Adaptation to altitude as a vehicle for experiential learning of physiology by university undergraduates

A review of methods for assessment of cognitive function in high-altitude hypoxic environments

Hypoxic environments like those present at high altitudes may negatively affect brain function. Varying levels of hypoxia, whether acute or chronic, are previously shown to impair cognitive function in humans. Assessment and prevention of such cognitive impairment require detection of cognitive changes and impairment using specific cognitive function assessment tools. This paper summarizes the findings of previous research, outlines the methods for cognitive function assessment used at a high altitude, elaborates the need to develop standardized and systematic cognitive function assessment tools for high-altitude hypoxia environments.

Cognition and Neuropsychological Changes at Altitude-A Systematic Review of Literature

High-altitude (HA) exposure affects cognitive functions, but studies have found inconsistent results. The aim of this systematic review was to evaluate the effects of HA exposure on cognitive functions in healthy subjects. A structural overview of the applied neuropsychological tests was provided with a classification of superordinate cognitive domains. A literature search was performed using PubMed up to October 2021 according to PRISMA guidelines. Eligibility criteria included a healthy human cohort exposed to altitude in the field (at minimum 2440 m [8000 ft]) or in a hypoxic environment in a laboratory, and an assessment of cognitive domains. The literature search identified 52 studies (29 of these were field studies; altitude range: 2440 m-8848 m [8000-29,029 ft]). Researchers applied 112 different neuropsychological tests. Attentional capacity, concentration, and executive functions were the most frequently studied. In the laboratory, the ratio of altitude-induced impairments (64.7%) was twice as high compared to results showing no change or improved results (35.3%), but altitudes studied were similar in the chamber compared to field studies. In the field, the opposite results were found (66.4 % no change or improvements, 33.6% impairments). Since better acclimatization can be assumed in the field studies, the findings support the hypothesis that sufficient acclimatization has beneficial effects on cognitive functions at HA. However, it also becomes apparent that research in this area would benefit most if a consensus could be reached on a standardized framework of freely available neurocognitive tests.

Long-Term Impact of Living and Learning at High Altitude: An Altitude Physiology Class for Undergraduate Students

Alma College initiated an Altitude Physiology class in 1997 devoted to living and learning at high altitude (3440 m). The class incorporated several key elements of High-Impact Educational Practice including a strong student-research component and collaborative groups assignments. A retrospective survey was administered to alumni of the class to determine its long-term impact. Student responses ranged from “agree” to “strongly agree” with statements regarding the class’s impact on positive learning outcomes such as critical thinking, knowledge acquisition, synthesis of knowledge, and understanding of research. Students generally favored non-traditional formats such as living at altitude for gaining understanding of environmental physiology.

Cold pressor test using strain-gauge plethysmography

This laboratory activity is designed to teach students how to measure forearm muscle blood flow (FBF) to describe the mechanisms of peripheral blood flow thermal regulation in healthy subjects. The cold pressor test (CPT) is the clinical procedure used in the experiment to induce arterial vasoconstriction. Strain-gauge plethysmography is applied on the patient's forearm to noninvasive monitor vasoconstriction effects on local blood perfusion and physiological parameters such as blood pressure (BP) and heart rate (HR). Patients with an altered peripheral vascular resistance (e.g., in hypertension) have different responses to the CPT from healthy subjects. To date, experimental evidence remains unexplained, as we do not know if the BP and HR increase is caused by a decrease in flow rate or an increase in peripheral vascular resistance during the test. To clarify this situation, we have to quantify the parameter we assume is being conditioned by the regulatory physiological intervention, i.e., peripheral vascular resistance. Peripheral vascular resistance quantification can be calculated as the ratio between muscle flow and mean arterial pressure. Students will learn how to apply the instrumental procedure to collect and analyze data before, during, and after the CPT and to describe the physiological responses of the peripheral vascular system to external stressors. They will also learn how to distinguish healthy from pathological responses on the basis of how sympathetic nervous system reactions influence the biomechanics of peripheral vessels.