Spatial Frequency Thresholds for Detecting Latent Facial Signals of Threat

Perception ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 214-227
Author(s):  
Nicholas Watier ◽  
Brock DeGagne
Keyword(s):  
Spatial Frequency ◽  
Face Processing ◽  
Visual Information ◽  
Forced Choice ◽  
Face Identification ◽  
Staircase Procedure ◽  
Spatial Frequencies

This study examined whether latent facial signals of threat can be detected at more extreme ranges of spatial frequencies (SFs), and thus with fewer frequencies from an optimal middle band for face identification, compared with latent nonthreatening facial signals. Using an adaptive staircase procedure and a two-interval forced-choice same-different task, SF thresholds from the lower and higher ends of the SF spectrum were obtained for nonexpressive threatening and nonthreatening faces. Threatening faces were discriminated from neutral faces more quickly and accurately, and engendered more extreme SF thresholds, compared with nonthreatening faces. The results indicate that the components of latent threatening facial signals can be detected under a greater degree of impoverished visual information for face processing compared with their nonthreatening counterparts.

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.

scholarly journals Dynamics of spatial frequency tuning in mouse visual cortex

2012 ◽  
Vol 107 (11) ◽  
pp. 2937-2949 ◽  
Author(s):  
Samme Vreysen ◽  
Bin Zhang ◽  
Yuzo M. Chino ◽  
Lutgarde Arckens ◽  
Gert Van den Bergh
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Visual Information ◽  
Frequency Tuning ◽  
Neuronal Response ◽  
Correlation Technique ◽  
Low Frequencies ◽  
Temporal Shift ◽  
Spatial Frequency Tuning ◽  
Spatial Frequencies

Neuronal spatial frequency tuning in primary visual cortex (V1) substantially changes over time. In both primates and cats, a shift of the neuron's preferred spatial frequency has been observed from low frequencies early in the response to higher frequencies later in the response. In most cases, this shift is accompanied by a decreased tuning bandwidth. Recently, the mouse has gained attention as a suitable animal model to study the basic mechanisms of visual information processing, demonstrating similarities in basic neuronal response properties between rodents and highly visual mammals. Here we report the results of extracellular single-unit recordings in the anesthetized mouse where we analyzed the dynamics of spatial frequency tuning in V1 and the lateromedial area LM within the lateral extrastriate area V2L. We used a reverse-correlation technique to demonstrate that, as in monkeys and cats, the preferred spatial frequency of mouse V1 neurons shifted from low to higher frequencies later in the response. However, this was not correlated with a clear selectivity increase or enhanced suppression of responses to low spatial frequencies. These results suggest that the neuronal connections responsible for the temporal shift in spatial frequency tuning may considerably differ between mice and monkeys.

scholarly journals The Role of Spatial Frequencies for Facial Pain Categorization

2021 ◽  
Author(s):  
Isabelle Charbonneau ◽  
Joël Guérette ◽  
Stéphanie Cormier ◽  
Caroline Blais ◽  
Guillaume Lalonde-Beaudoin ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Visual Information ◽  
Facial Pain ◽  
A Priori ◽  
Data Driven ◽  
Low Level ◽  
Spatial Frequencies ◽  
Pain Recognition ◽  
Practical Implications

Abstract Studies on low-level visual information underlying pain categorization have led to inconsistent findings. Some are showing an advantage for low spatial frequency information (SFs) and others a preponderance of mid SFs. This study aims to clarify this gap in knowledge since these results have different theoretical and practical implications, such as how far away an observer can be in order to categorize pain. This study addresses this question by using two complementary methods: a data-driven method without a priori about the most useful SFs for pain recognition and a more ecological method that simulates the distance of stimuli presentation. We reveal a broad range of important SF for pain recognition starting from low to relatively high SFs and showed that performance is optimal in a short to medium distance (1.2 to 4.8 meters) but declines significantly when mid SFs are no longer available. This study reconciles previous results that show an advantage of LSFs over HSFs when using arbitrary cutoffs, but above all reveal the prominent role of mid-SFs for pain recognition across two experimental tasks.

scholarly journals Binocular Summation Is Intact in Intermittent Exotropia After Surgery

2021 ◽  
Vol 8 ◽  
Author(s):  
Meiping Xu ◽  
Yiya Chen ◽  
Yiyi Peng ◽  
Zhifen He ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Visual Information ◽  
Threshold Level ◽  
Contrast Threshold ◽  
Binocular Summation ◽  
Intermittent Exotropia ◽  
Probability Summation ◽  
Spatial Frequencies ◽  
Significant Difference

Purpose: To determine binocular summation of surgically treated intermittent exotropia (IXT) patients by measuring the contrast threshold.Methods: We recruited 38 surgically treated IXT patients aged 8–24 years and 20 age-matched healthy controls. All participants had normal or corrected-to-normal visual acuity (Snellen ≥ 20/20) in both eyes. The IXT patients had undergone the surgery at least a year prior to the study. Twenty-one of them obtained good alignment and 17 experienced a recurrence of exotropia. We measured the observers' monocular and binocular contrast sensitivities (CS) at six spatial frequencies (1.5, 3, 6, 12, 18, 24 cycles/degree) as an index of visual information processing at the threshold level. Binocular summation was evaluated against a baseline model of simple probability summation based on the CS at each spatial frequency and the area under the log contrast sensitivity function (AULCSF).Results: The exo-deviation of IXTs with good alignment was −6.38 ± 3.61 prism diopters (pd) at 33 cm and −5.14 ± 4.07 pd at 5 m. For the patients with recurrence, it was −23.47 ± 5.53 pd and −21.12 ± 4.28 pd, respectively. There was no significant difference in the binocular summation ratio (BSR) between the surgically treated IXT patients, including those with good alignment and recurrence, and normal controls at each spatial frequency [F(2,55) = 0.416, P = 0.662] and AULCSF [F(2,55) = 0.469, P = 0.628]. In addition, the BSR was not associated with stereopsis (r = −0.151, P = 0.365).Conclusion: Our findings of normal contrast sensitivity binocular summation ratio in IXT after surgical treatment suggest that the ability of the visual cortex in processing binocular information is intact at the contrast threshold level.

Spatial-Frequency Discrimination, Brain Lateralisation, and Acute Intake of Alcohol

Perception ◽  
1998 ◽  
Vol 27 (6) ◽  
pp. 729-736 ◽  
Author(s):  
Reidulf G Watten ◽  
Svein Magnussen ◽  
Mark W Greenlee
Keyword(s):  
Visual Field ◽  
Spatial Frequency ◽  
Visual Information ◽  
Right Hemisphere ◽  
Frequency Discrimination ◽  
Right Visual Field ◽  
Double Blind ◽  
Spatial Frequencies ◽  
Balanced Placebo Design ◽  
Acute Intake

The effect of alcohol (breath-alcohol level of 0.1%) on perceptual discrimination of low (1.5 cycles deg−1) and high (8 cycles deg−1) spatial frequencies in the left and right visual field was measured in eighteen right-handed males, in a double-blind, balanced placebo design. Discrimination thresholds for briefly (180 ms) presented sinusoidal gratings were determined by two-alternative forced-choice judgments with four interleaving psychophysical staircases providing random trial-to-trial variation of reference spatial frequency and visual field, in addition to a random (±10%) jitter of reference spatial frequency. Alcohol produced overall higher discrimination thresholds but did not alter the visual-field balance: no main effect of visual field was observed, but in both placebo and alcohol conditions spatial frequency interacted with visual field in the direction predicted by the spatial-frequency hypothesis of hemispheric asymmetry in visual-information processing, with left-visual-field/right-hemisphere superiority in discrimination of low spatial frequencies and right-visual-field/left-hemisphere superiority in discrimination of high spatial frequencies.

Are Spatial Frequencies Integrated from Coarse to Fine?

Perception ◽  
10.1068/p3257 ◽  
2002 ◽  
Vol 31 (8) ◽  
pp. 955-967 ◽  
Author(s):  
Eugene McSorley ◽  
John M Findlay
Keyword(s):  
Spatial Frequency ◽  
Choice Experiment ◽  
Forced Choice ◽  
Square Wave ◽  
Spatial Frequencies ◽  
Task Differences ◽  
Series Of Experiments ◽  
Coarse To Fine ◽  
Opposite Form

The existence of a temporal anisotropy in the integration of spatial frequencies, such that spatial frequencies are integrated more effectively if they are available from low to high through time, has been examined in a series of experiments. In the first experiment, the first three harmonics of a square wave were presented in a low-to-high or a high-to-low sequence in a temporal two-interval forced-choice experiment. Subjects were asked to indicate which sequence appeared to resemble a square wave more. A high-to-low sequence of spatial frequencies was judged to more resemble the target than the low-to-high sequence. These results support a temporal anisotropy in the integration of spatial frequencies of exactly the opposite form to that suggested from previous results. Further experiments established that this was not due to task differences or to subjects basing their decision on the final spatial frequency shown. An interpretation is offered in which an isotropic mechanism for spatial-frequency integration is combined with a recency bias.

Multisensory Integration Is Modulated by Auditory Sound Frequency and Visual Spatial Frequency

2019 ◽  
Vol 32 (7) ◽  
pp. 589-611
Author(s):  
Jessica J. Green ◽  
Allison M. Pierce ◽  
Spencer L. Mac Adams
Keyword(s):  
Spatial Frequency ◽  
Frequency Spectrum ◽  
Visual Information ◽  
Sound Frequency ◽  
Audiovisual Speech ◽  
Low Level ◽  
Speech Stimuli ◽  
Visual Spatial ◽  
Spatial Frequencies ◽  
Stimulus Features

Abstract Accurate integration of auditory and visual information is essential for our ability to communicate with others. Previous studies have shown that the temporal discrepancies over which audiovisual speech stimuli will be integrated into a coherent percept are much wider than those typically observed for simple stimuli like beeps and flashes of light. However, our sensitivity to the low-level features of simple stimuli is not constant. We hypothesized that part of the enhanced integration of audiovisual speech may be due to it consisting predominantly of the sound frequencies and visual spatial frequencies that humans are most sensitive to. Here, we examined integration behaviors for pure tones across the sound frequency spectrum and visual gratings across the spatial frequency spectrum to examine how these low-level features modulate integration. The temporal window of integration was modulated by both sound frequency and visual spatial frequency, with the widest integration window occurring when both stimuli fell within their respective peak sensitivity ranges. These results suggest that part of the increased tolerance for temporal asynchrony typically observed for audiovisual speech may be due to the differential integration of low-level stimulus features that are dominant within complex audiovisual speech.

scholarly journals Rapid and Coarse Face Detection in Cortex

2017 ◽  
Author(s):  
Laura Cabral ◽  
Bobby Stojanoski ◽  
Rhodri Cusack
Keyword(s):  
Spatial Frequency ◽  
Face Processing ◽  
Rapid Detection ◽  
Reaction Times ◽  
Subcortical Structures ◽  
Detection Mechanism ◽  
Temporal Lobes ◽  
Spatial Frequencies ◽  
Natural Difference ◽  
Subcortical Pathway

Humans have structures dedicated to the processing of faces, which include cortical components (e.g. areas in occipital and temporal lobes) and subcortical components (e.g. superior colliculus and amygdala). Although faces are processed more quickly than stimuli from other categories, there is a lack of consensus regarding whether cortical or subcortical structures are responsible for rapid face processing. In order to probe this, we exploited the asymmetry in the strength of projections to subcortical structures between the nasal and temporal hemiretina. Participants detected faces from unrecognizable control stimuli and performed the same task for houses. In Experiments 1 and 3, at the fastest reaction times, participants detected faces more accurately than houses. However, there was no benefit of presenting to the subcortical pathway. In Experiment 2, we probed the coarseness of the rapid pathway, making the foil stimuli more similar to faces and houses. This eliminated the rapid detection advantage, suggesting that rapid face processing is limited to coarse representations. In Experiment 4, we sought to determine whether the natural difference between spatial frequencies of faces and houses were driving the effects seen in Experiments 1 and 3. We spatially filtered the faces and houses so that they were matched. Better rapid detection was again found for faces relative to houses, but we found no benefit of preferentially presenting to the subcortical pathway. Taken together, the results of our experiments suggest a cortical, coarse rapid detection mechanism, which was not dependent on spatial frequency.

Recognition of Positive and Negative Bandpass-Filtered Images

Perception ◽  
1986 ◽  
Vol 15 (5) ◽  
pp. 595-602 ◽  
Author(s):  
Tony Hayes ◽  
M Concetta Morrone ◽  
David C Burr
Keyword(s):  
Spatial Frequency ◽  
Visual System ◽  
Visual Information ◽  
Recognition Performance ◽  
Low Frequency ◽  
High Spatial Frequency ◽  
Spatial Frequencies ◽  
Negative Images ◽  
Frequency Components

A study is reported in which the significance for vision of low- and high-spatial-frequency components of photographic positive and negative images was investigated by measuring recognition of bandpass-filtered photographs of faces. The results show that a 1.5 octave bandpass-filtered image contains sufficient visual information for good recognition performance, provided the filter is centred close to 20 cycles facewidth−1. At low spatial frequencies negatives are more difficult to recognize than positives, but at high spatial frequencies there is no difference in recognition, implying that it is the low-frequency components of negatives which present difficulties for the visual system.

scholarly journals The role of spatial frequencies for facial pain categorization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabelle Charbonneau ◽  
Joël Guérette ◽  
Stéphanie Cormier ◽  
Caroline Blais ◽  
Guillaume Lalonde-Beaudoin ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Visual Information ◽  
Facial Pain ◽  
A Priori ◽  
Data Driven ◽  
Low Level ◽  
Spatial Frequencies ◽  
Pain Recognition ◽  
Practical Implications

AbstractStudies on low-level visual information underlying pain categorization have led to inconsistent findings. Some show an advantage for low spatial frequency information (SFs) and others a preponderance of mid SFs. This study aims to clarify this gap in knowledge since these results have different theoretical and practical implications, such as how far away an observer can be in order to categorize pain. This study addresses this question by using two complementary methods: a data-driven method without a priori expectations about the most useful SFs for pain recognition and a more ecological method that simulates the distance of stimuli presentation. We reveal a broad range of important SFs for pain recognition starting from low to relatively high SFs and showed that performance is optimal in a short to medium distance (1.2–4.8 m) but declines significantly when mid SFs are no longer available. This study reconciles previous results that show an advantage of LSFs over HSFs when using arbitrary cutoffs, but above all reveal the prominent role of mid-SFs for pain recognition across two complementary experimental tasks.

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