Emotion and working memory: How fear and happiness selectively enhance remembering of low and high spatial frequency faces

This study used the swept spatial-frequency method to compare retinal and cortical acuity in anesthetized young adult rhesus monkeys. Visual evoked potentials (VEPs) and pattern electroretinographic responses (PERGs) were recorded from 25 monkeys (age range: 4–12 years) anesthetized with a continuous infusion of propofol. The stimuli were temporally countermodulated sine-wave gratings that increased in spatial frequency within a 10.24-s period. All animals were refracted using acuity estimated from the zero micro-volt intercept of the linear regression of evoked potential amplitude on spatial frequency. Average sweep acuities were 23.7 cycles/deg ± 1.5 S.E.M. and 23.1 cycles/deg ± 1.8 S.E.M. for the PERG and VEP, respectively. VEP and PERG acuities were within the range expected based on acuities estimated from behavioral studies in macaques. PERG and VEP acuities were highly correlated (r = 0.90) and equally sensitive to spherical blur. On a subset of animals, test–retest reliability of animals, and interocular correlations, were high (r = 0.87 and r = 0.83, respectively). Increasing propofol dosage 8-fold did not degrade PERG or VEP acuity. This study demonstrates that high spatial-frequency acuities can be rapidly obtained from young adult rhesus monkeys under a wide dose range of propofol anesthesia using the swept spatial-frequency method.

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Theoretical and Experimental Investigation of the Formation of High Spatial Frequency Periodic Structures on Metal Surfaces Irradiated by Ultrashort Laser Pulses

Physics of Wave Phenomena ◽

10.3103/s1541308x18040027 ◽

2018 ◽

Vol 26 (4) ◽

pp. 264-273 ◽

Cited By ~ 3

Author(s):

N. A. Kirichenko ◽

E. V. Barmina ◽

G. A. Shafeev

Keyword(s):

Experimental Investigation ◽

Spatial Frequency ◽

Metal Surfaces ◽

Periodic Structures ◽

High Spatial Frequency ◽

Laser Pulses ◽

Ultrashort Laser Pulses ◽

Ultrashort Laser

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Epifluorescence-based three-dimensional traction force microscopy

Scientific Reports ◽

10.1038/s41598-020-72931-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Lauren Hazlett ◽

Alexander K. Landauer ◽

Mohak Patel ◽

Hadley A. Witt ◽

Jin Yang ◽

...

Keyword(s):

Spatial Frequency ◽

Open Source ◽

Single Particle ◽

Three Dimensional ◽

Traction Force ◽

High Spatial Frequency ◽

Epifluorescence Microscopy ◽

Traction Force Microscopy ◽

Force Microscopy ◽

Out Of Plane

Abstract We introduce a novel method to compute three-dimensional (3D) displacements and both in-plane and out-of-plane tractions on nominally planar transparent materials using standard epifluorescence microscopy. Despite the importance of out-of-plane components to fully understanding cell behavior, epifluorescence images are generally not used for 3D traction force microscopy (TFM) experiments due to limitations in spatial resolution and measuring out-of-plane motion. To extend an epifluorescence-based technique to 3D, we employ a topology-based single particle tracking algorithm to reconstruct high spatial-frequency 3D motion fields from densely seeded single-particle layer images. Using an open-source finite element (FE) based solver, we then compute the 3D full-field stress and strain and surface traction fields. We demonstrate this technique by measuring tractions generated by both single human neutrophils and multicellular monolayers of Madin–Darby canine kidney cells, highlighting its acuity in reconstructing both individual and collective cellular tractions. In summary, this represents a new, easily accessible method for calculating fully three-dimensional displacement and 3D surface tractions at high spatial frequency from epifluorescence images. We released and support the complete technique as a free and open-source code package.

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Contrast thresholds reveal different visual masking functions in humans and praying mantises

10.1101/135970 ◽

2017 ◽

Author(s):

Ghaith Tarawneh ◽

Vivek Nityananda ◽

Ronny Rosner ◽

Steven Errington ◽

William Herbert ◽

...

Keyword(s):

Spatial Frequency ◽

Motion Detection ◽

Visual Masking ◽

High Spatial Frequency ◽

Visual Noise ◽

Frequency Noise ◽

Detection Systems ◽

Spatial Frequencies ◽

Summary Statement ◽

Contrast Thresholds

AbstractRecently, we showed a novel property of the Hassenstein-Reichardt detector: namely, that insect motion detection can be masked by “invisible” noise, i.e. visual noise presented at spatial frequencies to which the animals do not respond when presented as a signal. While this study compared the effect of noise on human and insect motion perception, it used different ways of quantifying masking in two species. This was because the human studies measured contrast thresholds, which were too time-consuming to acquire in the insect given the large number of stimulus parameters examined. Here, we run longer experiments in which we obtained contrast thresholds at just two signal and two noise frequencies. We examine the increase in threshold produced by noise at either the same frequency as the signal, or a different frequency. We do this in both humans and praying mantises (Sphodromantis lineola), enabling us to compare these species directly in the same paradigm. Our results confirm our earlier finding: whereas in humans, visual noise masks much more effectively when presented at the signal spatial frequency, in insects, noise is roughly equivalently effective whether presented at the same frequency or a lower frequency. In both species, visual noise presented at a higher spatial frequency is a less effective mask.Summary StatementWe here show that despite having similar motion detection systems, insects and humans differ in the effect of low and high spatial frequency noise on their contrast thresholds.

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Is Peripheral Motion Detection Affected by Myopia?

Frontiers in Neuroscience ◽

10.3389/fnins.2021.683153 ◽

2021 ◽

Vol 15 ◽

Author(s):

Junhan Wei ◽

Deying Kong ◽

Xi Yu ◽

Lili Wei ◽

Yue Xiong ◽

...

Keyword(s):

Visual Field ◽

Spatial Frequency ◽

Motion Detection ◽

High Speed ◽

Detection Threshold ◽

High Spatial Frequency ◽

Spherical Equivalent ◽

Detection Thresholds ◽

Significant Difference ◽

Motion Speed

PurposeThe current study was to investigate whether myopia affected peripheral motion detection and whether the potential effect interacted with spatial frequency, motion speed, or eccentricity.MethodsSeventeen young adults aged 22–26 years participated in the study. They were six low to medium myopes [spherical equivalent refractions −1.0 to −5.0 D (diopter)], five high myopes (<-5.5 D) and six emmetropes (+0.5 to −0.5 D). All myopes were corrected by self-prepared, habitual soft contact lenses. A four-alternative forced-choice task in which the subject was to determine the location of the phase-shifting Gabor from the four quadrants (superior, inferior, nasal, and temporal) of the visual field, was employed. The experiment was blocked by eccentricity (20° and 27°), spatial frequency (0.6, 1.2, 2.4, and 4.0 cycles per degree (c/d) for 20° eccentricity, and 0.6, 1.2, 2.0, and 3.2 c/d for 27° eccentricity), as well as the motion speed [2 and 6 degree per second (d/s)].ResultsMixed-model analysis of variances showed no significant difference in the thresholds of peripheral motion detection between three refractive groups at either 20° (F[2,14] = 0.145, p = 0.866) or 27° (F[2,14] = 0.475, p = 0.632). At 20°, lower motion detection thresholds were associated with higher myopia (p < 0.05) mostly for low spatial frequency and high-speed targets in the nasal and superior quadrants, and for high spatial frequency and high-speed targets in the temporal quadrant in myopic viewers. Whereas at 27°, no significant correlation was found between the spherical equivalent and the peripheral motion detection threshold under all conditions (all p > 0.1). Spatial frequency, speed, and quadrant of the visual field all showed significant effect on the peripheral motion detection threshold.ConclusionThere was no significant difference between the three refractive groups in peripheral motion detection. However, lower motion detection thresholds were associated with higher myopia, mostly for low spatial frequency targets, at 20° in myopic viewers.

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