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Does normobaric hypoxia sustain altitude acclimatization‐induced improvements in fluid intelligence during reintroduction to altitude?
Author(s) -
Beidleman Beth A.,
Sils Ingrid V.,
Cymerman Allen,
Fulco Charles S.,
Staab Janet E.,
Muza Stephen R.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.909.3
Subject(s) - acclimatization , effects of high altitude on humans , hypoxia (environmental) , cognition , effects of sleep deprivation on cognitive performance , altitude (triangle) , medicine , psychology , biology , oxygen , chemistry , mathematics , ecology , psychiatry , geometry , organic chemistry , anatomy
This study examined whether normobaric hypoxia (NH)treatment is more efficacious than no treatment for sustaining high altitude (HA)acclimatization‐induced improvements in cognitive function during re‐introduction to altitude (RA) following 12‐day return to sea level (SL). Sixteen SL residents (age=23±6 yrs; mean±SE) participated in tests in the following order: 1) 4 d at SL, 2) 12 d at HA (4300 m), 3) 12 d at SL post HA acclimatization(Post) where each received either NH (n=9; FiO2=0.122) or Sham (n=8; FiO2=0.207)treatment, and 4) 24‐h re‐introduction to 4300 m (RA) in a hypobaric chamber. Cognitive performance was assessed using eight tests from the Automated Neuropsychological Assessment Metrics (ANAM) battery as measured by the number of correct responses per minute after 4 hours at SL, HA1, HA11, and RA. Simple reaction time (SRT) and SRT following cognitive fatigue (SRT2) were used to assess psychomotor performance . Go/no‐go (GNG) was used to assess attention and execution function Code substitution delayed (CDD) and Sternberg‐six letter memory (ST6) were used to assess long‐term memory (one component of crystallized intelligence). Procedural reaction time (PRT), mathematical processing (MTH), and spatial discrimination(SPD) were used to assess fluid intelligence . There were no differences in any measure of cognitive performance between the NH and Sham groups so data were combined. The PRT and MTH, respectively, decreased ~17% from SL (119±3; 34±3) to HA1 (99±5; 28±2) (P<0.05), then increased (P<0.05) at HA11 (114±4; 38±3), and remained unchanged at RA (113±3; 34±3). Similarly, SPD decreased ~14% from SL (44±3) to HA1 (38±1) (P<0.05) then increased (P<0.05)at HA11 (45±3), and remained unchanged at RA (45±3). SRT, SRT2, GNG, CDD, and ST6 were unchanged across any of the test days. These results demonstrate that psychomotor performance (SRT and SRT2), attention/executive function (GNG), and long‐term memory (CDD and ST6) were not impacted by acute or chronic exposure to 4300 m altitude. However, fluid intelligence, reflected in measures of processing speed (PRT), working memory(MTH), and spatial discrimination (SPD), decreased dramatically with acute exposure to 4300 m and improved with HA acclimatization. Moreover, improvements in fluid intelligence induced by HA‐acclimatization were retained during RA after 12 days at SL whether or not NH treatment was utilized. Authors' views not official U.S. Army or DoD policy. Support or Funding Information US Army Medical and Materiel Command This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .