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“Breathing Carbon Dioxide (4% for 1 Hour) Slows Response Selection, Not Stimulus Encoding”, Vercruyssen 2014

2014-vercruyssen.pdf: “Breathing Carbon Dioxide (4% for 1 Hour) Slows Response Selection, Not Stimulus Encoding”⁠, Max Vercruyssen (2014; similar):

This experiment sought to determine whether breathing carbon dioxide (CO2), a toxic environmental stressor known to impair reaction time, slows human information processing in the stimulus encoding or response selection stage, or both, and whether this effect is influenced by time-on-task and exposure duration. In a 2 X 2 X 2 X 4 (Gas X Degradation X Compatibility X Time-on-Task) within-participants design, six highly practiced (more than 10,000 trials) healthy young male participants performed a serial choice reaction time (SCRT) task while breathing either 4% CO2 (with 50% O2) or room air (0.03% CO2 and 21% O2) for 60 minutes. Task variables manipulated were stimulus degradation (intact vs. degraded) and stimulus-response compatibility (high vs. low). Data from each 20-min SCRT test were subdivided into 5-min and 2-min intervals to determine the effects of time-on-task (and exposure duration). There were statistically-significant increases in SCRT from breathing carbon dioxide (p =.004), degrading the stimulus (p <.001), lowering compatibility (p =.004), and increasing time-on-task (p =.020). Lowering compatibility served to exaggerate the impairment produced by carbon dioxide inhalation (p =.038). Time-on-task (and exposure duration), however, did not interact with gas, degradation, or compatibility. Thus, SCRT, analyzed according to the Additive Factors Method (Sternberg, 1969, 1998), (1) was sensitive to the degrading effects of breathing CO2 at an undetectable concentration that did not produce clinical symptoms, (2) determined the locus of this effect was associated with the response selection stage of processing, (3) demonstrated that the progressive deterioration in performance due to increases in time-on-task (and exposure duration) affects both the stimulus encoding and response selection stages in a similar manner, and (4) ruled out alternative explanations by showing the results did not vary with distribution analyses, data trimming, error analyses, and analyses for tradeoffs of speed-accuracy, SCRT-DT, and other performance operating characteristics.

“Cognitive Performance and Mood During Respirator Wear and Exercise”, Caretti 1999

1999-caretti.pdf: “Cognitive Performance and Mood During Respirator Wear and Exercise”⁠, David M. Caretti (1999; similar):

The combined effects of respirator wear and low-intensity work on decision making and mood were assessed in 8 subjects during 60 min of low-intensity treadmill walking with and without a respirator to determine whether the stresses of respirator wear negatively impact decision making.

Subjects completed walks during no mask wear, wear of a respirator with high inspiratory resistance, and wear of a respirator with low resistance. Cognitive tasks included choice reaction (CHO), serial addition/​subtraction (ADD), logical reasoning (LOG), and serial reaction (SER). Mood was measured using a questionnaire with 36 adjectives representing the factors of activity, anger, depression, fear, happiness, and fatigue. Data were obtained pre-exercise, after 20 and 40 min of walking, and post-exercise.

Combined respirator wear and low-intensity exercise did not affect accuracy, speed, or throughput in any of the cognitive tasks. Likewise, no statistically-significant effects of condition on the 6 mood factor scores were observed.

These results show that the combination of respirator wear and low-level activity does not adversely alter cognitive performance or mood.

“The Effect of Moderately Increased CO2 Concentration on Perception of Coherent Motion”, Yang et al 1997

1997-yang.pdf: “The effect of moderately increased CO2 concentration on perception of coherent motion”⁠, Yuede Yang, Changnian Sun, Ming Sun (1997-01-01)

“Effect of Low-concentration CO2 on Stereoacuity and Energy Expenditure”, Sun et al 1996

1996-sun.pdf: “Effect of low-concentration CO2 on stereoacuity and energy expenditure”⁠, Ming Sun, Changnian Sun, Yuede Yang (1996-01-01)

“Effects of Hypercapnia and Bedrest on Psychomotor Performance”, Storm & Giannetta 1974

1974-storm.pdf: “Effects of hypercapnia and bedrest on psychomotor performance”⁠, William F. Storm, Carl L. Giannetta (1974-01-01)

“High Fidelity Simulations In The Evaluation Of Environmental Stress: Acute CO2 Exposure”, Wamsley et al 1969

1969-wamsley.pdf: “High Fidelity Simulations In The Evaluation Of Environmental Stress: Acute CO2 Exposure”⁠, James R. Wamsley, Edward W. Youngling, William F. Behm (1969-01-01)

“High Fidelity Simulations in the Evaluation of Environmental Stress: Acute CO2 Exposure”, Walmsley et al 1969

1969-walmsley.pdf: “High fidelity simulations in the evaluation of environmental stress: Acute CO2 exposure”⁠, James R. Walmsley, Edward W. Youngling, William F. Behm (1969-01-01)

“A Concept of Triple Tolerance Limits Based on Chronic Carbon Dioxide Toxicity Studies”, Schaefer 1961

1961-schaefer.pdf: “A concept of triple tolerance limits based on chronic carbon dioxide toxicity studies”⁠, Karl E. Schaefer (1961-01-01)

“The Influence Of Hyperpnea And Of Variations Of O2- And CO2-Tension In The Inspired Air Upon Hearing”, Gellhorn & Spiesman 1935

1935-gellhorn.pdf: “The Influence Of Hyperpnea And Of Variations Of O2- And CO2-Tension In The Inspired Air Upon Hearing”⁠, Ernst Gellhorn, Irwin G. Spiesman (1935-01-01)

“Influence of Variations of O2 and CO2 Tension in Inspired Air Upon Hearing”, Gellhorn & Spiesman 1934

1934-gellhorn.pdf: “Influence of Variations of O2 and CO2 Tension in Inspired Air Upon Hearing”⁠, Ernst Gellhorn, Irwin Spiesman (1934-01-01)

“The Physiological Effects of High Concentrations of Carbon Dioxide”, Brown 1930

1930-brown.pdf: “The physiological effects of high concentrations of carbon dioxide”⁠, E. W. Brown (1930-01-01)

Miscellaneous