatibility effect: a continuous versus threshold mechanism.

PubMed

Liu, Peng; Chen, Xuhai; Dai, Dongyang; Wang, Yongchun; Wang, Yonghui

2014-07-01

The current study investigated the mechanism underlying subliminal inhibition using the negative compatibility effect (NCE) paradigm. We hypothesized that a decrease in prime activation affects the subsequent inhibitory process, delaying onset of inhibition and reducing its strength. Two experiments tested this hypothesis using arrow stimuli as primes and targets. Two different irrelevant masks (i.e., a mask sharing no prime features) were presented in succession in each trial to not only ensure that primes were processed subliminally, but also avoid feature updating between primes and masks. Prime/target compatibility and prime background density were manipulated in Experiment 1. Results showed that under subliminal inhibitory condition, the NCE disappears when the density increases (i.e., pixel density in the prime's background of 25 %) in Experiment 1. However, when we fixed the prime's background at the density of 25 % and manipulated prime/target compatibility as well as inter-stimuli-interval (ISI) between mask and target in Experiment 2, behavioral results showed marginally significant NCEs in the 150-ms ISI condition. Electrophysiological evidence showed the lateralized readiness potential for compatible trials was significantly more positive than that for incompatible trials during the two consecutive time windows (i.e., 400-450 and 450-500 ms) in the 150-ms ISI condition. In addition, the NCE size was significant smaller in Experiment 2 than in Experiment 1. All of the results support predictions of the continuous subliminal inhibitory mechanism hypothesis which posits that decreases in prime activation strength lead to delay in inhibitory onset and decline in inhibitory strength.

Progress on EUV mask fabrication for 32-nm technology node and beyond

NASA Astrophysics Data System (ADS)

Zhang, Guojing; Yan, Pei-Yang; Liang, Ted; Park, Seh-jin; Sanchez, Peter; Shu, Emily Y.; Ultanir, Erdem A.; Henrichs, Sven; Stivers, Alan; Vandentop, Gilroy; Lieberman, Barry; Qu, Ping

2007-05-01

Extreme ultraviolet lithography (EUVL) tool development achieved a big milestone last year as two full-field Alpha Demo Tools (ADT) were shipped to customers by ASML. In the future horizon, a full field "EUV1" exposure tool from Nikon will be available by the end of 20071 and the pre-production EUV exposure tools from ASML are targeted for 20092. It is essential that high quality EUVL masks can be made and delivered to the EUVL tool users to support the technology development. In the past year, we have demonstrated mask fabrication with low stress absorber deposition and good etch process control yielding a vertical etch profile and a mask CD control of 5.7 nm for 32 nm (1x) space and 7.4 nm for 32 nm (1x) lines. Mask pattern resolution of 15 nm (1x) dense lines was achieved. Full field reflective mask die-to-die inspection at a 125nm pixel size was demonstrated after low defect multilayer blanks became available. In this paper, we will present details of the Intel EUVL Mask Pilot Line progress in EUVL mask defect reduction, pattern CD performance, program defect mask design and inspection, in-house absorber film development and its performance, and EUVL metrology tool development. We will demonstrate an overall improvement in EUV mask manufacturing readiness due to our Pilot Line activities.

Task-Dependent Masked Priming Effects in Visual Word Recognition

PubMed Central

Kinoshita, Sachiko; Norris, Dennis

2012-01-01

A method used widely to study the first 250 ms of visual word recognition is masked priming: These studies have yielded a rich set of data concerning the processes involved in recognizing letters and words. In these studies, there is an implicit assumption that the early processes in word recognition tapped by masked priming are automatic, and masked priming effects should therefore be invariant across tasks. Contrary to this assumption, masked priming effects are modulated by the task goal: For example, only word targets show priming in the lexical decision task, but both words and non-words do in the same-different task; semantic priming effects are generally weak in the lexical decision task but are robust in the semantic categorization task. We explain how such task dependence arises within the Bayesian Reader account of masked priming (Norris and Kinoshita, 2008), and how the task dissociations can be used to understand the early processes in lexical access. PMID:22675316

Simulation-based MDP verification for leading-edge masks

NASA Astrophysics Data System (ADS)

Su, Bo; Syrel, Oleg; Pomerantsev, Michael; Hagiwara, Kazuyuki; Pearman, Ryan; Pang, Leo; Fujimara, Aki

2017-07-01

For IC design starts below the 20nm technology node, the assist features on photomasks shrink well below 60nm and the printed patterns of those features on masks written by VSB eBeam writers start to show a large deviation from the mask designs. Traditional geometry-based fracturing starts to show large errors for those small features. As a result, other mask data preparation (MDP) methods have become available and adopted, such as rule-based Mask Process Correction (MPC), model-based MPC and eventually model-based MDP. The new MDP methods may place shot edges slightly differently from target to compensate for mask process effects, so that the final patterns on a mask are much closer to the design (which can be viewed as the ideal mask), especially for those assist features. Such an alteration generally produces better masks that are closer to the intended mask design. Traditional XOR-based MDP verification cannot detect problems caused by eBeam effects. Much like model-based OPC verification which became a necessity for OPC a decade ago, we see the same trend in MDP today. Simulation-based MDP verification solution requires a GPU-accelerated computational geometry engine with simulation capabilities. To have a meaningful simulation-based mask check, a good mask process model is needed. The TrueModel® system is a field tested physical mask model developed by D2S. The GPU-accelerated D2S Computational Design Platform (CDP) is used to run simulation-based mask check, as well as model-based MDP. In addition to simulation-based checks such as mask EPE or dose margin, geometry-based rules are also available to detect quality issues such as slivers or CD splits. Dose margin related hotspots can also be detected by setting a correct detection threshold. In this paper, we will demonstrate GPU-acceleration for geometry processing, and give examples of mask check results and performance data. GPU-acceleration is necessary to make simulation-based mask MDP verification acceptable.

Consonant identification in noise using Hilbert-transform temporal fine-structure speech and recovered-envelope speech for listeners with normal and impaired hearinga)

PubMed Central

Léger, Agnès C.; Reed, Charlotte M.; Desloge, Joseph G.; Swaminathan, Jayaganesh; Braida, Louis D.

2015-01-01

Consonant-identification ability was examined in normal-hearing (NH) and hearing-impaired (HI) listeners in the presence of steady-state and 10-Hz square-wave interrupted speech-shaped noise. The Hilbert transform was used to process speech stimuli (16 consonants in a-C-a syllables) to present envelope cues, temporal fine-structure (TFS) cues, or envelope cues recovered from TFS speech. The performance of the HI listeners was inferior to that of the NH listeners both in terms of lower levels of performance in the baseline condition and in the need for higher signal-to-noise ratio to yield a given level of performance. For NH listeners, scores were higher in interrupted noise than in steady-state noise for all speech types (indicating substantial masking release). For HI listeners, masking release was typically observed for TFS and recovered-envelope speech but not for unprocessed and envelope speech. For both groups of listeners, TFS and recovered-envelope speech yielded similar levels of performance and consonant confusion patterns. The masking release observed for TFS and recovered-envelope speech may be related to level effects associated with the manner in which the TFS processing interacts with the interrupted noise signal, rather than to the contributions of TFS cues per se. PMID:26233038

Incidental Learning of S-R Contingencies in the Masked Prime Task

ERIC Educational Resources Information Center

Schlaghecken, Friederike; Blagrove, Elisabeth; Maylor, Elizabeth A.

2007-01-01

Subliminal motor priming effects in the masked prime paradigm can only be obtained when primes are part of the task set. In 2 experiments, the authors investigated whether the relevant task set feature needs to be explicitly instructed or could be extracted automatically in an incidental learning paradigm. Primes and targets were symmetrical…

A Novel Strategy for Bitter Taste Masking of Gankeshuangqing Dispersible Tablets Based on Particle Coating Technology.

PubMed

Han, Xue; Zhang, Ding-Kun; Zhang, Fang; Lin, Jun-Zhi; Jiang, Hong; Lan, Yang; Xiong, Xi; Han, Li; Yang, Ming; Fu, Chao-Mei

2017-01-01

Currently, acute upper respiratory tract infections (AURTIs) are increasingly becoming a significant health burden. Gankeshuangqing dispersible tablets (GKSQDT) which have a good effect on treating AURTIs. GKSQDT is composed of baicalin and andrographolide. However, its severe bitterness limits application of patients. Due to the addition of plentiful accessories, common masking methods are unsuitable for GKSQDT. It is thus necessary to develop a new masking method. The Previous study showed that baicalin was less bitter than andrographolide. Thus, particle coating technology was adapted to prepare composite particles that baicalin coated on the surface of andrographolide to decrease bitterness. Initially, particle size of baicalin and coating time of composite was investigated to prepare composite. Then, scanning electron microscopy, wettability, and infrared (IR) spectrogram were used to characterize the microstructure of composite. Furthermore, electronic tongue test, animal preference experiment, and human sensory test were applied to evaluate the masking effect. To produce composite, baicalin should be ground in vibromill for 6 min. Then, andrographolide fine powder was added to grind together for 6 min. Contact angle of composite was smaller than mixture, and more similar to baicalin. Other physical characterization including microstructure, wettability, and IR also suggested that andrographolide was successfully coated by baicalin superfine. Furthermore, taste-masking test indicated taste-masked tablets was less bitter than original tablets. The study indicated that particle coating technology can be used for taste masking of GKSQDT without adding other substance. Moreover, it provides a new strategy of taste masking for national medicine. A new strategy to mask bitterness without adding any other substance based on coating technology was providedThe masking effect was confirmed by electronic tongue test, animal preference experiment and human sensory test. Abbreviations used: AURTIs: Acute Upper Respiratory Tract Infections; GSQDT: Gankeshuangqing Dispersible Tablets; IR: Infrared Spectrogram; LHPC: Low-substituted Hydroxypropyl Cellulose; CAs: Contact Angles; FTIR: Fourier Transform Infrared Spectra.

Mask roughness induced LER: a rule of thumb -- paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

McClinton, Brittany; Naulleau, Patrick

2010-03-12

Much work has already been done on how both the resist and line-edge roughness (LER) on the mask affect the final printed LER. What is poorly understood, however, is the extent to which system-level effects such as mask surface roughness, illumination conditions, and defocus couple to speckle at the image plane, and currently factor into LER limits. Here, we propose a 'rule-of-thumb' simplified solution that provides a fast and powerful method to obtain mask roughness induced LER. We present modeling data on an older generation mask with a roughness of 230 pm as well as the ultimate target roughness ofmore » 50 pm. Moreover, we consider feature sizes of 50 nm and 22 nm, and show that as a function of correlation length, the LER peaks at the condition that the correlation length is approximately equal to the resolution of the imaging optic.« less

Preserved subliminal processing and impaired conscious access in schizophrenia

PubMed Central

Del Cul, Antoine; Dehaene, Stanislas; Leboyer, Marion

2006-01-01

Background Studies of visual backward masking have frequently revealed an elevated masking threshold in schizophrenia. This finding has frequently been interpreted as indicating a low-level visual deficit. However, more recent models suggest that masking may also involve late and higher-level integrative processes, while leaving intact early “bottom-up” visual processing. Objectives We tested the hypothesis that the backward masking deficit in schizophrenia corresponds to a deficit in the late stages of conscious perception, whereas the subliminal processing of masked stimuli is fully preserved. Method 28 patients with schizophrenia and 28 normal controls performed two backward-masking experiments. We used Arabic digits as stimuli and varied quasi-continuously the interval with a subsequent mask, thus allowing us to progressively “unmask” the stimuli. We finely quantified their degree of visibility using both objective and subjective measures to evaluate the threshold duration for access to consciousness. We also studied the priming effect caused by the variably masked numbers on a comparison task performed on a subsequently presented and highly visible target number. Results The threshold delay between digit and mask necessary for the conscious perception of the masked stimulus was longer in patients compared to control subjects. This higher consciousness threshold in patients was confirmed by an objective and a subjective measure, and both measures were highly correlated for patients as well as for controls. However, subliminal priming of masked numbers was effective and identical in patients compared to controls. Conclusions Access to conscious report of masked stimuli is impaired in schizophrenia, while fast bottom-up processing of the same stimuli, as assessed by subliminal priming, is preserved. These findings suggest a high-level origin of the masking deficit in schizophrenia, although they leave open for further research its exact relation to previously identified bottom-up visual processing abnormalities. PMID:17146006

The semantic origin of unconscious priming: Behavioral and event-related potential evidence during category congruency priming from strongly and weakly related masked words.

PubMed

Ortells, Juan J; Kiefer, Markus; Castillo, Alejandro; Megías, Montserrat; Morillas, Alejandro

2016-01-01

The mechanisms underlying masked congruency priming, semantic mechanisms such as semantic activation or non-semantic mechanisms, for example response activation, remain a matter of debate. In order to decide between these alternatives, reaction times (RTs) and event-related potentials (ERPs) were recorded in the present study, while participants performed a semantic categorization task on visible word targets that were preceded either 167 ms (Experiment 1) or 34 ms before (Experiment 2) by briefly presented (33 ms) novel (unpracticed) masked prime words. The primes and targets belonged to different categories (unrelated), or they were either strongly or weakly semantically related category co-exemplars. Behavioral (RT) and electrophysiological masked congruency priming effects were significantly greater for strongly related pairs than for weakly related pairs, indicating a semantic origin of effects. Priming in the latter condition was not statistically reliable. Furthermore, priming effects modulated the N400 event-related potential (ERP) component, an electrophysiological index of semantic processing, but not ERPs in the time range of the N200 component, associated with response conflict and visuo-motor response priming. The present results demonstrate that masked congruency priming from novel prime words also depends on semantic processing of the primes and is not exclusively driven by non-semantic mechanisms such as response activation. Copyright © 2015 Elsevier B.V. All rights reserved.

Design of wavefront coding optical system with annular aperture

NASA Astrophysics Data System (ADS)

Chen, Xinhua; Zhou, Jiankang; Shen, Weimin

2016-10-01

Wavefront coding can extend the depth of field of traditional optical system by inserting a phase mask into the pupil plane. In this paper, the point spread function (PSF) of wavefront coding system with annular aperture are analyzed. Stationary phase method and fast Fourier transform (FFT) method are used to compute the diffraction integral respectively. The OTF invariance is analyzed for the annular aperture with cubic phase mask under different obscuration ratio. With these analysis results, a wavefront coding system using Maksutov-Cassegrain configuration is designed finally. It is an F/8.21 catadioptric system with annular aperture, and its focal length is 821mm. The strength of the cubic phase mask is optimized with user-defined operand in Zemax. The Wiener filtering algorithm is used to restore the images and the numerical simulation proves the validity of the design.

Optimized phase mask to realize retro-reflection reduction for optical systems

NASA Astrophysics Data System (ADS)

He, Sifeng; Gong, Mali

2017-10-01

Aiming at the threats to the active laser detection systems of electro-optical devices due to the cat-eye effect, a novel solution is put forward to realize retro-reflection reduction in this paper. According to the demands of both cat-eye effect reduction and the image quality maintenance of electro-optical devices, a symmetric phase mask is achieved from a stationary phase method and a fast Fourier transform algorithm. Then, based on a comparison of peak normalized cross-correlation (PNCC) between the different defocus parameters, the optimal imaging position can be obtained. After modification with the designed phase mask, the cat-eye effect peak intensity can be reduced by two orders of magnitude while maintaining good image quality and high modulation transfer function (MTF). Furthermore, a practical design example is introduced to demonstrate the feasibility of our proposed approach.

Software on diffractive optics and computer-generated holograms

NASA Astrophysics Data System (ADS)

Doskolovich, Leonid L.; Golub, Michael A.; Kazanskiy, Nikolay L.; Khramov, Alexander G.; Pavelyev, Vladimir S.; Seraphimovich, P. G.; Soifer, Victor A.; Volotovskiy, S. G.

1995-01-01

The `Quick-DOE' software for an IBM PC-compatible computer is aimed at calculating the masks of diffractive optical elements (DOEs) and computer generated holograms, computer simulation of DOEs, and for executing a number of auxiliary functions. In particular, among the auxiliary functions are the file format conversions, mask visualization on display from a file, implementation of fast Fourier transforms, and arranging and preparation of composite images for the output on a photoplotter. The software is aimed for use by opticians, DOE designers, and the programmers dealing with the development of the program for DOE computation.

SeaWiFS technical report series. Volume 31: Stray light in the SeaWiFS radiometer

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Acker, James G. (Editor); Barnes, Robert A.; Holmes, Alan W.; Esaias, Wayne E.

1995-01-01

Some of the measurements from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) will not be useful as ocean measurements. For the ocean data set, there are procedures in place to mask the SeaWiFS measurements of clouds and ice. Land measurements will also be masked using a geographic technique based on each measurment's latitude and longitude. Each of these masks involves a source of light much brighter than the ocean. Because of stray light in the SeaWiFS radiometer, light from these bright sources can contaminate ocean measurements located a variable number of pixels away from a bright source. In this document, the sources of stray light in the sensor are examined, and a method is developed for masking measurements near bright targets for stray light effects. In addition, a procedure is proposed for reducing the effects of stray light in the flight data from SeaWiFS. This correction can also reduce the number of pixels masked for stray light. Without these corrections, local area scenes must be masked 10 pixels before and after bright targets in the along-scan direction. The addition of these corrections reduces the along-scan masks to four pixels before and after bright sources. In the along-track direction, the flight data are not corrected, and are masked two pixels before and after. Laboratory measurements have shown that stray light within the instrument changes in a direct ratio to the intensity of the bright source. The measurements have also shown that none of the bands show peculiarities in their stray light response. In other words, the instrument's response is uniform from band to band. The along-scan correction is based on each band's response to a 1 pixel wide bright sources. Since these results are based solely on preflight laboratory measurements, their successful implementation requires compliance with two additional criteria. First, since SeaWiFS has a large data volume, the correction and masking procedures must be such that they can be converted into computationally fast algorithms. Second, they must be shown to operate properly on flight data. The laboratory results, and the corrections and masking procedures that derive from them, should be considered as zeroeth order estimates of the effects that will be found on orbit.

Temporal Limitations in the Effective Binding of Attended Target Attributes in the Mutual Masking of Visual Objects

ERIC Educational Resources Information Center

Hommuk, Karita; Bachmann, Talis

2009-01-01

The problem of feature binding has been examined under conditions of distributed attention or with spatially dispersed stimuli. We studied binding by asking whether selective attention to a feature of a masked object enables perceptual access to the other features of that object using conditions in which spatial attention was directed at a single…

Reading Aloud in Persian: ERP Evidence for an Early Locus of the Masked Onset Priming Effect

ERIC Educational Resources Information Center

Timmer, Kalinka; Vahid-Gharavi, Narges; Schiller, Niels O.

2012-01-01

The current study investigates reading aloud words in Persian, a language that does not mark all its vowels in the script. Behaviorally, a "masked onset priming effect" (MOPE) was revealed for transparent words, with faster speech onset latencies in the phoneme-matching condition (i.e. phonological prime and target onset overlap; e.g. [image…

Spatial Release from Masking in Adults with Bilateral Cochlear Implants: Effects of Distracter Azimuth and Microphone Location

ERIC Educational Resources Information Center

Davis, Timothy J.; Gifford, René H.

2018-01-01

Purpose: The primary purpose of this study was to derive spatial release from masking (SRM) performance-azimuth functions for bilateral cochlear implant (CI) users to provide a thorough description of SRM as a function of target/distracter spatial configuration. The secondary purpose of this study was to investigate the effect of the microphone…

Joint seismic data denoising and interpolation with double-sparsity dictionary learning

NASA Astrophysics Data System (ADS)

Zhu, Lingchen; Liu, Entao; McClellan, James H.

2017-08-01

Seismic data quality is vital to geophysical applications, so that methods of data recovery, including denoising and interpolation, are common initial steps in the seismic data processing flow. We present a method to perform simultaneous interpolation and denoising, which is based on double-sparsity dictionary learning. This extends previous work that was for denoising only. The original double-sparsity dictionary learning algorithm is modified to track the traces with missing data by defining a masking operator that is integrated into the sparse representation of the dictionary. A weighted low-rank approximation algorithm is adopted to handle the dictionary updating as a sparse recovery optimization problem constrained by the masking operator. Compared to traditional sparse transforms with fixed dictionaries that lack the ability to adapt to complex data structures, the double-sparsity dictionary learning method learns the signal adaptively from selected patches of the corrupted seismic data, while preserving compact forward and inverse transform operators. Numerical experiments on synthetic seismic data indicate that this new method preserves more subtle features in the data set without introducing pseudo-Gibbs artifacts when compared to other directional multi-scale transform methods such as curvelets.

Masked translation priming effects with low proficient bilinguals.

PubMed

Dimitropoulou, Maria; Duñabeitia, Jon Andoni; Carreiras, Manuel

2011-02-01

Non-cognate masked translation priming lexical decision studies with unbalanced bilinguals suggest that masked translation priming effects are asymmetric as a function of the translation direction (significant effects only in the dominant [L1] to nondominant [L2] language translation direction). However, in contrast to the predictions of most current accounts of masked translation priming effects, bidirectional effects have recently been reported with a group of low proficient bilinguals Duyck & Warlop 2009 (Experimental Psychology 56:173-179). In a series of masked translation priming lexical decision experiments we examined whether the same pattern of effects would emerge with late and low proficient Greek (L1)-Spanish (L2) bilinguals. Contrary to the results obtained by Duyck and Warlop, and in line with the results found in most studies in the masked priming literature, significant translation priming effects emerged only when the bilinguals performed the task with L1 primes and L2 targets. The existence of the masked translation priming asymmetry with low proficient bilinguals suggests that cross-linguistic automatic lexico-semantic links may be established very early in the process of L2 acquisition. These findings could help to define models of bilingualism that consider L2 proficiency level to be a determining factor.

Fabless company mask technology approach: fabless but not fab-careless

NASA Astrophysics Data System (ADS)

Hisamura, Toshiyuki; Wu, Xin

2009-10-01

There are two different foundry-fabless working models in the aspect of mask. Some foundries have in-house mask facility while others contract with merchant mask vendors. Significant progress has been made in both kinds of situations. Xilinx as one of the pioneers of fabless semiconductor companies has been continually working very closely with both merchant mask vendors and mask facilities of foundries in past many years, contributed well in both technology development and benefited from corporations. Our involvement in manufacturing is driven by the following three elements: The first element is to understand the new fabrication and mask technologies and then find a suitable design / layout style to better utilize these new technologies and avoid potential risks. Because Xilinx has always been involved in early stage of advanced technology nodes, this early understanding and adoption is especially important. The second element is time to market. Reduction in mask and wafer manufacturing cycle-time can ensure faster time to market. The third element is quality. Commitment to quality is our highest priority for our customers. We have enough visibility on any manufacturing issues affecting the device functionality. Good correlation has consistently been observed between FPGA speed uniformity and the poly mask Critical Dimension (CD) uniformity performance. To achieve FPGA speed uniformity requirement, the manufacturing process as well as the mask and wafer CD uniformity has to be monitored. Xilinx works closely with the wafer foundries and mask suppliers to improve productivity and the yield from initial development stage of mask making operations. As an example, defect density reduction is one of the biggest challenges for mask supplier in development stage to meet the yield target satisfying the mask cost and mask turn-around-time (TAT) requirement. Historically, masks were considered to be defect free but at these advanced process nodes, that assumption no longer holds true. There is a need to be flexible enough on unrepairable defect at early stage but also a need for efficient risk management system on mask defect waivers. Mask defects are often waived in low design criticality area in favor of scrapping the mask and delaying the mask and wafer schedule. Xilinx's involvement in mask manufacturing has contributed significantly to our success in past many nodes and will continue.

Spatial covert attention increases contrast sensitivity across the CSF: support for signal enhancement

NASA Technical Reports Server (NTRS)

Carrasco, M.; Penpeci-Talgar, C.; Eckstein, M.

2000-01-01

This study is the first to report the benefits of spatial covert attention on contrast sensitivity in a wide range of spatial frequencies when a target alone was presented in the absence of a local post-mask. We used a peripheral precue (a small circle indicating the target location) to explore the effects of covert spatial attention on contrast sensitivity as assessed by orientation discrimination (Experiments 1-4), detection (Experiments 2 and 3) and localization (Experiment 3) tasks. In all four experiments the target (a Gabor patch ranging in spatial frequency from 0.5 to 10 cpd) was presented alone in one of eight possible locations equidistant from fixation. Contrast sensitivity was consistently higher for peripherally- than for neutrally-cued trials, even though we eliminated variables (distracters, global masks, local masks, and location uncertainty) that are known to contribute to an external noise reduction explanation of attention. When observers were presented with vertical and horizontal Gabor patches an external noise reduction signal detection model accounted for the cueing benefit in a discrimination task (Experiment 1). However, such a model could not account for this benefit when location uncertainty was reduced, either by: (a) Increasing overall performance level (Experiment 2); (b) increasing stimulus contrast to enable fine discriminations of slightly tilted suprathreshold stimuli (Experiment 3); and (c) presenting a local post-mask (Experiment 4). Given that attentional benefits occurred under conditions that exclude all variables predicted by the external noise reduction model, these results support the signal enhancement model of attention.

Scatterometry measurement of nested lines, dual space, and rectangular contact CD on phase-shift masks

NASA Astrophysics Data System (ADS)

Lee, Kyung M.; Yedur, Sanjay; Henrichs, Sven; Tavassoli, Malahat; Baik, Kiho

2007-03-01

Evaluation of lithography process or stepper involves very large quantity of CD measurements and measurement time. In this paper, we report on a application of Scatterometry based metrology for evaluation of binary photomask lithography. Measurements were made on mask level with ODP scatterometer then on wafer with CD-SEM. 4 to 1 scaling from mask to wafer means 60nm line on wafer translates to 240nm on mask, easily measurable on ODP. Calculation of scatterometer profile information was performed by a in-situ library-based analysis (5sec/site). We characterized the CD uniformity, linearity, and metal film thickness uniformity. Results show that linearity measured from fixed-pitch, varying line/space ratio targets show good correlation to top-down CD-SEM with R2 of more than 0.99. ODP-SEM correlation results for variable pitch shows that careful examination of scatterometer profile results in order to obtain better correlation to CD SEM, since both tools react differently to the target profile variation. ODP results show that global CD distribution is clearly measurable with less outliers compared to CD SEM data. This is thought to be due to 'averaging' effect of scatterometer. The data show that Scatterometry provides a nondestructive and faster mean of characterizing lithography stepper performanceprofiles. APSM 1st level (before Cr removal) 'dual-space' CDs and EPSM rectangular contacts were also measured with and results demonstrates that Scatterometer is capable of measuring these targets with reasonable correlation to SEM.

Attentional modulation of informational masking on early cortical representations of speech signals.

PubMed

Zhang, Changxin; Arnott, Stephen R; Rabaglia, Cristina; Avivi-Reich, Meital; Qi, James; Wu, Xihong; Li, Liang; Schneider, Bruce A

2016-01-01

To recognize speech in a noisy auditory scene, listeners need to perceptually segregate the target talker's voice from other competing sounds (stream segregation). A number of studies have suggested that the attentional demands placed on listeners increase as the acoustic properties and informational content of the competing sounds become more similar to that of the target voice. Hence we would expect attentional demands to be considerably greater when speech is masked by speech than when it is masked by steady-state noise. To investigate the role of attentional mechanisms in the unmasking of speech sounds, event-related potentials (ERPs) were recorded to a syllable masked by noise or competing speech under both active (the participant was asked to respond when the syllable was presented) or passive (no response was required) listening conditions. The results showed that the long-latency auditory response to a syllable (/bi/), presented at different signal-to-masker ratios (SMRs), was similar in both passive and active listening conditions, when the masker was a steady-state noise. In contrast, a switch from the passive listening condition to the active one, when the masker was two-talker speech, significantly enhanced the ERPs to the syllable. These results support the hypothesis that the need to engage attentional mechanisms in aid of scene analysis increases as the similarity (both acoustic and informational) between the target speech and the competing background sounds increases. Copyright © 2015 Elsevier B.V. All rights reserved.

Masked immediate-repetition-priming effect on the early lexical process in the bilateral anterior temporal areas assessed by neuromagnetic responses.

PubMed

Fujimaki, Norio; Hayakawa, Tomoe; Ihara, Aya; Matani, Ayumu; Wei, Qiang; Terazono, Yasushi; Murata, Tsutomu

2010-10-01

A masked priming paradigm has been used to measure unconscious and automatic context effects on the processing of words. However, its spatiotemporal neural basis has not yet been clarified. To test the hypothesis that masked repetition priming causes enhancement of neural activation, we conducted a magnetoencephalography experiment in which a prime was visually presented for a short duration (50 ms), preceded by a mask pattern, and followed by a target word that was represented by a Japanese katakana syllabogram. The prime, which was identical to the target, was represented by another hiragana syllabogram in the "Repeated" condition, whereas it was a string of unreadable pseudocharacters in the "Unrepeated" condition. Subjects executed a categorical decision task on the target. Activation was significantly larger for the Repeated condition than for the Unrepeated condition at a time window of 150-250 ms in the right occipital area, 200-250 ms in the bilateral ventral occipitotemporal areas, and 200-250 ms and 200-300 ms in the left and right anterior temporal areas, respectively. These areas have been reported to be related to processing of visual-form/orthography and lexico-semantics, and the enhanced activation supports the hypothesis. However, the absence of the priming effect in the areas related to phonological processing implies that automatic phonological priming effect depends on task requirements. 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Visual masking and the dynamics of human perception, cognition, and consciousness A century of progress, a contemporary synthesis, and future directions.

PubMed

Ansorge, Ulrich; Francis, Gregory; Herzog, Michael H; Oğmen, Haluk

2008-07-15

The 1990s, the "decade of the brain," witnessed major advances in the study of visual perception, cognition, and consciousness. Impressive techniques in neurophysiology, neuroanatomy, neuropsychology, electrophysiology, psychophysics and brain-imaging were developed to address how the nervous system transforms and represents visual inputs. Many of these advances have dealt with the steady-state properties of processing. To complement this "steady-state approach," more recent research emphasized the importance of dynamic aspects of visual processing. Visual masking has been a paradigm of choice for more than a century when it comes to the study of dynamic vision. A recent workshop (http://lpsy.epfl.ch/VMworkshop/), held in Delmenhorst, Germany, brought together an international group of researchers to present state-of-the-art research on dynamic visual processing with a focus on visual masking. This special issue presents peer-reviewed contributions by the workshop participants and provides a contemporary synthesis of how visual masking can inform the dynamics of human perception, cognition, and consciousness.

Visual masking and the dynamics of human perception, cognition, and consciousness A century of progress, a contemporary synthesis, and future directions

PubMed Central

Ansorge, Ulrich; Francis, Gregory; Herzog, Michael H.; Öğmen, Haluk

2008-01-01

The 1990s, the “decade of the brain,” witnessed major advances in the study of visual perception, cognition, and consciousness. Impressive techniques in neurophysiology, neuroanatomy, neuropsychology, electrophysiology, psychophysics and brain-imaging were developed to address how the nervous system transforms and represents visual inputs. Many of these advances have dealt with the steady-state properties of processing. To complement this “steady-state approach,” more recent research emphasized the importance of dynamic aspects of visual processing. Visual masking has been a paradigm of choice for more than a century when it comes to the study of dynamic vision. A recent workshop (http://lpsy.epfl.ch/VMworkshop/), held in Delmenhorst, Germany, brought together an international group of researchers to present state-of-the-art research on dynamic visual processing with a focus on visual masking. This special issue presents peer-reviewed contributions by the workshop participants and provides a contemporary synthesis of how visual masking can inform the dynamics of human perception, cognition, and consciousness. PMID:20517493

Method and Apparatus for Evaluating the Visual Quality of Processed Digital Video Sequences

NASA Technical Reports Server (NTRS)

Watson, Andrew B. (Inventor)

2002-01-01

A Digital Video Quality (DVQ) apparatus and method that incorporate a model of human visual sensitivity to predict the visibility of artifacts. The DVQ method and apparatus are used for the evaluation of the visual quality of processed digital video sequences and for adaptively controlling the bit rate of the processed digital video sequences without compromising the visual quality. The DVQ apparatus minimizes the required amount of memory and computation. The input to the DVQ apparatus is a pair of color image sequences: an original (R) non-compressed sequence, and a processed (T) sequence. Both sequences (R) and (T) are sampled, cropped, and subjected to color transformations. The sequences are then subjected to blocking and discrete cosine transformation, and the results are transformed to local contrast. The next step is a time filtering operation which implements the human sensitivity to different time frequencies. The results are converted to threshold units by dividing each discrete cosine transform coefficient by its respective visual threshold. At the next stage the two sequences are subtracted to produce an error sequence. The error sequence is subjected to a contrast masking operation, which also depends upon the reference sequence (R). The masked errors can be pooled in various ways to illustrate the perceptual error over various dimensions, and the pooled error can be converted to a visual quality measure.

Masked nonword repetition effects in yes/no and go/no-go lexical decision: a test of the evidence accumulation and deadline accounts.

PubMed

Perea, Manuel; Gómez, Pablo; Fraga, Isabel

2010-06-01

The pattern of masked repetition priming effects for word and nonword targets differs across tasks: Masked-priming effects in lexical decision occur for positive responses (i.e., words), but not for negative responses (nonwords), whereas masked-priming effects in the cross-case same-different task occur for positive responses (same), but not for negative responses (different)--regardless of lexical status. Here, we examined whether masked nonword priming effects are greater when the task involves an active go response to nonwords than when it involves the standard yes/no procedure in lexical decision. The obtained masked repetition priming effect for nonwords was of similar size in yes/no and go/no-go tasks. This finding is compatible with accounts of nonword priming that posit that nonword responses are produced by actively accumulating evidence for the nonword alternative in yes/no and go/no-go procedures, whereas it is inconsistent with the assumption of a deadline for no responses in the yes/no task.

Direct Mask Overlay Inspection

NASA Astrophysics Data System (ADS)

Hsia, Liang-Choo; Su, Lo-Soun

1983-11-01

In this paper, we present a mask inspection methodology and procedure that involves direct X-Y measurements. A group of dice is selected for overlay measurement; four measurement targets were laid out in the kerf of each die. The measured coordinates are then fit-ted to either a "historical" grid, which reflects the individual tool bias, or to an ideal grid squares fashion. Measurements are done using a Nikon X-Y laser interferometric measurement system, which provides a reference grid. The stability of the measurement system is essential. We then apply appropriate statistics to the residual after the fit to determine the overlay performance. Statistical methods play an important role in the product disposition. The acceptance criterion is, however, a compromise between the cost for mask making and the final device yield. In order to satisfy the demand on mask houses for quality of masks and high volume, mixing lithographic tools in mask making has become more popular, in particular, mixing optical and E-beam tools. In this paper, we also discuss the inspection procedure for mixing different lithographic tools.

Compressed sensing with cyclic-S Hadamard matrix for terahertz imaging applications

NASA Astrophysics Data System (ADS)

Ermeydan, Esra Şengün; ćankaya, Ilyas

2018-01-01

Compressed Sensing (CS) with Cyclic-S Hadamard matrix is proposed for single pixel imaging applications in this study. In single pixel imaging scheme, N = r . c samples should be taken for r×c pixel image where . denotes multiplication. CS is a popular technique claiming that the sparse signals can be reconstructed with samples under Nyquist rate. Therefore to solve the slow data acquisition problem in Terahertz (THz) single pixel imaging, CS is a good candidate. However, changing mask for each measurement is a challenging problem since there is no commercial Spatial Light Modulators (SLM) for THz band yet, therefore circular masks are suggested so that for each measurement one or two column shifting will be enough to change the mask. The CS masks are designed using cyclic-S matrices based on Hadamard transform for 9 × 7 and 15 × 17 pixel images within the framework of this study. The %50 compressed images are reconstructed using total variation based TVAL3 algorithm. Matlab simulations demonstrates that cyclic-S matrices can be used for single pixel imaging based on CS. The circular masks have the advantage to reduce the mechanical SLMs to a single sliding strip, whereas the CS helps to reduce acquisition time and energy since it allows to reconstruct the image from fewer samples.

The Relationship between Reversed Masked Priming and the Tri-Phasic Pattern of the Lateralised Readiness Potential

PubMed Central

Seiss, Ellen; Klippel, Marie; Hope, Christopher; Boy, Frederic; Sumner, Petroc

2014-01-01

One of the potential explanations for negative compatibility effects (NCE) in subliminal motor priming tasks has been perceptual prime-target interactions. Here, we investigate whether the characteristic tri-phasic LRP pattern associated with the NCE is caused by these prime-target interactions. We found that both the prime-related phase and the critical reversal phase remain present even on trials where the target is omitted, confirming they are elicited by the prime and mask, not by prime-target interactions. We also report that shape and size of the reversal phase are associated with response speed, consistent with a causal role for the reversal for the subsequent response latency. Additionally, we analysed sequential modulation of the NCE by previous conflicting events, even though such conflict is subliminal. In accordance with previous literature, this modulation is small but significant. PMID:24728088

Translation-coupling systems

DOEpatents

Pfleger, Brian; Mendez-Perez, Daniel

2013-11-05

Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

Translation-coupling systems

DOEpatents

Pfleger, Brian; Mendez-Perez, Daniel

2015-05-19

Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

Simultaneous masking between electric and acoustic stimulation in cochlear implant users with residual low-frequency hearing.

PubMed

Krüger, Benjamin; Büchner, Andreas; Nogueira, Waldo

2017-09-01

Ipsilateral electric-acoustic stimulation (EAS) is becoming increasingly important in cochlear implant (CI) treatment. Improvements in electrode designs and surgical techniques have contributed to improved hearing preservation during implantation. Consequently, CI implantation criteria have been expanded toward people with significant residual low-frequency hearing, who may benefit from the combined use of both the electric and acoustic stimulation in the same ear. However, only few studies have investigated the mutual interaction between electric and acoustic stimulation modalities. This work characterizes the interaction between both stimulation modalities using psychophysical masking experiments and cone beam computer tomography (CBCT). Two psychophysical experiments for electric and acoustic masking were performed to measure the hearing threshold elevation of a probe stimulus in the presence of a masker stimulus. For electric masking, the probe stimulus was an acoustic tone while the masker stimulus was an electric pulse train. For acoustic masking, the probe stimulus was an electric pulse train and the masker stimulus was an acoustic tone. Five EAS users, implanted with a CI and ipsilateral residual low-frequency hearing, participated in the study. Masking was determined at different electrodes and different acoustic frequencies. CBCT scans were used to determine the individual place-pitch frequencies of the intracochlear electrode contacts by using the Stakhovskaya place-to-frequency transformation. This allows the characterization of masking as a function of the difference between electric and acoustic stimulation sites, which we term the electric-acoustic frequency difference (EAFD). The results demonstrate a significant elevation of detection thresholds for both experiments. In electric masking, acoustic-tone thresholds increased exponentially with decreasing EAFD. In contrast, for the acoustic masking experiment, threshold elevations were present regardless of the tested EAFDs. Based on the present findings, we conclude that there is an asymmetry between the electric and the acoustic masker modalities. These observations have implications for the design and fitting of EAS sound-coding strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Speckle reduction in digital holography with resampling ring masks

NASA Astrophysics Data System (ADS)

Zhang, Wenhui; Cao, Liangcai; Jin, Guofan

2018-01-01

One-shot digital holographic imaging has the advantages of high stability and low temporal cost. However, the reconstruction is affected by the speckle noise. Resampling ring-mask method in spectrum domain is proposed for speckle reduction. The useful spectrum of one hologram is divided into several sub-spectra by ring masks. In the reconstruction, angular spectrum transform is applied to guarantee the calculation accuracy which has no approximation. N reconstructed amplitude images are calculated from the corresponding sub-spectra. Thanks to speckle's random distribution, superimposing these N uncorrelated amplitude images would lead to a final reconstructed image with lower speckle noise. Normalized relative standard deviation values of the reconstructed image are used to evaluate the reduction of speckle. Effect of the method on the spatial resolution of the reconstructed image is also quantitatively evaluated. Experimental and simulation results prove the feasibility and effectiveness of the proposed method.

Fourier plane image amplifier

DOEpatents

Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

1995-01-01

A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

Fourier plane image amplifier

DOEpatents

Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

1995-12-12

A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

True and masked three-coordinate T-shaped platinum(II) intermediates.

PubMed

Ortuño, Manuel A; Conejero, Salvador; Lledós, Agustí

2013-01-01

Although four-coordinate square-planar geometries, with a formally 16-electron counting, are absolutely dominant in isolated Pt(II) complexes, three-coordinate, 14-electron Pt(II) complexes are believed to be key intermediates in a number of platinum-mediated organometallic transformations. Although very few authenticated three-coordinate Pt(II) complexes have been characterized, a much larger number of complexes can be described as operationally three-coordinate in a kinetic sense. In these compounds, which we have called masked T-shaped complexes, the fourth position is occupied by a very weak ligand (agostic bond, solvent molecule or counteranion), which can be easily displaced. This review summarizes the structural features of the true and masked T-shaped Pt(II) complexes reported so far and describes synthetic strategies employed for their formation. Moreover, recent experimental and theoretical reports are analyzed, which suggest the involvement of such intermediates in reaction mechanisms, particularly C-H bond-activation processes.

Optical image encryption system using nonlinear approach based on biometric authentication

NASA Astrophysics Data System (ADS)

Verma, Gaurav; Sinha, Aloka

2017-07-01

A nonlinear image encryption scheme using phase-truncated Fourier transform (PTFT) and natural logarithms is proposed in this paper. With the help of the PTFT, the input image is truncated into phase and amplitude parts at the Fourier plane. The phase-only information is kept as the secret key for the decryption, and the amplitude distribution is modulated by adding an undercover amplitude random mask in the encryption process. Furthermore, the encrypted data is kept hidden inside the face biometric-based phase mask key using the base changing rule of logarithms for secure transmission. This phase mask is generated through principal component analysis. Numerical experiments show the feasibility and the validity of the proposed nonlinear scheme. The performance of the proposed scheme has been studied against the brute force attacks and the amplitude-phase retrieval attack. Simulation results are presented to illustrate the enhanced system performance with desired advantages in comparison to the linear cryptosystem.

How much is enough? An analysis of CD measurement amount for mask characterization

NASA Astrophysics Data System (ADS)

Ullrich, Albrecht; Richter, Jan

2009-10-01

The demands on CD (critical dimension) metrology amount in terms of both reproducibility and measurement uncertainty steadily increase from node to node. Different mask characterization requirements have to be addressed like very small features, unevenly distributed features, contacts, semi-dense structures to name only a few. Usually this enhanced need is met by an increasing number of CD measurements, where the new CD requirements are added to the well established CD characterization recipe. This leads straight forwardly to prolonged cycle times and highly complex evaluation routines. At the same time mask processes are continuously improved to become more stable. The enhanced stability offers potential to actually reduce the number of measurements. Thus, in this work we will start to address the fundamental question of how many CD measurements are needed for mask characterization for a given confidence level. We used analysis of variances (ANOVA) to distinguish various contributors like mask making process, measurement tool stability and measurement methodology. These contributions have been investigated for classical photomask CD specifications e.g. mean to target, CD uniformity, target offset tolerance and x-y bias. We found depending on specification that the importance of the contributors interchanges. Interestingly, not only short and long-term metrology contributions are dominant. Also the number of measurements and their spatial distribution on the mask layout (sampling methodology) can be the most important part of the variance. The knowledge of contributions can be used to optimize the sampling plan. As a major finding, we conclude that there is potential to reduce a significant amount of measurements without loosing confidence at all. Here, full sampling in x and y as well as full sampling for different features can be shortened substantially almost up to 50%.

Intelligibility of Target Signals in Sequential and Simultaneous Segregation Tasks

DTIC Science & Technology

2009-03-01

SUBJECT TERMS Informational masking; energetic masking, multimasker penalty, speech perception 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...alter- nation rates were high enough to directly interfere with the perception of the F0 values of the speech signals and that they thus disrupted the...segregation effects seen in this experiment and those in which stream segregation with tones was examined. Experiments examining the perception of

Effect of Syllable Congruency in Sixth Graders in the Lexical Decision Task with Masked Priming

ERIC Educational Resources Information Center

Chetail, Fabienne; Mathey, Stephanie

2012-01-01

The aim of this study was to investigate the role of the syllable in visual recognition of French words in Grade 6. To do so, the syllabic congruency effect was examined in the lexical decision task combined with masked priming. Target words were preceded by pseudoword primes sharing the first letters that either corresponded to the syllable…

A phantom study of the immobilization and the indications for using virtual isocenter in stereoscopic X‐ray image guidance system referring to position localizer in frameless radiosurgery

PubMed Central

Chang, Hsiao‐Han; Lee, Hsiao‐Fei; Sung, Chien‐Cheng; Liao, Tsung‐I

2013-01-01

A frameless radiosurgery system is using a set of thermoplastic mask for fixation and stereoscopic X‐ray imaging for alignment. The accuracy depends on mask fixation and imaging. Under certain circumstances, the guidance images may contain insufficient bony structures, resulting in lesser accuracy. A virtual isocenter function is designed for such scenarios. In this study, we investigated the immobilization and the indications for using virtual isocenter. Twenty‐four arbitrary imaginary treatment targets (ITTs) in phantom were evaluated. The external Localizer with positioner films was used as reference. The alignments by using actual and virtual isocenter in image guidance were compared. The deviation of the alignment after mask removing and then resetting was also checked. The results illustrated that the mean deviation between the alignment by image guidance using actual isocenter (Isoimg) and the localizer(Isoloc) was 2.26mm±1.16mm (standard deviation, SD), 1.66mm±0.83mm for using virtual isocenter. The deviation of the alignment by the image guidance using actual isocenter to the localizer before and after mask resetting was 7.02mm±5.8mm. The deviations before and after mask resetting were insignificant for the target center from skull edge larger than 80 mm on craniocaudal direction. The deviations between the alignment using actual and virtual isocenter in image guidance were not significant if the minimum distance from target center to skull edge was larger or equal to 30 mm. Due to an unacceptable deviation after mask resetting, the image guidance is necessary to improve the accuracy of frameless immobilization. A treatment isocenter less than 30 mm from the skull bone should be an indication for using virtual isocenter to align in image guidance. The virtual isocenter should be set as caudally as possible, and the sella of skull should be the ideal point. PACS numbers: 87.55.kh, 87.55.ne, 87.55.tm PMID:23835379

An Asymmetric Image Encryption Based on Phase Truncated Hybrid Transform

NASA Astrophysics Data System (ADS)

Khurana, Mehak; Singh, Hukum

2017-09-01

To enhance the security of the system and to protect it from the attacker, this paper proposes a new asymmetric cryptosystem based on hybrid approach of Phase Truncated Fourier and Discrete Cosine Transform (PTFDCT) which adds non linearity by including cube and cube root operation in the encryption and decryption path respectively. In this cryptosystem random phase masks are used as encryption keys and phase masks generated after the cube operation in encryption process are reserved as decryption keys and cube root operation is required to decrypt image in decryption process. The cube and cube root operation introduced in the encryption and decryption path makes system resistant against standard attacks. The robustness of the proposed cryptosystem has been analysed and verified on the basis of various parameters by simulating on MATLAB 7.9.0 (R2008a). The experimental results are provided to highlight the effectiveness and suitability of the proposed cryptosystem and prove the system is secure.

Impact of study oximeter masking algorithm on titration of oxygen therapy in the Canadian oxygen trial.

PubMed

Schmidt, Barbara; Roberts, Robin S; Whyte, Robin K; Asztalos, Elizabeth V; Poets, Christian; Rabi, Yacov; Solimano, Alfonso; Nelson, Harvey

2014-10-01

To compare oxygen saturations as displayed to caregivers on offset pulse oximeters in the 2 groups of the Canadian Oxygen Trial. In 5 double-blind randomized trials of oxygen saturation targeting, displayed saturations between 88% and 92% were offset by 3% above or below the true values but returned to true values below 84% and above 96%. During the transition, displayed values remained static at 96% in the lower and at 84% in the higher target group during a 3% change in true saturations. In contrast, displayed values changed rapidly from 88% to 84% in the lower and from 92% to 96% in the higher target group during a 1% change in true saturations. We plotted the distributions of median displayed saturations on days with >12 hours of supplemental oxygen in 1075 Canadian Oxygen Trial participants to reconstruct what caregivers observed at the bedside. The oximeter masking algorithm was associated with an increase in both stability and instability of displayed saturations that occurred during the transition between offset and true displayed values at opposite ends of the 2 target ranges. Caregivers maintained saturations at lower displayed values in the higher than in the lower target group. This differential management reduced the separation between the median true saturations in the 2 groups by approximately 3.5%. The design of the oximeter masking algorithm may have contributed to the smaller-than-expected separation between true saturations in the 2 study groups of recent saturation targeting trials in extremely preterm infants. Copyright © 2014 Elsevier Inc. All rights reserved.

Inhibition of return is not impaired but masked by increased facilitation in schizophrenia patients.

PubMed

Kalogeropoulou, Fenia; Woodruff, Peter W R; Vivas, Ana B

2015-01-01

When attention is attracted to an irrelevant location, performance on a subsequent target is hindered at that location in relation to novel, not previously attended, locations. This phenomenon is known as inhibition of return (IOR). Previous research has shown that IOR is not observed, or its onset is delayed, in schizophrenia patients. In the present study, the authors tested the hypothesis that IOR may be intact but masked by increased facilitation in schizophrenia patients. To test this hypothesis, they used a procedure that usually reduces or eliminates the early facilitation. In the first experiment, the authors used the typical single-cue IOR task in the group of healthy adults (N = 28) and in a group of schizophrenia patients (N = 32). In the second experiment, they manipulated cue-target discriminability by presenting spatially overlapping cues and targets where the cues were more intense than the targets. In Experiment 1, they did not find significant IOR effects in the group of schizophrenia patients, even with cue-target intervals as long as 3,200 ms. However, in Experiment 2, IOR effects were significant at the 350- and 450-ms cue-target intervals for healthy and patients, respectively. This is the first study that shows that schizophrenia patients can actually show inhibitory effects very similar to healthy controls, even when no help is provided to shift their attention away from the irrelevant location. The authors suggest that inhibition is intact in schizophrenia patients, but it is usually masked by increased facilitation. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Subliminal access to abstract face representations does not rely on attention.

PubMed

Harry, Bronson; Davis, Chris; Kim, Jeesun

2012-03-01

The present study used masked repetition priming to examine whether face representations can be accessed without attention. Two experiments using a face recognition task (fame judgement) presented masked repetition and control primes in spatially unattended locations prior to target onset. Experiment 1 (n=20) used the same images as primes and as targets and Experiment 2 (n=17) used different images of the same individual as primes and targets. Repetition priming was observed across both experiments regardless of whether spatial attention was cued to the location of the prime. Priming occurred for both famous and non-famous targets in Experiment 1 but was only reliable for famous targets in Experiment 2, suggesting that priming in Experiment 1 indexed access to view-specific representations whereas priming in Experiment 2 indexed access to view-invariant, abstract representations. Overall, the results indicate that subliminal access to abstract face representations does not rely on attention. Copyright © 2011 Elsevier Inc. All rights reserved.

The "electrophysiological sandwich": a method for amplifying ERP priming effects.

PubMed

Ktori, Maria; Grainger, Jonathan; Dufau, Stéphane; Holcomb, Phillip J

2012-08-01

We describe the results of a study that combines ERP recordings and sandwich priming, a variant of masked priming that provides a brief preview of the target prior to prime presentation (S. J. Lupker & C. J. Davis, 2009). This has been shown to increase the size of masked priming effects seen in behavioral responses. We found the same increase in sensitivity to ERP priming effects in an orthographic priming experiment manipulating the position of overlap of letters shared by primes and targets. Targets were 6-letter words and primes were formed of the 1st, 3rd, 4th, and 6th letters of targets in the related condition. Primes could be concatenated or hyphenated and could be centered on fixation or displaced by two letter spaces to the left or right. Priming effects with concatenated and/or displaced primes only started to emerge at 250 ms post-target onset, whereas priming effects from centrally located hyphenated primes emerged about 100 ms earlier. Copyright © 2012 Society for Psychophysiological Research.

The “Electrophysiological Sandwich”: A Method for Amplifying ERP Priming Effects

PubMed Central

Ktori, Maria; Grainger, Jonathan; Dufau, Stéphane; Holcomb, Phillip J.

2012-01-01

We describe the results of a study that combines ERP recordings and sandwich priming, a variant of masked priming that provides a brief preview of the target prior to prime presentation (Lupker & Davis, 2009). This has been shown to increase the size of masked priming effects seen in behavioral responses. We found the same increase in sensitivity to ERP priming effects in an orthographic priming experiment manipulating the position of overlap of letters shared by primes and targets. Targets were 6-letter words and primes were formed of the 1st, 3rd, 4th, and 6th letters of targets in the related condition. Primes could be concatenated or hyphenated and could be centered on fixation or displaced by two letter spaces to the left or right. Priming effects with concatenated and/or displaced primes only started to emerge at 250ms post-target onset, whereas priming effects from centrally located hyphenated primes emerged about 100ms earlier. PMID:22681238

Ship detection from high-resolution imagery based on land masking and cloud filtering

NASA Astrophysics Data System (ADS)

Jin, Tianming; Zhang, Junping

2015-12-01

High resolution satellite images play an important role in target detection application presently. This article focuses on the ship target detection from the high resolution panchromatic images. Taking advantage of geographic information such as the coastline vector data provided by NOAA Medium Resolution Coastline program, the land region is masked which is a main noise source in ship detection process. After that, the algorithm tries to deal with the cloud noise which appears frequently in the ocean satellite images, which is another reason for false alarm. Based on the analysis of cloud noise's feature in frequency domain, we introduce a windowed noise filter to get rid of the cloud noise. With the help of morphological processing algorithms adapted to target detection, we are able to acquire ship targets in fine shapes. In addition, we display the extracted information such as length and width of ship targets in a user-friendly way i.e. a KML file interpreted by Google Earth.

The contents of visual working memory reduce uncertainty during visual search.

PubMed

Cosman, Joshua D; Vecera, Shaun P

2011-05-01

Information held in visual working memory (VWM) influences the allocation of attention during visual search, with targets matching the contents of VWM receiving processing benefits over those that do not. Such an effect could arise from multiple mechanisms: First, it is possible that the contents of working memory enhance the perceptual representation of the target. Alternatively, it is possible that when a target is presented among distractor items, the contents of working memory operate postperceptually to reduce uncertainty about the location of the target. In both cases, a match between the contents of VWM and the target should lead to facilitated processing. However, each effect makes distinct predictions regarding set-size manipulations; whereas perceptual enhancement accounts predict processing benefits regardless of set size, uncertainty reduction accounts predict benefits only with set sizes larger than 1, when there is uncertainty regarding the target location. In the present study, in which briefly presented, masked targets were presented in isolation, there was a negligible effect of the information held in VWM on target discrimination. However, in displays containing multiple masked items, information held in VWM strongly affected target discrimination. These results argue that working memory representations act at a postperceptual level to reduce uncertainty during visual search.

Estimating subglottal pressure via airflow interruption with auditory masking.

PubMed

Hoffman, Matthew R; Jiang, Jack J

2009-11-01

Current noninvasive measurement of subglottal pressure using airflow interruption often produces inconsistent results due to the elicitation of audio-laryngeal reflexes. Auditory feedback could be considered as a means of ensuring measurement accuracy and precision. The purpose of this study was to determine if auditory masking could be used with the airflow interruption system to improve intrasubject consistency. A prerecorded sample of subject phonation was played on a loop over headphones during the trials with auditory masking. This provided subjects with a target pitch and blocked out distracting ambient noise created by the airflow interrupter. Subglottal pressure was noninvasively measured using the airflow interruption system. Thirty subjects, divided into two equal groups, performed 10 trials without auditory masking and 10 trials with auditory masking. Group one performed the normal trials first, followed by the trials with auditory masking. Group two performed the auditory masking trials first, followed by the normal trials. Intrasubject consistency was improved by adding auditory masking, resulting in a decrease in average intrasubject standard deviation from 0.93+/-0.51 to 0.47+/-0.22 cm H(2)O (P < 0.001). Auditory masking can be used effectively to combat audio-laryngeal reflexes and aid subjects in maintaining constant glottal configuration and frequency, thereby increasing intrasubject consistency when measuring subglottal pressure. By considering auditory feedback, a more reliable method of measurement was developed. This method could be used by clinicians, as reliable, immediately available values of subglottal pressure are useful in evaluating laryngeal health and monitoring treatment progress.

Ion beam deposition system for depositing low defect density extreme ultraviolet mask blanks

NASA Astrophysics Data System (ADS)

Jindal, V.; Kearney, P.; Sohn, J.; Harris-Jones, J.; John, A.; Godwin, M.; Antohe, A.; Teki, R.; Ma, A.; Goodwin, F.; Weaver, A.; Teora, P.

2012-03-01

Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 22 nm node and beyond. EUVL requires a low defect density reflective mask blank, which is considered to be one of the top two critical technology gaps for commercialization of the technology. At the SEMATECH Mask Blank Development Center (MBDC), research on defect reduction in EUV mask blanks is being pursued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key components in the ion beam deposition system that is currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH's current research is focused on in-house tool components to reduce their contributions to mask blank defects. SEMATECH is also working closely with the supplier to incorporate this learning into a next-generation deposition tool. This paper will describe requirements for the next-generation tool that are essential to realize low defect density EUV mask blanks. The goal of our work is to enable model-based predictions of defect performance and defect improvement for targeted process improvement and component learning to feed into the new deposition tool design. This paper will also highlight the defect reduction resulting from process improvements and the restrictions inherent in the current tool geometry and components that are an impediment to meeting HVM quality EUV mask blanks will be outlined.

Prevalence, Determinants, and Clinical Significance of Masked Hypertension in a Population-Based Sample of African Americans: The Jackson Heart Study.

PubMed

Diaz, Keith M; Veerabhadrappa, Praveen; Brown, Michael D; Whited, Matthew C; Dubbert, Patricia M; Hickson, DeMarc A

2015-07-01

The disproportionate rates of cardiovascular disease in African Americans may, in part, be due to suboptimal assessment of blood pressure (BP) with clinic BP measurements alone. To date, however, the prevalence of masked hypertension in African Americans has not been fully delineated. The purpose of this study was to evaluate masked hypertension prevalence in a large population-based sample of African Americans and examine its determinants and association with indices of target organ damage (TOD). Clinic and 24-hour ambulatory BP monitoring were conducted in 972 African Americans enrolled in the Jackson Heart Study. Common carotid artery intima-media thickness, left ventricular mass index, and the urinary albumin:creatinine excretion ratio were evaluated as indices of TOD. Masked hypertension prevalence was 25.9% in the overall sample and 34.4% in participants with normal clinic BP. All indices of TOD were significantly higher in masked hypertensives compared to sustained normotensives and were similar between masked hypertensives and sustained hypertensives. Male gender, smoking, diabetes, and antihypertensive medication use were independent determinants of masked hypertension in multivariate analyses. In this population-based cohort of African Americans, approximately one-third of participants with presumably normal clinic BP had masked hypertension when BP was assessed in their daily environment. Masked hypertension was accompanied by a greater degree of TOD in this cohort. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Functional neuroanatomy of visual masking deficits in schizophrenia.

PubMed

Green, Michael F; Lee, Junghee; Cohen, Mark S; Engel, Steven A; Korb, Alexander S; Nuechterlein, Keith H; Wynn, Jonathan K; Glahn, David C

2009-12-01

Visual masking procedures assess the earliest stages of visual processing. Patients with schizophrenia reliably show deficits on visual masking, and these procedures have been used to explore vulnerability to schizophrenia, probe underlying neural circuits, and help explain functional outcome. To identify and compare regional brain activity associated with one form of visual masking (ie, backward masking) in schizophrenic patients and healthy controls. Subjects received functional magnetic resonance imaging scans. While in the scanner, subjects performed a backward masking task and were given 3 functional localizer activation scans to identify early visual processing regions of interest (ROIs). University of California, Los Angeles, and the Department of Veterans Affairs Greater Los Angeles Healthcare System. Nineteen patients with schizophrenia and 19 healthy control subjects. Main Outcome Measure The magnitude of the functional magnetic resonance imaging signal during backward masking. Two ROIs (lateral occipital complex [LO] and the human motion selective cortex [hMT+]) showed sensitivity to the effects of masking, meaning that signal in these areas increased as the target became more visible. Patients had lower activation than controls in LO across all levels of visibility but did not differ in other visual processing ROIs. Using whole-brain analyses, we also identified areas outside the ROIs that were sensitive to masking effects (including bilateral inferior parietal lobe and thalamus), but groups did not differ in signal magnitude in these areas. The study results support a key role in LO for visual masking, consistent with previous studies in healthy controls. The current results indicate that patients fail to activate LO to the same extent as controls during visual processing regardless of stimulus visibility, suggesting a neural basis for the visual masking deficit, and possibly other visual integration deficits, in schizophrenia.

Unconscious and out of control: subliminal priming is insensitive to observer expectations.

PubMed

Cressman, Erin K; Lam, Melanie Y; Franks, Ian M; Enns, James T; Chua, Romeo

2013-09-01

We asked whether the influence of an invisible prime on movement is dependent on conscious movement expectations. Participants reached to a central target, which triggered a directional prime-mask arrow sequence. Participants were instructed that the visible arrows (masks) would most often signal a movement modification in a specific (biased) direction. Kinematic analyses revealed that responses to the visible mask were influenced by participants' intentional bias, as movements were fastest when the more probable mask was displayed. In addition, responses were influenced by the invisible prime without regard to its relationship to the more probable mask. Analysis of the time of initial trajectory modifications revealed that both primes influenced responses in a similar manner after accounting for participants' bias. These results imply that invisible stimuli automatically activate their associated responses and that unconscious priming of the motor system is insensitive to the conscious expectations of the participant making the pointing movements. Copyright © 2013 Elsevier Inc. All rights reserved.

Masking disrupts reentrant processing in human visual cortex.

PubMed

Fahrenfort, J J; Scholte, H S; Lamme, V A F

2007-09-01

In masking, a stimulus is rendered invisible through the presentation of a second stimulus shortly after the first. Over the years, authors have typically explained masking by postulating some early disruption process. In these feedforward-type explanations, the mask somehow "catches up" with the target stimulus, disrupting its processing either through lateral or interchannel inhibition. However, studies from recent years indicate that visual perception--and most notably visual awareness itself--may depend strongly on cortico-cortical feedback connections from higher to lower visual areas. This has led some researchers to propose that masking derives its effectiveness from selectively interrupting these reentrant processes. In this experiment, we used electroencephalogram measurements to determine what happens in the human visual cortex during detection of a texture-defined square under nonmasked (seen) and masked (unseen) conditions. Electro-encephalogram derivatives that are typically associated with reentrant processing turn out to be absent in the masked condition. Moreover, extrastriate visual areas are still activated early on by both seen and unseen stimuli, as shown by scalp surface Laplacian current source-density maps. This conclusively shows that feedforward processing is preserved, even when subject performance is at chance as determined by objective measures. From these results, we conclude that masking derives its effectiveness, at least partly, from disrupting reentrant processing, thereby interfering with the neural mechanisms of figure-ground segmentation and visual awareness itself.

Development of Auditory Selective Attention: Why Children Struggle to Hear in Noisy Environments

PubMed Central

2015-01-01

Children’s hearing deteriorates markedly in the presence of unpredictable noise. To explore why, 187 school-age children (4–11 years) and 15 adults performed a tone-in-noise detection task, in which the masking noise varied randomly between every presentation. Selective attention was evaluated by measuring the degree to which listeners were influenced by (i.e., gave weight to) each spectral region of the stimulus. Psychometric fits were also used to estimate levels of internal noise and bias. Levels of masking were found to decrease with age, becoming adult-like by 9–11 years. This change was explained by improvements in selective attention alone, with older listeners better able to ignore noise similar in frequency to the target. Consistent with this, age-related differences in masking were abolished when the noise was made more distant in frequency to the target. This work offers novel evidence that improvements in selective attention are critical for the normal development of auditory judgments. PMID:25706591

The impact of realistic source shape and flexibility on source mask optimization

NASA Astrophysics Data System (ADS)

Aoyama, Hajime; Mizuno, Yasushi; Hirayanagi, Noriyuki; Kita, Naonori; Matsui, Ryota; Izumi, Hirohiko; Tajima, Keiichi; Siebert, Joachim; Demmerle, Wolfgang; Matsuyama, Tomoyuki

2013-04-01

Source mask optimization (SMO) is widely used to make state-of-the-art semiconductor devices in high volume manufacturing. To realize mature SMO solutions in production, the Intelligent Illuminator, which is an illumination system on Nikon scanner, is useful because it can provide generation of freeform sources with high fidelity to the target. Proteus SMO, which employs co-optimization method and an insertion of validation with mask 3D effect and resist properties for an accurate prediction of wafer printing, can take into account the properties of Intelligent Illuminator. We investigate an impact of the source properties on the SMO to pattern of a static-random access memory. Quality of a source made on the scanner compared to the SMO target is evaluated with in-situ measurement and aerial image simulation using its measurement data. Furthermore we discuss an evaluation of a universality of the source to use it in multiple scanners with a validation with estimated value of scanner errors.

Selective targeting of melanoma by PEG-masked protein-based multifunctional nanoparticles

PubMed Central

Vannucci, Luca; Falvo, Elisabetta; Fornara, Manuela; Di Micco, Patrizio; Benada, Oldrich; Krizan, Jiri; Svoboda, Jan; Hulikova-Capkova, Katarina; Morea, Veronica; Boffi, Alberto; Ceci, Pierpaolo

2012-01-01

Background Nanoparticle-based systems are promising for the development of imaging and therapeutic agents. The main advantage of nanoparticles over traditional systems lies in the possibility of loading multiple functionalities onto a single molecule, which are useful for therapeutic and/or diagnostic purposes. These functionalities include targeting moieties which are able to recognize receptors overexpressed by specific cells and tissues. However, targeted delivery of nanoparticles requires an accurate system design. We present here a rationally designed, genetically engineered, and chemically modified protein-based nanoplatform for cell/tissue-specific targeting. Methods Our nanoparticle constructs were based on the heavy chain of the human protein ferritin (HFt), a highly symmetrical assembly of 24 subunits enclosing a hollow cavity. HFt-based nanoparticles were produced using both genetic engineering and chemical functionalization methods to impart several functionalities, ie, the α-melanocyte-stimulating hormone peptide as a melanoma-targeting moiety, stabilizing and HFt-masking polyethylene glycol molecules, rhodamine fluorophores, and magnetic resonance imaging agents. The constructs produced were extensively characterized by a number of physicochemical techniques, and assayed for selective melanoma-targeting in vitro and in vivo. Results Our HFt-based nanoparticle constructs functionalized with the α-melanocyte-stimulating hormone peptide moiety and polyethylene glycol molecules were specifically taken up by melanoma cells but not by other cancer cell types in vitro. Moreover, experiments in melanoma-bearing mice indicate that these constructs have an excellent tumor-targeting profile and a long circulation time in vivo. Conclusion By masking human HFt with polyethylene glycol and targeting it with an α-melanocyte-stimulating hormone peptide, we developed an HFt-based melanoma-targeting nanoplatform for application in melanoma diagnosis and treatment. These results could be of general interest, because the same strategy can be exploited to develop ad hoc nanoplatforms for specific delivery towards any cell/tissue type for which a suitable targeting moiety is available. PMID:22619508

The Role of Eyes and Mouth in the Memory of a Face

ERIC Educational Resources Information Center

McKelvie, Stuart J.

1976-01-01

Investigates the relative importance that the eyes and mouth play in the representation in memory of a human face. Systematically applies two kinds of transformation--masking the eyes or the mouths on photographs of faces--and observes the effects on recognition. (Author/RK)

What You May Not See Might Slow You Down Anyway: Masked Images and Driving

PubMed Central

Lewis-Evans, Ben; de Waard, Dick; Jolij, Jacob; Brookhuis, Karel A.

2012-01-01

Many theories of driver behaviour suggest that unconscious or implicit emotions play a functional role in the shaping and control of behaviour. This has not been experimentally tested however. Therefore, in this study the effects of emotive masked images on driver behaviour were examined. While driving a simulator, participants were repeatedly exposed to negative or neutral emotionally laden target images that were sandwich masked by emotionally neutral images. These images were encountered across two different trials each of which consisted of 3–4 minutes of driving on a rural road. The results indicate an effect of the negative target images primarily in reducing the extent of familiarisation occurring between the first and second experimental drives. This is evident in a reduced decrease in heart rate and a reduced increase in high band heart rate variability and actual travelling speed from the first to second drives if the negative target image was presented in the second drive. In addition to these findings there was no clear effect of the target image on subjective ratings of effort or feelings of risk. There was however an effect of gender, with the majority of the effects found in the study being limited to the larger female dataset. These findings suggest that unconscious or implicit emotional stimuli may well influence driver behaviour without explicit awareness. PMID:22279549

OPC and PSM design using inverse lithography: a nonlinear optimization approach

NASA Astrophysics Data System (ADS)

Poonawala, Amyn; Milanfar, Peyman

2006-03-01

We propose a novel method for the fast synthesis of low complexity model-based optical proximity correction (OPC) and phase shift masks (PSM) to improve the resolution and pattern fidelity of optical microlithography. We use the pixel-based mask representation, a continuous function formulation, and gradient based iterative optimization techniques to solve the above inverse problem. The continuous function formulation allows analytic calculation of the gradient. Pixel-based parametrization provides tremendous liberty in terms of the features possible in the synthesized masks, but also suffers the inherent disadvantage that the masks are very complex and difficult to manufacture. We therefore introduce the regularization framework; a useful tool which provides the flexibility to promote certain desirable properties in the solution. We employ the above framework to ensure that the estimated masks have only two or three (allowable) transmission values and are also comparatively simple and easy to manufacture. The results demonstrate that we are able to bring the CD on target using OPC masks. Furthermore, we were also able to boost the contrast of the aerial image using attenuated, strong, and 100% transmission phase shift masks. Our algorithm automatically (and optimally) adds assist-bars, dog-ears, serifs, anti-serifs, and other custom structures best suited for printing the desired pattern.

The CD control improvement by using CDSEM 2D measurement of complex OPC patterns

NASA Astrophysics Data System (ADS)

Chou, William; Cheng, Jeffrey; Lee, Adder; Cheng, James; Tzeng, Alex C.; Lu, Colbert; Yang, Ray; Lee, Hong Jen; Bandoh, Hideaki; Santo, Izumi; Zhang, Hao; Chen, Chien Kang

2016-10-01

As the process node becomes more advanced, the accuracy and precision in OPC pattern CD are required in mask manufacturing. CD SEM is an essential tool to confirm the mask quality such as CD control, CD uniformity and CD mean to target (MTT). Unfortunately, in some cases of arbitrary enclosed patterns or aggressive OPC patterns, for instance, line with tiny jogs and curvilinear SRAF, CD variation depending on region of interest (ROI) is a very serious problem in mask CD control, even it decreases the wafer yield. For overcoming this situation, the 2-dimensional (2D) method by Holon is adopted. In this paper, we summarize the comparisons of error budget between conventional (1D) and 2D data using CD SEM and the CD performance between mask and wafer by complex OPC patterns including ILT features.

An in-vitro-in-vivo taste assessment of bitter drug: comparative electronic tongues study.

PubMed

Maniruzzaman, Mohammed; Douroumis, Dennis

2015-01-01

The efficiency of the Astree e-tongue and Taste Sensing system TS5000Z for the evaluation of the taste masking effect of hot melt extruded formulations was investigated in this study. Hot melt extrusion (HME) processing was optimized using Randcastle single screw extruder (USA) to manufacture extrudates with desirable characteristics. Cationic model drug propranolol HCl (PRP) was processed with the anionic polymers - Eudragit L100 (L100) and Eudragit L100-55 (Acryl-EZE). Solid state of the drug in polymer matrices was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry, particle size analysis, Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) analysis. In-vitro taste masking efficiency of the two polymers was performed by using two different e-tongues (Astree e-tongue and TS5000Z). The results obtained from both e-tongues were further compared and contrast to find out the sensor outputs in all formulations. Solid state analysis of the extruded formulations revealed the presence of amorphous PRP. Both e-tongues were able to detect the taste masking variations of the extrudates and were in good agreement with the in-vivo results obtained from a panel of six healthy human volunteers (R(2)  > 0.84). However, each e-tongue sensor demonstrated different sensitivity, suggesting a careful consideration of the experimental findings during melt extrusion, is necessary for the development of taste-masked formulations. Furthermore, FTIR spectroscopy and NMR studies revealed possible drug polymer intermolecular interactions as the mechanism of successful taste masking. HME can effectively be used to manufacture taste-masked extruded formulations, while both e-tongues demonstrated satisfactory taste analysis for the development of taste-masked formulations. © 2014 Royal Pharmaceutical Society.

Musical training, individual differences and the cocktail party problem.

PubMed

Swaminathan, Jayaganesh; Mason, Christine R; Streeter, Timothy M; Best, Virginia; Kidd, Gerald; Patel, Aniruddh D

2015-06-26

Are musicians better able to understand speech in noise than non-musicians? Recent findings have produced contradictory results. Here we addressed this question by asking musicians and non-musicians to understand target sentences masked by other sentences presented from different spatial locations, the classical 'cocktail party problem' in speech science. We found that musicians obtained a substantial benefit in this situation, with thresholds ~6 dB better than non-musicians. Large individual differences in performance were noted particularly for the non-musically trained group. Furthermore, in different conditions we manipulated the spatial location and intelligibility of the masking sentences, thus changing the amount of 'informational masking' (IM) while keeping the amount of 'energetic masking' (EM) relatively constant. When the maskers were unintelligible and spatially separated from the target (low in IM), musicians and non-musicians performed comparably. These results suggest that the characteristics of speech maskers and the amount of IM can influence the magnitude of the differences found between musicians and non-musicians in multiple-talker "cocktail party" environments. Furthermore, considering the task in terms of the EM-IM distinction provides a conceptual framework for future behavioral and neuroscientific studies which explore the underlying sensory and cognitive mechanisms contributing to enhanced "speech-in-noise" perception by musicians.

An object-mediated updating account of insensitivity to transsaccadic change

PubMed Central

Tas, A. Caglar; Moore, Cathleen M.; Hollingworth, Andrew

2012-01-01

Recent evidence has suggested that relatively precise information about the location and visual form of a saccade target object is retained across a saccade. However, this information appears to be available for report only when the target is removed briefly, so that the display is blank when the eyes land. We hypothesized that the availability of precise target information is dependent on whether a post-saccade object is mapped to the same object representation established for the presaccade target. If so, then the post-saccade features of the target overwrite the presaccade features, a process of object mediated updating in which visual masking is governed by object continuity. In two experiments, participants' sensitivity to the spatial displacement of a saccade target was improved when that object changed surface feature properties across the saccade, consistent with the prediction of the object-mediating updating account. Transsaccadic perception appears to depend on a mechanism of object-based masking that is observed across multiple domains of vision. In addition, the results demonstrate that surface-feature continuity contributes to visual stability across saccades. PMID:23092946

Visual consciousness and intertrial feature priming.

PubMed

Peremen, Ziv; Hilo, Rinat; Lamy, Dominique

2013-04-01

Intertrial repetition priming plays a striking role in visual search. For instance, when searching for a target with a unique color, performance is substantially better when the specific color of the target repeats on successive trials (Maljkovic & Nakayama, 1994). Recent research has relied on objective measures of performance to show that priming improves the perceptual quality of the repeated target. Here, we examined the relation between priming and conscious perception of the target by adding a subjective measure of perception. We used backward masking to create liminal perception, that is, different levels of subjectively conscious perception of the target using exactly the same stimulus conditions. The displays in either probe trials (in which priming benefits are measured, experiment 1) or in prime trials (in which memory traces are laid down, experiment 2) were masked. The results showed that intertrial priming improves full access to awareness of the repeated target but only for targets that already achieved partial access to awareness. In addition, they show that full awareness of the target is necessary in both the prime and probe trials for intertrial priming effects to emerge. Implications for the role of implicit short-term memory in visual search are discussed.

[A digital micromirror device-based Hadamard transform near infrared spectrometer].

PubMed

Liu, Jia; Chen, Fen-Fei; Liao, Cheng-Sheng; Xu, Qian; Zeng, Li-Bo; Wu, Qiong-Shui

2011-10-01

A Hadamard transform near infrared spectrometer based on a digital micromirror device was constructed. The optical signal was collected by optical fiber, a grating was used for light diffraction, a digital micromirror device (DMD) was applied instead of traditional mechanical Hadamard masks for optical modulation, and an InGaAs near infrared detector was used as the optic sensor. The original spectrum was recovered by fast Hadamard transform algrithms. The advantages of the spectrometer, such as high resolution, signal-noise-ratio, stability, sensitivity and response speed were proved by experiments, which indicated that it is very suitable for oil and food-safety applications.

Joint transform correlator optical encryption system: Extensions of the recorded encrypted signal and its inverse Fourier transform

NASA Astrophysics Data System (ADS)

Galizzi, Gustavo E.; Cuadrado-Laborde, Christian

2015-10-01

In this work we study the joint transform correlator setup, finding two analytical expressions for the extensions of the joint power spectrum and its inverse Fourier transform. We found that an optimum efficiency is reached, when the bandwidth of the key code is equal to the sum of the bandwidths of the image plus the random phase mask (RPM). The quality of the decryption is also affected by the ratio between the bandwidths of the RPM and the input image, being better as this ratio increases. In addition, the effect on the decrypted image when the detection area is lower than the encrypted signal extension was analyzed. We illustrate these results through several numerical examples.

Diverging on Diversity and Difference: The Mask of Inclusion

ERIC Educational Resources Information Center

Pillay, V.; McLellan, C. E.

2010-01-01

In this paper we argue that the cliched phrases, "dealing with difference" and "dealing with diversity", despite their commitment to accepting and appreciating difference and diversity, may be used in counterproductive ways to camouflage resistance to change and transformation. In a small sample of interviews conducted at a…

Integration Has Arrived Down South.

ERIC Educational Resources Information Center

Jennings, Lillian Pegues

Education serves as a backdrop and a disguise, masking the transformation of this country from an industrialized blue-collar dependent system to a technocratic system dependent upon fewer, but highly educated workers. This movement has tremendous implications for race relations in this country. An in-depth study of the history of school reform…

Theoretical modeling of masking DNA application in aptamer-facilitated biomarker discovery.

PubMed

Cherney, Leonid T; Obrecht, Natalia M; Krylov, Sergey N

2013-04-16

In aptamer-facilitated biomarker discovery (AptaBiD), aptamers are selected from a library of random DNA (or RNA) sequences for their ability to specifically bind cell-surface biomarkers. The library is incubated with intact cells, and cell-bound DNA molecules are separated from those unbound and amplified by the polymerase chain reaction (PCR). The partitioning/amplification cycle is repeated multiple times while alternating target cells and control cells. Efficient aptamer selection in AptaBiD relies on the inclusion of masking DNA within the cell and library mixture. Masking DNA lacks primer regions for PCR amplification and is typically taken in excess to the library. The role of masking DNA within the selection mixture is to outcompete any nonspecific binding sequences within the initial library, thus allowing specific DNA sequences (i.e., aptamers) to be selected more efficiently. Efficient AptaBiD requires an optimum ratio of masking DNA to library DNA, at which aptamers still bind specific binding sites but nonaptamers within the library do not bind nonspecific binding sites. Here, we have developed a mathematical model that describes the binding processes taking place within the equilibrium mixture of masking DNA, library DNA, and target cells. An obtained mathematical solution allows one to estimate the concentration of masking DNA that is required to outcompete the library DNA at a desirable ratio of bound masking DNA to bound library DNA. The required concentration depends on concentrations of the library and cells as well as on unknown cell characteristics. These characteristics include the concentration of total binding sites on the cell surface, N, and equilibrium dissociation constants, K(nsL) and K(nsM), for nonspecific binding of the library DNA and masking DNA, respectively. We developed a theory that allows the determination of N, K(nsL), and K(nsM) based on measurements of EC50 values for cells mixed separately with the library and masking DNA (EC50 is the concentration of fluorescently labeled DNA at which half of the maximum fluorescence signal from DNA-bound cells is reached). We also obtained expressions for signals from bound DNA (measured by flow cytometry) in terms of N, K(nsL), and K(nsM). These expressions can be used for the verification of N, K(nsL), and K(nsM) values found from EC50 measurements. The developed procedure was applied to MCF-7 breast cancer cells, and corresponding values of N, K(nsL), and K(nsM) were established for the first time. The concentration of masking DNA required for AptaBiD with MCF-7 breast cancer cells was also estimated.

Masked priming effect reflects evidence accumulated by the prime.

PubMed

Kinoshita, Sachiko; Norris, Dennis

2010-01-01

In the same-different match task, masked priming is observed with the same responses but not different responses. Norris and Kinoshita's (2008) Bayesian reader account of masked priming explains this pattern based on the same principle as that explaining the absence of priming for nonwords in the lexical decision task. The pattern of priming follows from the way the model makes optimal decisions in the two tasks; priming does not depend on first activating the prime and then the target. An alternative explanation is in terms of a bias towards responding "same" that exactly counters the facilitatory effect of lexical access. The present study tested these two views by varying both the degree to which the prime predicts the response and the visibility of the prime. Unmasked primes produced effects expected from the view that priming is influenced by the degree to which the prime predicts the response. In contrast, with masked primes, the size of priming for the same response was completely unaffected by predictability. These results rule out response bias as an explanation of the absence of masked priming for different responses and, in turn, indicate that masked priming is not a consequence of automatic lexical access of the prime.

The influence of target-masker similarity on across-ear interference in dichotic listening

NASA Astrophysics Data System (ADS)

Brungart, Douglas; Simpson, Brian

2004-05-01

In most dichotic listening tasks, the comprehension of a target speech signal presented in one ear is unaffected by the presence of irrelevant speech in the opposite ear. However, recent results have shown that contralaterally presented interfering speech signals do influence performance when a second interfering speech signal is present in the same ear as the target speech. In this experiment, we examined the influence of target-masker similarity on this effect by presenting ipsilateral and contralateral masking phrases spoken by the same talker, a different same-sex talker, or a different-sex talker than the one used to generate the target speech. The results show that contralateral target-masker similarity has the greatest influence on performance when an easily segregated different-sex masker is presented in the target ear, and the least influence when a difficult-to-segregate same-talker masker is presented in the target ear. These results indicate that across-ear interference in dichotic listening is not directly related to the difficulty of the segregation task in the target ear, and suggest that contralateral maskers are least likely to interfere with dichotic speech perception when the same general strategy could be used to segregate the target from the masking voices in the ipsilateral and contralateral ears.

SEMATECH EUVL mask program status

NASA Astrophysics Data System (ADS)

Yun, Henry; Goodwin, Frank; Huh, Sungmin; Orvek, Kevin; Cha, Brian; Rastegar, Abbas; Kearney, Patrick

2009-04-01

As we approach the 22nm half-pitch (hp) technology node, the industry is rapidly running out of patterning options. Of the several lithography techniques highlighted in the International Technology Roadmap for Semiconductors (ITRS), the leading contender for the 22nm hp insertion is extreme ultraviolet lithography (EUVL). Despite recent advances with EUV resist and improvements in source power, achieving defect free EUV mask blank and enabling the EUV mask infrastructure still remain critical issues. To meet the desired EUV high volume manufacturing (HVM) insertion target date of 2013, these obstacles must be resolved on a timely bases. Many of the EUV mask related challenges remain in the pre-competitive stage and a collaborative industry based consortia, such as SEMATECH can play an important role to enable the EUVL landscape. SEMATECH based in Albany, NY is an international consortium representing several of the largest manufacturers in the semiconductor market. Full members include Intel, Samsung, AMD, IBM, Panasonic, HP, TI, UMC, CNSE (College of Nanoscience and Engineering), and Fuller Road Management. Within the SEMATECH lithography division a major thrust is centered on enabling the EUVL ecosystem from mask development, EUV resist development and addressing EUV manufacturability concerns. An important area of focus for the SEMATECH mask program has been the Mask Blank Development Center (MBDC). At the MBDC key issues in EUV blank development such as defect reduction and inspection capabilities are actively pursued together with research partners, key suppliers and member companies. In addition the mask program continues a successful track record of working with the mask community to manage and fund critical mask tools programs. This paper will highlight recent status of mask projects and longer term strategic direction at the MBDC. It is important that mask technology be ready to support pilot line development HVM by 2013. In several areas progress has been made but a continued collaborative effort will be needed along with timely infrastructure investments to meet these challenging goals.

Improving the CD linearity and proximity performance of photomasks written on the Sigma7500-II DUV laser writer through embedded OPC

NASA Astrophysics Data System (ADS)

Österberg, Anders; Ivansen, Lars; Beyerl, Angela; Newman, Tom; Bowhill, Amanda; Sahouria, Emile; Schulze, Steffen

2007-10-01

Optical proximity correction (OPC) is widely used in wafer lithography to produce a printed image that best matches the design intent while optimizing CD control. OPC software applies corrections to the mask pattern data, but in general it does not compensate for the mask writer and mask process characteristics. The Sigma7500-II deep-UV laser mask writer projects the image of a programmable spatial light modulator (SLM) using partially coherent optics similar to wafer steppers, and the optical proximity effects of the mask writer are in principle correctable with established OPC methods. To enhance mask patterning, an embedded OPC function, LinearityEqualize TM, has been developed for the Sigma7500- II that is transparent to the user and which does not degrade mask throughput. It employs a Calibre TM rule-based OPC engine from Mentor Graphics, selected for the computational speed necessary for mask run-time execution. A multinode cluster computer applies optimized table-based CD corrections to polygonized pattern data that is then fractured into an internal writer format for subsequent data processing. This embedded proximity correction flattens the linearity behavior for all linewidths and pitches, which targets to improve the CD uniformity on production photomasks. Printing results show that the CD linearity is reduced to below 5 nm for linewidths down to 200 nm, both for clear and dark and for isolated and dense features, and that sub-resolution assist features (SRAF) are reliably printed down to 120 nm. This reduction of proximity effects for main mask features and the extension of the practical resolution for SRAFs expands the application space of DUV laser mask writing.

When things go pear shaped: contour variations of contacts

NASA Astrophysics Data System (ADS)

Utzny, Clemens

2013-04-01

Traditional control of critical dimensions (CD) on photolithographic masks considers the CD average and a measure for the CD variation such as the CD range or the standard deviation. Also systematic CD deviations from the mean such as CD signatures are subject to the control. These measures are valid for mask quality verification as long as patterns across a mask exhibit only size variations and no shape variation. The issue of shape variations becomes especially important in the context of contact holes on EUV masks. For EUV masks the CD error budget is much smaller than for standard optical masks. This means that small deviations from the contact shape can impact EUV waver prints in the sense that contact shape deformations induce asymmetric bridging phenomena. In this paper we present a detailed study of contact shape variations based on regular product data. Two data sets are analyzed: 1) contacts of varying target size and 2) a regularly spaced field of contacts. Here, the methods of statistical shape analysis are used to analyze CD SEM generated contour data. We demonstrate that contacts on photolithographic masks do not only show size variations but exhibit also pronounced nontrivial shape variations. In our data sets we find pronounced shape variations which can be interpreted as asymmetrical shape squeezing and contact rounding. Thus we demonstrate the limitations of classic CD measures for describing the feature variations on masks. Furthermore we show how the methods of statistical shape analysis can be used for quantifying the contour variations thus paving the way to a new understanding of mask linearity and its specification.

Optimal control of the population dynamics of the ground vibrational state of a polyatomic molecule

NASA Astrophysics Data System (ADS)

de Clercq, Ludwig E.; Botha, Lourens R.; Rohwer, Erich G.; Uys, Hermann; Du Plessis, Anton

2011-03-01

Simulating coherent control with femtosecond pulses on a polyatomic molecule with anharmonic splitting was demonstrated. The simulation mimicked pulse shaping of a Spatial Light Modulator (SLM) and the interaction was described with the Von Neumann equation. A transform limited pulse with a fluence of 600 J/m2 produced 18% of the population in an arbitrarily chosen upper vibrational state, n =2. Phase only and amplitude only shaped pulse produced optimum values of 60% and 40% respectively, of the population in the vibrational state, n=2, after interaction with the ultra short pulse. The combination of phase and amplitude shaping produced the best results, 80% of the population was in the targeted vibrational state, n=2, after interaction. These simulations were carried out with all the population initially in the ground vibrational level. It was found that even at room temperatures (300 Kelvin) that the population in the selected level is comparable with the case where all population is initially in the ground vibrational state. With a 10% noise added to the amplitude and phase masks, selective excitation of the targeted vibrational state is still possible.

On the Labile Memory Buffer in the Attentional Blink: Masking the T2 Representation by Onset Transients Mediates the AB

ERIC Educational Resources Information Center

Jannati, Ali; Spalek, Thomas M.; Di Lollo, Vincent

2011-01-01

Report of a second target (T2) is impaired when presented within 500 ms of the first (T1). This attentional blink (AB) is known to cause a delay in T2 processing during which T2 must be stored in a labile memory buffer. We explored the buffer's characteristics using different types of masks after T2. These characteristics were inferred by…

Space-valence priming with subliminal and supraliminal words.

PubMed

Ansorge, Ulrich; Khalid, Shah; König, Peter

2013-01-01

To date it is unclear whether (1) awareness-independent non-evaluative semantic processes influence affective semantics and whether (2) awareness-independent affective semantics influence non-evaluative semantic processing. In the current study, we investigated these questions with the help of subliminal (masked) primes and visible targets in a space-valence across-category congruence effect. In line with (1), we found that subliminal space prime words influenced valence classification of supraliminal target words (Experiment 1): classifications were faster with a congruent prime (e.g., the prime "up" before the target "happy") than with an incongruent prime (e.g., the prime "up" before the target "sad"). In contrast to (2), no influence of subliminal valence primes on the classification of supraliminal space targets into up- and down-words was found (Experiment 2). Control conditions showed that standard masked response priming effects were found with both subliminal prime types, and that an across-category congruence effect was also found with supraliminal valence primes and spatial target words. The final Experiment 3 confirmed that the across-category congruence effect indeed reflected priming of target categorization of a relevant meaning category. Together, the data jointly confirmed prediction (1) that awareness-independent non-evaluative semantic priming influences valence judgments.

Listeners Experience Linguistic Masking Release in Noise-Vocoded Speech-in-Speech Recognition.

PubMed

Viswanathan, Navin; Kokkinakis, Kostas; Williams, Brittany T

2018-02-15

The purpose of this study was to evaluate whether listeners with normal hearing perceiving noise-vocoded speech-in-speech demonstrate better intelligibility of target speech when the background speech was mismatched in language (linguistic release from masking [LRM]) and/or location (spatial release from masking [SRM]) relative to the target. We also assessed whether the spectral resolution of the noise-vocoded stimuli affected the presence of LRM and SRM under these conditions. In Experiment 1, a mixed factorial design was used to simultaneously manipulate the masker language (within-subject, English vs. Dutch), the simulated masker location (within-subject, right, center, left), and the spectral resolution (between-subjects, 6 vs. 12 channels) of noise-vocoded target-masker combinations presented at +25 dB signal-to-noise ratio (SNR). In Experiment 2, the study was repeated using a spectral resolution of 12 channels at +15 dB SNR. In both experiments, listeners' intelligibility of noise-vocoded targets was better when the background masker was Dutch, demonstrating reliable LRM in all conditions. The pattern of results in Experiment 1 was not reliably different across the 6- and 12-channel noise-vocoded speech. Finally, a reliable spatial benefit (SRM) was detected only in the more challenging SNR condition (Experiment 2). The current study is the first to report a clear LRM benefit in noise-vocoded speech-in-speech recognition. Our results indicate that this benefit is available even under spectrally degraded conditions and that it may augment the benefit due to spatial separation of target speech and competing backgrounds.

A backwards glance at words: Using reversed-interior masked primes to test models of visual word identification

PubMed Central

Lupker, Stephen J.

2017-01-01

The experiments reported here used “Reversed-Interior” (RI) primes (e.g., cetupmor-COMPUTER) in three different masked priming paradigms in order to test between different models of orthographic coding/visual word recognition. The results of Experiment 1, using a standard masked priming methodology, showed no evidence of priming from RI primes, in contrast to the predictions of the Bayesian Reader and LTRS models. By contrast, Experiment 2, using a sandwich priming methodology, showed significant priming from RI primes, in contrast to the predictions of open bigram models, which predict that there should be no orthographic similarity between these primes and their targets. Similar results were obtained in Experiment 3, using a masked prime same-different task. The results of all three experiments are most consistent with the predictions derived from simulations of the Spatial-coding model. PMID:29244824

The temporal dynamics of masked repetition picture priming effects: manipulations of stimulus-onset asynchrony (SOA) and prime duration

PubMed Central

Eddy, Marianna D.; Holcomb, Phillip J.

2010-01-01

The current study used event-related potentials (ERPs) and masked repetition priming to examine the time-course of picture processing. We manipulated the stimulus-onset asynchrony (110 ms, 230 ms, 350 ms, 470 ms) between repeated and unrepeated prime-target pairs while holding the prime duration constant (50 ms) (Experiment 1) as well as the prime duration (30 ms, 50 ms, 70 ms, 90 ms) (Experiment 2) with a constant SOA of 110 ms in a masked repetition priming paradigm with pictures. The aim of this study was to further elucidate the mechanisms underlying previously observed ERP components in masked priming with pictures. We found both the N/P190 and N400 are modulated by changes in prime duration and SOA, however, it appears that longer prime exposure rather than a longer SOA leads to more in-depth processing as indexed by larger N400 effects. PMID:20403342

Object Trimming: When Masking Dots Alter Rather than Replace Target Representations

ERIC Educational Resources Information Center

Kahan, Todd A.; Enns, James T.

2010-01-01

Five experiments demonstrate that when dots appear beside a briefly presented target object, and persist on view longer than the target, the flanked object is perceptually altered by the dots. Three methods are used to explore this "object trimming effect". Experiments 1-3 assess participants' conscious reports of trimmed digits, Experiment 4 uses…

Effect of attention on the detection and identification of masked spatial patterns.

PubMed

Põder, Endel

2005-01-01

The effect of attention on the detection and identification of vertically and horizontally oriented Gabor patterns in the condition of simultaneous masking with obliquely oriented Gabors was studied. Attention was manipulated by varying the set size in a visual-search experiment. In the first experiment, small target Gabors were presented on the background of larger masking Gabors. In the detection task, the effect of set size was as predicted by unlimited-capacity signal detection theory. In the orientation identification task, increasing the set size from 1 to 8 resulted in a much larger decline in performance. The results of the additional experiments suggest that attention can reduce the crowding effect of maskers.

Amplification of the BCR/ABL fusion gene clustered on a masked Philadelphia chromosome in a patient with myeloblastic crisis of chronic myelocytic leukemia.

PubMed

Gargallo, Patricia M; Cuello, Maria Teresa; Aranguren, Pedro Negri; Larripa, Irene B

2003-06-01

Although the chronic phase of chronic myelocytic leukemia (CML) is characterized by the Philadelphia (Ph) chromosome creating a hybrid BCR/ABL gene, additional genetic changes involved in blast crisis are poorly understood. We report a 4-8-fold amplification by tandem duplication of the BCR/ABL fusion gene clustered on a masked Ph chromosome in a 61-year-old male patient with CML in myeloblastic crisis. Our finding suggests that the BCR/ABL amplification may play a role as a novel mechanism in the progression to an aggressive blast transformation in some cases of Ph-positive CML.

Spectrographic imaging system

DOEpatents

Morris, Michael D.; Treado, Patrick J.

1991-01-01

An imaging system for providing spectrographically resolved images. The system incorporates a one-dimensional spatial encoding mask which enables an image to be projected onto a two-dimensional image detector after spectral dispersion of the image. The dimension of the image which is lost due to spectral dispersion on the two-dimensional detector is recovered through employing a reverse transform based on presenting a multiplicity of different spatial encoding patterns to the image. The system is especially adapted for detecting Raman scattering of monochromatic light transmitted through or reflected from physical samples. Preferably, spatial encoding is achieved through the use of Hadamard mask which selectively transmits or blocks portions of the image from the sample being evaluated.

Evoked-potential recovery during double click stimulation in a beluga whale: implications for biosonar gain control.

PubMed

Supin, Alexander Ya; Popov, Vladimir V

2015-05-01

Auditory evoked potentials (AEPs) were recorded in a beluga whale Delphinapterus leucas using a double-pulse stimulation paradigm, specifically measuring the recovery (release from masking) of the second (test) response as a function of delay after the first (conditioning) pulse at various levels of the conditioning and test stimuli. The conditioning/test stimulus level ratio influenced the recovery time (the higher the ratio, the longer the recovery). This interrelation was used to evaluate the intensity/time trade in release from forward masking. Trade was evaluated as 32.2 dB per time decade. Data were considered as simulating interactions between the transmitted pulse and echo during echolocation, assuming that a transmitted sonar pulse produces forward masking of the echo response. With increased target distance, the attenuation of the echo may be compensated by the release from masking. According to the model, the compensation results in substantial stabilization of the echo response even if the intensity/time trade of release from masking is not precisely equal to the rate of echo attenuation with distance.

Unconscious manipulation of free choice by novel primes.

PubMed

Ocampo, Brenda

2015-07-01

The extent to which non-conscious perception can influence behaviour has been a topic of considerable controversy in psychology for decades. Although a challenging task, convincing empirical demonstrations have emerged suggesting that non-consciously perceived 'prime' stimuli can influence motor responses to subsequent targets. Interestingly, recent studies have shown that the influence of masked primes is not restricted to target-elicited responses, but can also bias free-choices between alternative behaviours. The present experiment extends these findings by showing that free-choices could also be biased by novel primes that never appeared as targets and therefore could not trigger acquired stimulus-response (S-R) mappings. This new evidence suggests that free-choice behaviour can be influenced by non-consciously triggered semantic representations. Furthermore, the results reported here support accounts of masked priming that posit an automatic semantic categorisation of non-consciously perceived visual stimuli. Copyright © 2015 Elsevier Inc. All rights reserved.

The Emergence of Visual Awareness: Temporal Dynamics in Relation to Task and Mask Type

PubMed Central

Kiefer, Markus; Kammer, Thomas

2017-01-01

One aspect of consciousness phenomena, the temporal emergence of visual awareness, has been subject of a controversial debate. How can visual awareness, that is the experiential quality of visual stimuli, be characterized best? Is there a sharp discontinuous or dichotomous transition between unaware and fully aware states, or does awareness emerge gradually encompassing intermediate states? Previous studies yielded conflicting results and supported both dichotomous and gradual views. It is well conceivable that these conflicting results are more than noise, but reflect the dynamic nature of the temporal emergence of visual awareness. Using a psychophysical approach, the present research tested whether the emergence of visual awareness is context-dependent with a temporal two-alternative forced choice task. During backward masking of word targets, it was assessed whether the relative temporal sequence of stimulus thresholds is modulated by the task (stimulus presence, letter case, lexical decision, and semantic category) and by mask type. Four masks with different similarity to the target features were created. Psychophysical functions were then fitted to the accuracy data in the different task conditions as a function of the stimulus mask SOA in order to determine the inflection point (conscious threshold of each feature) and slope of the psychophysical function (transition from unaware to aware within each feature). Depending on feature-mask similarity, thresholds in the different tasks were highly dispersed suggesting a graded transition from unawareness to awareness or had less differentiated thresholds indicating that clusters of features probed by the tasks quite simultaneously contribute to the percept. The latter observation, although not compatible with the notion of a sharp all-or-none transition between unaware and aware states, suggests a less gradual or more discontinuous emergence of awareness. Analyses of slopes of the fitted psychophysical functions also indicated that the emergence of awareness of single features is variable and might be influenced by the continuity of the feature dimensions. The present work thus suggests that the emergence of awareness is neither purely gradual nor dichotomous, but highly dynamic depending on the task and mask type. PMID:28316583

Generation of dark hollow beam by use of phase-only filtering

NASA Astrophysics Data System (ADS)

Liu, Zhengjun; Dai, Jingmin; Zhao, Xiaoyi; Sun, Xiaogang; Liu, Shutian; Ashfaq Ahmad, Muhammad

2009-11-01

A simple but effective scheme to generate dark hollow beams is proposed by use of phase-only filtering and optical Fourier transform. A Gaussian beam of fundamental mode is modulated by a pre-designed phase mask, which is a piecewise modification of an axicon lens, and followed by a Fourier transform to generate an ideal dark hollow beam at the focal plane. This method has an advantage that the total energy of the beam is conserved under paraxial approximation. Numerical calculations are provided to show the validity of the proposed scheme.

Image Data Compression Having Minimum Perceptual Error

NASA Technical Reports Server (NTRS)

Watson, Andrew B. (Inventor)

1997-01-01

A method is presented for performing color or grayscale image compression that eliminates redundant and invisible image components. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The quantization matrix comprises visual masking by luminance and contrast technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

An alternative route for the synthesis of silicon nanowires via porous anodic alumina masks

PubMed Central

2011-01-01

Amorphous Si nanowires have been directly synthesized by a thermal processing of Si substrates. This method involves the deposition of an anodic aluminum oxide mask on a crystalline Si (100) substrate. Fe, Au, and Pt thin films with thicknesses of ca. 30 nm deposited on the anodic aluminum oxide-Si substrates have been used as catalysts. During the thermal treatment of the samples, thin films of the metal catalysts are transformed in small nanoparticles incorporated within the pore structure of the anodic aluminum oxide mask, directly in contact with the Si substrate. These homogeneously distributed metal nanoparticles are responsible for the growth of Si nanowires with regular diameter by a simple heating process at 800°C in an Ar-H2 atmosphere and without an additional Si source. The synthesized Si nanowires have been characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman. PMID:21849077

The eye as a window to the listening brain: neural correlates of pupil size as a measure of cognitive listening load.

PubMed

Zekveld, Adriana A; Heslenfeld, Dirk J; Johnsrude, Ingrid S; Versfeld, Niek J; Kramer, Sophia E

2014-11-01

An important aspect of hearing is the degree to which listeners have to deploy effort to understand speech. One promising measure of listening effort is task-evoked pupil dilation. Here, we use functional magnetic resonance imaging (fMRI) to identify the neural correlates of pupil dilation during comprehension of degraded spoken sentences in 17 normal-hearing listeners. Subjects listened to sentences degraded in three different ways: the target female speech was masked by fluctuating noise, by speech from a single male speaker, or the target speech was noise-vocoded. The degree of degradation was individually adapted such that 50% or 84% of the sentences were intelligible. Control conditions included clear speech in quiet, and silent trials. The peak pupil dilation was larger for the 50% compared to the 84% intelligibility condition, and largest for speech masked by the single-talker masker, followed by speech masked by fluctuating noise, and smallest for noise-vocoded speech. Activation in the bilateral superior temporal gyrus (STG) showed the same pattern, with most extensive activation for speech masked by the single-talker masker. Larger peak pupil dilation was associated with more activation in the bilateral STG, bilateral ventral and dorsal anterior cingulate cortex and several frontal brain areas. A subset of the temporal region sensitive to pupil dilation was also sensitive to speech intelligibility and degradation type. These results show that pupil dilation during speech perception in challenging conditions reflects both auditory and cognitive processes that are recruited to cope with degraded speech and the need to segregate target speech from interfering sounds. Copyright © 2014 Elsevier Inc. All rights reserved.

Combination of binaural and harmonic masking release effects in the detection of a single component in complex tones.

PubMed

Klein-Hennig, Martin; Dietz, Mathias; Hohmann, Volker

2018-03-01

Both harmonic and binaural signal properties are relevant for auditory processing. To investigate how these cues combine in the auditory system, detection thresholds for an 800-Hz tone masked by a diotic (i.e., identical between the ears) harmonic complex tone were measured in six normal-hearing subjects. The target tone was presented either diotically or with an interaural phase difference (IPD) of 180° and in either harmonic or "mistuned" relationship to the diotic masker. Three different maskers were used, a resolved and an unresolved complex tone (fundamental frequency: 160 and 40 Hz) with four components below and above the target frequency and a broadband unresolved complex tone with 12 additional components. The target IPD provided release from masking in most masker conditions, whereas mistuning led to a significant release from masking only in the diotic conditions with the resolved and the narrowband unresolved maskers. A significant effect of mistuning was neither found in the diotic condition with the wideband unresolved masker nor in any of the dichotic conditions. An auditory model with a single analysis frequency band and different binaural processing schemes was employed to predict the data of the unresolved masker conditions. Sensitivity to modulation cues was achieved by including an auditory-motivated modulation filter in the processing pathway. The predictions of the diotic data were in line with the experimental results and literature data in the narrowband condition, but not in the broadband condition, suggesting that across-frequency processing is involved in processing modulation information. The experimental and model results in the dichotic conditions show that the binaural processor cannot exploit modulation information in binaurally unmasked conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Power in the Production of Spaces Transformed by Rural Tourism

ERIC Educational Resources Information Center

Frisvoll, Svein

2012-01-01

The article critiques Halfacree's conceptualisation of rural space for masking the workings of power within "black boxes" such as "structural coherence" and "trial by space". One consequence is that rural change's social activities and also their social and personal consequences are cloaked, thereby rendering the localised fault lines of rurality…

When You Wish upon a Star It Makes a Difference Who You Are: Children's Culture and the Wonderful World of Disney.

ERIC Educational Resources Information Center

Giroux, Henry A.

1995-01-01

The boundaries between entertainment, education, and commercialization collapse through Disney's reach into diverse spheres of everyday life. Disney's "innocence" is a promotional mask covering its aggressive marketing techniques and influence in transforming children into active consumers. Although Disney's films are joyous and…

Critical and Transformative Literacies: Music and General Education

ERIC Educational Resources Information Center

Benedict, Cathy L.

2012-01-01

Even though there are multiple literacies, the preoccupation and even reliance on the primacy of functional literacy, as seen as an end-point in the formal process of schooling, masks an ideology that rarely goes interrogated throughout all disciplines. This article considers the obligation and structure of functional literacy, and, in particular,…

Associative priming in a masked perceptual identification task: evidence for automatic processes.

PubMed

Pecher, Diane; Zeelenberg, René; Raaijmakers, Jeroen G W

2002-10-01

Two experiments investigated the influence of automatic and strategic processes on associative priming effects in a perceptual identification task in which prime-target pairs are briefly presented and masked. In this paradigm, priming is defined as a higher percentage of correctly identified targets for related pairs than for unrelated pairs. In Experiment 1, priming was obtained for mediated word pairs. This mediated priming effect was affected neither by the presence of direct associations nor by the presentation time of the primes, indicating that automatic priming effects play a role in perceptual identification. Experiment 2 showed that the priming effect was not affected by the proportion (.90 vs. .10) of related pairs if primes were presented briefly to prevent their identification. However, a large proportion effect was found when primes were presented for 1000 ms so that they were clearly visible. These results indicate that priming in a masked perceptual identification task is the result of automatic processes and is not affected by strategies. The present paradigm provides a valuable alternative to more commonly used tasks such as lexical decision.

Semantic priming effects from single words in a lexical decision task.

PubMed

Noguera, Carmen; Ortells, Juan J; Abad, María J F; Carmona, Encarnación; Daza, M Teresa

2007-06-01

The present research examines the semantic priming effects of a centrally presented single prime word to which participants were instructed to either "attend and remember" or "ignore". The prime word was followed by a central probe target on which the participants made a lexical decision task. The main variables manipulated across experiments were prime duration (50 or 100 ms), the presence or absence of a mask following the prime, and the presence (or absence) and type of distractor stimulus (random set of consonants or pseudowords) on the probe display. There was a consistent interaction between the instructions and the semantic priming effects. Relative to the "attend and remember" instruction, an "ignore" instruction produced reduced positive priming from single primes presented for 100 ms, irrespective of the presence or absence of a prime mask, and regardless of whether the probe target was presented with or without distractors. Additionally, reliable negative priming was found from ignored primes presented for briefer durations (50 ms) and immediately followed by a mask. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.

Invisibility and interpretation.

PubMed

Herzog, Michael H; Hermens, Frouke; Oğmen, Haluk

2014-01-01

Invisibility is often thought to occur because of the low-level limitations of the visual system. For example, it is often assumed that backward masking renders a target invisible because the visual system is simply too slow to resolve the target and the mask separately. Here, we propose an alternative explanation in which invisibility is a goal rather than a limitation and occurs naturally when making sense out of the plethora of incoming information. For example, we present evidence that (in)visibility of an element can strongly depend on how it groups with other elements. Changing grouping changes visibility. In addition, we will show that features often just appear to be invisible but are in fact visible in a way the experimenter is not aware of.

Invisibility and interpretation

PubMed Central

Herzog, Michael H.; Hermens, Frouke; Öğmen, Haluk

2014-01-01

Invisibility is often thought to occur because of the low-level limitations of the visual system. For example, it is often assumed that backward masking renders a target invisible because the visual system is simply too slow to resolve the target and the mask separately. Here, we propose an alternative explanation in which invisibility is a goal rather than a limitation and occurs naturally when making sense out of the plethora of incoming information. For example, we present evidence that (in)visibility of an element can strongly depend on how it groups with other elements. Changing grouping changes visibility. In addition, we will show that features often just appear to be invisible but are in fact visible in a way the experimenter is not aware of. PMID:25278910

Time course of dichoptic masking in normals and suppression in amblyopes.

PubMed

Zhou, Jiawei; McNeal, Suzanne; Babu, Raiju J; Baker, Daniel H; Bobier, William R; Hess, Robert F

2014-04-17

To better understand the relationship between dichoptic masking in normal vision and suppression in amblyopia we address three questions: First, what is the time course of dichoptic masking in normals and amblyopes? Second, is interocular suppression low-pass or band-pass in its spatial dependence? And third, in the above two regards, is dichoptic masking in normals different from amblyopic suppression? We measured the dependence of dichoptic masking in normal controls and amblyopes on the temporal duration of presentation under three conditions; monocular (the nontested eye-i.e., dominant eye of normals or nonamblyopic eye of amblyopes, being patched), dichoptic-luminance (the nontested eye seeing a mean luminance-i.e., a DC component) and dichoptic-contrast (the nontested eye seeing high-contrast visual noise). The subject had to detect a letter in the other eye, the contrast of which was varied. We found that threshold elevation relative to the patched condition occurred in both normals and amblyopes when the nontested eye saw either 1/f or band-pass filtered noise, but not just mean luminance (i.e., there was no masking from the DC component that corresponds to a channel responsive to a spatial frequency of 0 cyc/deg); longer presentation of the target (corresponding to lower temporal frequencies) produced greater threshold elevation. Dichoptic masking exhibits similar properties in both subject groups, being low-pass temporally and band-pass spatially, so that masking was greatest at the longest presentation durations and was not greatly affected by mean luminance in the nontested eye. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

An optimized OPC and MDP flow for reducing mask write time and mask cost

NASA Astrophysics Data System (ADS)

Yang, Ellyn; Li, Cheng He; Park, Se Jin; Zhu, Yu; Guo, Eric

2010-09-01

In the process of optical proximity correction, layout edge or fragment is migrating to proper position in order to minimize edge placement error (EPE). During this fragment migration, several factors other than EPE can be also taken into account as a part of cost function for optimal fragment displacement. Several factors are devised in favor of OPC stability, which can accommodate room for high mask error enhancement factor (MEEF), lack of process window, catastrophic pattern failure such as pinch/bridge and improper fragmentation. As technology node becomes finer, there happens conflict between OPC accuracy and stability. Especially for metal layers, OPC has focused on the stability by loss of accurate OPC results. On this purpose, several techniques have been introduced, which are target smoothing, process window aware OPC, model-based retargeting and adaptive OPC. By utilizing those techniques, OPC enables more stabilized patterning, instead of realizing design target exactly on wafer. Inevitably, post-OPC layouts become more complicated because those techniques invoke additional edge, or fragments prior to correction or during OPC iteration. As a result, jogs of post OPC layer can be dramatically increased, which results in huge number of shot count after data fracturing. In other words, there is trade-off relationship between data complexity and various methods for OPC stability. In this paper, those relationships have been investigated with respect to several technology nodes. The mask shot count reduction is achieved by reducing the number of jogs with which EPE difference are within pre-specified value. The effect of jog smoothing on OPC output - in view of OPC performance and mask data preparation - was studied quantitatively for respective technology nodes.

An open-architecture approach to defect analysis software for mask inspection systems

NASA Astrophysics Data System (ADS)

Pereira, Mark; Pai, Ravi R.; Reddy, Murali Mohan; Krishna, Ravi M.

2009-04-01

Industry data suggests that Mask Inspection represents the second biggest component of Mask Cost and Mask Turn Around Time (TAT). Ever decreasing defect size targets lead to more sensitive mask inspection across the chip, thus generating too many defects. Hence, more operator time is being spent in analyzing and disposition of defects. Also, the fact that multiple Mask Inspection Systems and Defect Analysis strategies would typically be in use in a Mask Shop or a Wafer Foundry further complicates the situation. In this scenario, there is a need for a versatile, user friendly and extensible Defect Analysis software that reduces operator analysis time and enables correct classification and disposition of mask defects by providing intuitive visual and analysis aids. We propose a new vendor-neutral defect analysis software, NxDAT, based on an open architecture. The open architecture of NxDAT makes it easily extensible to support defect analysis for mask inspection systems from different vendors. The capability to load results from mask inspection systems from different vendors either directly or through a common interface enables the functionality of establishing correlation between inspections carried out by mask inspection systems from different vendors. This capability of NxDAT enhances the effectiveness of defect analysis as it directly addresses the real-life scenario where multiple types of mask inspection systems from different vendors co-exist in mask shops or wafer foundries. The open architecture also potentially enables loading wafer inspection results as well as loading data from other related tools such as Review Tools, Repair Tools, CD-SEM tools etc, and correlating them with the corresponding mask inspection results. A unique concept of Plug-In interface to NxDAT further enhances the openness of the architecture of NxDAT by enabling end-users to add their own proprietary defect analysis and image processing algorithms. The plug-in interface makes it possible for the end-users to make use of their collected knowledge through the years of experience in mask inspection process by encapsulating the knowledge into software utilities and plugging them into NxDAT. The plug-in interface is designed with the intent of enabling the pro-active mask defect analysis teams to build competitive differentiation into their defect analysis process while protecting their knowledge internally within their company. By providing interface with all major standard layout and mask data formats, NxDAT enables correlation of defect data on reticles with design and mask databases, further extending the effectiveness of defect analysis for D2DB inspection. NxDAT also includes many other advanced features for easy and fast navigation, visual display of defects, defect selection, multi-tier classification, defect clustering and gridding, sophisticated CD and contact measurement analysis, repeatability analysis such as adder analysis, defect trend, capture rate etc.

Space-Valence Priming with Subliminal and Supraliminal Words

PubMed Central

Ansorge, Ulrich; Khalid, Shah; König, Peter

2013-01-01

To date it is unclear whether (1) awareness-independent non-evaluative semantic processes influence affective semantics and whether (2) awareness-independent affective semantics influence non-evaluative semantic processing. In the current study, we investigated these questions with the help of subliminal (masked) primes and visible targets in a space-valence across-category congruence effect. In line with (1), we found that subliminal space prime words influenced valence classification of supraliminal target words (Experiment 1): classifications were faster with a congruent prime (e.g., the prime “up” before the target “happy”) than with an incongruent prime (e.g., the prime “up” before the target “sad”). In contrast to (2), no influence of subliminal valence primes on the classification of supraliminal space targets into up- and down-words was found (Experiment 2). Control conditions showed that standard masked response priming effects were found with both subliminal prime types, and that an across-category congruence effect was also found with supraliminal valence primes and spatial target words. The final Experiment 3 confirmed that the across-category congruence effect indeed reflected priming of target categorization of a relevant meaning category. Together, the data jointly confirmed prediction (1) that awareness-independent non-evaluative semantic priming influences valence judgments. PMID:23439863

Binaural segregation in multisource reverberant environments.

PubMed

Roman, Nicoleta; Srinivasan, Soundararajan; Wang, DeLiang

2006-12-01

In a natural environment, speech signals are degraded by both reverberation and concurrent noise sources. While human listening is robust under these conditions using only two ears, current two-microphone algorithms perform poorly. The psychological process of figure-ground segregation suggests that the target signal is perceived as a foreground while the remaining stimuli are perceived as a background. Accordingly, the goal is to estimate an ideal time-frequency (T-F) binary mask, which selects the target if it is stronger than the interference in a local T-F unit. In this paper, a binaural segregation system that extracts the reverberant target signal from multisource reverberant mixtures by utilizing only the location information of target source is proposed. The proposed system combines target cancellation through adaptive filtering and a binary decision rule to estimate the ideal T-F binary mask. The main observation in this work is that the target attenuation in a T-F unit resulting from adaptive filtering is correlated with the relative strength of target to mixture. A comprehensive evaluation shows that the proposed system results in large SNR gains. In addition, comparisons using SNR as well as automatic speech recognition measures show that this system outperforms standard two-microphone beamforming approaches and a recent binaural processor.

Cross-talk free selective reconstruction of individual objects from multiplexed optical field data

NASA Astrophysics Data System (ADS)

Zea, Alejandro Velez; Barrera, John Fredy; Torroba, Roberto

2018-01-01

In this paper we present a data multiplexing method for simultaneous storage in a single package composed by several optical fields of tridimensional (3D) objects, and their individual cross-talk free retrieval. Optical field data are extracted from off axis Fourier holograms, and then sampled by multiplying them with random binary masks. The resulting sampled optical fields can be used to reconstruct the original objects. Sampling causes a loss of quality that can be controlled by the number of white pixels in the binary masks and by applying a padding procedure on the optical field data. This process can be performed using a different binary mask for each optical field, and then added to form a multiplexed package. With the adequate choice of sampling and padding, we can achieve a volume reduction in the multiplexed package over the addition of all individual optical fields. Moreover, the package can be multiplied by a binary mask to select a specific optical field, and after the reconstruction procedure, the corresponding 3D object is recovered without any cross-talk. We demonstrate the effectiveness of our proposal for data compression with a comparison with discrete cosine transform filtering. Experimental results confirm the validity of our proposal.

Optimized distributed computing environment for mask data preparation

NASA Astrophysics Data System (ADS)

Ahn, Byoung-Sup; Bang, Ju-Mi; Ji, Min-Kyu; Kang, Sun; Jang, Sung-Hoon; Choi, Yo-Han; Ki, Won-Tai; Choi, Seong-Woon; Han, Woo-Sung

2005-11-01

As the critical dimension (CD) becomes smaller, various resolution enhancement techniques (RET) are widely adopted. In developing sub-100nm devices, the complexity of optical proximity correction (OPC) is severely increased and applied OPC layers are expanded to non-critical layers. The transformation of designed pattern data by OPC operation causes complexity, which cause runtime overheads to following steps such as mask data preparation (MDP), and collapse of existing design hierarchy. Therefore, many mask shops exploit the distributed computing method in order to reduce the runtime of mask data preparation rather than exploit the design hierarchy. Distributed computing uses a cluster of computers that are connected to local network system. However, there are two things to limit the benefit of the distributing computing method in MDP. First, every sequential MDP job, which uses maximum number of available CPUs, is not efficient compared to parallel MDP job execution due to the input data characteristics. Second, the runtime enhancement over input cost is not sufficient enough since the scalability of fracturing tools is limited. In this paper, we will discuss optimum load balancing environment that is useful in increasing the uptime of distributed computing system by assigning appropriate number of CPUs for each input design data. We will also describe the distributed processing (DP) parameter optimization to obtain maximum throughput in MDP job processing.

An iterative sinogram gap-filling method with object- and scanner-dedicated discrete cosine transform (DCT)-domain filters for high resolution PET scanners.

PubMed

Kim, Kwangdon; Lee, Kisung; Lee, Hakjae; Joo, Sungkwan; Kang, Jungwon

2018-01-01

We aimed to develop a gap-filling algorithm, in particular the filter mask design method of the algorithm, which optimizes the filter to the imaging object by an adaptive and iterative process, rather than by manual means. Two numerical phantoms (Shepp-Logan and Jaszczak) were used for sinogram generation. The algorithm works iteratively, not only on the gap-filling iteration but also on the mask generation, to identify the object-dedicated low frequency area in the DCT-domain that is to be preserved. We redefine the low frequency preserving region of the filter mask at every gap-filling iteration, and the region verges on the property of the original image in the DCT domain. The previous DCT2 mask for each phantom case had been manually well optimized, and the results show little difference from the reference image and sinogram. We observed little or no difference between the results of the manually optimized DCT2 algorithm and those of the proposed algorithm. The proposed algorithm works well for various types of scanning object and shows results that compare to those of the manually optimized DCT2 algorithm without perfect or full information of the imaging object.

Removal of bone in CT angiography by multiscale matched mask bone elimination.

PubMed

Gratama van Andel, H A F; Venema, H W; Streekstra, G J; van Straten, M; Majoie, C B L M; den Heeten, G J; Grimbergen, C A

2007-10-01

For clear visualization of vessels in CT angiography (CTA) images of the head and neck using maximum intensity projection (MIP) or volume rendering (VR) bone has to be removed. In the past we presented a fully automatic method to mask the bone [matched mask bone elimination (MMBE)] for this purpose. A drawback is that vessels adjacent to bone may be partly masked as well. We propose a modification, multiscale MMBE, which reduces this problem by using images at two scales: a higher resolution than usual for image processing and a lower resolution to which the processed images are transformed for use in the diagnostic process. A higher in-plane resolution is obtained by the use of a sharper reconstruction kernel. The out-of-plane resolution is improved by deconvolution or by scanning with narrower collimation. The quality of the mask that is used to remove bone is improved by using images at both scales. After masking, the desired resolution for the normal clinical use of the images is obtained by blurring with Gaussian kernels of appropriate widths. Both methods (multiscale and original) were compared in a phantom study and with clinical CTA data sets. With the multiscale approach the width of the strip of soft tissue adjacent to the bone that is masked can be reduced from 1.0 to 0.2 mm without reducing the quality of the bone removal. The clinical examples show that vessels adjacent to bone are less affected and therefore better visible. Images processed with multiscale MMBE have a slightly higher noise level or slightly reduced resolution compared with images processed by the original method and the reconstruction and processing time is also somewhat increased. Nevertheless, multiscale MMBE offers a way to remove bone automatically from CT angiography images without affecting the integrity of the blood vessels. The overall image quality of MIP or VR images is substantially improved relative to images processed with the original MMBE method.

Two novel motion-based algorithms for surveillance video analysis on embedded platforms

NASA Astrophysics Data System (ADS)

Vijverberg, Julien A.; Loomans, Marijn J. H.; Koeleman, Cornelis J.; de With, Peter H. N.

2010-05-01

This paper proposes two novel motion-vector based techniques for target detection and target tracking in surveillance videos. The algorithms are designed to operate on a resource-constrained device, such as a surveillance camera, and to reuse the motion vectors generated by the video encoder. The first novel algorithm for target detection uses motion vectors to construct a consistent motion mask, which is combined with a simple background segmentation technique to obtain a segmentation mask. The second proposed algorithm aims at multi-target tracking and uses motion vectors to assign blocks to targets employing five features. The weights of these features are adapted based on the interaction between targets. These algorithms are combined in one complete analysis application. The performance of this application for target detection has been evaluated for the i-LIDS sterile zone dataset and achieves an F1-score of 0.40-0.69. The performance of the analysis algorithm for multi-target tracking has been evaluated using the CAVIAR dataset and achieves an MOTP of around 9.7 and MOTA of 0.17-0.25. On a selection of targets in videos from other datasets, the achieved MOTP and MOTA are 8.8-10.5 and 0.32-0.49 respectively. The execution time on a PC-based platform is 36 ms. This includes the 20 ms for generating motion vectors, which are also required by the video encoder.

Speech recognition in one- and two-talker maskers in school-age children and adults: Development of perceptual masking and glimpsing

PubMed Central

Buss, Emily; Leibold, Lori J.; Porter, Heather L.; Grose, John H.

2017-01-01

Children perform more poorly than adults on a wide range of masked speech perception paradigms, but this effect is particularly pronounced when the masker itself is also composed of speech. The present study evaluated two factors that might contribute to this effect: the ability to perceptually isolate the target from masker speech, and the ability to recognize target speech based on sparse cues (glimpsing). Speech reception thresholds (SRTs) were estimated for closed-set, disyllabic word recognition in children (5–16 years) and adults in a one- or two-talker masker. Speech maskers were 60 dB sound pressure level (SPL), and they were either presented alone or in combination with a 50-dB-SPL speech-shaped noise masker. There was an age effect overall, but performance was adult-like at a younger age for the one-talker than the two-talker masker. Noise tended to elevate SRTs, particularly for older children and adults, and when summed with the one-talker masker. Removing time-frequency epochs associated with a poor target-to-masker ratio markedly improved SRTs, with larger effects for younger listeners; the age effect was not eliminated, however. Results were interpreted as indicating that development of speech-in-speech recognition is likely impacted by development of both perceptual masking and the ability recognize speech based on sparse cues. PMID:28464682

Eyes wide open: Pupil size as a proxy for inhibition in the masked-priming paradigm.

PubMed

Geller, Jason; Still, Mary L; Morris, Alison L

2016-05-01

A core assumption underlying competitive-network models of word recognition is that in order for a word to be recognized, the representations of competing orthographically similar words must be inhibited. This inhibitory mechanism is revealed in the masked-priming lexical-decision task (LDT) when responses to orthographically similar word prime-target pairs are slower than orthographically different word prime-target pairs (i.e., inhibitory priming). In English, however, behavioral evidence for inhibitory priming has been mixed. In the present study, we utilized a physiological correlate of cognitive effort never before used in the masked-priming LDT, pupil size, to replicate and extend behavioral demonstrations of inhibitory effects (i.e., Nakayama, Sears, & Lupker, Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008, Exp. 1). Previous research had suggested that pupil size is a reliable indicator of cognitive load, making it a promising index of lexical inhibition. Our pupillometric data replicated and extended previous behavioral findings, in that inhibition was obtained for orthographically similar word prime-target pairs. However, our response time data provided only a partial replication of Nakayama et al. Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008. These results provide converging lines of evidence that inhibition operates in word recognition and that pupillometry is a useful addition to word recognition researchers' toolbox.

QR code-based non-linear image encryption using Shearlet transform and spiral phase transform

NASA Astrophysics Data System (ADS)

Kumar, Ravi; Bhaduri, Basanta; Hennelly, Bryan

2018-02-01

In this paper, we propose a new quick response (QR) code-based non-linear technique for image encryption using Shearlet transform (ST) and spiral phase transform. The input image is first converted into a QR code and then scrambled using the Arnold transform. The scrambled image is then decomposed into five coefficients using the ST and the first Shearlet coefficient, C1 is interchanged with a security key before performing the inverse ST. The output after inverse ST is then modulated with a random phase mask and further spiral phase transformed to get the final encrypted image. The first coefficient, C1 is used as a private key for decryption. The sensitivity of the security keys is analysed in terms of correlation coefficient and peak signal-to noise ratio. The robustness of the scheme is also checked against various attacks such as noise, occlusion and special attacks. Numerical simulation results are shown in support of the proposed technique and an optoelectronic set-up for encryption is also proposed.

Lactate signalling regulates fungal β-glucan masking and immune evasion

PubMed Central

Ballou, Elizabeth R.; Avelar, Gabriela M.; Childers, Delma S.; Mackie, Joanna; Bain, Judith M.; Wagener, Jeanette; Kastora, Stavroula L.; Panea, Mirela D.; Hardison, Sarah E.; Walker, Louise A.; Erwig, Lars P.; Munro, Carol A.; Gow, Neil A.R.; Brown, Gordon D.; MacCallum, Donna M.; Brown, Alistair J.P.

2017-01-01

Summary Paragraph As they proliferate, fungi expose antigens at their cell surface that are potent stimulators of the innate immune response, and yet the commensal fungus Candida albicans is able to colonize immuno-competent individuals. We show that C. albicans may evade immune detection by presenting a moving immunological target. We report that the exposure of β-glucan, a key Pathogen Associated Molecular Pattern (PAMP) located at the cell surface of C. albicans and other pathogenic Candida species, is modulated in response to changes in carbon source. Exposure to lactate induces β-glucan masking in C. albicans via a signaling pathway that has recruited an evolutionarily conserved receptor (Gpr1) and transcriptional factor (Crz1) from other well-characterized pathways. In response to lactate, these regulators control the expression of cell wall related genes that contribute to β-glucan masking. This represents the first description of active PAMP masking by a Candida species, a process that reduces the visibility of the fungus to the immune system. PMID:27941860

Not Everybody Sees the Ness in the Darkness: Individual Differences in Masked Suffix Priming

PubMed Central

Medeiros, Joyse; Duñabeitia, Jon Andoni

2016-01-01

The present study explores the role of individual differences in polymorphemic word recognition. Participants completed a masked priming lexical decision experiment on suffixed words in which targets could be preceded by suffix-related words (words sharing the same suffix) or by affixed primes with a different suffix. Participants also completed a monomorphemic word lexical decision and were divided in two groups (fast and slow readers) according to their performance in this task. When the suffix priming data were analyzed taking into consideration participants' reading speed as a proxy for their greater reliance on orthography or on semantics, a significant interaction between reading speed and the magnitude of the masked suffix priming effects emerged. Only slow participants showed significant priming effects, whereas faster participants showed negligible masked suffix priming effects. These results demonstrate that different reading profiles modulate the access to morphological information in a qualitatively different manner and that individual differences in reading determine the manner in which polymorphemic words are processed. PMID:27790180

Studying the inner regions of young stars and their disks with aperture masking interferometry

NASA Astrophysics Data System (ADS)

Greenbaum, Alexandra; Sivaramakrishnan, Anand; GPI Instrument Team; NIRISS Instrument Team

2017-01-01

High resolution aperture masking interferometry complements coronagraphic imagers to provide a unique perspective on star and planet formation at more moderate contrast. By targeting young stars, especially those with disks, we aim to understand complex protoplanetary environments. Ground-based non-redundant masking (NRM) paired with spectrographs and polarimeters probes both thermally emitting young companions, possibly embedded in the disk or gap and scattered light in protoplanetary disks. And soon the community will have access to the most stable NRM conditions yet, with the Near Infrared Imager and Slitless Spectrograph (NIRISS) Aperture Masking Interferometry (AMI) mode on the James Webb Space Telescope. I will present my thesis work commissioning the Gemini Planet Imager’s NRM, highlighting results through both its spectroscopy and polarimetry modes, which set the stage for future space-based imaging. I will also give an overview of NIRISS-AMI capabilities and performance predictions for imaging young low-mass companions and disks, and how it will complement other instruments on JWST.

The temporal dynamics of masked repetition picture priming effects: manipulations of stimulus-onset asynchrony (SOA) and prime duration.

PubMed

Eddy, Marianna D; Holcomb, Phillip J

2010-06-22

The current study used event-related potentials (ERPs) and masked repetition priming to examine the time-course of picture processing. We manipulated the stimulus-onset asynchrony (110 ms, 230 ms, 350 ms, and 470 ms) between repeated and unrepeated prime-target pairs while holding the prime duration constant (50 ms) (Experiment 1) as well as the prime durations (30 ms, 50 ms, 70 ms, and 90 ms) (Experiment 2) with a constant SOA of 110 ms in a masked repetition priming paradigm with pictures. The aim of this study was to further elucidate the mechanisms underlying previously observed ERP components in masked priming with pictures. We found that both the N/P190 and N400 are modulated by changes in prime duration and SOA, however, it appears that longer prime exposure rather than a longer SOA leads to more in-depth processing as indexed by larger N400 effects. (c) 2010 Elsevier B.V. All rights reserved.

Eye movements and the span of the effective stimulus in visual search.

PubMed

Bertera, J H; Rayner, K

2000-04-01

The span of the effective stimulus during visual search through an unstructured alphanumeric array was investigated by using eye-contingent-display changes while the subjects searched for a target letter. In one condition, a window exposing the search array moved in synchrony with the subjects' eye movements, and the size of the window was varied. Performance reached asymptotic levels when the window was 5 degrees. In another condition, a foveal mask moved in synchrony with each eye movement, and the size of the mask was varied. The foveal mask conditions were much more detrimental to search behavior than the window conditions, indicating the importance of foveal vision during search. The size of the array also influenced performance, but performance reached asymptote for all array sizes tested at the same window size, and the effect of the foveal mask was the same for all array sizes. The results indicate that both acuity and difficulty of the search task influenced the span of the effective stimulus during visual search.

The Influence of Target and Masker Characteristics on Infants' and Adults' Detection of Speech

ERIC Educational Resources Information Center

Oster, Monika-Maria; Werner, Lynne A.

2017-01-01

Purpose: Several investigators have compared infants' detection of speech in speech and nonspeech maskers to evaluate developmental differences in masking. Such comparisons have produced contradictory results, possibly because each investigation used different stimuli. The current study examined target and masker effects on infants' and adults'…

The Effect of Nonmasking Distractors on the Priming of Motor Responses

ERIC Educational Resources Information Center

Jaskowski, Piotr

2007-01-01

Masked stimuli (primes) can affect the preparation of a motor response to subsequently presented target. In numerous studies, it has been shown that the compatibility effect is biphasic as it develops over time: positive (benefits for compatible trials and costs for incompatible trials) for short prime-target temporal distances and negative…

Morpho-Semantic Processing in Word Recognition: Evidence from Balanced and Biased Ambiguous Morphemes

ERIC Educational Resources Information Center

Tsang, Yiu-Kei; Chen, Hsuan-Chih

2013-01-01

The role of morphemic meaning in Chinese word recognition was examined with the masked and unmasked priming paradigms. Target words contained ambiguous morphemes biased toward the dominant or the subordinate meanings. Prime words either contained the same ambiguous morphemes in the subordinate interpretations or were unrelated to the targets. In…

Dolphin biosonar target detection in noise: wrap up of a past experiment.

PubMed

Au, Whitlow W L

2014-07-01

The target detection capability of bottlenose dolphins in the presence of artificial masking noise was first studied by Au and Penner [J. Acoust. Soc. Am. 70, 687-693 (1981)] in which the dolphins' target detection threshold was determined as a function of the ratio of the echo energy flux density and the estimated received noise spectral density. Such a metric was commonly used in human psychoacoustics despite the fact that the echo energy flux density is not compatible with noise spectral density which is averaged intensity per Hz. Since the earlier detection in noise studies, two important parameters, the dolphin integration time applicable to broadband clicks and the dolphin's auditory filter shape, were determined. The inclusion of these two parameters allows for the estimation of the received energy flux density of the masking noise so that the dolphin target detection can now be determined as a function of the ratio of the received energy of the echo over the received noise energy. Using an integration time of 264 μs and an auditory bandwidth of 16.7 kHz, the ratio of the echo energy to noise energy at the target detection threshold is approximately 1 dB.

The spatial unmasking of speech: evidence for within-channel processing of interaural time delay.

PubMed

Edmonds, Barrie A; Culling, John F

2005-05-01

Across-frequency processing by common interaural time delay (ITD) in spatial unmasking was investigated by measuring speech reception thresholds (SRTs) for high- and low-frequency bands of target speech presented against concurrent speech or a noise masker. Experiment 1 indicated that presenting one of these target bands with an ITD of +500 micros and the other with zero ITD (like the masker) provided some release from masking, but full binaural advantage was only measured when both target bands were given an ITD of + 500 micros. Experiment 2 showed that full binaural advantage could also be achieved when the high- and low-frequency bands were presented with ITDs of equal but opposite magnitude (+/- 500 micros). In experiment 3, the masker was also split into high- and low-frequency bands with ITDs of equal but opposite magnitude (+/-500 micros). The ITD of the low-frequency target band matched that of the high-frequency masking band and vice versa. SRTs indicated that, as long as the target and masker differed in ITD within each frequency band, full binaural advantage could be achieved. These results suggest that the mechanism underlying spatial unmasking exploits differences in ITD independently within each frequency channel.

Known-plaintext attack on a joint transform correlator encrypting system.

PubMed

Barrera, John Fredy; Vargas, Carlos; Tebaldi, Myrian; Torroba, Roberto; Bolognini, Nestor

2010-11-01

We demonstrate in this Letter that a joint transform correlator shows vulnerability to known-plaintext attacks. An unauthorized user, who intercepts both an object and its encrypted version, can obtain the security key code mask. In this contribution, we conduct a hybrid heuristic attack scheme merge to a Gerchberg-Saxton routine to estimate the encrypting key to decode different ciphertexts encrypted with that same key. We also analyze the success of this attack for different pairs of plaintext-ciphertext used to get the encrypting code. We present simulation results for the decrypting procedure to demonstrate the validity of our analysis.

Automatic Masking for Robust 3D-2D Image Registration in Image-Guided Spine Surgery.

PubMed

Ketcha, M D; De Silva, T; Uneri, A; Kleinszig, G; Vogt, S; Wolinsky, J-P; Siewerdsen, J H

During spinal neurosurgery, patient-specific information, planning, and annotation such as vertebral labels can be mapped from preoperative 3D CT to intraoperative 2D radiographs via image-based 3D-2D registration. Such registration has been shown to provide a potentially valuable means of decision support in target localization as well as quality assurance of the surgical product. However, robust registration can be challenged by mismatch in image content between the preoperative CT and intraoperative radiographs, arising, for example, from anatomical deformation or the presence of surgical tools within the radiograph. In this work, we develop and evaluate methods for automatically mitigating the effect of content mismatch by leveraging the surgical planning data to assign greater weight to anatomical regions known to be reliable for registration and vital to the surgical task while removing problematic regions that are highly deformable or often occluded by surgical tools. We investigated two approaches to assigning variable weight (i.e., "masking") to image content and/or the similarity metric: (1) masking the preoperative 3D CT ("volumetric masking"); and (2) masking within the 2D similarity metric calculation ("projection masking"). The accuracy of registration was evaluated in terms of projection distance error (PDE) in 61 cases selected from an IRB-approved clinical study. The best performing of the masking techniques was found to reduce the rate of gross failure (PDE > 20 mm) from 11.48% to 5.57% in this challenging retrospective data set. These approaches provided robustness to content mismatch and eliminated distinct failure modes of registration. Such improvement was gained without additional workflow and has motivated incorporation of the masking methods within a system under development for prospective clinical studies.

In-vivo heat retention comparison of eyelid warming masks.

PubMed

Bitton, Etty; Lacroix, Zoé; Léger, Stéphanie

2016-08-01

Meibomian gland dysfunction (MGD) is one of the most common causes of evaporative dry eye. Warm compresses (WC) are recommended as adjunct therapy to slowly transfer heat to the meibomian glands to melt or soften the stagnant meibum with targeted temperatures of 40-45°C. This clinical study evaluated the heat retention profiles of commercially available eyelid warming masks over a 12-min interval. Five eyelid-warming masks (MGDRx Eyebag(®), EyeDoctor(®), Bruder(®), Tranquileyes XR™, Thera°Pearl(®)) were heated following manufacturer's instructions and heat retention was assessed at 1-min intervals for 12min. A facecloth warmed with hot tap water was used as comparison. Twelve (n=12) subjects participated in the study (10F:2M, ranging in age from 21 to 30 with an average of 23.2±3.8years). Each mask demonstrated a unique heat retention profile, reaching maximum temperature at different times and having a different final temperature at the end of the 12-min evaluation. After heating, all eyelid warming masks reached a temperature near 37°C within the first minute. The facecloth was significantly cooler than all other masks as of the 2-min mark (p<0.05). Reusability, availability and heat retention profiles should be considered when selecting an eyelid warming masks for adjunct WC therapy in the management of MGD. All masks tested, with the exception of the facecloth, demonstrated stable heat retention throughout the 12min, bringing further awareness that patient education is required to discuss the shortcomings of the heat retention of the facecloth, if only heated once. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Automatic masking for robust 3D-2D image registration in image-guided spine surgery

NASA Astrophysics Data System (ADS)

Ketcha, M. D.; De Silva, T.; Uneri, A.; Kleinszig, G.; Vogt, S.; Wolinsky, J.-P.; Siewerdsen, J. H.

2016-03-01

During spinal neurosurgery, patient-specific information, planning, and annotation such as vertebral labels can be mapped from preoperative 3D CT to intraoperative 2D radiographs via image-based 3D-2D registration. Such registration has been shown to provide a potentially valuable means of decision support in target localization as well as quality assurance of the surgical product. However, robust registration can be challenged by mismatch in image content between the preoperative CT and intraoperative radiographs, arising, for example, from anatomical deformation or the presence of surgical tools within the radiograph. In this work, we develop and evaluate methods for automatically mitigating the effect of content mismatch by leveraging the surgical planning data to assign greater weight to anatomical regions known to be reliable for registration and vital to the surgical task while removing problematic regions that are highly deformable or often occluded by surgical tools. We investigated two approaches to assigning variable weight (i.e., "masking") to image content and/or the similarity metric: (1) masking the preoperative 3D CT ("volumetric masking"); and (2) masking within the 2D similarity metric calculation ("projection masking"). The accuracy of registration was evaluated in terms of projection distance error (PDE) in 61 cases selected from an IRB-approved clinical study. The best performing of the masking techniques was found to reduce the rate of gross failure (PDE > 20 mm) from 11.48% to 5.57% in this challenging retrospective data set. These approaches provided robustness to content mismatch and eliminated distinct failure modes of registration. Such improvement was gained without additional workflow and has motivated incorporation of the masking methods within a system under development for prospective clinical studies.

Automatic pattern localization across layout database and photolithography mask

NASA Astrophysics Data System (ADS)

Morey, Philippe; Brault, Frederic; Beisser, Eric; Ache, Oliver; Röth, Klaus-Dieter

2016-03-01

Advanced process photolithography masks require more and more controls for registration versus design and critical dimension uniformity (CDU). The distribution of the measurement points should be distributed all over the whole mask and may be denser in areas critical to wafer overlay requirements. This means that some, if not many, of theses controls should be made inside the customer die and may use non-dedicated patterns. It is then mandatory to access the original layout database to select patterns for the metrology process. Finding hundreds of relevant patterns in a database containing billions of polygons may be possible, but in addition, it is mandatory to create the complete metrology job fast and reliable. Combining, on one hand, a software expertise in mask databases processing and, on the other hand, advanced skills in control and registration equipment, we have developed a Mask Dataprep Station able to select an appropriate number of measurement targets and their positions in a huge database and automatically create measurement jobs on the corresponding area on the mask for the registration metrology system. In addition, the required design clips are generated from the database in order to perform the rendering procedure on the metrology system. This new methodology has been validated on real production line for the most advanced process. This paper presents the main challenges that we have faced, as well as some results on the global performances.

Substantiating In Vivo Magnetic Brain Tumor Targeting of Cationic Iron Oxide Nanocarriers via Adsorptive Surface Masking

PubMed Central

Chertok, Beata; David, Allan E.; Moffat, Bradford A.; Yang, Victor C.

2009-01-01

Cationic magnetic nanoparticles are attractive as potential vehicles for tumor drug delivery due to their favorable interactions with both the tumor milieu and the therapeutic cargo. However, systemic delivery of these nanoparticles to the tumor site is compromised by their rapid plasma clearance. We developed a simple method for in vivo protection of cationic nanocarriers, using non-covalent surface masking with a conjugate of low molecular weight heparin and polyethylene glycol. Surface masking resulted in an 11-fold increase in plasma AUC and a 2-fold increase in the magnetic capture of systemically injected nanoparticles in orthotopic rodent brain tumors. Overall, the described methodology could expand the prospective applications for cationic magnetic nanoparticles in magnetically-mediated gene/drug delivery. PMID:19782394

Subliminal repetition primes help detection of phonemes in a picture: Evidence for a phonological level of the priming effects.

PubMed

Manoiloff, Laura; Segui, Juan; Hallé, Pierre

2016-01-01

In this research, we combine a cross-form word-picture visual masked priming procedure with an internal phoneme monitoring task to examine repetition priming effects. In this paradigm, participants have to respond to pictures whose names begin with a prespecified target phoneme. This task unambiguously requires retrieving the word-form of the target picture's name and implicitly orients participants' attention towards a phonological level of representation. The experiments were conducted within Spanish, whose highly transparent orthography presumably promotes fast and automatic phonological recoding of subliminal, masked visual word primes. Experiments 1 and 2 show that repetition primes speed up internal phoneme monitoring in the target, compared to primes beginning with a different phoneme from the target, or sharing only their first phoneme with the target. This suggests that repetition primes preactivate the phonological code of the entire target picture's name, hereby speeding up internal monitoring, which is necessarily based on such a code. To further qualify the nature of the phonological code underlying internal phoneme monitoring, a concurrent articulation task was used in Experiment 3. This task did not affect the repetition priming effect. We propose that internal phoneme monitoring is based on an abstract phonological code, prior to its translation into articulation.

New SHARE 2010 HSI-LiDAR dataset: re-calibration, detection assessment and delivery

NASA Astrophysics Data System (ADS)

Ientilucci, Emmett J.

2016-09-01

This paper revisits hyperspectral data collected from the SpecTIR hyperspectral airborne Rochester Experiment (SHARE) in 2010. It has been determined that there were calibration issues in the SWIR portion of the data. This calibration issue is discussed and has been rectified. Approaches for calibration to radiance and compensation to reflectance are discussed based on in-scene information and radiative transfer codes. In addition to the entire flight line, a much large target detection test and evaluation chip has been created which includes an abundance of potential false alarms. New truth masks are created along with results from target detection algorithms. Co-registered LiDAR data is also presented. Finally, all ground truth information (ground photos, metadata, MODTRAN tape5, ASD ground spectral measurements, target truth masks, etc.), in addition to the HSI flight lines and co-registered LiDAR data, has been organized, packaged and uploaded to the Center for Imaging Science / Digital Imaging and Remote Sensing Lab web server for public use.

Importance of phase alignment for interocular suppression.

PubMed

Maehara, Goro; Huang, Pi-Chun; Hess, Robert F

2009-07-01

We measured contrast thresholds for Gabor targets in the presence of maskers which had higher or lower spatial frequencies than the targets. A high-pass fractal masker elevated target contrast thresholds at low and intermediate pedestal contrasts in both monocular and dichoptic modes of presentation, suggesting that the masking occurs after a monocular processing stage. Moreover we found that a high-pass checkerboard masker elevated thresholds at the low and intermediate pedestal contrasts and that most of this threshold elevation disappeared when the phase of the masker's spatial components were scrambled. This masking was effective only in the dichoptic presentation, not in the monocular presentation. These results indicate that phase alignment of the high spatial frequency components plays a crucial role for interocular suppression. We speculate that phase alignments signal the existence of a luminance contour in the monocular image and that this signal suppresses processing of information in the other eye when there is no corresponding signal in that eye.

Formulation and evaluation of sublingual tablets containing Sumatriptan succinate

PubMed Central

Prajapati, Shailesh T; Patel, Parth B; Patel, Chhagan N

2012-01-01

Objective: Sumatriptan succinate is a selective 5-hydroxytryptamine-1 receptor agonist effective in the acute treatment of migraine headaches, having low bioavailability of about 15% orally due to first-pass metabolism. The purpose of this research was to mask the intensely bitter taste of Sumatriptan succinate and to formulate fast-acting, taste-masked sublingual tablet formulation. Materials and Methods: Taste masking was performed by solid dispersion method with mannitol and ion exchange with Kyron T 114 because it releases the drug in salivary pH. The resultant batches were evaluated for in-vivo taste masking as well compatability study (Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC)). For a better feel in the mouth, menthol and sweetener Na saccharine were added to the tablet formulation. The tablets were prepared by direct compression and evaluated for weight variation, thickness, friability, drug content, hardness, disintegration time, wetting time, in vitro drug release, and in vitro permeation study. Results and Discussion: Optimized batches disintegrated in vitro within 28-34 s. Maximum drug release could be achieved with in 10 min for the solid dispersion batches and 14-15 min for the ion-exchange batches with Kyron T 114. The optimized tablet formulation showed better taste and the formulated sublingual tablets may act as a potential alternate for the Sumatriptan succinate oral tablet. Conclusion: Sumatriptan succinate can be successfully taste-masked by both the solid dispersion method using mannitol by the melting method and Ion exchange resin with Kyron T114. It was also concluded that prepared formulation improve bioavailability by prevention of first pass metabolism. PMID:23373008

Etch bias inversion during EUV mask ARC etch

NASA Astrophysics Data System (ADS)

Lajn, Alexander; Rolff, Haiko; Wistrom, Richard

2017-07-01

The introduction of EUV lithography to high volume manufacturing is now within reach for 7nm technology node and beyond (1), at least for some steps. The scheduling is in transition from long to mid-term. Thus, all contributors need to focus their efforts on the production requirements. For the photo mask industry, these requirements include the control of defectivity, CD performance and lifetime of their masks. The mask CD performance including CD uniformity, CD targeting, and CD linearity/ resolution, is predominantly determined by the photo resist performance and by the litho and etch processes. State-of-the-art chemically amplified resists exhibit an asymmetric resolution for directly and indirectly written features, which usually results in a similarly asymmetric resolution performance on the mask. This resolution gap may reach as high as multiple tens of nanometers on the mask level in dependence of the chosen processes. Depending on the printing requirements of the wafer process, a reduction or even an increase of this gap may be required. A potential way of tuning via the etch process, is to control the lateral CD contribution during etch. Aside from process tuning knobs like pressure, RF powers and gases, which usually also affect CD linearity and CD uniformity, the simplest knob is the etch time itself. An increased over etch time results in an increased CD contribution in the normal case. , We found that the etch CD contribution of ARC layer etch on EUV photo masks is reduced by longer over etch times. Moreover, this effect can be demonstrated to be present for different etch chambers and photo resists.

Application of advanced structure to multi-tone mask for FPD process

NASA Astrophysics Data System (ADS)

Song, Jin-Han; Jeong, Jin-Woong; Kim, Kyu-Sik; Jeong, Woo-Gun; Yun, Sang-Pil; Lee, Dong-Heok; Choi, Sang-Soo

2017-07-01

In accordance with improvement of FPD technology, masks such as phase shift mask (PSM) and multi-tone mask (MTM) for a particular purpose also have been developed. Above all, the MTM consisted of more than tri-tone transmittance has a substantial advantage which enables to reduce the number of mask demand in FPD fabrication process contrast to normal mask of two-tone transmittance.[1,2] A chromium (Cr)-based MTM (Typically top type) is being widely employed because of convenience of etch process caused by its only Cr-based structure consisted of Cr absorber layer and Cr half-tone layer. However, the top type of Cr-based MTM demands two Cr sputtering processes after each layer etching process and writing process. For this reason, a different material from the Cr-based MTM is required for reduction of mask fabrication time and cost. In this study, we evaluate a MTM which has a structure combined Cr with molybdenum silicide (MoSi) to resolve the issues mentioned above. The MoSi which is demonstrated by integrated circuit (IC) process is a suitable material for MTM evaluation. This structure could realize multi-transmittance in common with the Cr-based MTM. Moreover, it enables to reduce the number of sputtering process. We investigate a optimized structure upon consideration of productivity along with performance such as critical dimension (CD) variation and transmittance range of each structure. The transmittance is targeted at h-line wavelength (405 nm) in the evaluation. Compared with Cr-based MTM, the performances of all Cr-/MoSi-based MTMs are considered.

Investigating the intrinsic cleanliness of automated handling designed for EUV mask pod-in-pod systems

NASA Astrophysics Data System (ADS)

Brux, O.; van der Walle, P.; van der Donck, J. C. J.; Dress, P.

2011-11-01

Extreme Ultraviolet Lithography (EUVL) is the most promising solution for technology nodes 16nm (hp) and below. However, several unique EUV mask challenges must be resolved for a successful launch of the technology into the market. Uncontrolled introduction of particles and/or contamination into the EUV scanner significantly increases the risk for device yield loss and potentially scanner down-time. With the absence of a pellicle to protect the surface of the EUV mask, a zero particle adder regime between final clean and the point-of-exposure is critical for the active areas of the mask. A Dual Pod concept for handling EUV masks had been proposed by the industry as means to minimize the risk of mask contamination during transport and storage. SuSS-HamaTech introduces MaskTrackPro InSync as a fully automated solution for the handling of EUV masks in and out of this Dual Pod System and therefore constitutes an interface between various tools inside the Fab. The intrinsic cleanliness of each individual handling and storage step of the inner shell (EIP) of this Dual Pod and the EUV mask inside the InSync Tool has been investigated to confirm the capability for minimizing the risk of cross-contamination. An Entegris Dual Pod EUV-1000A-A110 has been used for the qualification. The particle detection for the qualification procedure was executed with the TNO's RapidNano Particle Scanner, qualified for particle sizes down to 50nm (PSL equivalent). It has been shown that the target specification of < 2 particles @ 60nm per 25 cycles has been achieved. In case where added particles were measured, the EIP has been identified as a potential root cause for Ni particle generation. Any direct Ni-Al contact has to be avoided to mitigate the risk of material abrasion.

Evidence for Separate Contributions of High and Low Spatial Frequencies during Visual Word Recognition.

PubMed

Winsler, Kurt; Holcomb, Phillip J; Midgley, Katherine J; Grainger, Jonathan

2017-01-01

Previous studies have shown that different spatial frequency information processing streams interact during the recognition of visual stimuli. However, it is a matter of debate as to the contributions of high and low spatial frequency (HSF and LSF) information for visual word recognition. This study examined the role of different spatial frequencies in visual word recognition using event-related potential (ERP) masked priming. EEG was recorded from 32 scalp sites in 30 English-speaking adults in a go/no-go semantic categorization task. Stimuli were white characters on a neutral gray background. Targets were uppercase five letter words preceded by a forward-mask (#######) and a 50 ms lowercase prime. Primes were either the same word (repeated) or a different word (un-repeated) than the subsequent target and either contained only high, only low, or full spatial frequency information. Additionally within each condition, half of the prime-target pairs were high lexical frequency, and half were low. In the full spatial frequency condition, typical ERP masked priming effects were found with an attenuated N250 (sub-lexical) and N400 (lexical-semantic) for repeated compared to un-repeated primes. For HSF primes there was a weaker N250 effect which interacted with lexical frequency, a significant reversal of the effect around 300 ms, and an N400-like effect for only high lexical frequency word pairs. LSF primes did not produce any of the classic ERP repetition priming effects, however they did elicit a distinct early effect around 200 ms in the opposite direction of typical repetition effects. HSF information accounted for many of the masked repetition priming ERP effects and therefore suggests that HSFs are more crucial for word recognition. However, LSFs did produce their own pattern of priming effects indicating that larger scale information may still play a role in word recognition.

Masking release due to linguistic and phonetic dissimilarity between the target and masker speech

PubMed Central

Calandruccio, Lauren; Brouwer, Susanne; Van Engen, Kristin J.; Dhar, Sumitrajit; Bradlow, Ann R.

2013-01-01

Purpose To investigate masking release for speech maskers for linguistically and phonetically close (English and Dutch) and distant (English and Mandarin) language pairs. Method Twenty monolingual speakers of English with normal-audiometric thresholds participated. Data are reported for an English sentence recognition task in English, Dutch and Mandarin competing speech maskers (Experiment I) and noise maskers (Experiment II) that were matched either to the long-term-average-speech spectra or to the temporal modulations of the speech maskers from Experiment I. Results Results indicated that listener performance increased as the target-to-masker linguistic distance increased (English-in-English < English-in-Dutch < English-in-Mandarin). Conclusions Spectral differences between maskers can account for some, but not all, of the variation in performance between maskers; however, temporal differences did not seem to play a significant role. PMID:23800811

Measurement of EUV lithography pupil amplitude and phase variation via image-based methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levinson, Zachary; Verduijn, Erik; Wood, Obert R.

2016-04-01

Here, an approach to image-based EUV aberration metrology using binary mask targets and iterative model-based solutions to extract both the amplitude and phase components of the aberrated pupil function is presented. The approach is enabled through previously developed modeling, fitting, and extraction algorithms. We seek to examine the behavior of pupil amplitude variation in real-optical systems. Optimized target images were captured under several conditions to fit the resulting pupil responses. Both the amplitude and phase components of the pupil function were extracted from a zone-plate-based EUV mask microscope. The pupil amplitude variation was expanded in three different bases: Zernike polynomials,more » Legendre polynomials, and Hermite polynomials. It was found that the Zernike polynomials describe pupil amplitude variation most effectively of the three.« less

Particle contamination effects in EUVL: enhanced theory for the analytical determination of critical particle sizes

NASA Astrophysics Data System (ADS)

Brandstetter, Gerd; Govindjee, Sanjay

2012-03-01

Existing analytical and numerical methodologies are discussed and then extended in order to calculate critical contamination-particle sizes, which will result in deleterious effects during EUVL E-chucking in the face of an error budget on the image-placement-error (IPE). The enhanced analytical models include a gap dependant clamping pressure formulation, the consideration of a general material law for realistic particle crushing and the influence of frictional contact. We present a discussion of the defects of the classical de-coupled modeling approach where particle crushing and mask/chuck indentation are separated from the global computation of mask bending. To repair this defect we present a new analytic approach based on an exact Hankel transform method which allows a fully coupled solution. This will capture the contribution of the mask indentation to the image-placement-error (estimated IPE increase of 20%). A fully coupled finite element model is used to validate the analytical models and to further investigate the impact of a mask back-side CrN-layer. The models are applied to existing experimental data with good agreement. For a standard material combination, a given IPE tolerance of 1 nm and a 15 kPa closing pressure, we derive bounds for single particles of cylindrical shape (radius × height < 44 μm) and spherical shape (diameter < 12 μm).

Programmable CGH on photochromic material using DMD generated masks

NASA Astrophysics Data System (ADS)

Alata, Romain; Zamkotsian, Frédéric; Lanzoni, Patrick; Pariani, Giorgio; Bianco, Andrea; Bertarelli, Chiara

2018-02-01

Computer Generated Holograms (CGHs) are used for wavefront shaping and complex optics testing, including aspherical and free-form optics. Today, CGHs are recorded directly with a laser or intermediate masks, allowing only the realization of binary CGHs; they are efficient but can reconstruct only pixilated images. We propose a Digital Micromirror Device (DMD) as a reconfigurable mask, to record rewritable binary and grayscale CGHs on a photochromic plate. The DMD is composed of 2048x1080 individually controllable micro-mirrors, with a pitch of 13.68 μm. This is a real-time reconfigurable mask, perfect for recording CGHs. The photochromic plate is opaque at rest and becomes transparent when it is illuminated with visible light of suitable wavelength. We have successfully recorded the very first amplitude grayscale CGH, in equally spaced levels, so called stepped CGH. We recorded up to 1000x1000 pixels CGHs with a contrast greater than 50, using Fresnel as well as Fourier coding scheme. Fresnel's CGH are obtained by calculating the inverse Fresnel transform of the original image at a given focus, ranging from 50cm to 2m. The reconstruction of the recorded images with a 632.8nm He-Ne laser beam leads to images with a high fidelity in shape, intensity, size and location. These results reveal the high potential of this method for generating programmable/rewritable grayscale CGHs, which combine DMDs and photochromic substrates.

Permeability of priming of pop out to expectations.

PubMed

Pascucci, David; Mastropasqua, Tommaso; Turatto, Massimo

2012-09-29

It is well established that repetition of the same target color across consecutive trials enhances search efficiency for pop-out targets; this phenomenon is known as Priming of Pop out (PoP). In three experiments, we addressed whether PoP interacts with top-down expectations in altering target visibility, which was manipulated via metacontrast masking. The target color either remained the same for n consecutive trials (blocked condition) or changed unpredictably (random condition). The results showed that PoP reduced the efficacy of masking and that its beneficial effect can be either potentiated or attenuated by participants' expectations about the upcoming target color. These findings undermine the view that PoP should be impermeable to top-down factors. In addition, we found evidence that both explicit and implicit expectations interact with PoP. The former can be induced via instructions on the rate of alternation of the target color, and the latter can be induced by random sequences in which repetitions of the same target color exceed those predicted by an internal model of randomness for binary events. In the latter case, more than three repetitions of the same target color led to a decline in target visibility. We speculate that, in the random condition, after few repetitions of the same target, participants developed an expectation for a change; this phenomenon is similar to the "gambler's fallacy." Finally, our analyses revealed no effect of expectation on switch trials (i.e., when the target color changed), which casts doubt on the efficacy of top-down control in feature search.

Short-term visual deprivation can enhance spatial release from masking.

PubMed

Pagé, Sara; Sharp, Andréanne; Landry, Simon P; Champoux, François

2016-08-15

This research aims to study the effect of short-term visual deprivation on spatial release from masking, a major component of the cocktail party effect that allows people to detect an auditory target in noise. The Masking Level Difference (MLD) test was administered on healthy individuals over three sessions: before (I) and after 90min of visual deprivation (II), and after 90min of re-exposure to light (III). A non-deprived control group performed the same tests, but remained sighted between sessions I and II. The non-deprived control group displayed constant results across sessions. However, performance in the MLD test was improved following short-term visual deprivation and performance returned to pre-deprivation values after light re-exposure. This study finds that short-term visual deprivation transiently enhances the spatial release from masking. These data suggest the significant potential for enhancing a process involved in the cocktail party effect in normally developing individuals and adds to an emerging literature on the potential to enhance auditory ability after only a brief period of visual deprivation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Method and apparatus for wavefront sensing

DOEpatents

Bahk, Seung-Whan

2016-08-23

A method of measuring characteristics of a wavefront of an incident beam includes obtaining an interferogram associated with the incident beam passing through a transmission mask and Fourier transforming the interferogram to provide a frequency domain interferogram. The method also includes selecting a subset of harmonics from the frequency domain interferogram, individually inverse Fourier transforming each of the subset of harmonics to provide a set of spatial domain harmonics, and extracting a phase profile from each of the set of spatial domain harmonics. The method further includes removing phase discontinuities in the phase profile, rotating the phase profile, and reconstructing a phase front of the wavefront of the incident beam.

Image data compression having minimum perceptual error

NASA Technical Reports Server (NTRS)

Watson, Andrew B. (Inventor)

1995-01-01

A method for performing image compression that eliminates redundant and invisible image components is described. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

Image-adapted visually weighted quantization matrices for digital image compression

NASA Technical Reports Server (NTRS)

Watson, Andrew B. (Inventor)

1994-01-01

A method for performing image compression that eliminates redundant and invisible image components is presented. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

Frameless fractionated stereotactic radiation therapy of intracranial lesions: impact of cone beam CT based setup correction on dose distribution

PubMed Central

2013-01-01

Background The purpose of this study was to evaluate the impact of Cone Beam CT (CBCT) based setup correction on total dose distributions in fractionated frameless stereotactic radiation therapy of intracranial lesions. Methods Ten patients with intracranial lesions treated with 30 Gy in 6 fractions were included in this study. Treatment planning was performed with Oncentra® for a SynergyS® (Elekta Ltd, Crawley, UK) linear accelerator with XVI® Cone Beam CT, and HexaPOD™ couch top. Patients were immobilized by thermoplastic masks (BrainLab, Reuther). After initial patient setup with respect to lasers, a CBCT study was acquired and registered to the planning CT (PL-CT) study. Patient positioning was corrected according to the correction values (translational, rotational) calculated by the XVI® system. Afterwards a second CBCT study was acquired and registered to the PL-CT to confirm the accuracy of the corrections. An in-house developed software was used for rigid transformation of the PL-CT to the CBCT geometry, and dose calculations for each fraction were performed on the transformed CT. The total dose distribution was achieved by back-transformation and summation of the dose distributions of each fraction. Dose distributions based on PL-CT, CBCT (laser set-up), and final CBCT were compared to assess the influence of setup inaccuracies. Results The mean displacement vector, calculated over all treatments, was reduced from (4.3 ± 1.3) mm for laser based setup to (0.5 ± 0.2) mm if CBCT corrections were applied. The mean rotational errors around the medial-lateral, superior-inferior, anterior-posterior axis were reduced from (−0.1 ± 1.4)°, (0.1 ± 1.2)° and (−0.2 ± 1.0)°, to (0.04 ± 0.4)°, (0.01 ± 0.4)° and (0.02 ± 0.3)°. As a consequence the mean deviation between planned and delivered dose in the planning target volume (PTV) could be reduced from 12.3% to 0.4% for D95 and from 5.9% to 0.1% for Dav. Maximum deviation was reduced from 31.8% to 0.8% for D95, and from 20.4% to 0.1% for Dav. Conclusion Real dose distributions differ substantially from planned dose distributions, if setup is performed according to lasers only. Thermoplasic masks combined with a daily CBCT enabled a sufficient accuracy in dose distribution. PMID:23800172

The forward masking effects of low-level laser glare on target location performance in a visual search task

NASA Astrophysics Data System (ADS)

Reddix, M. D.; Dandrea, J. A.; Collyer, P. D.

1992-01-01

The present study examined the effects of low-intensity laser glue, far below a level that would cause ocular damage or flashblindness, on the visually guided performance of aviators. With a forward-masking paradigm, this study showed that the time at which laser glare is experienced, relative to initial acquisition of visual information, differentially affects the speed and accuracy of target-location performance. Brief exposure (300 ms) to laser glare, terminating with a visual scene's onset, produced significant decrements in target-location performance relative to a no-glare control whereas a 150 and 300-ms delay of display onset (DDO) had very little effect. The intensity of the light entering the eye and producing these effects was far below the Maximum Permissible Exposure (MPE) limit for safe viewing of coherent light produced by an argon laser. In addition, these effects were modulated by the distance of the target from the center of the visual display. This study demonstrated that the presence of laser glare is not sufficient, in and of itself, to diminish target-location performance. The time at which laser glare is experienced is an important factor in determining the probability and extent of visually mediated performance decrements.

A frequency-based window width optimized two-dimensional S-Transform profilometry

NASA Astrophysics Data System (ADS)

Zhong, Min; Chen, Feng; Xiao, Chao

2017-11-01

A new scheme is proposed to as a frequency-based window width optimized two-dimensional S-Transform profilometry, in which parameters pu and pv are introduced to control the width of a two-dimensional Gaussian window. Unlike the standard two-dimensional S-transform using the Gaussian window with window width proportional to the reciprocal local frequency of the tested signal, the size of window width for the optimized two-dimensional S-Transform varies with the pu th (pv th) power of the reciprocal local frequency fx (fy) in x (y) direction. The paper gives a detailed theoretical analysis of optimized two-dimensional S-Transform in fringe analysis as well as the characteristics of the modified Gauss window. Simulations are applied to evaluate the proposed scheme, the results show that the new scheme has better noise reduction ability and can extract phase distribution more precise in comparison with the standard two-dimensional S-transform even though the surface of the measured object varies sharply. Finally, the proposed scheme is demonstrated on three-dimensional surface reconstruction for a complex plastic cat mask to show its effectiveness.

Femtosecond optical packet generation by a direct space-to-time pulse shaper.

PubMed

Leaird, D E; Weiner, A M

1999-06-15

We demonstrate femtosecond operation of a direct space-to-time pulse shaper in which there is direct mapping (no Fourier transform) between the spatial position of the masking function and the temporal position in the output waveform. We use this apparatus to generate trains of 20 pulses as an ultrafast optical data packet over an approximately 40-ps temporal window.

Center for Advanced Bioengineering for Soldier Survivability

DTIC Science & Technology

2012-06-01

Wound Care, PI Boyan; Breast Cancer Targets, PI Boyan; and Chondral Lesions, PI Boyan). We had previously awarded four targeted seed grants for...Biocompatibility of Superhydrophobic Coated Polymers for Biomedical Applications” will develop technologies for preventing biofilm formation on polymeric...dental group is currently working on a BioMASK that could use the superhydrophobic coating technology. They are also working on reducing biofilm from

Unconscious Congruency Priming from Unpracticed Words Is Modulated by Prime-Target Semantic Relatedness

ERIC Educational Resources Information Center

Ortells, Juan J.; Mari-Beffa, Paloma; Plaza-Ayllon, Vanesa

2013-01-01

Participants performed a 2-choice categorization task on visible word targets that were preceded by novel (unpracticed) prime words. The prime words were presented for 33 ms and followed either immediately (Experiments 1-3) or after a variable delay (Experiments 1 and 4) by a pattern mask. Both subjective and objective measures of prime visibility…

A Chitin-Like Component on Sclerotic Cells of Fonsecaea pedrosoi Inhibits Dectin-1-Mediated Murine Th17 Development by Masking β-Glucans

PubMed Central

Li, Ruoyu; Chen, Sharon C.-A.; Liu, Weihuang; Liu, Wei; Chen, Liuqing; Chen, Yao; Zhang, Xu; Tong, Zhongsheng; Xia, Yun; Xia, Ping; Wang, Yan; Duan, Yiqun

2014-01-01

Fonsecaea pedrosoi (F. pedrosoi), a major agent of chromoblastomycosis, has been shown to be recognized primarily by C-type lectin receptors (CLRs) in a murine model of chromoblastomycosis. Specifically, the β-glucan receptor, Dectin-1, mediates Th17 development and consequent recruitment of neutrophils, and is evidenced to have the capacity to bind to saprophytic hyphae of F. pedrosoi in vitro. However, when embedded in tissue, most etiological agents of chromoblastomycosis including F. pedrosoi will transform into the sclerotic cells, which are linked to the greatest survival of melanized fungi in tissue. In this study, using immunocompetent and athymic (nu/nu) murine models infected subcutaneously or intraperitoneally with F. pedrosoi, we demonstrated that T lymphocytes play an active role in the resolution of localized footpad infection, and there existed a significantly decreased expression of Th17-defining transcription factor Rorγt and inefficient recruitment of neutrophils in chronically infected spleen where the inoculated mycelium of F. pedrosoi transformed into the sclerotic cells. We also found that Dectin-1-expressing histocytes and neutrophils participated in the enclosure of transformed sclerotic cells in the infectious foci. Furthermore, we induced the formation of sclerotic cells in vitro, and evidenced a significantly decreased binding capacity of human or murine-derived Dectin-1 to the induced sclerotic cells in comparison with the saprophytic mycelial forms. Our analysis of β-glucans-masking components revealed that it is a chitin-like component, but not the mannose moiety on the sclerotic cells, that interferes with the binding of β-glucans by human or murine Dectin-1. Notably, we demonstrated that although Dectin-1 contributed to the development of IL-17A-producing CD3+CD4+ murine splenocytes upon in vitro-stimulation by saprophytic F. pedrosoi, the masking effect of chitin components partly inhibited Dectin-1-mediated Th17 development upon in vitro-stimulation by induced sclerotic cells. Therefore, these findings extend our understanding of the chronicity of chromoblastomycosis. PMID:25490199

Rapid estimation of high-parameter auditory-filter shapes

PubMed Central

Shen, Yi; Sivakumar, Rajeswari; Richards, Virginia M.

2014-01-01

A Bayesian adaptive procedure, the quick-auditory-filter (qAF) procedure, was used to estimate auditory-filter shapes that were asymmetric about their peaks. In three experiments, listeners who were naive to psychoacoustic experiments detected a fixed-level, pure-tone target presented with a spectrally notched noise masker. The qAF procedure adaptively manipulated the masker spectrum level and the position of the masker notch, which was optimized for the efficient estimation of the five parameters of an auditory-filter model. Experiment I demonstrated that the qAF procedure provided a convergent estimate of the auditory-filter shape at 2 kHz within 150 to 200 trials (approximately 15 min to complete) and, for a majority of listeners, excellent test-retest reliability. In experiment II, asymmetric auditory filters were estimated for target frequencies of 1 and 4 kHz and target levels of 30 and 50 dB sound pressure level. The estimated filter shapes were generally consistent with published norms, especially at the low target level. It is known that the auditory-filter estimates are narrower for forward masking than simultaneous masking due to peripheral suppression, a result replicated in experiment III using fewer than 200 qAF trials. PMID:25324086

Detection and classification of underwater targets by echolocating dolphins

NASA Astrophysics Data System (ADS)

Au, Whitlow

2003-10-01

Many experiments have been performed with echolocating dolphins to determine their target detection and discrimination capabilities. Target detection experiments have been performed in a naturally noisy environment, with masking noise and with both phantom echoes and masking noise, and in reverberation. The echo energy to rms noise spectral density for the Atlantic bottlenose dolphin (Tursiops truncatus) at the 75% correct response threshold is approximately 7.5 dB whereas for the beluga whale (Delphinapterus leucas) the threshold is approximately 1 dB. The dolphin's detection threshold in reverberation is approximately 2.5 dB vs 2 dB for the beluga. The difference in performance between species can probably be ascribed to differences in how both species perceived the task. The bottlenose dolphin may be performing a combination detection/discrimination task whereas the beluga may be performing a simple detection task. Echolocating dolphins also have the capability to make fine discriminate of target properties such as wall thickness difference of water-filled cylinders and material differences in metallic plates. The high resolution property of the animal's echolocation signals and the high dynamic range of its auditory system are important factors in their outstanding discrimination capabilities.

a New Mask for Automatic Building Detection from High Density Point Cloud Data and Multispectral Imagery

NASA Astrophysics Data System (ADS)

Awrangjeb, M.; Siddiqui, F. U.

2017-11-01

In complex urban and residential areas, there are buildings which are not only connected with and/or close to one another but also partially occluded by their surrounding vegetation. Moreover, there may be buildings whose roofs are made of transparent materials. In transparent buildings, there are point returns from both the ground (or materials inside the buildings) and the rooftop. These issues confuse the previously proposed building masks which are generated from either ground points or non-ground points. The normalised digital surface model (nDSM) is generated from the non-ground points and usually it is hard to find individual buildings and trees using the nDSM. In contrast, the primary building mask is produced using the ground points, thereby it misses the transparent rooftops. This paper proposes a new building mask based on the non-ground points. The dominant directions of non-ground lines extracted from the multispectral imagery are estimated. A dummy grid with the target mask resolution is rotated at each dominant direction to obtain the corresponding height values from the non-ground points. Three sub-masks are then generated from the height grid by estimating the gradient function. Two of these sub-masks capture planar surfaces whose height remain constant in along and across the dominant direction, respectively. The third sub-mask contains only the flat surfaces where the height (ideally) remains constant in all directions. All the sub-masks generated in all estimated dominant directions are combined to produce the candidate building mask. Although the application of the gradient function helps in removal of most of the vegetation, the final building mask is obtained through removal of planar vegetation, if any, and tiny isolated false candidates. Experimental results on three Australian data sets show that the proposed method can successfully remove vegetation, thereby separate buildings from occluding vegetation and detect buildings with transparent roof materials. While compared to existing building detection techniques, the proposed technique offers higher objectbased completeness, correctness and quality, specially in complex scenes with aforementioned issues. It is not only capable of detecting transparent buildings, but also small garden sheds which are sometimes as small as 5 m2 in area.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gratama van Andel, H. A. F.; Venema, H. W.; Streekstra, G. J.

For clear visualization of vessels in CT angiography (CTA) images of the head and neck using maximum intensity projection (MIP) or volume rendering (VR) bone has to be removed. In the past we presented a fully automatic method to mask the bone [matched mask bone elimination (MMBE)] for this purpose. A drawback is that vessels adjacent to bone may be partly masked as well. We propose a modification, multiscale MMBE, which reduces this problem by using images at two scales: a higher resolution than usual for image processing and a lower resolution to which the processed images are transformed formore » use in the diagnostic process. A higher in-plane resolution is obtained by the use of a sharper reconstruction kernel. The out-of-plane resolution is improved by deconvolution or by scanning with narrower collimation. The quality of the mask that is used to remove bone is improved by using images at both scales. After masking, the desired resolution for the normal clinical use of the images is obtained by blurring with Gaussian kernels of appropriate widths. Both methods (multiscale and original) were compared in a phantom study and with clinical CTA data sets. With the multiscale approach the width of the strip of soft tissue adjacent to the bone that is masked can be reduced from 1.0 to 0.2 mm without reducing the quality of the bone removal. The clinical examples show that vessels adjacent to bone are less affected and therefore better visible. Images processed with multiscale MMBE have a slightly higher noise level or slightly reduced resolution compared with images processed by the original method and the reconstruction and processing time is also somewhat increased. Nevertheless, multiscale MMBE offers a way to remove bone automatically from CT angiography images without affecting the integrity of the blood vessels. The overall image quality of MIP or VR images is substantially improved relative to images processed with the original MMBE method.« less

Correction to Schlaghecken, Birak, and Maylor (2011).

PubMed

Schlaghecken, Friederike; Birak, Kulbir S; Maylor, Elizabeth A

2012-06-01

Reports an error in "Age-related deficits in low-level inhibitory motor control" by Friederike Schlaghecken, Kulbir S. Birak and Elizabeth A. Maylor (Psychology and Aging, 2011[Dec], Vol 26[4], 905-918). The authors discovered that the method proposed for individually extracting priming effects from time course analysis may lead to some spurious effects. In view of possible spurious effects from their application of time course analysis, the authors adopted an alternative strategy that retains their attempt to take an individual approach to identifying NCEs in older participants who may vary more than young participants in terms of the prime-target SOA at which NCEs initially appear. This reanalysis is presented in the erratum. (The following abstract of the original article appeared in record 2011-10375-001.) Inhibitory control functions in old age were investigated with the "masked prime" paradigm in which participants executed speeded manual choice responses to simple visual targets. These were preceded-either immediately or at some earlier time-by a backward-masked prime. Young adults produced positive compatibility effects (PCEs)-faster and more accurate responses for matching than for nonmatching prime-target pairs-when prime and target immediately followed each other, and the reverse effect (negative compatibility effect, NCE) for targets that followed the prime after a short interval. Older adults produced similar PCEs to young adults, indicating intact low-level motor activation, but failed to produce normal NCEs even with longer delays (Experiment 1), increased opportunity for prime processing (Experiment 2), and prolonged learning (Experiment 3). However, a fine-grained analysis of each individual's time course of masked priming effects revealed NCEs in the majority of older adults, of the same magnitude as those of young adults. These were significantly delayed (even more than expected on the basis of general slowing), indicating a disproportionate impairment of low-level inhibitory motor control in old age. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

A nanohybrid system for taste masking of sildenafil.

PubMed

Lee, Ji-Hee; Choi, Goeun; Oh, Yeon-Ji; Park, Je Won; Choy, Young Bin; Park, Mung Chul; Yoon, Yeo Joon; Lee, Hwa Jeong; Chang, Hee Chul; Choy, Jin-Ho

2012-01-01

A nanohybrid was prepared with an inorganic clay material, montmorillonite (MMT), for taste masking of sildenafil (SDN). To further improve the taste-masking efficiency and enhance the drug-release rate, we coated the nanohybrid of SDN-MMT with a basic polymer, polyvinylacetal diethylaminoacetate (AEA). Powder X-ray diffraction and Fourier transform infrared experiments showed that SDN was successfully intercalated into the interlayer space of MMT. The AEA-coated SDN-MMT nanohybrid showed drug release was much suppressed at neutral pH (release rate, 4.70 ± 0.53%), suggesting a potential for drug taste masking at the buccal cavity. We also performed in vitro drug release experiments in a simulated gastric fluid (pH = 1.2) and compared the drug-release profiles of AEA-coated SDN-MMT and Viagra(®), an approved dosage form of SDN. As a result, about 90% of SDN was released from the AEA-coated SDN-MMT during the first 2 hours while almost 100% of drug was released from Viagra(®). However, an in vivo experiment showed that the AEA-coated SDN-MMT exhibited higher drug exposure than Viagra(®). For the AEA-coated SDN-MMT, the area under the plasma concentration- time curve from 0 hours to infinity (AUC(0-∞)) and maximum concentration (C(max)) were 78.8 ± 2.32 μg · hour/mL and 12.4 ± 0.673 μg/mL, respectively, both of which were larger than those obtained with Viagra(®) (AUC(0-∞) = 69.2 ± 3.19 μg · hour/mL; C(max) = 10.5 ± 0.641 μg/mL). Therefore, we concluded that the MMT-based nanohybrid is a promising delivery system for taste masking of SDN with possibly improved drug exposure.

A nanohybrid system for taste masking of sildenafil

PubMed Central

Lee, Ji-Hee; Choi, Goeun; Oh, Yeon-Ji; Park, Je Won; Choy, Young Bin; Park, Mung Chul; Yoon, Yeo Joon; Lee, Hwa Jeong; Chang, Hee Chul; Choy, Jin-Ho

2012-01-01

A nanohybrid was prepared with an inorganic clay material, montmorillonite (MMT), for taste masking of sildenafil (SDN). To further improve the taste-masking efficiency and enhance the drug-release rate, we coated the nanohybrid of SDN–MMT with a basic polymer, polyvinylacetal diethylaminoacetate (AEA). Powder X-ray diffraction and Fourier transform infrared experiments showed that SDN was successfully intercalated into the interlayer space of MMT. The AEA-coated SDN–MMT nanohybrid showed drug release was much suppressed at neutral pH (release rate, 4.70 ± 0.53%), suggesting a potential for drug taste masking at the buccal cavity. We also performed in vitro drug release experiments in a simulated gastric fluid (pH = 1.2) and compared the drug-release profiles of AEA-coated SDN–MMT and Viagra®, an approved dosage form of SDN. As a result, about 90% of SDN was released from the AEA-coated SDN–MMT during the first 2 hours while almost 100% of drug was released from Viagra®. However, an in vivo experiment showed that the AEA-coated SDN–MMT exhibited higher drug exposure than Viagra®. For the AEA-coated SDN–MMT, the area under the plasma concentration– time curve from 0 hours to infinity (AUC0-∞) and maximum concentration (Cmax) were 78.8 ± 2.32 μg · hour/mL and 12.4 ± 0.673 μg/mL, respectively, both of which were larger than those obtained with Viagra® (AUC0-∞ = 69.2 ± 3.19 μg · hour/mL; Cmax = 10.5 ± 0.641 μg/mL). Therefore, we concluded that the MMT-based nanohybrid is a promising delivery system for taste masking of SDN with possibly improved drug exposure. PMID:22619517

Mapping auditory nerve firing density using high-level compound action potentials and high-pass noise masking a

PubMed Central

Earl, Brian R.; Chertoff, Mark E.

2012-01-01

Future implementation of regenerative treatments for sensorineural hearing loss may be hindered by the lack of diagnostic tools that specify the target(s) within the cochlea and auditory nerve for delivery of therapeutic agents. Recent research has indicated that the amplitude of high-level compound action potentials (CAPs) is a good predictor of overall auditory nerve survival, but does not pinpoint the location of neural damage. A location-specific estimate of nerve pathology may be possible by using a masking paradigm and high-level CAPs to map auditory nerve firing density throughout the cochlea. This initial study in gerbil utilized a high-pass masking paradigm to determine normative ranges for CAP-derived neural firing density functions using broadband chirp stimuli and low-frequency tonebursts, and to determine if cochlear outer hair cell (OHC) pathology alters the distribution of neural firing in the cochlea. Neural firing distributions for moderate-intensity (60 dB pSPL) chirps were affected by OHC pathology whereas those derived with high-level (90 dB pSPL) chirps were not. These results suggest that CAP-derived neural firing distributions for high-level chirps may provide an estimate of auditory nerve survival that is independent of OHC pathology. PMID:22280596

Localized Principal Component Analysis based Curve Evolution: A Divide and Conquer Approach

PubMed Central

Appia, Vikram; Ganapathy, Balaji; Yezzi, Anthony; Faber, Tracy

2014-01-01

We propose a novel localized principal component analysis (PCA) based curve evolution approach which evolves the segmenting curve semi-locally within various target regions (divisions) in an image and then combines these locally accurate segmentation curves to obtain a global segmentation. The training data for our approach consists of training shapes and associated auxiliary (target) masks. The masks indicate the various regions of the shape exhibiting highly correlated variations locally which may be rather independent of the variations in the distant parts of the global shape. Thus, in a sense, we are clustering the variations exhibited in the training data set. We then use a parametric model to implicitly represent each localized segmentation curve as a combination of the local shape priors obtained by representing the training shapes and the masks as a collection of signed distance functions. We also propose a parametric model to combine the locally evolved segmentation curves into a single hybrid (global) segmentation. Finally, we combine the evolution of these semilocal and global parameters to minimize an objective energy function. The resulting algorithm thus provides a globally accurate solution, which retains the local variations in shape. We present some results to illustrate how our approach performs better than the traditional approach with fully global PCA. PMID:25520901

Developmental Conductive Hearing Loss Reduces Modulation Masking Release

PubMed Central

Chen, Yi-Wen; Sanes, Dan H.

2016-01-01

Hearing-impaired individuals experience difficulties in detecting or understanding speech, especially in background sounds within the same frequency range. However, normally hearing (NH) human listeners experience less difficulty detecting a target tone in background noise when the envelope of that noise is temporally gated (modulated) than when that envelope is flat across time (unmodulated). This perceptual benefit is called modulation masking release (MMR). When flanking masker energy is added well outside the frequency band of the target, and comodulated with the original modulated masker, detection thresholds improve further (MMR+). In contrast, if the flanking masker is antimodulated with the original masker, thresholds worsen (MMR−). These interactions across disparate frequency ranges are thought to require central nervous system (CNS) processing. Therefore, we explored the effect of developmental conductive hearing loss (CHL) in gerbils on MMR characteristics, as a test for putative CNS mechanisms. The detection thresholds of NH gerbils were lower in modulated noise, when compared with unmodulated noise. The addition of a comodulated flanker further improved performance, whereas an antimodulated flanker worsened performance. However, for CHL-reared gerbils, all three forms of masking release were reduced when compared with NH animals. These results suggest that developmental CHL impairs both within- and across-frequency processing and provide behavioral evidence that CNS mechanisms are affected by a peripheral hearing impairment. PMID:28215119

Aided speech recognition in single-talker competition by elderly hearing-impaired listeners

NASA Astrophysics Data System (ADS)

Coughlin, Maureen; Humes, Larry

2004-05-01

This study examined the speech-identification performance in one-talker interference conditions that increased in complexity while audibility was ensured over a wide bandwidth (200-4000 Hz). Factorial combinations of three independent variables were used to vary the amount of informational masking. These variables were: (1) competition playback direction (forward or reverse); (2) gender match between target and competition talkers (same or different); and (3) target talker uncertainty (one of three possible talkers from trial to trial). Four groups of listeners, two elderly hearing-impaired groups differing in age (65-74 and 75-84 years) and two young normal-hearing groups, were tested. One of the groups of young normal-hearing listeners was tested under acoustically equivalent test conditions and one was tested under perceptually equivalent test conditions. The effect of each independent variable on speech-identification performance and informational masking was generally consistent with expectations. Group differences in the observed informational masking were most pronounced for the oldest group of hearing-impaired listeners. The eight measures of speech-identification performance were found to be strongly correlated with one another, and individual differences in speech understanding performance among the elderly were found to be associated with age and level of education. [Work supported, in part, by NIA.

Beyond a mask and against the bottleneck: retroactive dual-task interference during working memory consolidation of a masked visual target.

PubMed

Nieuwenstein, Mark; Wyble, Brad

2014-06-01

While studies on visual memory commonly assume that the consolidation of a visual stimulus into working memory is interrupted by a trailing mask, studies on dual-task interference suggest that the consolidation of a stimulus can continue for several hundred milliseconds after a mask. As a result, estimates of the time course of working memory consolidation differ more than an order of magnitude. Here, we contrasted these opposing views by examining if and for how long the processing of a masked display of visual stimuli can be disturbed by a trailing 2-alternative forced choice task (2-AFC; a color discrimination task or a visual or auditory parity judgment task). The results showed that the presence of the 2-AFC task produced a pronounced retroactive interference effect that dissipated across stimulus onset asynchronies of 250-1,000 ms, indicating that the processing elicited by the 2-AFC task interfered with the gradual consolidation of the earlier shown stimuli. Furthermore, this interference effect occurred regardless of whether the to-be-remembered stimuli comprised a string of letters or an unfamiliar complex visual shape, and it occurred regardless of whether these stimuli were masked. Conversely, the interference effect was reduced when the memory load for the 1st task was reduced, or when the 2nd task was a color detection task that did not require decision making. Taken together, these findings show that the formation of a durable and consciously accessible working memory trace for a briefly shown visual stimulus can be disturbed by a trailing 2-AFC task for up to several hundred milliseconds after the stimulus has been masked. By implication, the current findings challenge the common view that working memory consolidation involves an immutable central processing bottleneck, and they also make clear that consolidation does not stop when a stimulus is masked. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Complete Imageless solution for overlay front-end manufacturing

NASA Astrophysics Data System (ADS)

Herisson, David; LeCacheux, Virginie; Touchet, Mathieu; Vachellerie, Vincent; Lecarpentier, Laurent; Felten, Franck; Polli, Marco

2005-09-01

Imageless option of KLA-Tencor RDM system (Recipe Data Management) is a new method of recipe creation, using only the mask design to define alignment target and measurement parameters. This technique is potentially the easiest tool to improve recipe management of a large amount of products in logic fab. Overlay recipes are created without wafer, by using a synthetic image (copy of gds mask file) for alignment pattern and target design like shape (frame in frame) and size for the measurement. A complete gauge study on critical CMOS 90nm Gate level has been conducted to evaluate reliability and robustness of the imageless recipe. We show that Imageless limits drastically the number of templates used for recipe creation, and improves or maintains measurement capability compare to manual recipe creation (operator dependant). Imageless appears to be a suitable solution for high volume manufacturing, as shown by the results obtained on production lots.

Retina-V1 model of detectability across the visual field

PubMed Central

Bradley, Chris; Abrams, Jared; Geisler, Wilson S.

2014-01-01

A practical model is proposed for predicting the detectability of targets at arbitrary locations in the visual field, in arbitrary gray scale backgrounds, and under photopic viewing conditions. The major factors incorporated into the model include (a) the optical point spread function of the eye, (b) local luminance gain control (Weber's law), (c) the sampling array of retinal ganglion cells, (d) orientation and spatial frequency–dependent contrast masking, (e) broadband contrast masking, and (f) efficient response pooling. The model is tested against previously reported threshold measurements on uniform backgrounds (the ModelFest data set and data from Foley, Varadharajan, Koh, & Farias, 2007) and against new measurements reported here for several ModelFest targets presented on uniform, 1/f noise, and natural backgrounds at retinal eccentricities ranging from 0° to 10°. Although the model has few free parameters, it is able to account quite well for all the threshold measurements. PMID:25336179

Apparatus for measuring surface particulate contamination

DOEpatents

Woodmansee, Donald E.

2002-01-01

An apparatus for measuring surface particulate contamination includes a tool for collecting a contamination sample from a target surface, a mask having an opening of known area formed therein for defining the target surface, and a flexible connector connecting the tool to the mask. The tool includes a body portion having a large diameter section defining a surface and a small diameter section extending from the large diameter section. A particulate collector is removably mounted on the surface of the large diameter section for collecting the contaminants. The tool further includes a spindle extending from the small diameter section and a spool slidingly mounted on the spindle. A spring is disposed between the small diameter section and the spool for biasing the spool away from the small diameter section. An indicator is provided on the spindle so as to be revealed when the spool is pressed downward to compress the spring.

Subliminal speech perception and auditory streaming.

PubMed

Dupoux, Emmanuel; de Gardelle, Vincent; Kouider, Sid

2008-11-01

Current theories of consciousness assume a qualitative dissociation between conscious and unconscious processing: while subliminal stimuli only elicit a transient activity, supraliminal stimuli have long-lasting influences. Nevertheless, the existence of this qualitative distinction remains controversial, as past studies confounded awareness and stimulus strength (energy, duration). Here, we used a masked speech priming method in conjunction with a submillisecond interaural delay manipulation to contrast subliminal and supraliminal processing at constant prime, mask and target strength. This delay induced a perceptual streaming effect, with the prime popping out in the supraliminal condition. By manipulating the prime-target interval (ISI), we show a qualitatively distinct profile of priming longevity as a function of prime awareness. While subliminal priming disappeared after half a second, supraliminal priming was independent of ISI. This shows that the distinction between conscious and unconscious processing depends on high-level perceptual streaming factors rather than low-level features (energy, duration).

Effects of stimulus font and size on masked repetition priming: An event-related potentials (ERP) investigation.

PubMed

Chauncey, Krysta; Holcomb, Phillip J; Grainger, Jonathan

2008-01-01

The size and font of target words were manipulated in a masked repetition priming paradigm with ERP recordings. Repetition priming effects were found in four ERP components: the N/P150, N250, P325, and N400. Neither a change in font nor a change in size across prime and target were found to affect repetition priming in the N250, P325, and N400 components. Changing font was, however, found to affect repetition priming in the N/P150 component, while the interaction between repetition priming and size was not significant in this component. These results confirm our interpretation of the N/P150 as a component sensitive to feature-level processing, and suggest that the type of prelexical and lexical processing reflected in the N250, P325, and N400 components is performed on representations that are invariant to changes in both font and size.

EUVL back-insertion layout optimization

NASA Astrophysics Data System (ADS)

Civay, D.; Laffosse, E.; Chesneau, A.

2018-03-01

Extreme ultraviolet lithography (EUVL) is targeted for front-up insertion at advanced technology nodes but will be evaluated for back insertion at more mature nodes. EUVL can put two or more mask levels back on one mask, depending upon what level(s) in the process insertion occurs. In this paper, layout optimization methods are discussed that can be implemented when EUVL back insertion is implemented. The layout optimizations can be focused on improving yield, reliability or density, depending upon the design needs. The proposed methodology modifies the original two or more colored layers and generates an optimized single color EUVL layout design.

Some simple guides to finding useful information in exploration geochemical data

USGS Publications Warehouse

Singer, D.A.; Kouda, R.

2001-01-01

Most regional geochemistry data reflect processes that can produce superfluous bits of noise and, perhaps, information about the mineralization process of interest. There are two end-member approaches to finding patterns in geochemical data-unsupervised learning and supervised learning. In unsupervised learning, data are processed and the geochemist is given the task of interpreting and identifying possible sources of any patterns. In supervised learning, data from known subgroups such as rock type, mineralized and nonmineralized, and types of mineralization are used to train the system which then is given unknown samples to classify into these subgroups. To locate patterns of interest, it is helpful to transform the data and to remove unwanted masking patterns. With trace elements use of a logarithmic transformation is recommended. In many situations, missing censored data can be estimated using multiple regression of other uncensored variables on the variable with censored values. In unsupervised learning, transformed values can be standardized, or normalized, to a Z-score by subtracting the subset's mean and dividing by its standard deviation. Subsets include any source of differences that might be related to processes unrelated to the target sought such as different laboratories, regional alteration, analytical procedures, or rock types. Normalization removes effects of different means and measurement scales as well as facilitates comparison of spatial patterns of elements. These adjustments remove effects of different subgroups and hopefully leave on the map the simple and uncluttered pattern(s) related to the mineralization only. Supervised learning methods, such as discriminant analysis and neural networks, offer the promise of consistent and, in certain situations, unbiased estimates of where mineralization might exist. These methods critically rely on being trained with data that encompasses all populations fairly and that can possibly fall into only the identified populations. ?? 2001 International Association for Mathematical Geology.

Research on the Improved Image Dodging Algorithm Based on Mask Technique

NASA Astrophysics Data System (ADS)

Yao, F.; Hu, H.; Wan, Y.

2012-08-01

The remote sensing image dodging algorithm based on Mask technique is a good method for removing the uneven lightness within a single image. However, there are some problems with this algorithm, such as how to set an appropriate filter size, for which there is no good solution. In order to solve these problems, an improved algorithm is proposed. In this improved algorithm, the original image is divided into blocks, and then the image blocks with different definitions are smoothed using the low-pass filters with different cut-off frequencies to get the background image; for the image after subtraction, the regions with different lightness are processed using different linear transformation models. The improved algorithm can get a better dodging result than the original one, and can make the contrast of the whole image more consistent.

Bias in masked word identification: unconscious influences of repetition priming.

PubMed

Masson, Michael E J

2002-12-01

The beneficial influence of a prior study episode on subsequent identification of a word includes a large bias component, revealed in the forced-choice variant of the masked word identification test. In that type of test, subjects show a preference for a studied probe over a nonstudied probe, regardless of which one matches the masked target word. The forced-choice test was used in the present experiments to test the possibility that this bias effect is due to conscious recollection. Results show that bias was strongly attenuated (1) by changes in modality between study and test, and (2) under certain conditions, by using a conceptually driven study task. The bias effect was found only when probes were orthographically similar to one another, as predicted by the counter model (Ratcliff & McKoon, 1997). These results provide strong evidence that the bias effect is not mediated by conscious recollection.

Spontaneous Gender Categorization in Masking and Priming Studies: Key for Distinguishing Jane from John Doe but Not Madonna from Sinatra

PubMed Central

Habibi, Ruth; Khurana, Beena

2012-01-01

Facial recognition is key to social interaction, however with unfamiliar faces only generic information, in the form of facial stereotypes such as gender and age is available. Therefore is generic information more prominent in unfamiliar versus familiar face processing? In order to address the question we tapped into two relatively disparate stages of face processing. At the early stages of encoding, we employed perceptual masking to reveal that only perception of unfamiliar face targets is affected by the gender of the facial masks. At the semantic end; using a priming paradigm, we found that while to-be-ignored unfamiliar faces prime lexical decisions to gender congruent stereotypic words, familiar faces do not. Our findings indicate that gender is a more salient dimension in unfamiliar relative to familiar face processing, both in early perceptual stages as well as later semantic stages of person construal. PMID:22389697

SU-E-T-541: Bolus Effect of Thermoplastic Masks in IMRT and VMAT Head and Neck Treatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhen, H; Nedzi, L; Chen, S

2014-06-01

Purpose: To quantitatively evaluate the bolus effect of thermoplalstic mask on patient skin dose during multi-field IMRT and VMAT treatment. Methods: The clinically approved target contours for five head and neck patients were deformably registered to an anthropomorphic Rando phantom. Two plans: Multifield IMRT plan with 7-9 beams and VMAT plan with 2-4 arcs were created for each patient following same dose constraints. 3mm skin was excluded from PTVs but not constrained during optimization. The prescription dose was 200-220 cGy/fraction. A thermoplastic head and shoulder mask was customized for the Rando phantom. Each plan was delivered to the phantom twicemore » with and without mask. During each delivery, two rectangular strips of EBT3 films (1cm x 6.8cm) were placed across the anterior upper and lower neck near PTVs to measure the surface dose. For consistency films were positioned at same locations for same patient. A total of 8 film strips were obtained for each patient. Film dose was calibrated in the range of 0-400cGy on the day of plan delivery. For dose comparison 3 regions of interests (ROIs) of 1×1 cm{sup 2} were selected at left, right and middle part of each film, resulting in 6 point doses at each plan delivery. Results: The films without mask show relatively uniform dose distribution while those with mask clearly show mesh pattern of mask, usually indicating an increase in skin dose. On average the increase in skin dose over all ROIs with mask was 31.9%(±14.8%) with a range of 11.4%- 58.4%. There is no statistically significant difference (p=0.44) between skin dose increase in VMAT (30.8%±15.3%) and IMRT delivery (33.0%±14.9%). Conclusion: Thermoplastic immobilization masks increase surface dose for HN patient by around 30%. The magnitude is comparable between multi-field IMRT and VMAT. Radiochromic EBT3 film serves as an effective tool to quantify bolus effect.« less

Phonologically-Based Priming in the Same-Different Task With L1 Readers.

PubMed

Lupker, Stephen J; Nakayama, Mariko; Yoshihara, Masahiro

2018-02-01

The present experiment provides an investigation of a promising new tool, the masked priming same-different task, for investigating the orthographic coding process. Orthographic coding is the process of establishing a mental representation of the letters and letter order in the word being read which is then used by readers to access higher-level (e.g., semantic) information about that word. Prior research (e.g., Norris & Kinoshita, 2008) had suggested that performance in this task may be based entirely on orthographic codes. As reported by Lupker, Nakayama, and Perea (2015a), however, in at least some circumstances, phonological codes also play a role. Specifically, even though their 2 languages are completely different orthographically, Lupker et al.'s Japanese-English bilinguals showed priming in this task when masked L1 primes were phonologically similar to L2 targets. An obvious follow-up question is whether Lupker et al.'s effect might have resulted from a strategy that was adopted by their bilinguals to aid in processing of, and memory for, the somewhat unfamiliar L2 targets. In the present experiment, Japanese readers responded to (Japanese) Kanji targets with phonologically identical primes (on "related" trials) being presented in a completely different but highly familiar Japanese script, Hiragana. Once again, significant priming effects were observed, indicating that, although performance in the masked priming same-different task may be mainly based on orthographic codes, phonological codes can play a role even when the stimuli being matched are familiar words from a reader's L1. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A generalized time-frequency subtraction method for robust speech enhancement based on wavelet filter banks modeling of human auditory system.

PubMed

Shao, Yu; Chang, Chip-Hong

2007-08-01

We present a new speech enhancement scheme for a single-microphone system to meet the demand for quality noise reduction algorithms capable of operating at a very low signal-to-noise ratio. A psychoacoustic model is incorporated into the generalized perceptual wavelet denoising method to reduce the residual noise and improve the intelligibility of speech. The proposed method is a generalized time-frequency subtraction algorithm, which advantageously exploits the wavelet multirate signal representation to preserve the critical transient information. Simultaneous masking and temporal masking of the human auditory system are modeled by the perceptual wavelet packet transform via the frequency and temporal localization of speech components. The wavelet coefficients are used to calculate the Bark spreading energy and temporal spreading energy, from which a time-frequency masking threshold is deduced to adaptively adjust the subtraction parameters of the proposed method. An unvoiced speech enhancement algorithm is also integrated into the system to improve the intelligibility of speech. Through rigorous objective and subjective evaluations, it is shown that the proposed speech enhancement system is capable of reducing noise with little speech degradation in adverse noise environments and the overall performance is superior to several competitive methods.

3D Printing All-Aromatic Polyimides using Mask-Projection Stereolithography: Processing the Nonprocessable.

PubMed

Hegde, Maruti; Meenakshisundaram, Viswanath; Chartrain, Nicholas; Sekhar, Susheel; Tafti, Danesh; Williams, Christopher B; Long, Timothy E

2017-08-01

High-performance, all-aromatic, insoluble, engineering thermoplastic polyimides, such as pyromellitic dianhydride and 4,4'-oxydianiline (PMDA-ODA) (Kapton), exhibit exceptional thermal stability (up to ≈600 °C) and mechanical properties (Young's modulus exceeding 2 GPa). However, their thermal resistance, which is a consequence of the all-aromatic molecular structure, prohibits processing using conventional techniques. Previous reports describe an energy-intensive sintering technique as an alternative technique for processing polyimides with limited resolution and part fidelity. This study demonstrates the unprecedented 3D printing of PMDA-ODA using mask-projection stereolithography, and the preparation of high-resolution 3D structures without sacrificing bulk material properties. Synthesis of a soluble precursor polymer containing photo-crosslinkable acrylate groups enables light-induced, chemical crosslinking for spatial control in the gel state. Postprinting thermal treatment transforms the crosslinked precursor polymer to PMDA-ODA. The dimensional shrinkage is isotropic, and postprocessing preserves geometric integrity. Furthermore, large-area mask-projection scanning stereolithography demonstrates the scalability of 3D structures. These unique high-performance 3D structures offer potential in fields ranging from water filtration and gas separation to automotive and aerospace technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved decryption quality and security of a joint transform correlator-based encryption system

NASA Astrophysics Data System (ADS)

Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet

2013-02-01

Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum. This nonlinearity also makes the system more resistant to chosen-plaintext attacks. We additionally explore the system resistance against this type of attack when a variety of probability density functions are used to generate the two random phase masks of the encryption-decryption process. Numerical results are presented and discussed.

Femtosecond direct space-to-time pulse shaping in an integrated-optic configuration.

PubMed

Leaird, D E; Weiner, A M

2004-07-01

We demonstrate femtosecond operation of an integrated-optic direct space-to-time pulse shaper for which there is a direct mapping (no Fourier transform) between the spatial position of the masking function and the temporal position in the output waveform. The apparatus is used to generate trains of more than 30 pulses as an ultrafast optical data packet over approximately an 80-ps temporal window.

A positron emission tomography study of the neural basis of informational and energetic masking effects in speech perception

NASA Astrophysics Data System (ADS)

Scott, Sophie K.; Rosen, Stuart; Wickham, Lindsay; Wise, Richard J. S.

2004-02-01

Positron emission tomography (PET) was used to investigate the neural basis of the comprehension of speech in unmodulated noise (``energetic'' masking, dominated by effects at the auditory periphery), and when presented with another speaker (``informational'' masking, dominated by more central effects). Each type of signal was presented at four different signal-to-noise ratios (SNRs) (+3, 0, -3, -6 dB for the speech-in-speech, +6, +3, 0, -3 dB for the speech-in-noise), with listeners instructed to listen for meaning to the target speaker. Consistent with behavioral studies, there was SNR-dependent activation associated with the comprehension of speech in noise, with no SNR-dependent activity for the comprehension of speech-in-speech (at low or negative SNRs). There was, in addition, activation in bilateral superior temporal gyri which was associated with the informational masking condition. The extent to which this activation of classical ``speech'' areas of the temporal lobes might delineate the neural basis of the informational masking is considered, as is the relationship of these findings to the interfering effects of unattended speech and sound on more explicit working memory tasks. This study is a novel demonstration of candidate neural systems involved in the perception of speech in noisy environments, and of the processing of multiple speakers in the dorso-lateral temporal lobes.

Detection algorithm for glass bottle mouth defect by continuous wavelet transform based on machine vision

NASA Astrophysics Data System (ADS)

Qian, Jinfang; Zhang, Changjiang

2014-11-01

An efficient algorithm based on continuous wavelet transform combining with pre-knowledge, which can be used to detect the defect of glass bottle mouth, is proposed. Firstly, under the condition of ball integral light source, a perfect glass bottle mouth image is obtained by Japanese Computar camera through the interface of IEEE-1394b. A single threshold method based on gray level histogram is used to obtain the binary image of the glass bottle mouth. In order to efficiently suppress noise, moving average filter is employed to smooth the histogram of original glass bottle mouth image. And then continuous wavelet transform is done to accurately determine the segmentation threshold. Mathematical morphology operations are used to get normal binary bottle mouth mask. A glass bottle to be detected is moving to the detection zone by conveyor belt. Both bottle mouth image and binary image are obtained by above method. The binary image is multiplied with normal bottle mask and a region of interest is got. Four parameters (number of connected regions, coordinate of centroid position, diameter of inner cycle, and area of annular region) can be computed based on the region of interest. Glass bottle mouth detection rules are designed by above four parameters so as to accurately detect and identify the defect conditions of glass bottle. Finally, the glass bottles of Coca-Cola Company are used to verify the proposed algorithm. The experimental results show that the proposed algorithm can accurately detect the defect conditions of the glass bottles and have 98% detecting accuracy.

A novel adaptive scoring system for segmentation validation with multiple reference masks

NASA Astrophysics Data System (ADS)

Moltz, Jan H.; Rühaak, Jan; Hahn, Horst K.; Peitgen, Heinz-Otto

2011-03-01

The development of segmentation algorithms for different anatomical structures and imaging protocols is an important task in medical image processing. The validation of these methods, however, is often treated as a subordinate task. Since manual delineations, which are widely used as a surrogate for the ground truth, exhibit an inherent uncertainty, it is preferable to use multiple reference segmentations for an objective validation. This requires a consistent framework that should fulfill three criteria: 1) it should treat all reference masks equally a priori and not demand consensus between the experts; 2) it should evaluate the algorithmic performance in relation to the inter-reference variability, i.e., be more tolerant where the experts disagree about the true segmentation; 3) it should produce results that are comparable for different test data. We show why current state-of-the-art frameworks as the one used at several MICCAI segmentation challenges do not fulfill these criteria and propose a new validation methodology. A score is computed in an adaptive way for each individual segmentation problem, using a combination of volume- and surface-based comparison metrics. These are transformed into the score by relating them to the variability between the reference masks which can be measured by comparing the masks with each other or with an estimated ground truth. We present examples from a study on liver tumor segmentation in CT scans where our score shows a more adequate assessment of the segmentation results than the MICCAI framework.

The binaural masking level difference: cortical correlates persist despite severe brain stem atrophy in progressive supranuclear palsy

PubMed Central

Rowe, James B.; Ghosh, Boyd C. P.; Carlyon, Robert P.; Plack, Christopher J.; Gockel, Hedwig E.

2014-01-01

Under binaural listening conditions, the detection of target signals within background masking noise is substantially improved when the interaural phase of the target differs from that of the masker. Neural correlates of this binaural masking level difference (BMLD) have been observed in the inferior colliculus and temporal cortex, but it is not known whether degeneration of the inferior colliculus would result in a reduction of the BMLD in humans. We used magnetoencephalography to examine the BMLD in 13 healthy adults and 13 patients with progressive supranuclear palsy (PSP). PSP is associated with severe atrophy of the upper brain stem, including the inferior colliculus, confirmed by voxel-based morphometry of structural MRI. Stimuli comprised in-phase sinusoidal tones presented to both ears at three levels (high, medium, and low) masked by in-phase noise, which rendered the low-level tone inaudible. Critically, the BMLD was measured using a low-level tone presented in opposite phase across ears, making it audible against the noise. The cortical waveforms from bilateral auditory sources revealed significantly larger N1m peaks for the out-of-phase low-level tone compared with the in-phase low-level tone, for both groups, indicating preservation of early cortical correlates of the BMLD in PSP. In PSP a significant delay was observed in the onset of the N1m deflection and the amplitude of the P2m was reduced, but these differences were not restricted to the BMLD condition. The results demonstrate that although PSP causes subtle auditory deficits, binaural processing can survive the presence of significant damage to the upper brain stem. PMID:25231610

The binaural masking level difference: cortical correlates persist despite severe brain stem atrophy in progressive supranuclear palsy.

PubMed

Hughes, Laura E; Rowe, James B; Ghosh, Boyd C P; Carlyon, Robert P; Plack, Christopher J; Gockel, Hedwig E

2014-12-15

Under binaural listening conditions, the detection of target signals within background masking noise is substantially improved when the interaural phase of the target differs from that of the masker. Neural correlates of this binaural masking level difference (BMLD) have been observed in the inferior colliculus and temporal cortex, but it is not known whether degeneration of the inferior colliculus would result in a reduction of the BMLD in humans. We used magnetoencephalography to examine the BMLD in 13 healthy adults and 13 patients with progressive supranuclear palsy (PSP). PSP is associated with severe atrophy of the upper brain stem, including the inferior colliculus, confirmed by voxel-based morphometry of structural MRI. Stimuli comprised in-phase sinusoidal tones presented to both ears at three levels (high, medium, and low) masked by in-phase noise, which rendered the low-level tone inaudible. Critically, the BMLD was measured using a low-level tone presented in opposite phase across ears, making it audible against the noise. The cortical waveforms from bilateral auditory sources revealed significantly larger N1m peaks for the out-of-phase low-level tone compared with the in-phase low-level tone, for both groups, indicating preservation of early cortical correlates of the BMLD in PSP. In PSP a significant delay was observed in the onset of the N1m deflection and the amplitude of the P2m was reduced, but these differences were not restricted to the BMLD condition. The results demonstrate that although PSP causes subtle auditory deficits, binaural processing can survive the presence of significant damage to the upper brain stem. Copyright © 2014 the American Physiological Society.

'Where' and 'what' in visual search.

PubMed

Atkinson, J; Braddick, O J

1989-01-01

A line segment target can be detected among distractors of a different orientation by a fast 'preattentive' process. One view is that this depends on detection of a 'feature gradient', which enables subjects to locate where the target is without necessarily identifying what it is. An alternative view is that a target can be identified as distinctive in a particular 'feature map' without subjects knowing where it is in that map. Experiments are reported in which briefly exposed arrays of line segments were followed by a pattern mask, and the threshold stimulus-mask interval determined for three tasks: 'what'--subjects reported whether the target was vertical or horizontal among oblique distractors; 'coarse where'--subjects reported whether the target was in the upper or lower half of the array; 'fine where'--subjects reported whether or not the target was in a set of four particular array positions. The threshold interval was significantly lower for the 'coarse where' than for the 'what' task, indicating that, even though localization in this task depends on the target's orientation difference, this localization is possible without absolute identification of target orientation. However, for the 'fine where' task, intervals as long as or longer than those for the 'what' task were required. It appears either that different localization processes work at different levels of resolution, or that a single localization process, independent of identification, can increase its resolution at the expense of processing speed. These possibilities are discussed in terms of distinct neural representations of the visual field and fixed or variable localization processes acting upon them.

Invited Article: Mask-modulated lensless imaging with multi-angle illuminations

NASA Astrophysics Data System (ADS)

Zhang, Zibang; Zhou, You; Jiang, Shaowei; Guo, Kaikai; Hoshino, Kazunori; Zhong, Jingang; Suo, Jinli; Dai, Qionghai; Zheng, Guoan

2018-06-01

The use of multiple diverse measurements can make lensless phase retrieval more robust. Conventional diversity functions include aperture diversity, wavelength diversity, translational diversity, and defocus diversity. Here we discuss a lensless imaging scheme that employs multiple spherical-wave illuminations from a light-emitting diode array as diversity functions. In this scheme, we place a binary mask between the sample and the detector for imposing support constraints for the phase retrieval process. This support constraint enforces the light field to be zero at certain locations and is similar to the aperture constraint in Fourier ptychographic microscopy. We use a self-calibration algorithm to correct the misalignment of the binary mask. The efficacy of the proposed scheme is first demonstrated by simulations where we evaluate the reconstruction quality using mean square error and structural similarity index. The scheme is then experimentally tested by recovering images of a resolution target and biological samples. The proposed scheme may provide new insights for developing compact and large field-of-view lensless imaging platforms. The use of the binary mask can also be combined with other diversity functions for better constraining the phase retrieval solution space. We provide the open-source implementation code for the broad research community.

Does conal prime CANAL more than cinal? Masked phonological priming effects in Spanish with the lexical decision task.

PubMed

Pollatsek, Alexander; Perea, Manuel; Carreiras, Manuel

2005-04-01

Evidence for an early involvement of phonology in word identification usually relies on the comparison between a target word preceded by a homophonic prime and an orthographic control (rait-RATE vs. raut-RATE). This comparison rests on the assumption that the two control primes are equally orthographically similar to the target. Here, we tested for phonological effects with a masked priming paradigm in which orthographic similarity between priming conditions was perfectly controlled at the letter level and in which identification of the prime was virtually at chance for both stimulus onset asynchronies (SOAs) (66 and 50 msec). In the key prime-target pairs, each prime differed from the target by one vowel letter, but one changed the sound of the initial c, and the other did not (cinal-CANAL vs. conal-CANAL). In the control prime-target pairs, the primes had the identical vowel manipulation, but neither changed the initial consonant sound (pinel-PANEL vs. ponel-PANEL). For both high- and low-frequency words, lexical decision responses to the target were slower when the prime changed the sound of the c than when it did not, whereas there was no difference for the controls at both SOAs. However, this phonological effect was small and was not significant when the SOA was 50 msec. The pattern of data is consistent with an early phonological coding of primes that occurs just a little later than orthographic coding.

Gain control in the sonar of odontocetes.

PubMed

Ya Supin, Alexander; Nachtigall, Paul E

2013-06-01

The sonar of odontocetes processes echo-signals within a wide range of echo levels. The level of echoes varies widely by tens of decibels depending on the level of the emitted sonar pulse, the target strength, the distance to the target, and the sound absorption by the water media. The auditory system of odontocetes must be capable of effective perception, analysis, and discrimination of echo-signals within all this variability. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control). To date, several mechanisms of the biosonar gain control have been revealed in odontocetes: (1) adjustment of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (2) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (3) active long-term control of hearing sensitivity. Recent investigations with the use of the auditory evoked-potential technique have demonstrated that these mechanisms effectively minimize the variation of the response to the echo when either the emitted sonar pulse level, or the target distance, or both vary within a wide range. A short review of these data is presented herein.

Spectro-temporal modulation masking patterns reveal frequency selectivity.

PubMed

Oetjen, Arne; Verhey, Jesko L

2015-02-01

The present study investigated the possibility that the human auditory system demonstrates frequency selectivity to spectro-temporal amplitude modulations. Threshold modulation depth for detecting sinusoidal spectro-temporal modulations was measured using a generalized masked threshold pattern paradigm with narrowband masker modulations. Four target spectro-temporal modulations were examined, differing in their temporal and spectral modulation frequencies: a temporal modulation of -8, 8, or 16 Hz combined with a spectral modulation of 1 cycle/octave and a temporal modulation of 4 Hz combined with a spectral modulation of 0.5 cycles/octave. The temporal center frequencies of the masker modulation ranged from 0.25 to 4 times the target temporal modulation. The spectral masker-modulation center-frequencies were 0, 0.5, 1, 1.5, and 2 times the target spectral modulation. For all target modulations, the pattern of average thresholds for the eight normal-hearing listeners was consistent with the hypothesis of a spectro-temporal modulation filter. Such a pattern of modulation-frequency sensitivity was predicted on the basis of psychoacoustical data for purely temporal amplitude modulations and purely spectral amplitude modulations. An analysis of separability indicates that, for the present data set, selectivity in the spectro-temporal modulation domain can be described by a combination of a purely spectral and a purely temporal modulation filter function.

Far-Infrared Blocked Impurity Band Detector Development

NASA Technical Reports Server (NTRS)

Hogue, H. H.; Guptill, M. T.; Monson, J. C.; Stewart, J. W.; Huffman, J. E.; Mlynczak, M. G.; Abedin, M. N.

2007-01-01

DRS Sensors & Targeting Systems, supported by detector materials supplier Lawrence Semiconductor Research Laboratory, is developing far-infrared detectors jointly with NASA Langley under the Far-IR Detector Technology Advancement Partnership (FIDTAP). The detectors are intended for spectral characterization of the Earth's energy budget from space. During the first year of this effort we have designed, fabricated, and evaluated pilot Blocked Impurity Band (BIB) detectors in both silicon and germanium, utilizing pre-existing customized detector materials and photolithographic masks. A second-year effort has prepared improved silicon materials, fabricated custom photolithographic masks for detector process, and begun detector processing. We report the characterization results from the pilot detectors and other progress.

Automated cellular pathology in noninvasive confocal microscopy

NASA Astrophysics Data System (ADS)

Ting, Monica; Krueger, James; Gareau, Daniel

2014-03-01

A computer algorithm was developed to automatically identify and count melanocytes and keratinocytes in 3D reflectance confocal microscopy (RCM) images of the skin. Computerized pathology increases our understanding and enables prevention of superficial spreading melanoma (SSM). Machine learning involved looking at the images to measure the size of cells through a 2-D Fourier transform and developing an appropriate mask with the erf() function to model the cells. Implementation involved processing the images to identify cells whose image segments provided the least difference when subtracted from the mask. With further simplification of the algorithm, the program may be directly implemented on the RCM images to indicate the presence of keratinocytes in seconds and to quantify the keratinocytes size in the en face plane as a function of depth. Using this system, the algorithm can identify any irregularities in maturation and differentiation of keratinocytes, thereby signaling the possible presence of cancer.

Two-dimensional analytical modeling of a linear variable filter for spectral order sorting.

PubMed

Ko, Cheng-Hao; Wu, Yueh-Hsun; Tsai, Jih-Run; Wang, Bang-Ji; Chakraborty, Symphony

2016-06-10

A two-dimensional thin film thickness model based on the geometry of a commercial coater which can calculate more effectively the profiles of linear variable filters (LVFs) has been developed. This is done by isolating the substrate plane as an independent coordinate (local coordinate), while the rotation and translation matrices are used to establish the coordinate transformation and combine the characteristic vector with the step function to build a borderline which can conclude whether the local mask will block the deposition or not. The height of the local mask has been increased up to 40 mm in the proposed model, and two-dimensional simulations are developed to obtain a thin film profile deposition on the substrate inside the evaporation chamber to achieve the specific request of producing a LVF zone width in a more economical way than previously reported [Opt. Express23, 5102 (2015)OPEXFF1094-408710.1364/OE.23.005102].

Surface nanostructuring in the carbon–silicon(100) system upon microwave plasma treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yafarov, R. K., E-mail: pirpc@yandex.ru; Shanygin, V. Ya.

2017-04-15

The study is concerned with the physical and chemical processes and the mechanisms of the effect of plasma preparation of a surface on the systematic features of condensation and surface phase transformations during the formation of Si–C mask domains on p-Si(100) crystals by the deposition of submonolayer C coatings in the microwave plasma of low-pressure ethanol vapors. It is shown that, at short durations of the deposition of carbon onto silicon wafers with a natural-oxide coating at a temperature of 100°C, the formation of domains is observed. The lateral dimensions of the domains lie in the range from 10–15 tomore » 200 nm, and the heights of ridges produced by the plasma chemical etching of silicon through the mask domain coatings vary in the range from 40 to 80 nm.« less

Data Reduction and Image Reconstruction Techniques for Non-redundant Masking

NASA Astrophysics Data System (ADS)

Sallum, S.; Eisner, J.

2017-11-01

The technique of non-redundant masking (NRM) transforms a conventional telescope into an interferometric array. In practice, this provides a much better constrained point-spread function than a filled aperture and thus higher resolution than traditional imaging methods. Here, we describe an NRM data reduction pipeline. We discuss strategies for NRM observations regarding dithering patterns and calibrator selection. We describe relevant image calibrations and use example Large Binocular Telescope data sets to show their effects on the scatter in the Fourier measurements. We also describe the various ways to calculate Fourier quantities, and discuss different calibration strategies. We present the results of image reconstructions from simulated observations where we adjust prior images, weighting schemes, and error bar estimation. We compare two imaging algorithms and discuss implications for reconstructing images from real observations. Finally, we explore how the current state of the art compares to next-generation Extremely Large Telescopes.

An improved algorithm of mask image dodging for aerial image

NASA Astrophysics Data System (ADS)

Zhang, Zuxun; Zou, Songbai; Zuo, Zhiqi

2011-12-01

The technology of Mask image dodging based on Fourier transform is a good algorithm in removing the uneven luminance within a single image. At present, the difference method and the ratio method are the methods in common use, but they both have their own defects .For example, the difference method can keep the brightness uniformity of the whole image, but it is deficient in local contrast; meanwhile the ratio method can work better in local contrast, but sometimes it makes the dark areas of the original image too bright. In order to remove the defects of the two methods effectively, this paper on the basis of research of the two methods proposes a balance solution. Experiments show that the scheme not only can combine the advantages of the difference method and the ratio method, but also can avoid the deficiencies of the two algorithms.

Femtosecond laser induced tunable surface transformations on (111) Si aided by square grids diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Weina; Jiang, Lan; Li, Xiaowei, E-mail: lixiaowei@bit.edu.cn

We report an extra freedom to modulate the femtosecond laser energy distribution to control the surface ablated structures through a copper-grid mask. Due to the reduced deposited pulse energy by changing the scanning speed or the pulse fluence, a sequential evolution of three distinctly different surface patterns with periodic distributions is formed, namely, striped ripple lines, ripple microdots, and surface modification. By changing the scanning speed, the number of the multiple dots in a lattice can be modulated. Moreover, by exploring the ablation process through the copper grid mask, it shows an abnormal enhanced ablation effect with strong dependence ofmore » the diffraction-aided fs laser ablated surface structures on polarization direction. The sensitivity shows a quasi-cosinusoid-function with a periodicity of π/2. Particularly, the connection process of striped ripple lines manifests a preferential formation direction with the laser polarization.« less

Automatic frame-centered object representation and integration revealed by iconic memory, visual priming, and backward masking.

PubMed

Lin, Zhicheng; He, Sheng

2012-10-25

Object identities ("what") and their spatial locations ("where") are processed in distinct pathways in the visual system, raising the question of how the what and where information is integrated. Because of object motions and eye movements, the retina-based representations are unstable, necessitating nonretinotopic representation and integration. A potential mechanism is to code and update objects according to their reference frames (i.e., frame-centered representation and integration). To isolate frame-centered processes, in a frame-to-frame apparent motion configuration, we (a) presented two preceding or trailing objects on the same frame, equidistant from the target on the other frame, to control for object-based (frame-based) effect and space-based effect, and (b) manipulated the target's relative location within its frame to probe frame-centered effect. We show that iconic memory, visual priming, and backward masking depend on objects' relative frame locations, orthogonal of the retinotopic coordinate. These findings not only reveal that iconic memory, visual priming, and backward masking can be nonretinotopic but also demonstrate that these processes are automatically constrained by contextual frames through a frame-centered mechanism. Thus, object representation is robustly and automatically coupled to its reference frame and continuously being updated through a frame-centered, location-specific mechanism. These findings lead to an object cabinet framework, in which objects ("files") within the reference frame ("cabinet") are orderly coded relative to the frame.

Extrinsic grouping factors in motion-induced blindness

PubMed Central

2018-01-01

We investigated how various grouping factors altered subjective disappearances of the individual targets in the motion-induced blindness display. The latter relies on a moving mask to render highly salient static targets temporarily subjectively invisible. Specifically, we employed two extrinsic grouping factors, the connectedness and the common region, and examined whether their presence would make targets more resilient against the suppression. In addition, we investigated whether the presence of an illusory Kanizsa triangle would affect the suppression of the inducing Pac-Man elements. We quantified the perceptual dynamics using the proportion of the disappearance time (this indicates whether targets became more resilient against the suppression), and the proportion of simultaneous disappearance and reappearance events (characterizes the tendency for the targets to disappear or reappear as a group). We report that a single mask that encompassed all targets (a common region grouping) significantly increased the proportion of simultaneous disappearance and reappearance events, but had no effect on the proportion of the disappearance time. In contrast, a line that connected two targets significantly decreased the total invisibility time, but had no impact on the simultaneity of the disappearance and reappearance events. We found no statistically significant effect of the presence of the illusory Kanizsa triangle on either measure. Finally, we found no interaction either between the common region and the connectedness or between the common region and the presence of the illusory Kanizsa triangle. Our results indicate that extrinsic grouping factors might influence the perception differently than the intrinsic ones and highlight the importance of using several measures to characterize the perceptual dynamics, as various grouping factors might affect it differentially. PMID:29381747

CDO budgeting

NASA Astrophysics Data System (ADS)

Nesladek, Pavel; Wiswesser, Andreas; Sass, Björn; Mauermann, Sebastian

2008-04-01

The Critical dimension off-target (CDO) is a key parameter for mask house customer, affecting directly the performance of the mask. The CDO is the difference between the feature size target and the measured feature size. The change of CD during the process is either compensated within the process or by data correction. These compensation methods are commonly called process bias and data bias, respectively. The difference between data bias and process bias in manufacturing results in systematic CDO error, however, this systematic error does not take into account the instability of the process bias. This instability is a result of minor variations - instabilities of manufacturing processes and changes in materials and/or logistics. Using several masks the CDO of the manufacturing line can be estimated. For systematic investigation of the unit process contribution to CDO and analysis of the factors influencing the CDO contributors, a solid understanding of each unit process and huge number of masks is necessary. Rough identification of contributing processes and splitting of the final CDO variation between processes can be done with approx. 50 masks with identical design, material and process. Such amount of data allows us to identify the main contributors and estimate the effect of them by means of Analysis of variance (ANOVA) combined with multivariate analysis. The analysis does not provide information about the root cause of the variation within the particular unit process, however, it provides a good estimate of the impact of the process on the stability of the manufacturing line. Additionally this analysis can be used to identify possible interaction between processes, which cannot be investigated if only single processes are considered. Goal of this work is to evaluate limits for CDO budgeting models given by the precision and the number of measurements as well as partitioning the variation within the manufacturing process. The CDO variation splits according to the suggested model into contributions from particular processes or process groups. Last but not least the power of this method to determine the absolute strength of each parameter will be demonstrated. Identification of the root cause of this variation within the unit process itself is not scope of this work.

Effect of two-step hygiene management on the prevention of nosocomial influenza in a season with high influenza activity.

PubMed

Ambrosch, A; Rockmann, F

2016-10-01

Rapid identification of patients infected with influenza virus, precise case definition and strict hygiene measures are important for the prevention of nosocomial transmission. To prove the usefulness of a case definition for rapid identification of patients with influenza and to investigate the effect of two-step hygiene management, including the continuous use of surgical masks by hospital staff, on the rate of nosocomial infections. All patients hospitalized between January and March 2015 with suspected influenza were enrolled. Real-time polymerase chain reaction testing for influenza was performed. Infected patients were managed according to the national hygiene guidelines, including the use of surgical masks by hospital staff during close contact with infected patients. When influenza activity increased, the continuous use of surgical masks by hospital staff was implemented as an add-on measure. Most patients enrolled in this study were elderly (N=212, mean age 75 years). Frequency of cough was the only clinical parameter of respiratory infection that differed between influenza-negative and influenza-positive patients. Compared with the targeted use of surgical masks during close contact with infected patients, the continuous use of surgical masks for the entire working shift resulted in a reduction of nosocomial infections from 31% to 16%, respectively (P<0.01). Discrimination between influenza A and other respiratory infections in elderly hospitalized patients was not possible based on clinical characteristics. With regard to hygiene management, the continuous use of surgical masks by hospital staff seems to be effective for the prevention of nosocomial infections. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The transformation of targeted killing and international order.

PubMed

Senn, Martin; Troy, Jodok

2017-05-04

This article introduces the special issue's question of whether and how the current transformation of targeted killing is transforming the global international order and provides the conceptual ground for the individual contributions to the special issue. It develops a two-dimensional concept of political order and introduces a theoretical framework that conceives the maintenance and transformation of international order as a dynamic interplay between its behavioral dimension in the form of violence and discursive processes and its institutional dimension in the form of ideas, norms, and rules. The article also conceptualizes targeted killing and introduces a typology of targeted-killing acts on the basis of their legal and moral legitimacy. Building on this conceptual groundwork, the article takes stock of the current transformation of targeted killing and summarizes the individual contributions to this special issue.

Full-wave and half-wave rectification in second-order motion perception

NASA Technical Reports Server (NTRS)

Solomon, J. A.; Sperling, G.

1994-01-01

Microbalanced stimuli are dynamic displays which do not stimulate motion mechanisms that apply standard (Fourier-energy or autocorrelational) motion analysis directly to the visual signal. In order to extract motion information from microbalanced stimuli, Chubb and Sperling [(1988) Journal of the Optical Society of America, 5, 1986-2006] proposed that the human visual system performs a rectifying transformation on the visual signal prior to standard motion analysis. The current research employs two novel types of microbalanced stimuli: half-wave stimuli preserve motion information following half-wave rectification (with a threshold) but lose motion information following full-wave rectification; full-wave stimuli preserve motion information following full-wave rectification but lose motion information following half-wave rectification. Additionally, Fourier stimuli, ordinary square-wave gratings, were used to stimulate standard motion mechanisms. Psychometric functions (direction discrimination vs stimulus contrast) were obtained for each type of stimulus when presented alone, and when masked by each of the other stimuli (presented as moving masks and also as nonmoving, counterphase-flickering masks). RESULTS: given sufficient contrast, all three types of stimulus convey motion. However, only one-third of the population can perceive the motion of the half-wave stimulus. Observers are able to process the motion information contained in the Fourier stimulus slightly more efficiently than the information in the full-wave stimulus but are much less efficient in processing half-wave motion information. Moving masks are more effective than counterphase masks at hampering direction discrimination, indicating that some of the masking effect is interference between motion mechanisms, and some occurs at earlier stages. When either full-wave and Fourier or half-wave and Fourier gratings are presented simultaneously, there is a wide range of relative contrasts within which the motion directions of both gratings are easily determinable. Conversely, when half-wave and full-wave gratings are combined, the direction of only one of these gratings can be determined with high accuracy. CONCLUSIONS: the results indicate that three motion computations are carried out, any two in parallel: one standard ("first order") and two non-Fourier ("second-order") computations that employ full-wave and half-wave rectification.

Microscopic validation of whole mouse micro-metastatic tumor imaging agents using cryo-imaging and sliding organ image registration.

PubMed

Liu, Yiqiao; Zhou, Bo; Qutaish, Mohammed; Wilson, David L

2016-01-01

We created a metastasis imaging, analysis platform consisting of software and multi-spectral cryo-imaging system suitable for evaluating emerging imaging agents targeting micro-metastatic tumor. We analyzed CREKA-Gd in MRI, followed by cryo-imaging which repeatedly sectioned and tiled microscope images of the tissue block face, providing anatomical bright field and molecular fluorescence, enabling 3D microscopic imaging of the entire mouse with single metastatic cell sensitivity. To register MRI volumes to the cryo bright field reference, we used our standard mutual information, non-rigid registration which proceeded: preprocess → affine → B-spline non-rigid 3D registration. In this report, we created two modified approaches: mask where we registered locally over a smaller rectangular solid, and sliding organ . Briefly, in sliding organ , we segmented the organ, registered the organ and body volumes separately and combined results. Though s liding organ required manual annotation, it provided the best result as a standard to measure other registration methods. Regularization parameters for standard and mask methods were optimized in a grid search. Evaluations consisted of DICE, and visual scoring of a checkerboard display. Standard had accuracy of 2 voxels in all regions except near the kidney, where there were 5 voxels sliding. After mask and sliding organ correction, kidneys sliding were within 2 voxels, and Dice overlap increased 4%-10% in mask compared to standard . Mask generated comparable results with sliding organ and allowed a semi-automatic process.

Microscopic validation of whole mouse micro-metastatic tumor imaging agents using cryo-imaging and sliding organ image registration

NASA Astrophysics Data System (ADS)

Liu, Yiqiao; Zhou, Bo; Qutaish, Mohammed; Wilson, David L.

2016-03-01

We created a metastasis imaging, analysis platform consisting of software and multi-spectral cryo-imaging system suitable for evaluating emerging imaging agents targeting micro-metastatic tumor. We analyzed CREKA-Gd in MRI, followed by cryo-imaging which repeatedly sectioned and tiled microscope images of the tissue block face, providing anatomical bright field and molecular fluorescence, enabling 3D microscopic imaging of the entire mouse with single metastatic cell sensitivity. To register MRI volumes to the cryo bright field reference, we used our standard mutual information, non-rigid registration which proceeded: preprocess --> affine --> B-spline non-rigid 3D registration. In this report, we created two modified approaches: mask where we registered locally over a smaller rectangular solid, and sliding organ. Briefly, in sliding organ, we segmented the organ, registered the organ and body volumes separately and combined results. Though sliding organ required manual annotation, it provided the best result as a standard to measure other registration methods. Regularization parameters for standard and mask methods were optimized in a grid search. Evaluations consisted of DICE, and visual scoring of a checkerboard display. Standard had accuracy of 2 voxels in all regions except near the kidney, where there were 5 voxels sliding. After mask and sliding organ correction, kidneys sliding were within 2 voxels, and Dice overlap increased 4%-10% in mask compared to standard. Mask generated comparable results with sliding organ and allowed a semi-automatic process.

Does visual letter similarity modulate masked form priming in young readers of Arabic?

PubMed

Perea, Manuel; Abu Mallouh, Reem; Mohammed, Ahmed; Khalifa, Batoul; Carreiras, Manuel

2018-05-01

We carried out a masked priming lexical decision experiment to study whether visual letter similarity plays a role during the initial phases of word processing in young readers of Arabic (fifth graders). Arabic is ideally suited to test these effects because most Arabic letters share their basic shape with at least one other letter and differ only in the number/position of diacritical points (e.g., ض - ص ;ظ - ط ;غ - ع ;ث - ت - ن ب ;ذ - د ;خ - ح - ج ;ق - ف ;ش - س ;ز - ر). We created two one-letter-different priming conditions for each target word, in which a letter from the consonantal root was substituted by another letter that did or did not keep the same shape (e.g., خدمة - حدمة vs. خدمة - فدمة). Another goal of the current experiment was to test the presence of masked orthographic priming effects, which are thought to be unreliable in Semitic languages. To that end, we included an unrelated priming condition. We found a sizable masked orthographic priming effect relative to the unrelated condition regardless of visual letter similarity, thereby revealing that young readers are able to quickly process the diacritical points of Arabic letters. Furthermore, the presence of masked orthographic priming effects in Arabic suggests that the word identification stream in Indo-European and Semitic languages is more similar than previously thought. Copyright © 2017 Elsevier Inc. All rights reserved.

A cocktail-party listening experiment with children

NASA Astrophysics Data System (ADS)

Wightman, Frederic; Callahan, Michael; Kistler, Doris

2003-04-01

In an experiment modeled after one reported recently by Brungart and Simpson [J. Acoust. Soc. Am. 112, 2985-2995 (2002)], 38 children (ages 4-16) and 10 adults responded to a monaural target speech signal in the presence of one or two distracter speech signals. The target speaker was a male and the distracter speakers were females. When two distracters were present they were in different ears. Performance at several different target ear S/N was measured and psychometric functions were fitted to estimate threshold, or the 50% performance level. The youngest children required approximately 20 dB higher S/N than adults to achieve threshold with a single distracter. This difference disappeared by age 16. The impact of adding the contralateral distracter, which is thought to contribute only informational masking, was roughly constant across age, however. Adult thresholds increased about 11 dB and the thresholds for the youngest children increased about 10 dB. This was surprising given previous experiments that showed much larger informational masking effects in young children. Also inconsistent with previous results is the lack of individual differences. Nearly all listeners showed almost the same contralateral distracter effect. [Work supported by NICHD.

Correlations of decision weights and cognitive function for the masked discrimination of vowels by young and old adults

PubMed Central

Lutfi, Robert A.

2014-01-01

Older adults are often reported in the literature to have greater difficulty than younger adults understanding speech in noise [Helfer and Wilber (1988). J. Acoust. Soc. Am, 859–893]. The poorer performance of older adults has been attributed to a general deterioration of cognitive processing, deterioration of cochlear anatomy, and/or greater difficulty segregating speech from noise. The current work used perturbation analysis [Berg (1990). J. Acoust. Soc. Am., 149–158] to provide a more specific assessment of the effect of cognitive factors on speech perception in noise. Sixteen older (age 56–79 years) and seventeen younger (age 19–30 years) adults discriminated a target vowel masked by randomly selected masker vowels immediately preceding and following the target. Relative decision weights on target and maskers resulting from the analysis revealed large individual differences across participants despite similar performance scores in many cases. On the most difficult vowel discriminations, the older adult decision weights were significantly correlated with inhibitory control (Color Word Interference test) and pure-tone threshold averages (PTA). Young adult decision weights were not correlated with any measures of peripheral (PTA) or central function (inhibition or working memory). PMID:25256580

Characteristics of spectro-temporal modulation frequency selectivity in humans.

PubMed

Oetjen, Arne; Verhey, Jesko L

2017-03-01

There is increasing evidence that the auditory system shows frequency selectivity for spectro-temporal modulations. A recent study of the authors has shown spectro-temporal modulation masking patterns that were in agreement with the hypothesis of spectro-temporal modulation filters in the human auditory system [Oetjen and Verhey (2015). J. Acoust. Soc. Am. 137(2), 714-723]. In the present study, that experimental data and additional data were used to model this spectro-temporal frequency selectivity. The additional data were collected to investigate to what extent the spectro-temporal modulation-frequency selectivity results from a combination of a purely temporal amplitude-modulation filter and a purely spectral amplitude-modulation filter. In contrast to the previous study, thresholds were measured for masker and target modulations with opposite directions, i.e., an upward pointing target modulation and a downward pointing masker modulation. The comparison of this data set with previous corresponding data with the same direction from target and masker modulations indicate that a specific spectro-temporal modulation filter is required to simulate all aspects of spectro-temporal modulation frequency selectivity. A model using a modified Gabor filter with a purely temporal and a purely spectral filter predicts the spectro-temporal modulation masking data.

Discussion and a new method of optical cryptosystem based on interference

NASA Astrophysics Data System (ADS)

Lu, Dajiang; He, Wenqi; Liao, Meihua; Peng, Xiang

2017-02-01

A discussion and an objective security analysis of the well-known optical image encryption based on interference are presented in this paper. A new method is also proposed to eliminate the security risk of the original cryptosystem. For a possible practical application, we expand this new method into a hierarchical authentication scheme. In this authentication system, with a pre-generated and fixed random phase lock, different target images indicating different authentication levels are analytically encoded into corresponding phase-only masks (phase keys) and amplitude-only masks (amplitude keys). For the authentication process, a legal user can obtain a specified target image at the output plane if his/her phase key, and amplitude key, which should be settled close against the fixed internal phase lock, are respectively illuminated by two coherent beams. By comparing the target image with all the standard certification images in the database, the system can thus verify the user's legality even his/her identity level. Moreover, in despite of the internal phase lock of this system being fixed, the crosstalk between different pairs of keys held by different users is low. Theoretical analysis and numerical simulation are both provided to demonstrate the validity of this method.

Suppression of displacement detection in the presence and absence of eye movements: a neuro-computational perspective.

PubMed

Bergelt, Julia; Hamker, Fred H

2016-02-01

Understanding the subjective experience of a visually stable world during eye movements has been an important research topic for many years. Various studies were conducted to reveal fundamental mechanisms of this phenomenon. For example, in the paradigm saccadic suppression of displacement (SSD), it has been observed that a small displacement of a saccade target could not easily be reported if this displacement took place during a saccade. New results from Zimmermann et al. (J Neurophysiol 112(12):3066-3076, 2014) show that the effect of being oblivious to small displacements occurs not only during saccades, but also if a mask is introduced while the target is displaced. We address the question of how neurons in the parietal cortex may be connected to each other to account for the SSD effect in experiments involving a saccade and equally well in the absence of an eye movement while perception is disrupted by a mask.

Wheat (Triticum aestivum L.) transformation using mature embryos.

PubMed

Medvecká, Eva; Harwood, Wendy A

2015-01-01

In most protocols for the Agrobacterium-mediated transformation of wheat, the preferred target tissues are immature embryos. However, transformation methods relying on immature embryos require the growth of plants under controlled conditions to provide a continuous supply of good-quality target tissue. The use of mature embryos as a target tissue has the advantage of only requiring good-quality seed as the starting material. Here we describe a transformation method based on the Agrobacterium-mediated transformation of callus cultures derived from mature wheat embryos of the genotype Bobwhite S56.

Wavelet-Smoothed Interpolation of Masked Scientific Data for JPEG 2000 Compression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brislawn, Christopher M.

2012-08-13

How should we manage scientific data with 'holes'? Some applications, like JPEG 2000, expect logically rectangular data, but some sources, like the Parallel Ocean Program (POP), generate data that isn't defined on certain subsets. We refer to grid points that lack well-defined, scientifically meaningful sample values as 'masked' samples. Wavelet-smoothing is a highly scalable interpolation scheme for regions with complex boundaries on logically rectangular grids. Computation is based on forward/inverse discrete wavelet transforms, so runtime complexity and memory scale linearly with respect to sample count. Efficient state-of-the-art minimal realizations yield small constants (O(10)) for arithmetic complexity scaling, and in-situ implementationmore » techniques make optimal use of memory. Implementation in two dimensions using tensor product filter banks is straighsorward and should generalize routinely to higher dimensions. No hand-tuning required when the interpolation mask changes, making the method aeractive for problems with time-varying masks. Well-suited for interpolating undefined samples prior to JPEG 2000 encoding. The method outperforms global mean interpolation, as judged by both SNR rate-distortion performance and low-rate artifact mitigation, for data distributions whose histograms do not take the form of sharply peaked, symmetric, unimodal probability density functions. These performance advantages can hold even for data whose distribution differs only moderately from the peaked unimodal case, as demonstrated by POP salinity data. The interpolation method is very general and is not tied to any particular class of applications, could be used for more generic smooth interpolation.« less

Comparison of algorithms for automatic border detection of melanoma in dermoscopy images

NASA Astrophysics Data System (ADS)

Srinivasa Raghavan, Sowmya; Kaur, Ravneet; LeAnder, Robert

2016-09-01

Melanoma is one of the most rapidly accelerating cancers in the world [1]. Early diagnosis is critical to an effective cure. We propose a new algorithm for more accurately detecting melanoma borders in dermoscopy images. Proper border detection requires eliminating occlusions like hair and bubbles by processing the original image. The preprocessing step involves transforming the RGB image to the CIE L*u*v* color space, in order to decouple brightness from color information, then increasing contrast, using contrast-limited adaptive histogram equalization (CLAHE), followed by artifacts removal using a Gaussian filter. After preprocessing, the Chen-Vese technique segments the preprocessed images to create a lesion mask which undergoes a morphological closing operation. Next, the largest central blob in the lesion is detected, after which, the blob is dilated to generate an image output mask. Finally, the automatically-generated mask is compared to the manual mask by calculating the XOR error [3]. Our border detection algorithm was developed using training and test sets of 30 and 20 images, respectively. This detection method was compared to the SRM method [4] by calculating the average XOR error for each of the two algorithms. Average error for test images was 0.10, using the new algorithm, and 0.99, using SRM method. In comparing the average error values produced by the two algorithms, it is evident that the average XOR error for our technique is lower than the SRM method, thereby implying that the new algorithm detects borders of melanomas more accurately than the SRM algorithm.

Spatial frequency filtered images reveal differences between masked and unmasked processing of emotional information.

PubMed

Rohr, Michaela; Wentura, Dirk

2014-10-01

High and low spatial frequency information has been shown to contribute differently to the processing of emotional information. In three priming studies using spatial frequency filtered emotional face primes, emotional face targets, and an emotion categorization task, we investigated this issue further. Differences in the pattern of results between short and masked, and short and long unmasked presentation conditions emerged. Given long and unmasked prime presentation, high and low frequency primes triggered emotion-specific priming effects. Given brief and masked prime presentation in Experiment 2, we found a dissociation: High frequency primes caused a valence priming effect, whereas low frequency primes yielded a differentiation between low and high arousing information within the negative domain. Brief and unmasked prime presentation in Experiment 3 revealed that subliminal processing of primes was responsible for the pattern observed in Experiment 2. The implications of these findings for theories of early emotional information processing are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

Emotional voice and emotional body postures influence each other independently of visual awareness.

PubMed

Stienen, Bernard M C; Tanaka, Akihiro; de Gelder, Beatrice

2011-01-01

Multisensory integration may occur independently of visual attention as previously shown with compound face-voice stimuli. We investigated in two experiments whether the perception of whole body expressions and the perception of voices influence each other when observers are not aware of seeing the bodily expression. In the first experiment participants categorized masked happy and angry bodily expressions while ignoring congruent or incongruent emotional voices. The onset between target and mask varied from -50 to +133 ms. Results show that the congruency between the emotion in the voice and the bodily expressions influences audiovisual perception independently of the visibility of the stimuli. In the second experiment participants categorized the emotional voices combined with masked bodily expressions as fearful or happy. This experiment showed that bodily expressions presented outside visual awareness still influence prosody perception. Our experiments show that audiovisual integration between bodily expressions and affective prosody can take place outside and independent of visual awareness.

Automated brainstem co-registration (ABC) for MRI.

PubMed

Napadow, Vitaly; Dhond, Rupali; Kennedy, David; Hui, Kathleen K S; Makris, Nikos

2006-09-01

Group data analysis in brainstem neuroimaging is predicated on accurate co-registration of anatomy. As the brainstem is comprised of many functionally heterogeneous nuclei densely situated adjacent to one another, relatively small errors in co-registration can manifest in increased variance or decreased sensitivity (or significance) in detecting activations. We have devised a 2-stage automated, reference mask guided registration technique (Automated Brainstem Co-registration, or ABC) for improved brainstem co-registration. Our approach utilized a brainstem mask dataset to weight an automated co-registration cost function. Our method was validated through measurement of RMS error at 12 manually defined landmarks. These landmarks were also used as guides for a secondary manual co-registration option, intended for outlier individuals that may not adequately co-register with our automated method. Our methodology was tested on 10 healthy human subjects and compared to traditional co-registration techniques (Talairach transform and automated affine transform to the MNI-152 template). We found that ABC had a significantly lower mean RMS error (1.22 +/- 0.39 mm) than Talairach transform (2.88 +/- 1.22 mm, mu +/- sigma) and the global affine (3.26 +/- 0.81 mm) method. Improved accuracy was also found for our manual-landmark-guided option (1.51 +/- 0.43 mm). Visualizing individual brainstem borders demonstrated more consistent and uniform overlap for ABC compared to traditional global co-registration techniques. Improved robustness (lower susceptibility to outliers) was demonstrated with ABC through lower inter-subject RMS error variance compared with traditional co-registration methods. The use of easily available and validated tools (AFNI and FSL) for this method should ease adoption by other investigators interested in brainstem data group analysis.

Lithographic image simulation for the 21st century with 19th-century tools

NASA Astrophysics Data System (ADS)

Gordon, Ronald L.; Rosenbluth, Alan E.

2004-01-01

Simulation of lithographic processes in semiconductor manufacturing has gone from a crude learning tool 20 years ago to a critical part of yield enhancement strategy today. Although many disparate models, championed by equally disparate communities, exist to describe various photoresist development phenomena, these communities would all agree that the one piece of the simulation picture that can, and must, be computed accurately is the image intensity in the photoresist. The imaging of a photomask onto a thin-film stack is one of the only phenomena in the lithographic process that is described fully by well-known, definitive physical laws. Although many approximations are made in the derivation of the Fourier transform relations between the mask object, the pupil, and the image, these and their impacts are well-understood and need little further investigation. The imaging process in optical lithography is modeled as a partially-coherent, Kohler illumination system. As Hopkins has shown, we can separate the computation into 2 pieces: one that takes information about the illumination source, the projection lens pupil, the resist stack, and the mask size or pitch, and the other that only needs the details of the mask structure. As the latter piece of the calculation can be expressed as a fast Fourier transform, it is the first piece that dominates. This piece involves computation of a potentially large number of numbers called Transmission Cross-Coefficients (TCCs), which are correlations of the pupil function weighted with the illumination intensity distribution. The advantage of performing the image calculations this way is that the computation of these TCCs represents an up-front cost, not to be repeated if one is only interested in changing the mask features, which is the case in Model-Based Optical Proximity Correction (MBOPC). The down side, however, is that the number of these expensive double integrals that must be performed increases as the square of the mask unit cell area; this number can cause even the fastest computers to balk if one needs to study medium- or long-range effects. One can reduce this computational burden by approximating with a smaller area, but accuracy is usually a concern, especially when building a model that will purportedly represent a manufacturing process. This work will review the current methodologies used to simulate the intensity distribution in air above the resist and address the above problems. More to the point, a methodology has been developed to eliminate the expensive numerical integrations in the TCC calculations, as the resulting integrals in many cases of interest can be either evaluated analytically, or replaced by analytical functions accurate to within machine precision. With the burden of computing these numbers lightened, more accurate representations of the image field can be realized, and better overall models are then possible.

Tensor Fukunaga-Koontz transform for small target detection in infrared images

NASA Astrophysics Data System (ADS)

Liu, Ruiming; Wang, Jingzhuo; Yang, Huizhen; Gong, Chenglong; Zhou, Yuanshen; Liu, Lipeng; Zhang, Zhen; Shen, Shuli

2016-09-01

Infrared small targets detection plays a crucial role in warning and tracking systems. Some novel methods based on pattern recognition technology catch much attention from researchers. However, those classic methods must reshape images into vectors with the high dimensionality. Moreover, vectorizing breaks the natural structure and correlations in the image data. Image representation based on tensor treats images as matrices and can hold the natural structure and correlation information. So tensor algorithms have better classification performance than vector algorithms. Fukunaga-Koontz transform is one of classification algorithms and it is a vector version method with the disadvantage of all vector algorithms. In this paper, we first extended the Fukunaga-Koontz transform into its tensor version, tensor Fukunaga-Koontz transform. Then we designed a method based on tensor Fukunaga-Koontz transform for detecting targets and used it to detect small targets in infrared images. The experimental results, comparison through signal-to-clutter, signal-to-clutter gain and background suppression factor, have validated the advantage of the target detection based on the tensor Fukunaga-Koontz transform over that based on the Fukunaga-Koontz transform.

The transformation of targeted killing and international order

PubMed Central

Senn, Martin; Troy, Jodok

2017-01-01

ABSTRACT This article introduces the special issue’s question of whether and how the current transformation of targeted killing is transforming the global international order and provides the conceptual ground for the individual contributions to the special issue. It develops a two-dimensional concept of political order and introduces a theoretical framework that conceives the maintenance and transformation of international order as a dynamic interplay between its behavioral dimension in the form of violence and discursive processes and its institutional dimension in the form of ideas, norms, and rules. The article also conceptualizes targeted killing and introduces a typology of targeted-killing acts on the basis of their legal and moral legitimacy. Building on this conceptual groundwork, the article takes stock of the current transformation of targeted killing and summarizes the individual contributions to this special issue. PMID:29097903

Missing texture reconstruction method based on error reduction algorithm using Fourier transform magnitude estimation scheme.

PubMed

Ogawa, Takahiro; Haseyama, Miki

2013-03-01

A missing texture reconstruction method based on an error reduction (ER) algorithm, including a novel estimation scheme of Fourier transform magnitudes is presented in this brief. In our method, Fourier transform magnitude is estimated for a target patch including missing areas, and the missing intensities are estimated by retrieving its phase based on the ER algorithm. Specifically, by monitoring errors converged in the ER algorithm, known patches whose Fourier transform magnitudes are similar to that of the target patch are selected from the target image. In the second approach, the Fourier transform magnitude of the target patch is estimated from those of the selected known patches and their corresponding errors. Consequently, by using the ER algorithm, we can estimate both the Fourier transform magnitudes and phases to reconstruct the missing areas.

Formulation and biopharmaceutical evaluation of bitter taste masking microparticles containing azithromycin loaded in dispersible tablets.

PubMed

Tung, Nguyen-Thach; Tran, Cao-Son; Nguyen, Tran-Linh; Hoang, Tung; Trinh, Thanh-Dat; Nguyen, Thi-Ngan

2018-05-01

The objective of this study was to prepare and evaluate some physiochemical and biopharmaceutical properties of bitter taste masking microparticles containing azithromycin loaded in dispersible tablets. In the first stage of the study, the bitter taste masking microparticles were prepared by solvent evaporation and spray drying method. When compared to the bitter threshold (32.43µg/ml) of azithromycin (AZI), the microparticles using AZI:Eudragit L100=1:4 and having a size distribution of 45-212µm did significantly mask the bitter taste of AZI. Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance spectroscopy ( 1 H NMR) proved that the taste masking of microparticles resulted from the intermolecular interaction of the amine group in AZI and the carbonyl group in Eudragit L100. Differential scanning calorimeter (DSC) analysis was used to display the amorphous state of AZI in microparticles. Images obtaining from optical microscopy and scanning electron microscopy (SEM) indicated the existence of microparticles in regular cube shape with many layers. In the second stage, dispersible tablets containing microparticles (DTs-MP) were prepared by direct compression technique. Stability study was conducted to screen pH modulators for DTs-MP, and a combination of alkali agents (CaCO 3 :NaH 2 PO 4 , 2:1) was added into DTs-MP to create microenvironment pH of 5.0-6.0 for the tablets. The disintegration time of optimum DTs-MP was 53±5.29s and strongly depended on the kinds of lubricant and diluent. The pharmacokinetic study in the rabbit model using liquid chromatography tandem mass spectrometry showed that the mean relative bioavailability (AUC) and mean maximum concentration (C max ) of DTs-MP were improved by 2.19 and 2.02 times, respectively, compared to the reference product (Zithromax®, Pfizer). Copyright © 2017 Elsevier B.V. All rights reserved.

Tannate complexes of antihistaminic drug: sustained release and taste masking approaches.

PubMed

Rahman, Ziyaur; Zidan, Ahmed S; Berendt, Robert T; Khan, Mansoor A

2012-01-17

The aim of this investigation was to evaluate the complexation potential of brompheniramine maleate (BPM) and tannic acid (TA) for sustained release and taste masking effects. The complexes (1:1-1:7 TA to BPM ratio) were prepared by the solvent evaporation method using methanol, phosphate buffer pH 6.8 or 0.1N HCl as common solvents. The complexes were characterized microscopically by scanning electron microscopy (SEM), chemically by Fourier transform infrared (FTIR) and solid-state NMR (SSNMR), thermally by differential scanning calorimetry (DSC), for crystallinity by powder X-ray powder diffraction (PXRD), for organoleptic evaluation by electronic tongue (e-tongue), and for solubility in 0.1N HCl and phosphate buffer pH 6.8. The dissolution studies were carried out using the USP II method at 50 rpm in 500 ml of dissolution media (0.1N HCl or phosphate buffer pH 6.8). SEM images revealed that the morphology of complexes were completely different from the individual components, and all complexes had the same morphological characteristics, irrespective of the solvent used for their preparation, pH or ratio of BPM and TA. The FTIR spectra showed the presence of chemical interactions between the TA and BPM. DSC, PXRD and SSNMR indicated that the drug lost its crystalline nature by formation of the complex. Complexation has significantly reduced the solubility of BPM and sustained the drug release up to 24h in phosphate buffer pH 6.8 media. The bitter taste of the BPM was completely masked which was indicated by Euclidean distance values which was far from the drug but near to its placebo in the complexes in all ratios studied. The taste masked complexes can be potentially developed as suitable dosage forms for pediatric use. In summary, complexation of BPM and TA effectively sustained the dissolution and masked the bitter taste of drug for the development of suitable dosage forms for pediatric use. Published by Elsevier B.V.

Saccade adaptation goes for the goal

PubMed Central

Madelain, Laurent; Herman, James P.; Harwood, Mark R.

2013-01-01

The oculomotor system maintains saccade accuracy by adjusting saccades that are consistently inaccurate. Four experiments were performed to determine the relative contribution of background and target postsaccadic displacement. Unlike typical saccade adaptation experiments, we used natural image scenes and masked target and background displacements during the saccade to exclude motion signals from allowing detection of the displacements. We found that the background had no effect on saccade gain while the target drove gain changes. Only when the target was blanked after the saccade did we observe some adaptation in the direction of the background displacement. We conclude that target selection is critical to saccade adaptation, and operates effectively against natural image backgrounds. PMID:23492925

Asynchronous glimpsing of speech: Spread of masking and task set-size

PubMed Central

Ozmeral, Erol J.; Buss, Emily; Hall, Joseph W.

2012-01-01

Howard-Jones and Rosen [(1993). J. Acoust. Soc. Am. 93, 2915–2922] investigated the ability to integrate glimpses of speech that are separated in time and frequency using a “checkerboard” masker, with asynchronous amplitude modulation (AM) across frequency. Asynchronous glimpsing was demonstrated only for spectrally wide frequency bands. It is possible that the reduced evidence of spectro-temporal integration with narrower bands was due to spread of masking at the periphery. The present study tested this hypothesis with a dichotic condition, in which the even- and odd-numbered bands of the target speech and asynchronous AM masker were presented to opposite ears, minimizing the deleterious effects of masking spread. For closed-set consonant recognition, thresholds were 5.1–8.5 dB better for dichotic than for monotic asynchronous AM conditions. Results were similar for closed-set word recognition, but for open-set word recognition the benefit of dichotic presentation was more modest and level dependent, consistent with the effects of spread of masking being level dependent. There was greater evidence of asynchronous glimpsing in the open-set than closed-set tasks. Presenting stimuli dichotically supported asynchronous glimpsing with narrower frequency bands than previously shown, though the magnitude of glimpsing was reduced for narrower bandwidths even in some dichotic conditions. PMID:22894234

Target design for materials processing very far from equilibrium

NASA Astrophysics Data System (ADS)

Barnard, John J.; Schenkel, Thomas

2016-10-01

Local heating and electronic excitations can trigger phase transitions or novel material states that can be stabilized by rapid quenching. An example on the few nanometer scale are phase transitions induced by the passage of swift heavy ions in solids where nitrogen-vacancy color centers form locally in diamonds when ions heat the diamond matrix to warm dense matter conditions at 0.5 eV. We optimize mask geometries for target materials such as silicon and diamond to induce phase transitions by intense ion pulses (e. g. from NDCX-II or from laser-plasma acceleration). The goal is to rapidly heat a solid target volumetrically and to trigger a phase transition or local lattice reconstruction followed by rapid cooling. The stabilized phase can then be studied ex situ. We performed HYDRA simulations that calculate peak temperatures for a series of excitation conditions and cooling rates of crystal targets with micro-structured masks. A simple analytical model, that includes ion heating and radial, diffusive cooling, was developed that agrees closely with the HYDRA simulations. The model gives scaling laws that can guide the design of targets over a wide range of parameters including those for NDCX-II and the proposed BELLA-i. This work was performed under the auspices of the U.S. DOE under contracts DE-AC52-07NA27344 (LLNL), DE-AC02-05CH11231 (LBNL) and was supported by the US DOE Office of Science, Fusion Energy Sciences. LLNL-ABS-697271.

Unconscious Semantic Activation Depends on Feature-Specific Attention Allocation

ERIC Educational Resources Information Center

Spruyt, Adriaan; De Houwer, Jan; Everaert, Tom; Hermans, Dirk

2012-01-01

We examined whether semantic activation by subliminally presented stimuli is dependent upon the extent to which participants assign attention to specific semantic stimulus features and stimulus dimensions. Participants pronounced visible target words that were preceded by briefly presented, masked prime words. Both affective and non-affective…

The Effects of Gendered Immigration Enforcement on Middle Childhood and Schooling

ERIC Educational Resources Information Center

Gallo, Sarah

2014-01-01

Drawing from an ethnographic study on Mexican immigrant fathers and their second-grade children, this article examines the masked realities behind current immigration policies that equate "illegal" with "Mexican immigrant" and how the enforcement of these policies, which overwhelmingly target Mexican immigrant men, affect…

Support from the Morphological Family When Unembedding the Stem

ERIC Educational Resources Information Center

Beyersmann, Elisabeth; Grainger, Jonathan

2018-01-01

Recent research investigating embedded stem priming effects with the masked priming paradigm and pseudoword primes (e.g., "quickify"--"quick") has shown that priming effects can be obtained even when the embedded target word is followed by a non-morphological ending (e.g., "quickald"--"quick"). Here we…

More insight into the interplay of response selection and visual attention in dual-tasks: masked visual search and response selection are performed in parallel.

PubMed

Reimer, Christina B; Schubert, Torsten

2017-09-15

Both response selection and visual attention are limited in capacity. According to the central bottleneck model, the response selection processes of two tasks in a dual-task situation are performed sequentially. In conjunction search, visual attention is required to select the items and to bind their features (e.g., color and form), which results in a serial search process. Search time increases as items are added to the search display (i.e., set size effect). When the search display is masked, visual attention deployment is restricted to a brief period of time and target detection decreases as a function of set size. Here, we investigated whether response selection and visual attention (i.e., feature binding) rely on a common or on distinct capacity limitations. In four dual-task experiments, participants completed an auditory Task 1 and a conjunction search Task 2 that were presented with an experimentally modulated temporal interval between them (Stimulus Onset Asynchrony, SOA). In Experiment 1, Task 1 was a two-choice discrimination task and the conjunction search display was not masked. In Experiment 2, the response selection difficulty in Task 1 was increased to a four-choice discrimination and the search task was the same as in Experiment 1. We applied the locus-of-slack method in both experiments to analyze conjunction search time, that is, we compared the set size effects across SOAs. Similar set size effects across SOAs (i.e., additive effects of SOA and set size) would indicate sequential processing of response selection and visual attention. However, a significantly smaller set size effect at short SOA compared to long SOA (i.e., underadditive interaction of SOA and set size) would indicate parallel processing of response selection and visual attention. In both experiments, we found underadditive interactions of SOA and set size. In Experiments 3 and 4, the conjunction search display in Task 2 was masked. Task 1 was the same as in Experiments 1 and 2, respectively. In both experiments, the d' analysis revealed that response selection did not affect target detection. Overall, Experiments 1-4 indicated that neither the response selection difficulty in the auditory Task 1 (i.e., two-choice vs. four-choice) nor the type of presentation of the search display in Task 2 (i.e., not masked vs. masked) impaired parallel processing of response selection and conjunction search. We concluded that in general, response selection and visual attention (i.e., feature binding) rely on distinct capacity limitations.

Multi-talker background and semantic priming effect

PubMed Central

Dekerle, Marie; Boulenger, Véronique; Hoen, Michel; Meunier, Fanny

2014-01-01

The reported studies have aimed to investigate whether informational masking in a multi-talker background relies on semantic interference between the background and target using an adapted semantic priming paradigm. In 3 experiments, participants were required to perform a lexical decision task on a target item embedded in backgrounds composed of 1–4 voices. These voices were Semantically Consistent (SC) voices (i.e., pronouncing words sharing semantic features with the target) or Semantically Inconsistent (SI) voices (i.e., pronouncing words semantically unrelated to each other and to the target). In the first experiment, backgrounds consisted of 1 or 2 SC voices. One and 2 SI voices were added in Experiments 2 and 3, respectively. The results showed a semantic priming effect only in the conditions where the number of SC voices was greater than the number of SI voices, suggesting that semantic priming depended on prime intelligibility and strategic processes. However, even if backgrounds were composed of 3 or 4 voices, reducing intelligibility, participants were able to recognize words from these backgrounds, although no semantic priming effect on the targets was observed. Overall this finding suggests that informational masking can occur at a semantic level if intelligibility is sufficient. Based on the Effortfulness Hypothesis, we also suggest that when there is an increased difficulty in extracting target signals (caused by a relatively high number of voices in the background), more cognitive resources were allocated to formal processes (i.e., acoustic and phonological), leading to a decrease in available resources for deeper semantic processing of background words, therefore preventing semantic priming from occurring. PMID:25400572

Detection of Fast Moving and Accelerating Targets Compensating Range and Doppler Migration

DTIC Science & Technology

2014-06-01

Radon -Fourier transform has been introduced to realize long- term coherent integration of the moving targets with range migration [8, 9]. Radon ...2010) Long-time coherent integration for radar target detection base on Radon -Fourier transform, in Proceedings of the IEEE Radar Conference, pp...432–436. 9. Xu, J., Yu, J., Peng, Y. & Xia, X. (2011) Radon -Fourier transform for radar target detection, I: Generalized Doppler filter bank, IEEE

A framework for small infrared target real-time visual enhancement

NASA Astrophysics Data System (ADS)

Sun, Xiaoliang; Long, Gucan; Shang, Yang; Liu, Xiaolin

2015-03-01

This paper proposes a framework for small infrared target real-time visual enhancement. The framework is consisted of three parts: energy accumulation for small infrared target enhancement, noise suppression and weighted fusion. Dynamic programming based track-before-detection algorithm is adopted in the energy accumulation to detect the target accurately and enhance the target's intensity notably. In the noise suppression, the target region is weighted by a Gaussian mask according to the target's Gaussian shape. In order to fuse the processed target region and unprocessed background smoothly, the intensity in the target region is treated as weight in the fusion. Experiments on real small infrared target images indicate that the framework proposed in this paper can enhances the small infrared target markedly and improves the image's visual quality notably. The proposed framework outperforms tradition algorithms in enhancing the small infrared target, especially for image in which the target is hardly visible.

Emotion-induced impairments in speeded word recognition tasks.

PubMed

Zeelenberg, René; Bocanegra, Bruno R; Pecher, Diane

2011-01-01

Recent studies show that emotional stimuli impair the identification of subsequently presented, briefly flashed stimuli. In the present study, we investigated whether emotional distractors (primes) impaired target processing when presentation of the target stimulus was not impoverished. In lexical decision, animacy decision, rhyme decision, and nonword naming, targets were presented in such a manner that they were clearly visible (i.e., targets were not masked and presented until participants responded). In all tasks taboo-sexual distractors caused a slowdown in responding to the subsequent neutral target. Our results indicate that the detrimental effects of emotional distractors are not confined to paradigms in which visibility of the target is limited. Moreover, impairments were obtained even when semantic processing of stimuli was not required.

Ship Signatures in RADARSAT-1 ScanSAR Narrow B Imagery: Analysis with AISLive Data

DTIC Science & Technology

2007-03-01

desired target subscene contains image border “airballs” (i.e., the zero padded region around the image); • Multi-Signature Target Masking – A...of figures Figure 1. Histogram of latencies from AIS broadcast times by the originating vessels to the AISLive snapshot acquistion time for the... zero -th approximation, and first approximation courses are , , , and , respectively. The path length is a function of: a) the offset totalD iC fC

Genetic transformation protocols using zygotic embryos as explants: an overview.

PubMed

Tahir, Muhammad; Waraich, Ejaz A; Stasolla, Claudio

2011-01-01

Genetic transformation of plants is an innovative research tool which has practical significance for the development of new and improved genotypes or cultivars. However, stable introduction of genes of interest into nuclear genomes depends on several factors such as the choice of target tissue, the method of DNA delivery in the target tissue, and the appropriate method to select the transformed plants. Mature or immature zygotic embryos have been a popular choice as explant or target tissue for genetic transformation in both angiosperms and gymnosperms. As a result, considerable protocols have emerged in the literature which have been optimized for various plant species in terms of transformation methods and selection procedures for transformed plants. This article summarizes the recent advances in plant transformation using zygotic embryos as explants.

Simultaneous Masking in a Dichotic Emotion Detection Task

ERIC Educational Resources Information Center

Voyer, Daniel; Soraggi, Mariana; Brake, Brandy; Wood, Heather-Dawn

2006-01-01

The present study investigated the possible role of ceiling effects in producing laterality effects of small magnitude in dichotic emotion detection. Twenty two right-handed undergraduate students participated in the present experiment. They were required to detect the presence of a target emotion in the expressions tones of happiness, sadness,…

The Processing of English Derived Words by Chinese-English Bilinguals

ERIC Educational Resources Information Center

Li, Junmin; Taft, Marcus; Xu, Joe

2017-01-01

This study examined the sensitivity of Chinese-English bilinguals to derivational word structure in English. In the first experiment, English monolinguals showed masked priming effects for prime-target pairs related both transparently (e.g., "hunter-HUNT") and opaquely (e.g., "corner-CORN") but not for those related purely in…

Testing for Lexical Competition during Reading: Fast Priming with Orthographic Neighbors

ERIC Educational Resources Information Center

Nakayama, Mariko; Sears, Christopher R.; Lupker, Stephen J.

2010-01-01

Recent studies have found that masked word primes that are orthographic neighbors of the target inhibit lexical decision latencies (Davis & Lupker, 2006; Nakayama, Sears, & Lupker, 2008), consistent with the predictions of lexical competition models of visual word identification (e.g., Grainger & Jacobs, 1996). In contrast, using the…

Exploring the contributions of the supplementary eye field to subliminal inhibition using double-pulse transcranial magnetic stimulation.

PubMed

Chiau, Hui-Yan; Muggleton, Neil G; Juan, Chi-Hung

2017-01-01

It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Subliminal Face Emotion Processing: A Comparison of Fearful and Disgusted Faces

PubMed Central

Khalid, Shah; Ansorge, Ulrich

2017-01-01

Prior research has provided evidence for (1) subcortical processing of subliminal facial expressions of emotion and (2) for the emotion-specificity of these processes. Here, we investigated if this is also true for the processing of the subliminal facial display of disgust. In Experiment 1, we used differently filtered masked prime faces portraying emotionally neutral or disgusted expressions presented prior to clearly visible target faces to test if the masked primes exerted an influence on target processing nonetheless. Whereas we found evidence for subliminal face congruence or priming effects, in particular, reverse priming by low spatial frequencies disgusted face primes, we did not find any support for a subcortical origin of the effect. In Experiment 2, we compared the influence of subliminal disgusted faces with that of subliminal fearful faces and demonstrated a behavioral performance difference between the two, pointing to an emotion-specific processing of the disgusted facial expressions. In both experiments, we also tested for the dependence of the subliminal emotional face processing on spatial attention – with mixed results, suggesting an attention-independence in Experiment 1 but not in Experiment 2 –, and we found perfect masking of the face primes – that is, proof of the subliminality of the prime faces. Based on our findings, we speculate that subliminal facial expressions of disgust could afford easy avoidance of these faces. This could be a unique effect of disgusted faces as compared to other emotional facial displays, at least under the conditions studied here. PMID:28680413

Subliminal Face Emotion Processing: A Comparison of Fearful and Disgusted Faces.

PubMed

Khalid, Shah; Ansorge, Ulrich

2017-01-01

Prior research has provided evidence for (1) subcortical processing of subliminal facial expressions of emotion and (2) for the emotion-specificity of these processes. Here, we investigated if this is also true for the processing of the subliminal facial display of disgust. In Experiment 1, we used differently filtered masked prime faces portraying emotionally neutral or disgusted expressions presented prior to clearly visible target faces to test if the masked primes exerted an influence on target processing nonetheless. Whereas we found evidence for subliminal face congruence or priming effects, in particular, reverse priming by low spatial frequencies disgusted face primes, we did not find any support for a subcortical origin of the effect. In Experiment 2, we compared the influence of subliminal disgusted faces with that of subliminal fearful faces and demonstrated a behavioral performance difference between the two, pointing to an emotion-specific processing of the disgusted facial expressions. In both experiments, we also tested for the dependence of the subliminal emotional face processing on spatial attention - with mixed results, suggesting an attention-independence in Experiment 1 but not in Experiment 2 -, and we found perfect masking of the face primes - that is, proof of the subliminality of the prime faces. Based on our findings, we speculate that subliminal facial expressions of disgust could afford easy avoidance of these faces. This could be a unique effect of disgusted faces as compared to other emotional facial displays, at least under the conditions studied here.

Automatic frame-centered object representation and integration revealed by iconic memory, visual priming, and backward masking

PubMed Central

Lin, Zhicheng; He, Sheng

2012-01-01

Object identities (“what”) and their spatial locations (“where”) are processed in distinct pathways in the visual system, raising the question of how the what and where information is integrated. Because of object motions and eye movements, the retina-based representations are unstable, necessitating nonretinotopic representation and integration. A potential mechanism is to code and update objects according to their reference frames (i.e., frame-centered representation and integration). To isolate frame-centered processes, in a frame-to-frame apparent motion configuration, we (a) presented two preceding or trailing objects on the same frame, equidistant from the target on the other frame, to control for object-based (frame-based) effect and space-based effect, and (b) manipulated the target's relative location within its frame to probe frame-centered effect. We show that iconic memory, visual priming, and backward masking depend on objects' relative frame locations, orthogonal of the retinotopic coordinate. These findings not only reveal that iconic memory, visual priming, and backward masking can be nonretinotopic but also demonstrate that these processes are automatically constrained by contextual frames through a frame-centered mechanism. Thus, object representation is robustly and automatically coupled to its reference frame and continuously being updated through a frame-centered, location-specific mechanism. These findings lead to an object cabinet framework, in which objects (“files”) within the reference frame (“cabinet”) are orderly coded relative to the frame. PMID:23104817

Delayed working memory consolidation during the attentional blink.

PubMed

Vogel, Edward K; Luck, Steven J

2002-12-01

After the detection of a target (T1) in a rapid stream of visual stimuli, there is a period of 400-600 msec during which a subsequent target (T2) is missed. This impairment in performance has been labeled the attentional blink. Recent theories propose that the attentional blink reflects a bottleneck in working memory consolidation such that T2 cannot be consolidated until after T1 is consolidated, and T2 is therefore masked by subsequent stimuli if it is presented while T1 is being consolidated. In support of this explanation, Giesbrecht & Di Lollo (1998) found that when T2 is the final item in the stimulus stream, no attentional blink is observed, because there are no subsequent stimuli that might mask T2. To provide a direct test of this explanation of the attentional blink, in the present study we used the P3 component of the event-related potential waveform to track the processing of T2. When T2 was followed by a masking item, we found that the P3 wave was completely suppressed during the attentional blink period, indicating that T2 was not consolidated in working memory. When T2 was the last item in the stimulus stream, however, we found that the P3 wave was delayed but not suppressed, indicating that T2 consolidation was not eliminated but simply delayed. These results are consistent with a fundamental limit on the consolidation of information in working memory.

A review of nanoimprint lithography for high-volume semiconductor device manufacturing

NASA Astrophysics Data System (ADS)

Resnick, Douglas J.; Choi, Jin

2017-06-01

Imprint lithography has been shown to be a promising technique for the replication of nanoscale features. Jet and flash imprint lithography (J-FIL) [jet and flash imprint lithography and J-FIL are trademarks of Molecular Imprints, Inc.] involves the field-by-field deposition and exposure of a low-viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid, which then quickly flows into the relief patterns in the mask by capillary action. After this filling step, the resist is cross-linked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. There are many criteria that determine whether a particular technology is ready for wafer manufacturing. Included on the list are overlay, throughput, and defectivity. The most demanding devices now require an overlay of better than 4 nm, 3σ. Throughput for an imprint tool is generally targeted at 80 wafers/h. Defectivity and mask life play a significant role relative to meeting the cost of ownership (CoO) requirements in the production of semiconductor devices. The purpose of this paper is to report the status of throughput and defectivity work and to describe the progress made in addressing overlay for advanced devices. To address high-order corrections, a high-order distortion correction (HODC) system is introduced. The combination of applying magnification actuation to the mask and temperature correction to the wafer is described in detail. Examples are presented for the correction of K7, K11, and K17 distortions as well as distortions on actual device wafers.

Masked Proportional Routing

NASA Technical Reports Server (NTRS)

Wolpert, David H. (Inventor)

2003-01-01

Distributed approach for determining a path connecting adjacent network nodes, for probabilistically or deterministically transporting an entity, with entity characteristic mu from a source node to a destination node. Each node i is directly connected to an arbitrary number J(mu) of nodes, labeled or numbered j=jl, j2, .... jJ(mu). In a deterministic version, a J(mu)-component baseline proportion vector p(i;mu) is associated with node i. A J(mu)-component applied proportion vector p*(i;mu) is determined from p(i;mu) to preclude an entity visiting a node more than once. Third and fourth J(mu)-component vectors, with components iteratively determined by Target(i;n(mu);mu),=alpha(mu).Target(i;n(mu)-1;mu)j+beta(mu).p* (i;mu)j and Actual(i;n(mu);+a(mu)j. Actual(i;n(mu)-l;mu)j+beta(mu).Sent(i;j'(mu);n(mu)-1;mu)j, are computed, where n(mu) is an entity sequence index and alpha(mu) and beta(mu) are selected numbers. In one embodiment, at each node i, the node j=j'(mu) with the largest vector component difference, Target(i;n(mu);mu)j'- Actual (i;n(mu);mu)j'. is chosen for the next link for entity transport, except in special gap circumstances, where the same link is optionally used for transporting consecutively arriving entities. The network nodes may be computer-controlled routers that switch collections of packets, frames, cells or other information units. Alternatively, the nodes may be waypoints for movement of physical items in a network or for transformation of a physical item. The nodes may be states of an entity undergoing state transitions, where allowed transitions are specified by the network and/or the destination node.

Electrochemical thinning of silicon

DOEpatents

Medernach, John W.

1994-01-01

Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR).

Spectrometer Baseline Control Via Spatial Filtering

NASA Technical Reports Server (NTRS)

Burleigh, M. R.; Richey, C. R.; Rinehart, S. A.; Quijada, M. A.; Wollack, E. J.

2016-01-01

An absorptive half-moon aperture mask is experimentally explored as a broad-bandwidth means of eliminating spurious spectral features arising from reprocessed radiation in an infrared Fourier transform spectrometer. In the presence of the spatial filter, an order of magnitude improvement in the fidelity of the spectrometer baseline is observed. The method is readily accommodated within the context of commonly employed instrument configurations and leads to a factor of two reduction in optical throughput. A detailed discussion of the underlying mechanism and limitations of the method are provided.