Retrieving high spatial frequency information in sonography for improved microcalcification detection

2014 ◽  
Author(s):  
Sara Bahramian ◽  
Michael F. Insana
Keyword(s):  
Spatial Frequency ◽  
High Spatial Frequency ◽  
Frequency Information ◽  
Microcalcification Detection

scholarly journals Noise detection: Summation of high spatial frequency information

2010 ◽  
Vol 5 (8) ◽  
pp. 482-482 ◽  
Author(s):  
C. P. Taylor ◽  
P. J. Bennett ◽  
A. B. Sekuler
Keyword(s):  
Spatial Frequency ◽  
High Spatial Frequency ◽  
Noise Detection ◽  
Frequency Information

Delineating the low and high spatial frequency inputs to face perception using transcranial random noise stimulation

2020 ◽  
Author(s):  
Bhuvanesh Awasthi
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Response Times ◽  
Random Noise ◽  
Temporal Cortex ◽  
High Spatial Frequency ◽  
Bayesian Approaches ◽  
Frequency Information ◽  
Transcranial Random Noise Stimulation ◽  
The Right

This study used high frequency transcranial Random Noise Stimulation (tRNS) to examine how low and high spatial frequency filtered faces are processed. In a response time behavioral task, healthy young adults categorized male and female faces, presented at fovea and periphery in alternate blocks, while sham and high frequency random noise was applied to occipito-parietal location on their scalp. Both the frequentist and bayesian approaches show that stimulation at the right occipito-temporal cortex significantly reduced response times to peripherally presented low spatial frequency information. This finding points to a possible plasticity in targeted regions induced by non-invasive neuromodulation of spatial frequency information in rapid perception of faces.

Increased fusiform area activation in schizophrenia during processing of spatial frequency-degraded faces, as revealed by fMRI

2009 ◽  
Vol 40 (7) ◽  
pp. 1159-1169 ◽  
Author(s):  
S. M. Silverstein ◽  
S. D. All ◽  
R. Kasi ◽  
S. Berten ◽  
B. Essex ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Perceptual Organization ◽  
Face Processing ◽  
Gender Discrimination ◽  
High Spatial Frequency ◽  
Superior Performance ◽  
Full Spectrum ◽  
Frequency Information ◽  
Form Processing ◽  
Patient Performance

BackgroundPeople with schizophrenia demonstrate perceptual organization impairments, and these are thought to contribute to their face processing difficulties.MethodWe examined the neural substrates of emotionally neutral face processing in schizophrenia by investigating neural activity under three stimulus conditions: faces characterized by the full spectrum of spatial frequencies, faces with low spatial frequency information removed [high spatial frequency (HSF) condition], and faces with high spatial frequency information removed [low spatial frequency (LSF) condition]. Face perception in the HSF condition is more reliant on local feature processing whereas perception in the LSF condition requires greater reliance on global form processing. Past studies of perceptual organization in schizophrenia indicate that patients perform relatively more poorly with degraded stimuli but also that, when global information is absent, patients may perform better than controls because of their relatively increased ability to initially process individual features. Therefore, we hypothesized that people with schizophrenia (n=14) would demonstrate greater face processing difficulties than controls (n=13) in the LSF condition, whereas they would demonstrate a smaller difference or superior performance in the HSF condition.ResultsIn a gender-discrimination task, behavioral data indicated high levels of accuracy for both groups, with a trend toward an interaction involving higher patient performance in the HSF condition and poorer patient performance in the LSF condition. Patients demonstrated greater activity in the fusiform gyrus compared to controls in both degraded conditions.ConclusionsThese data suggest that impairments in basic integration abilities may be compensated for by relatively increased activity in this region.

Is high-spatial frequency information used in the early stages of face detection?

2006 ◽  
Vol 1117 (1) ◽  
pp. 154-161 ◽  
Author(s):  
H. Halit ◽  
M. de Haan ◽  
P.G. Schyns ◽  
M.H. Johnson
Keyword(s):  
Spatial Frequency ◽  
Face Detection ◽  
High Spatial Frequency ◽  
Frequency Information ◽  
Early Stages

The Uncanny Valley Phenomenon and the Temporal Dynamics of Face Animacy Perception

Perception ◽  
2020 ◽  
Vol 49 (10) ◽  
pp. 1069-1089
Author(s):  
Shensheng Wang ◽  
Yuk F. Cheong ◽  
Daniel D. Dilks ◽  
Philippe Rochat
Keyword(s):  
Spatial Frequency ◽  
Exposure Time ◽  
Temporal Dynamics ◽  
High Spatial Frequency ◽  
Uncanny Valley ◽  
Frequency Information ◽  
Mind Perception ◽  
The Uncanny ◽  
Alternative Hypotheses ◽  
Face Exposure

Human replicas highly resembling people tend to elicit eerie sensations—a phenomenon known as the uncanny valley. To test whether this effect is attributable to people’s ascription of mind to (i.e., mind perception hypothesis) or subtraction of mind from androids (i.e., dehumanization hypothesis), in Study 1, we examined the effect of face exposure time on the perceived animacy of human, android, and mechanical-looking robot faces. In Study 2, in addition to exposure time, we also manipulated the spatial frequency of faces, by preserving either their fine (high spatial frequency) or coarse (low spatial frequency) information, to examine its effect on faces’ perceived animacy and uncanniness. We found that perceived animacy decreased as a function of exposure time only in android but not in human or mechanical-looking robot faces (Study 1). In addition, the manipulation of spatial frequency eliminated the decrease in android faces’ perceived animacy and reduced their perceived uncanniness (Study 2). These findings link perceived uncanniness in androids to the temporal dynamics of face animacy perception. We discuss these findings in relation to the dehumanization hypothesis and alternative hypotheses of the uncanny valley phenomenon.

scholarly journals The Primacy of Negative Interpretations When Resolving the Valence of Ambiguous Facial Expressions

2010 ◽  
Vol 21 (7) ◽  
pp. 901-907 ◽  
Author(s):  
Maital Neta ◽  
Paul J. Whalen
Keyword(s):  
Spatial Frequency ◽  
Facial Expressions ◽  
Visual Information ◽  
High Spatial Frequency ◽  
Negativity Bias ◽  
Negative Direction ◽  
Frequency Information ◽  
Amygdala Activity ◽  
Separate Line

Low-spatial-frequency (LSF) visual information is processed in an elemental fashion before a finer analysis of high-spatial-frequency information. Further, the amygdala is particularly responsive to LSF information contained within negative (e.g., fearful) facial expressions. In a separate line of research, it has been shown that surprised facial expressions are ambiguous in that they can be interpreted as either negatively or positively valenced. More negative interpretations of surprise are associated with increased ventral amygdala activity. In this report, we show that LSF presentations of surprised expressions bias the interpretation of surprised expressions in a negative direction, a finding suggesting that negative interpretations are first and fast during the resolution of ambiguous valence. We also examined the influence of subjects’ positivity-negativity bias on this effect.

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