Acute cold stress and mild hypothermia impact on short-term, working memory and attention

Abstract

The effect of single acute cold water exposure on the cognitive function (short-term, working memory and attention) was examined in 25 male subjects who were exposed to 14 °C cold water (air temperature ~22 °C, rh ~45%) in the semi-recumbent posture (up to the shoulders) until the rectal temperature (T_re) dropped to 35.5 °C. 6 subjects were excluded from the study, because we do not reach a necessary condition to drop their (T_re) to 35.5 °C in 170 minutes during a passive cooling procedure. During the cold exposure rectal (T_re), skin (T_sk) temperatures, heart rate (HR) were measured and cold strain (CSI) was calculated. A cognitive test battery (EFFECTON-COLD) was administrated two times (randomized): as a control measurement (CONTROL) and after the single acute cold water exposure (COLD). After COLD T_re and T_sk significantly decreased (p < 0.05). The average of HR and COLD time was 82.61 ± 4.09 and 93.68 ± 8.66, respectively. The COLD induced CSI resulted as high cold strain (7.02 ± 0.22). The present study manifested that mild hypothermia and high cold strain experienced in humans during acute cold stress, impair memory and attention tests performance in more complex tasks (tasks requiring working memory, attention concentration, sustention and speed of information processing) while simple tasks remain unaffected (tasks requiring short-term memory and attention concentration for fast response).