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Costantino Balestra - One of the best experts on this subject based on the ideXlab platform.

  • investigating Critical Flicker Fusion frequency for monitoring gas narcosis in divers
    Diving and Hyperbaric Medicine, 2020
    Co-Authors: Xavier C E Vrijdag, Costantino Balestra, Jamie Jw Sleigh, Hanna Van Waart, Simon J Mitchell
    Abstract:

    INTRODUCTION: La frequence critique de Fusion de scintillement (CFFF) a ete utilisee dans diverses etudes pour mesurer les effets cognitifs des melanges de gaz en profondeur, parfois avec des resultats contradictoires ou apparemment paradoxaux. Cette etude visait a evaluer une nouvelle methode automatique CFFF et a determiner si CFFF peut etre utilise pour surveiller la narcose induite par les gaz chez les plongeurs. Methodes: Trois experiences en chambre hyperbare ont ete realisees: 1) Mesures de CFFF automatisees et manuelles pendant la respiration a 608 kPa (n = 16 sujets); 2) Mesures manuelles de CFFF pendant la respiration d'air et d'heliox au niveau de la mer (101,3 kPa) et 608 kPa (n = 12); 3) Mesures manuelles de CFFF pendant la respiration d'oxygene au niveau de la mer, 142 et 284 kPa (n = 10). Tous les resultats ont ete compares a l'air respirable au niveau de la mer. RESULTATS: Seule la respiration d'oxygene au niveau de la mer, et a 284 kPa, a provoque une diminution significative du CFFF (respectivement 2,5% et 2,6% par rapport a l'air respirable au niveau de la mer. Aucune des autres conditions n'a montre de difference avec la respiration aerienne au niveau de la mer. CONCLUSIONS : CFFF n'a pas change de maniere significative dans nos experiences lors de la respiration d'air a 608 kPa par rapport a la respiration d'air a la pression au niveau de la mer en utilisant les deux appareils. D'apres nos resultats, le CFFF ne semble pas etre un outil sensible pour mesurer la narcose gazeuse chez les plongeurs dans notre laboratoire .

  • inert gas narcosis in scuba diving different gases different reactions
    European Journal of Applied Physiology, 2019
    Co-Authors: Monica Rocco, Luigi Maggi, Silvia Fiorelli, M Mercieri, P. Benedetto, G. Conte, Costantino Balestra, Paolo Pelaia, R A De Blasi
    Abstract:

    Purpose Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogen narcosis which can impact diver’s safety. Various human studies have clearly demonstrated brain impairment due to nitrogen narcosis in divers at 4 ATA using Critical Flicker Fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release.

  • Critical Flicker Fusion frequency a marker of cerebral arousal during modified gravitational conditions related to parabolic flights
    Frontiers in Physiology, 2018
    Co-Authors: Costantino Balestra, Marielaure Machado, Sigrid Theunissen, Ambre Balestra, Danilo Cialoni, Christian Clot, Stepane Besnard, Laura Kammacher
    Abstract:

    In-situ evaluation of human brain performance and arousal remains challenging during operational circumstances, hence the need for a rapid, reliable and reproducible tool. Here we hypothesized that the Critical Flicker Fusion frequency (CFFF) reflecting/requiring visual integration, visuo-motor skills and decision-taking process might be a powerful, fast and simple tool in modified gravity environments. Therefore 11 male healthy volunteers were assessed for higher cognitive functions with CFFF during parabolic flights. They were assessed at different time points: upon arrival to the base, 30 minutes after subcutaneous scopolamine administration, before parabolas, during hypergravity and microgravity at break time (between the 16th and the 17th parabola), on the return flight and on the ground after landing. First, a stable, and consistent measurement of CFFF could be obtained within 12 seconds. Second, under modified gravitational conditions, the perceptual ability of participants is significantly modified. Compared to the baseline, evolution is characterized by a significant increase of CFFF when in microgravity (0g: 106.9±5.5%), and a significant decrease of CFFF while in hypergravity (2g: 94.5±3.8%). Other time-points were not statistically different from the baseline value. Although the underlying mechanism is still debated, we suggest that the CFFF test is a global marker of cerebral arousal as the result of visuo-motor and decision taking testing based on a simple visual stimulus with an uncomplicated set up that could be used under various environmental conditions. The authors express an opinion that it would be advisable to introduce CFFF measurement during spaceflights as it allows individual longitudinal assessment of individual ability even under conditions of incomplete physiological compensation, as shown here during parabolic flights.

  • Critical Flicker Fusion Frequency: A Marker of Cerebral Arousal During Modified Gravitational Conditions Related to Parabolic Flights
    'Frontiers Media SA', 2018
    Co-Authors: Costantino Balestra, Marielaure Machado, Sigrid Theunissen, Ambre Balestra, Danilo Cialoni, Christian Clot, Stepane Besnard, Laura Kammacher
    Abstract:

    In situ evaluation of human brain performance and arousal remains challenging during operational circumstances, hence the need for a rapid, reliable and reproducible tool. Here we hypothesized that the Critical Flicker Fusion frequency (CFFF) reflecting/requiring visual integration, visuo-motor skills and decision-taking process might be a powerful, fast and simple tool in modified gravity environments. Therefore 11 male healthy volunteers were assessed for higher cognitive functions with CFFF during parabolic flights. They were assessed at different time points: upon arrival to the base, 30 min after subcutaneous scopolamine administration, before parabolas, during hypergravity and microgravity at break time (between the 16th and the 17th parabola), on the return flight and on the ground after landing. First, a stable, and consistent measurement of CFFF could be obtained within 12 s. Second, under modified gravitational conditions, the perceptual ability of participants is significantly modified. Compared to the baseline, evolution is characterized by a significant increase of CFFF when in microgravity (0g: 106.9 ± 5.5%), and a significant decrease of CFFF while in hypergravity (2g: 94.5 ± 3.8%). Other time-points were not statistically different from the baseline value. Although the underlying mechanism is still debated, we suggest that the CFFF test is a global marker of cerebral arousal as the result of visuo-motor and decision taking testing based on a simple visual stimulus with an uncomplicated set up that could be used under various environmental conditions. The authors express an opinion that it would be advisable to introduce CFFF measurement during spaceflights as it allows individual longitudinal assessment of individual ability even under conditions of incomplete physiological compensation, as shown here during parabolic flights

  • functional comparison between Critical Flicker Fusion frequency and simple cognitive tests in subjects breathing air or oxygen in normobaria
    Diving and Hyperbaric Medicine, 2013
    Co-Authors: Walter Hemelryck, Costantino Balestra, Peter Germonpre, Miroslav Rozloznik, Pierre Lafere
    Abstract:

    Introduction Measurement of inert gas narcosis and its degree is difficult during operational circumstances, hence the need for a reliable, reproducible and adaptable tool. Although being an indirect measure of brain function, if reliable, Critical Flicker Fusion frequency (CFFF) could address this need and be used for longitudinal studies on cortical arousal in humans. Methods To test the reliability of this method, the comparison between CFFF and three tests (Math-Processing Task, Trail-Making Task, and Perceptual Vigilance Task) from the Psychology Experiment Building Language battery (PEBL) were used to evaluate the effect of 10 minutes of 100% normobaric oxygen breathing on mental performance in 20 healthy male volunteers. Results Breathing normobaric oxygen significantly improved all but one of the measured parameters, with an increase of CFFF (117.3 ± 10.04% of baseline, P 0.4). Conclusions The CFFF test provides an assessment of cognitive function that is similar to some tests from PEBL, but requires a less complicated set up and could be used under various environmental conditions including diving. Further research is needed to assess the combined effects of increased pressure and variations in inspired gas mixtures during diving.

Peter Germonpre - One of the best experts on this subject based on the ideXlab platform.

  • functional comparison between Critical Flicker Fusion frequency and simple cognitive tests in subjects breathing air or oxygen in normobaria
    Diving and Hyperbaric Medicine, 2013
    Co-Authors: Walter Hemelryck, Costantino Balestra, Peter Germonpre, Miroslav Rozloznik, Pierre Lafere
    Abstract:

    Introduction Measurement of inert gas narcosis and its degree is difficult during operational circumstances, hence the need for a reliable, reproducible and adaptable tool. Although being an indirect measure of brain function, if reliable, Critical Flicker Fusion frequency (CFFF) could address this need and be used for longitudinal studies on cortical arousal in humans. Methods To test the reliability of this method, the comparison between CFFF and three tests (Math-Processing Task, Trail-Making Task, and Perceptual Vigilance Task) from the Psychology Experiment Building Language battery (PEBL) were used to evaluate the effect of 10 minutes of 100% normobaric oxygen breathing on mental performance in 20 healthy male volunteers. Results Breathing normobaric oxygen significantly improved all but one of the measured parameters, with an increase of CFFF (117.3 ± 10.04% of baseline, P 0.4). Conclusions The CFFF test provides an assessment of cognitive function that is similar to some tests from PEBL, but requires a less complicated set up and could be used under various environmental conditions including diving. Further research is needed to assess the combined effects of increased pressure and variations in inspired gas mixtures during diving.

  • Persistence of Critical Flicker Fusion frequency impairment after a 33 mfw SCUBA dive: evidence of prolonged nitrogen narcosis?
    European Journal of Applied Physiology, 2012
    Co-Authors: C. Balestra, Pierre Lafere, Peter Germonpre
    Abstract:

    One of the possible risks incurred while diving is inert gas narcosis (IGN), yet its mechanism of action remains a matter of controversy. Although providing insights in the basic mechanisms of IGN, research has been primarily limited to animal studies. A human study, in real diving conditions, was needed. Twenty volunteers within strict biometrical criteria (male, age 30–40 years, BMI 20–23, non smoker) were selected. They performed a no-decompression dive to a depth of 33 mfw for 20 min and were assessed by the means of Critical Flicker Fusion frequency (CFFF) measurement before the dive, during the dive upon arriving at the bottom, 5 min before the ascent, and 30 min after surfacing. After this late measurement, divers breathed oxygen for 15 min and were assessed a final time. Compared to the pre-dive value the mean value of each measurement was significantly different ( p  

  • Persistence of Critical Flicker Fusion frequency impairment after a 33 mfw SCUBA dive: evidence of prolonged nitrogen narcosis?
    European journal of applied physiology, 2012
    Co-Authors: Costantino Balestra, Pierre Lafere, Peter Germonpre
    Abstract:

    One of the possible risks incurred while diving is inert gas narcosis (IGN), yet its mechanism of action remains a matter of controversy. Although providing insights in the basic mechanisms of IGN, research has been primarily limited to animal studies. A human study, in real diving conditions, was needed. Twenty volunteers within strict biometrical criteria (male, age 30–40 years, BMI 20–23, non smoker) were selected. They performed a no-decompression dive to a depth of 33 mfw for 20 min and were assessed by the means of Critical Flicker Fusion frequency (CFFF) measurement before the dive, during the dive upon arriving at the bottom, 5 min before the ascent, and 30 min after surfacing. After this late measurement, divers breathed oxygen for 15 min and were assessed a final time. Compared to the pre-dive value the mean value of each measurement was significantly different (p < 0.001). An increase of CFFF to 104 ± 5.1 % upon arriving to the bottom is followed by a decrease to 93.5 ± 4.3 %. This impairment of CFFF persisted 30 min after surfacing, still decreased to 96.3 ± 8.2 % compared to pre-dive CFFF. Post-dive measures made after 15 min of oxygen were not different from control (without nitrogen supersaturation), 124.4 ± 10.8 versus 124.2 ± 3.9 %. This simple study suggests that IGN (at least partially) depends on gas-protein interactions and that the cerebral impairment persists for at least 30 min after surfacing. This could be an important consideration in situations where precise and accurate judgment or actions are essential.

Yossi Mandel - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of Critical Flicker-Fusion Frequency Measurement Methods for the Investigation of Visual Temporal Resolution
    Scientific Reports, 2017
    Co-Authors: Auria Eisen-enosh, Nairouz Farah, Zvia Burgansky-eliash, Uri Polat, Yossi Mandel
    Abstract:

    Recent studies highlight the importance of the temporal domain in visual processing. Critical Flicker-Fusion Frequency (CFF), the frequency at which a Flickering light is perceived as continuous, is widely used for evaluating visual temporal processing. However, substantial variability in the psychophysical paradigms, used for measuring CFF, leads to substantial variability in the reported results. Here, we report on a comprehensive comparison of CFF measurements through three different psychophysical paradigms: methods of limits; method of constant stimuli, and staircase method. Our results demonstrate that the CFF can be reliably measured with high repeatability by all three psychophysics methods. However, correlations (r = 0.92, p≪0.001) and agreement (Bland Altman test indicated 95% confidence limit variation of ±3.6 Hz), were highest between the staircase and the constant stimuli methods. The time required to complete the test was significantly longer for the constant stimuli method as compared to other methods (p 

  • evaluation of Critical Flicker Fusion frequency measurement methods for the investigation of visual temporal resolution
    Scientific Reports, 2017
    Co-Authors: Auria Eisenenosh, Nairouz Farah, Uri Polat, Zvia Burganskyeliash, Yossi Mandel
    Abstract:

    Recent studies highlight the importance of the temporal domain in visual processing. Critical Flicker-Fusion Frequency (CFF), the frequency at which a Flickering light is perceived as continuous, is widely used for evaluating visual temporal processing. However, substantial variability in the psychophysical paradigms, used for measuring CFF, leads to substantial variability in the reported results. Here, we report on a comprehensive comparison of CFF measurements through three different psychophysical paradigms: methods of limits; method of constant stimuli, and staircase method. Our results demonstrate that the CFF can be reliably measured with high repeatability by all three psychophysics methods. However, correlations (r = 0.92, p≪0.001) and agreement (Bland Altman test indicated 95% confidence limit variation of ±3.6 Hz), were highest between the staircase and the constant stimuli methods. The time required to complete the test was significantly longer for the constant stimuli method as compared to other methods (p < 0.001). Our results highlight the suitability of the adaptive paradigm for efficiently measuring temporal resolution in the visual system.

Pierre Lafere - One of the best experts on this subject based on the ideXlab platform.

  • functional comparison between Critical Flicker Fusion frequency and simple cognitive tests in subjects breathing air or oxygen in normobaria
    Diving and Hyperbaric Medicine, 2013
    Co-Authors: Walter Hemelryck, Costantino Balestra, Peter Germonpre, Miroslav Rozloznik, Pierre Lafere
    Abstract:

    Introduction Measurement of inert gas narcosis and its degree is difficult during operational circumstances, hence the need for a reliable, reproducible and adaptable tool. Although being an indirect measure of brain function, if reliable, Critical Flicker Fusion frequency (CFFF) could address this need and be used for longitudinal studies on cortical arousal in humans. Methods To test the reliability of this method, the comparison between CFFF and three tests (Math-Processing Task, Trail-Making Task, and Perceptual Vigilance Task) from the Psychology Experiment Building Language battery (PEBL) were used to evaluate the effect of 10 minutes of 100% normobaric oxygen breathing on mental performance in 20 healthy male volunteers. Results Breathing normobaric oxygen significantly improved all but one of the measured parameters, with an increase of CFFF (117.3 ± 10.04% of baseline, P 0.4). Conclusions The CFFF test provides an assessment of cognitive function that is similar to some tests from PEBL, but requires a less complicated set up and could be used under various environmental conditions including diving. Further research is needed to assess the combined effects of increased pressure and variations in inspired gas mixtures during diving.

  • Persistence of Critical Flicker Fusion frequency impairment after a 33 mfw SCUBA dive: evidence of prolonged nitrogen narcosis?
    European Journal of Applied Physiology, 2012
    Co-Authors: C. Balestra, Pierre Lafere, Peter Germonpre
    Abstract:

    One of the possible risks incurred while diving is inert gas narcosis (IGN), yet its mechanism of action remains a matter of controversy. Although providing insights in the basic mechanisms of IGN, research has been primarily limited to animal studies. A human study, in real diving conditions, was needed. Twenty volunteers within strict biometrical criteria (male, age 30–40 years, BMI 20–23, non smoker) were selected. They performed a no-decompression dive to a depth of 33 mfw for 20 min and were assessed by the means of Critical Flicker Fusion frequency (CFFF) measurement before the dive, during the dive upon arriving at the bottom, 5 min before the ascent, and 30 min after surfacing. After this late measurement, divers breathed oxygen for 15 min and were assessed a final time. Compared to the pre-dive value the mean value of each measurement was significantly different ( p  

  • Persistence of Critical Flicker Fusion frequency impairment after a 33 mfw SCUBA dive: evidence of prolonged nitrogen narcosis?
    European journal of applied physiology, 2012
    Co-Authors: Costantino Balestra, Pierre Lafere, Peter Germonpre
    Abstract:

    One of the possible risks incurred while diving is inert gas narcosis (IGN), yet its mechanism of action remains a matter of controversy. Although providing insights in the basic mechanisms of IGN, research has been primarily limited to animal studies. A human study, in real diving conditions, was needed. Twenty volunteers within strict biometrical criteria (male, age 30–40 years, BMI 20–23, non smoker) were selected. They performed a no-decompression dive to a depth of 33 mfw for 20 min and were assessed by the means of Critical Flicker Fusion frequency (CFFF) measurement before the dive, during the dive upon arriving at the bottom, 5 min before the ascent, and 30 min after surfacing. After this late measurement, divers breathed oxygen for 15 min and were assessed a final time. Compared to the pre-dive value the mean value of each measurement was significantly different (p < 0.001). An increase of CFFF to 104 ± 5.1 % upon arriving to the bottom is followed by a decrease to 93.5 ± 4.3 %. This impairment of CFFF persisted 30 min after surfacing, still decreased to 96.3 ± 8.2 % compared to pre-dive CFFF. Post-dive measures made after 15 min of oxygen were not different from control (without nitrogen supersaturation), 124.4 ± 10.8 versus 124.2 ± 3.9 %. This simple study suggests that IGN (at least partially) depends on gas-protein interactions and that the cerebral impairment persists for at least 30 min after surfacing. This could be an important consideration in situations where precise and accurate judgment or actions are essential.

Balestra Costantino - One of the best experts on this subject based on the ideXlab platform.

  • Investigating Critical Flicker Fusion frequency for monitoring gas narcosis in divers.
    'Diving and Hyperbaric Medicine Journal', 2020
    Co-Authors: Xavier C E Vrijdag, Balestra Costantino, Van Waart Hanna, Jamie Jw Sleigh, Mitchell, Simon J
    Abstract:

    Critical Flicker Fusion frequency (CFFF) has been used in various studies to measure the cognitive effects of gas mixtures at depth, sometimes with conflicting or apparently paradoxical results. This study aimed to evaluate a novel automatic CFFF method and investigate whether CFFF can be used to monitor gas-induced narcosis in divers.info:eu-repo/semantics/publishe

  • Inert gas narcosis in scuba diving, different gases different reactions.
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Rocco Monica, Pelaia P, Di Benedetto Paolo, Conte G, Maggi L, Fiorelli S, Mercieri M, Balestra Costantino, De Blasi R A, Road Project Investigators
    Abstract:

    Underwater divers face several potential neurological hazards when breathing compressed gas mixtures including nitrogen narcosis which can impact diver's safety. Various human studies have clearly demonstrated brain impairment due to nitrogen narcosis in divers at 4 ATA using Critical Flicker Fusion frequency (CFFF) as a cortical performance indicator. However, recently some authors have proposed a probable adaptive phenomenon during repetitive exposure to high nitrogen pressure in rats, where they found a reversal effect on dopamine release.info:eu-repo/semantics/publishe

  • Early detection of diving-related cognitive impairment of different nitrogen-oxygen gas mixtures using Critical Flicker Fusion frequency.
    'Diving and Hyperbaric Medicine Journal', 2019
    Co-Authors: Lafère Pierre, Hemelryck Walter, Germonpré Peter, Matity Lyubisa, Guerrero François, Balestra Costantino
    Abstract:

    Cognitive impairment related to inert gas narcosis (IGN) is a threat to diving safety and operations at depth that might be reduced by using enriched air nitrox (EANx) mixtures. Using Critical Flicker Fusion frequency (CFFF), a possible early detection of cognitive abilities/cerebral arousal impairment when breathing different oxygen (O2) fractions was investigated.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

  • Early Detection of Diving-Related Cognitive Impairment of Different Nitrogen-Oxygen Gas Mixtures Using Critical Flicker Fusion Frequency
    'Diving and Hyperbaric Medicine Journal', 2019
    Co-Authors: Lafère Pierre, Hemelryck Walter, Germonpré Peter, Matity Lyubisa, Guerrero François, Balestra Costantino
    Abstract:

    Introduction: Cognitive impairment related to inert gas narcosis (IGN) is a threat to diving safety and operations at depth that might be reduced by using enriched air nitrox (EANx) mixtures. Using Critical Flicker Fusion frequency (CFFF), a possible early detection of cognitive abilities/cerebral arousal impairment when breathing different oxygen (O2) fractions was investigated.Methods: Eight male volunteers performed, in random order, two dry chamber dives breathing either air or EANx40 (40% O₂-60% nitrogen) for 20 minutes (min) at 0.4 MPa. Cognition and arousal were assessed before the dive; upon arrival at 0.4 MPa; after 15 min exposure at 0.4 MPa; on surfacing and 30 min post-dive using behavioural computer-based testing psychology experiment building language (PEBL) and by CFFF while continuously recording brain oxygenation with near-infrared spectroscopy.Results: In both breathing conditions, CFFF and PEBL demonstrated a significant inverse correlation (Pearson r of -0.90, P < 0.0001), improved cognitive abilities/cerebral arousal occurred upon arrival at 0.4 MPa followed by a progressive deterioration. Initial brain activation was associated with a significant increase in oxyhaemoglobin (HbO2) and a simultaneous decrease of deoxyhaemoglobin (HHb). The magnitude of the changes was significantly greater under EANx (P = 0.038).Conclusions: Since changes were not related to haemodynamic variables, HbO₂ and HHb values indicate a significant, O₂-dependent activation in the prefrontal cortex. Owing to the correlation with some tests from the PEBL, CFFF could be a convenient measure of cognitive performance/ability in extreme environments, likely under the direct influence of oxygen partial pressure, a potent modulator of IGN symptoms.info:eu-repo/semantics/publishe

  • Critical Flicker Fusion Frequency: A Marker of Cerebral Arousal During Modified Gravitational Conditions Related to Parabolic Flights.
    'Frontiers Media SA', 2018
    Co-Authors: Balestra Costantino, Machado Marie-laure, Theunissen Sigrid, Balestra Ambre, Cialoni Danilo, Clot Christian, Besnard Stépane, Kammacher Laura, Delzenne Julie, Germonpré Peter
    Abstract:

    In situ evaluation of human brain performance and arousal remains challenging during operational circumstances, hence the need for a rapid, reliable and reproducible tool. Here we hypothesized that the Critical Flicker Fusion frequency (CFFF) reflecting/requiring visual integration, visuo-motor skills and decision-taking process might be a powerful, fast and simple tool in modified gravity environments. Therefore 11 male healthy volunteers were assessed for higher cognitive functions with CFFF during parabolic flights. They were assessed at different time points: upon arrival to the base, 30 min after subcutaneous scopolamine administration, before parabolas, during hypergravity and microgravity at break time (between the 16th and the 17th parabola), on the return flight and on the ground after landing. First, a stable, and consistent measurement of CFFF could be obtained within 12 s. Second, under modified gravitational conditions, the perceptual ability of participants is significantly modified. Compared to the baseline, evolution is characterized by a significant increase of CFFF when in microgravity (0g: 106.9 ± 5.5%), and a significant decrease of CFFF while in hypergravity (2g: 94.5 ± 3.8%). Other time-points were not statistically different from the baseline value. Although the underlying mechanism is still debated, we suggest that the CFFF test is a global marker of cerebral arousal as the result of visuo-motor and decision taking testing based on a simple visual stimulus with an uncomplicated set up that could be used under various environmental conditions. The authors express an opinion that it would be advisable to introduce CFFF measurement during spaceflights as it allows individual longitudinal assessment of individual ability even under conditions of incomplete physiological compensation, as shown here during parabolic flights.info:eu-repo/semantics/publishe