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.

scholarly journals Daily high-frequency transcranial random noise stimulation of bilateral temporal cortex in chronic tinnitus – a pilot study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Peter M. Kreuzer ◽  
Timm B. Poeppl ◽  
Rainer Rupprecht ◽  
Veronika Vielsmeier ◽  
Astrid Lehner ◽  
...  
Keyword(s):  
Pilot Study ◽  
High Frequency ◽  
Random Noise ◽  
Temporal Cortex ◽  
Chronic Tinnitus ◽  
Transcranial Random Noise Stimulation ◽  
Stimulation Of

Pigeons use low rather than high spatial frequency information to make visual category discriminations

2013 ◽  
Author(s):  
Stephen E. G. Lea ◽  
Guido De Filippo ◽  
Ruth Dakin ◽  
Christina Meier
Keyword(s):  
Spatial Frequency ◽  
High Spatial Frequency ◽  
Frequency Information

scholarly journals Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

2021 ◽  
Author(s):  
Filippo Ghin ◽  
Louise O’Hare ◽  
Andrea Pavan
Keyword(s):  
High Frequency ◽  
Discrimination Task ◽  
Temporal Dynamics ◽  
Random Noise ◽  
Decomposition Analysis ◽  
Oscillatory Activity ◽  
Motion Direction ◽  
Time Frequency ◽  
Direction Discrimination ◽  
Transcranial Random Noise Stimulation

AbstractThere is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) is effective in improving behavioural performance in several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In the present study, electroencephalogram (EEG) was used to investigate the spatial and temporal dynamics of cortical activity modulated by offline hf-tRNS on performance on a motion direction discrimination task. We used EEG to measure the amplitude of motion-related VEPs over the parieto-occipital cortex, as well as oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis was also performed to investigate the shift in event-related spectral perturbation (ERSP) in response to the motion stimuli between the pre- and post-stimulation period. The results showed that the accuracy of the motion direction discrimination task was not modulated by offline hf-tRNS. Although the motion task was able to elicit motion-dependent VEP components (P1, N2, and P2), none of them showed any significant change between pre- and post-stimulation. We also found a time-dependent increase of the PSD in alpha and beta bands regardless of the stimulation protocol. Finally, time–frequency analysis showed a modulation of ERSP power in the hf-tRNS condition for gamma activity when compared to pre-stimulation periods and Sham stimulation. Overall, these results show that offline hf-tRNS may induce moderate aftereffects in brain oscillatory activity.

scholarly journals Transcranial random noise stimulation (tRNS): a wide range of frequencies is needed for increasing cortical excitability

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Beatrice Moret ◽  
Rita Donato ◽  
Massimo Nucci ◽  
Giorgia Cona ◽  
Gianluca Campana
Keyword(s):  
Frequency Band ◽  
High Frequency ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Random Noise ◽  
High Frequency Band ◽  
Neural Excitability ◽  
Transcranial Random Noise Stimulation ◽  
Wide Range

Abstract Transcranial random noise stimulation (tRNS) is a recent neuromodulation protocol. The high-frequency band (hf-tRNS) has shown to be the most effective in enhancing neural excitability. The frequency band of hf-tRNS typically spans from 100 to 640 Hz. Here we asked whether both the lower and the higher half of the high-frequency band are needed for increasing neural excitability. Three frequency ranges (100–400 Hz, 400–700 Hz, 100–700 Hz) and Sham conditions were delivered for 10 minutes at an intensity of 1.5 mA over the primary motor cortex (M1). Single-pulse transcranial magnetic stimulation (TMS) was delivered over the same area at baseline, 0, 10, 20, 30, 45 and 60 minutes after stimulation, while motor evoked potentials (MEPs) were recorded to evaluate changes in cortical excitability. Only the full-band condition (100–700 Hz) was able to modulate excitability by enhancing MEPs at 10 and 20 minutes after stimulation: neither the higher nor the lower sub-range of the high-frequency band significantly modulated cortical excitability. These results show that the efficacy of tRNS is strictly related to the width of the selected frequency range.

Spatial Scale Interactions and Visual-Tracking Performance

Perception ◽  
1997 ◽  
Vol 26 (8) ◽  
pp. 1047-1058 ◽  
Author(s):  
Howard C Hughes ◽  
David M Aronchick ◽  
Michael D Nelson
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Visual Information ◽  
Low Frequency ◽  
High Spatial Frequency ◽  
Performance Measure ◽  
High Frequency Component ◽  
Stimulus Velocity ◽  
Spatial Frequencies ◽  
Wide Range

It has previously been observed that low spatial frequencies (≤ 1.0 cycles deg−1) tend to dominate high spatial frequencies (≥ 5.0 cycles deg−1) in several types of visual-information-processing tasks. This earlier work employed reaction times as the primary performance measure and the present experiments address the possibility of low-frequency dominance by evaluating visually guided performance of a completely different response system: the control of slow-pursuit eye movements. Slow-pursuit gains (eye velocity/stimulus velocity) were obtained while observers attempted to track the motion of a sine-wave grating. The drifting gratings were presented on three types of background: a uniform background, a background consisting of a stationary grating, or a flickering background. Low-frequency dominance was evident over a wide range of velocities, in that a stationary high-frequency component produced little disruption in the pursuit of a drifting low spatial frequency, but a stationary low frequency interfered substantially with the tracking of a moving high spatial frequency. Pursuit was unaffected by temporal modulation of the background, suggesting that these effects are due to the spatial characteristics of the stationary grating. Similar asymmetries were observed with respect to the stability of fixation: active fixation was less stable in the presence of a drifting low frequency than in the presence of a drifting high frequency.

Pigeons use low rather than high spatial frequency information to make visual category discriminations.

2013 ◽  
Vol 39 (4) ◽  
pp. 377-382 ◽  
Author(s):  
Stephen E. G. Lea ◽  
Guido De Filippo ◽  
Ruth Dakin ◽  
Christina Meier
Keyword(s):  
Spatial Frequency ◽  
High Spatial Frequency ◽  
Frequency Information

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

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.

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