Critical flicker frequency responses in visual cortex

Wells, E.F; Bernstein, Geula M.; Scott, Bradley; Bennett, Patrick J.; Mendelson, J. R.

doi:10.1007/s002210100721

Cited by 47 publications

(40 citation statements)

References 18 publications

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“…Humans as well as cats can decode up to ϳ70 Hz of flickering visual stimuli. However, in rats, even though the critical flicker frequency (CFF) of electroretinogram responses could be as high as 50 Hz (Rubin and Kraft, 2007), the CFF of the cells in the visual cortex was found to be ϳ20 Hz (Wells et al, 2001). Evolutional merit of the features found at this synapse may exist for rats, and, as all visual information must pass through the LGN before it reaches the visual cortex, this synapse would be an ideal location for signal filtering optimized for each species.…”

Section: Discussionmentioning

confidence: 99%

Mechanisms Underlying Signal Filtering at a Multisynapse Contact

Budisantoso¹,

Matsui²,

Kamasawa³

et al. 2012

J. Neurosci.

111

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Visual information must be relayed through the lateral geniculate nucleus before it reaches the visual cortex. However, not all spikes created in the retina lead to postsynaptic spikes and properties of the retinogeniculate synapse contribute to this filtering. To understand the mechanisms underlying this filtering process, we conducted electrophysiology to assess the properties of signal transmission in the Long-Evans rat. We also performed SDS-digested freeze-fracture replica labeling to quantify the receptor and transporter distribution, as well as EM reconstruction to describe the 3D structure. To analyze the impact of transmitter diffusion on the activity of the receptors, simulations were integrated. We identified that a large contributor to the filtering is the marked paired-pulse depression at this synapse, which was intensified by the morphological characteristics of the contacts. The broad presynaptic and postsynaptic contact area restricts transmitter diffusion two dimensionally. Additionally, the presence of multiple closely arranged release sites invites intersynaptic spillover, which causes desensitization of AMPA receptors. The presence of AMPA receptors that slowly recover from desensitization along with the high presynaptic release probability and multivesicular release at each synapse also contribute to the depression. These features contrast with many other synapses where spatiotemporal spread of transmitter is limited by rapid transmitter clearance allowing synapses to operate more independently. We propose that the micrometer-order structure can ultimately affect the visual information processing.

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Section: Discussionmentioning

confidence: 99%

Mechanisms Underlying Signal Filtering at a Multisynapse Contact

Budisantoso¹,

Matsui²,

Kamasawa³

et al. 2012

J. Neurosci.

111

View full text Add to dashboard Cite

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“…We chose the tCSF because the stimuli can be designed to obviate individual differences mediated by optical effects (e.g., influence of light absorption by retinal L and Z is eliminated by using wavelengths not absorbed by MP) and because the retina is known to follow temporally varying stimuli much faster than brain, hence, high-frequency thresholds are determined by the rate limiter which, in this case, appears to be visual cortex [32]. An example of the tCSF, with the specific points we assessed, is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

A randomized placebo-controlled study on the effects of lutein and zeaxanthin on visual processing speed in young healthy subjects

Bovier

Hammond

2015

Archives of Biochemistry and Biophysics

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Speed of processing is a particularly important characteristic of the visual system. Often a behavioral reaction to a visual stimulus must be faster than the conscious perception of that stimulus, as is the case with many sports (e.g., baseball). Visual psychophysics provides a relatively simple and precise means of measuring visual processing speed called the temporal contrast sensitivity function (tCSF). Past study has shown that macular pigment (a collection of xanthophylls, lutein (L), meso-zeaxanthin (MZ) and zeaxanthin (Z), found in the retina) optical density (MPOD) is positively correlated with the tCSF. In this study, we found similar correlations when testing 102 young healthy subjects. As a follow-up, we randomized 69 subjects to receive a placebo (n=15) or one of two L and Z supplements (n=54). MPOD and tCSF were measured psychophysically at baseline and 4months. Neither MPOD nor tCSF changed for the placebo condition, but both improved significantly as a result of supplementation. These results show that an intervention with L and Z can increase processing speed even in young healthy subjects.

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“…People can see lights flashing on and off for up to about 50 flashes per second (50 Hz). CFF is useful for assessing the temporal characteristics of the visual system and visual perception [15]. Additionally, CFF thresholds correlate with various parameters of intelligence, and have been regarded by clinicians as a general measure of the cortical processing capacity.…”

Section: Introductionmentioning

confidence: 99%

Influence of different kind of clothing material on selected cardiovascular, respiratory and psychomotor parameters during moderate physical exercise

Ciesielska¹,

Mokwiński²,

Orłowska-Majdak³

2009

International Journal of Occupational Medicine and Environmental Health

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Objectives: The aim of the experiment was to analyze the influence that the clothing material may have on human physiology and thermal comfort both at rest and physical effort to answer the question which fabric is better, a natural or a synthetic one. Materials and Methods: We measured some psychomotor parameters: critical flicker frequency (CFF), reaction time to auditory/visual stimuli (RT), concentration of attention (CA); cardiovascular parameters: blood pressure (BP), heart rate (HR) and respiratory parameters: tidal volume (V T ), minute ventilation (V E ), oxygen consumption (V O2 ), carbon dioxide output (V CO2 ), respiratory exchange ratio (RER) in human volunteers before, during and after physical effort. The subjects performed a 15-min treadmill test on treadmill wearing clothes made of two different materials: 100% coarse wool and 100% acrylic. An interview was conducted directly before the exercise test to assess the subjects' general mood and wellbeing on that day. Besides, before and after the test, the subjects in their own words described the sensation they felt with respect to the physiological comfort of particular clothing. Results: The results showed that wearing clothes made of different fabrics had some influence on the cardiovascular and respiratory parameters during physical effort but it did not have any effect on the psychomotor skills. The perception of physiological comfort by the subjects wearing coarse wool or acrylic depended on their physiological state and differed at rest and after the physical effort. Conclusions: The course of physiological processes depends on the kind of clothing a given person is wearing. It is not possible to clearly define which of the two clothing materials: natural -wool, or synthetic -acrylic is better. Each of them exerts a different effect on the human organism. The usefulness of a given type of clothing material seems to depend on the human physiological state and the related thermoregulatory processes.

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Critical flicker frequency responses in visual cortex

Cited by 47 publications

References 18 publications

Mechanisms Underlying Signal Filtering at a Multisynapse Contact

Mechanisms Underlying Signal Filtering at a Multisynapse Contact

A randomized placebo-controlled study on the effects of lutein and zeaxanthin on visual processing speed in young healthy subjects

Influence of different kind of clothing material on selected cardiovascular, respiratory and psychomotor parameters during moderate physical exercise

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