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Diver Performance and the Effects of Cold
Abstract
The capability of divers was tested by a test battery composed of tests of tactile sensitivity, grip strength, manual dexterity, tracking, assembly of a structure by groups, mental arithmetic, symbol processing, simple problem solving and memory. At a diving tower and a flooded quarry, test data were collected for performance on dry land (control) and at water temperatures between 44° and 72°F. A limited sample of post-dive urine temperatures and skin temperatures were recorded. Divers wore a complete 3/16” wet suit, except that, during the tests, the hands were bare. The results show: hand impairment—losses in tactile sensitivity, grip strength and manual movement; the losses were proportional to degree of cold and exposure time; the losses follow a similar course to skin temperature decrease and hence are considered due mainly to peripheral physiological attenuations; psychomotor impairment—losses in manual dexterity, tracking and group assembly were proportionate to water temperature; mental impairment—losses in mental capability occurred in those cases where the task required intense attention and involved considerable short-term memory; “blocking” effects occurred at the lower temperatures. The causes of the losses in capability are discussed in terms of peripheral and central impairments, in terms of “water” effects and “cold” effects, and in terms of a hypothesis that immersion in cold water serves to distract the diver. Some practical and theoretical implications of the study are reviewed.
... 3) decreased total body heat content and/or storage [5,6]; 4) reduced attentional focus (i.e., the distraction hypothesis) [7]; 5) increased shivering [8]; and 6) decreased finger blood flow [9]. Manual dexterity during immersion depends on the type of task, depth and exposure time to the ambient environment. ...
... These findings agree with most studies that have assessed manual dexterity in cold water [1,7,28,29]. Chen, et al. reported a 54% decrease in gross dexterity (nut loosening) during a 34-minute forearm immersion in 11°C water [1]. ...
... Two previous investigations measured manual dexterity during full-body immersion in cold water. Bowen (1968) measured dexterity in subjects during a cold-water dive in 8-16°C water and reported that dexterity was reduced by 30% after 30 minutes of immersion versus dry conditions [7]. Similarly, Davis, et al. reported a 31% reduction in dexterity upon entering 20°C water, which fell an additional 17% when immersed in colder (5°C) water [28]. ...
Background:
Cold-water immersion impairs manual dexterity when finger temperature is below 15°C. This exposes divers to increased risk of error. We hypothesized that whole-body active heating would maintain finger temperatures and dexterity during cold-water immersion.
Methods:
Twelve subjects (six males) (22 ± 2 years old; BMI 23.9 ± 2.5; body fat 16 ± 6%) completed 60-minute head-out water immersion (HOWI) wearing a 7mm wetsuit and 3mm gloves in thermoneutral water (TN 25°C) and cold water (CW 10°C) while wearing a water-perfused suit (WP) with 37°C water circulated over the torso, arms, and legs. Gross (Minnesota Manual Dexterity Test [MMDT]) and fine (modified Purdue Pegboard [PPT]) dexterity were assessed before, during and after immersion. Core body and skin temperatures were recorded every 10 minutes.
Results:
MMDT (TN -25 ± 14%; CW -72 ± 23%; WP -67 ± 29%; p<0.05) and PPT (TN -16 ± 9%; CW: -45 ± 10%; WP: -38 ± 13%; p<0.05) performance decreased during immersion. MMDT and PPT did not differ between CW and WP. Immediately following immersion gross dexterity was recovered in all conditions. Post-immersion fine dexterity was still impaired in CW (p<0.01), but not WP or TN. Core and skin temperatures decreased during immersion in CW and WP (p<0.05) but did not differ between CW and WP.
Conclusion:
Manual dexterity decreased during immersion. Dexterity was further impaired during cold-water immersion and was not maintained by water perfusion active heating. Warm water perfusion did not maintain finger temperature above 15°C but hand temperature remained above these limits, suggesting a need to reassess thermal thresholds for working divers in cold-water conditions.
... When the entire body is cooled, there is likely a local effect at the periphery involving direct interference of sensory-motor functioning, and a general and central effect influencing higher centers that serve to control, direct, and coordinate action. 31 For example, if the hands are preferentially cooled in air to 13°C and the rest of the body is kept warm, then reliable decrements in manual performance are observed, which tend to increase for the first 40 minutes of exposure and change little if at all during the remainder of the first hour of exposure. 32,33 Cooling of the remaining body surface as low as 26°C does not cause further measurable decrement. ...
... In 1959, Keatinge 81 reported that two of his subjects experienced complete amnesia for the last few minutes of 20-minute immersions in 5°C water, during which time they experienced core temperature decreases to 34.2°C and 35.1°C. In 1968, Bowen 31 reported a 22% decrement in performance on the Clock Test, a measure of short-term memory, in subjects exposed to 8°C water. In 1970, Stang and Weiner 55 reported decrements on an arithmetic test during exposure to 10°C water for 90 minutes, with errors attributable to momentary lapses in concentration. ...
... In 1968, Bowen 31 reported a 12% decrease in accuracy on a symbol processing task completed by subjects immersed in 8°C water. This task consisted of a subject's reading an entry that listed, in sequence, a code number and four colors. ...
... Factors associated with diving that affect manual performance include cold, pressure, immersion in water (Heus et al., 1995;Morton and Provins, 1960;Provins and Morton, 1960;Mackworth, 1953;Bowen, 1968), equipment burden (Morrison et al., 1998) and anxiety (Bowen, 1968;Enander, 1984). Bradley (1969) investigated a number of different glove designs to determine what factors were associated with degraded manual performance. ...
... Factors associated with diving that affect manual performance include cold, pressure, immersion in water (Heus et al., 1995;Morton and Provins, 1960;Provins and Morton, 1960;Mackworth, 1953;Bowen, 1968), equipment burden (Morrison et al., 1998) and anxiety (Bowen, 1968;Enander, 1984). Bradley (1969) investigated a number of different glove designs to determine what factors were associated with degraded manual performance. ...
... In addition to cold, factors such as narcosis, the equipment burden, operating in a low light level, and operating in an unfamiliar underwater environment have been associated with increase arousal and anxiety in divers. Researchers have noted that performance decrements in open water diving are significantly higher than those in a hyperbaric chamber (Baddeley et al., 1975;Ellis, 1982;Stang &Wiener, 1970 andBowen, 1968). Although it is difficult to isolate the effect of anxiety from the effects of narcosis, light level, or immersion, research suggests that apart from immersion and narcosis, anxiety is higher in deeper dives, and night dives, and that these dives are associated with lower manual dexterity scores (Baddeley and Fleming 1967;Mears and Cleary, 1980). ...
... Temperature as a limiting factor in diving has the next most cogent influence on man's physiological and psychological well-being as well as his ability to perform useful work (refer to Bowen, 1968). ...
... Human Performance Underwater Bowen (1968) Decrements in manual dexterity, tracking, and group assembly were inversely related to water temperature. Bowen also noted alterations in mental performance particularly in tasks requiring considerable concentration and substantial amounts of short-term memory. ...
... The bulk of the underwater human performance research has primarily addressed questions related to cognitive functions underwater such as memory (Bowen, 1968), arithmetical reasoning (Bowen and Pepler, 1967), information processing (Reilly and Cameron, 1968), etc., or to perceptual and sensory functions such as vision (Kinney, Luria, and Weitzman, 1968), audition (Brady, Summitt, and Berghage, 1976), communication and weight discrimination (Sergeant, 1963;Hanna, 1964). Less information is available concerning man's motor capabilities underwater (Vaughn and Mavor, 1972;Bowen, 1968). ...
... There is abundant evidence that this will impair his manual dexterity (Fox, 1967;Bowen, 1968;Stang and Wiener, 1970), but there is very little evidence that cold had an adverse effect on his cognitive efficiency. Bowen (1968) did in fact study a number of cognitive tasks. ...
... There is abundant evidence that this will impair his manual dexterity (Fox, 1967;Bowen, 1968;Stang and Wiener, 1970), but there is very little evidence that cold had an adverse effect on his cognitive efficiency. Bowen (1968) did in fact study a number of cognitive tasks. They found some slight evidence for impairment and tentatively suggest that "cold water stress, in addition to causing specific sensory and motor losses, causes increasing losses of capability as the task becomes more complex and is more dependent on sustained attention and memory functions" (Bowen, 1968). ...
... Bowen (1968) did in fact study a number of cognitive tasks. They found some slight evidence for impairment and tentatively suggest that "cold water stress, in addition to causing specific sensory and motor losses, causes increasing losses of capability as the task becomes more complex and is more dependent on sustained attention and memory functions" (Bowen, 1968). ...
The report presents findings of the research efforts for 1971 in the study of underwater work performance and work tolerance conducted at the University of California, Los Angeles. The studies were directed towards the development of performance decrement curves related to the specific variables which affect underwater work. Experiments designed to add to the body of knowledge necessary to the formation of decrement curves were conducted. The experiments examined: (a) the effect of cold-water exposure upon memory, reasoning ability, and vigilance, (b) the effect of depth upon memory, (c) wet vs. dry training for a specific underwater task, and (d) the physiological and performance effects of heliox as a breathing gas in cold water.
... It has been found that diving performance is significantly impaired in cold water, and that this impairment is directly related to water temperature (Stang and Wiener, 1970). Diving performance has also been shown to deteriorate progressively with continued exposure to cold water (Bowen, 1968). ...
... The ring and peg test (RPT) developed by Bowen (1968) was the principle measure of performance. The RPT as described by Bowen is primarily a psychomotor test. ...
... Several major effects were found which replicate previous findings (Bowen. 1968). The four divers performed significantly worse o n the motor test during initial shallow warm water testing than under baseline conditions. This impairment is most likely associated with resistance and negative g factors encountered while moving the arms in water. This motor deficit became even more severe under shallow cold water cond ...
Motor and cognitive tests were administered to four Navy divers under dry baseline conditions, in warm and cold shallow water, and again in cold water at 183 m. It was found that water resistance, cold water, and prolonged exposure to cold water at depth resulted in significant decrements in motor performance. None of these factors, however, consistently or reliably impaired cognitive performance. Those cognitive impairments which were found could probably be accounted for by impaired motor performance. The motor effects of prolonged exposure to cold water at 183 m may be related to either severe heat debt or CO2 retention. These results indicate that present heating techniques are inadequate to protect divers from significant motor impairments after entering cold water at any depth, and from additional decrements after exposure to cold water for an hour at 183 m.
... Since manual performance in cold water is of interest to the underwater diving community, there has been some work involving whole body immersion. However, the cold exposure was either less severe or the subjects wore neoprene wet suits (2,25). In these latter studies, skin and muscle temperatures did not cool as much as seen in life-threatening conditions, and little variation was seen in core temperatures. ...
... Tests ofphysical performance: Many tests of physical performance have been administered to divers experi encing minimal discomfort in moderately cool water or wearing insulating wet suits in very cold water (2,25). Our choice of tests was limited to those imposing lim ited demands on the subjects. ...
... A peg and ring board was placed just above water level within easy reach of the subject. This task is similar to that used by Bowen (2) and requires moving 10 rings from their pegs to 10 other pegs and back to their original positions using the dominant hand. This test was scored as pegs per minute. ...
Six subjects performed three manual arm tasks: 1) prior to immersion in 8 degrees C water; 2) soon after immersion to the neck, but prior to any decrease in core temperature; and 3) every 15 min until core temperatures decreased 2-4.5 degrees C. The tasks were speed of flexion and extension of the fingers, handgrip strength and manual dexterity. There was no immediate effect of cold immersion; however, all scores decreased significantly after core temperature decreased 0.5 degrees C. Further decrease in core temperature was associated with a progressive impairment of performance, although at a slower rate than during the first 0.5 degrees C decrease. Flexion and extension of the fingers was affected relatively more than handgrip strength or manual dexterity. Decrement in performance is a result of peripheral cooling on sensorimotor function with a probable additional effect of central cooling on cerebral function.
... In addition, studies that have investigated if cold exposure affects aiming tasks, which are reliant on feedforward control, have shown that cold exposure does not affect this factor of manual performance (O'Brien et al. 2007;Rogers and Noddin, 1984;Tikuisis and Keefe, 2007). In contrast, tracking tasks, which are reliant on sensory feedback (e.g., Miall et al., 1993;Keele, 1968), are impaired from cold exposure (Bowen, 1968;Goonetilleke and Hoffmann, 2009). ...
... Most of the cold exposure research has used tasks that have low body orientation demands (i.e., high stability, no body transport). Out of the 56 manual performance studies described here, only four had at least one condition where the manual tests were performed from a standing posture (Teichner, 1958;O'Brien et al., 2011;Riley and Cochran, 1984;O'Brien et al. 2007), one was performed from a crouched position (Tikuisis and Keefe, 2007), three while submerged in water (Bowen, 1968;Stang and Wiener, 1970;Zander and Morrison, 2008), and one from a prone lying position (Immink et al., 2012). Therefore, based on what is reported in the literature we can see that manual performance is rarely studied while the body is in transport or in an unstable position. ...
Cold exposure causes impairments in manual performance and therefore has implications for the safety and performance of individuals who perform occupational and survival skills in cold environments. The existing body of literature on the effects of cold exposure on manual performance has provided a foundation of knowledge regarding how cold exposure impacts safety and performance. The purpose of this review is to provide an updated summary of the literature, identify gaps in the literature based on task classifications, and to discuss how optimizing training might be a meaningful way of enhancing the safety and performance of cold environment workers. Our review found that there is a limited amount of research on how to optimize training for cold environments. Our review also found that the current body of research is primarily based on findings from tasks that are biased towards motor or cognitive demands, but not both, and that most tasks studied are low in complexity. Based on these identified gaps in the literature, we discuss how concepts from the motor learning literature can inform future research to help determine the best methods for training in the cold. We also discuss how a more comprehensive understanding of the effects of cold exposure on manual performance could be developed by performing research that uses a broader range of tasks that vary based on both task complexity and the cognitive and motor demands. Research that addresses these issues could help to enhance the safety and performance of those who work in cold environments.
... S EVERAL STUDIES have demonstrated that cold ex posure elicits large decrements in the performance of physical tasks (5,9,12,26). These effects have important implications for work output or survival during activities which may expose humans to the cold (i.e., military oper ations, commercial diving, recreation activities, etc.). ...
... Several studies have been carried out during cold air exposure GORDON C. GIESBRECHT (12,18,25). Other studies on the effects of cold water on performance involved immersion of only hands or arms (9,22,23,30), or whole body immersion (5,26). In these latter studies the exposure was either less severe or the subjects wore neoprene wet suits, with little variation seen in core temperature. ...
... The majority of diving is completed in cold water, between approximately 8 °C and 14 °C (Bowen, 1968;Egstrom, 1997), but temperatures as low as -2 °C can be encountered in Canadian waters. To combat immersion in cold water, Canadian forces divers are equipped with full protective clothing, including 3-fingered Rubatex® G-231-N neoprene gloves. ...
... In the operational environment, divers require hand strength, fine motor control and tactile sensitivity. When compared to exposure to other environmental stressors, such as heat, increased pressure or wind, exposure to cold is reported to be the environmental factor that most significantly affects manual performance (Mackworth, 1953;Bowen, 1968;Stang and Wiener, 1970;Geisbrecht and Bristow,1992;Heus et al., 1995,). The research that documents the detrimental affects of cold on manual performance is extensive (Horvath and Freeman, 1947;Mackworth, 1953;Mortens and Provins, 1960;Fox, 1967). ...
... Similarly, inconsistent results of the effects of cold on reasoning skills (e.g., symbol processing, mental arithmetic) have been obtained. Some studies have reported significantly impaired reasoning [5,6], while others found no significant decrements, despite a decline in core body temperature [4]. The effect of non-hypothermic cold exposure on response times is also inconsistent. ...
... Two distinct explanations for the changes in cognitive performance during cold exposure have been presented. The negative effects of cold exposure and cold-related physiological changes on cognitive performance are consistent with the distraction hypothesis [5,7,14,31]. In the present study support for the distraction hypothesis was derived from the observation that decreased skin temperatures and thermal sensations of cold were associated with longer response times and a decreased efficiency in the simple reaction time task which measures simple visuomotor response times. ...
... There are some studies supporting the distraction hypothesis (e.g. Teichner 1958, Bowen 1968, Davis et al. 1975, Vaughan 1977. Another theory suggests that the general arousal level is increased by mild/moderate cold exposure, which initially leads to improved performance. ...
... Interestingly, performance in complex tasks was improved under cold and cold/dim conditions. This observation differs from some previous studies where especially complex tasks have been shown to be susceptible to both short-term moderate cooling (60-90 min at 5-10°C) (Bowen 1968, Ellis 1982, Enander 1987, Thomas et al. 1989) and more severe central cooling (Giesbrecht et al. 1993, Lockhart et al. 2005. However, it was hypothesised that with moderate cooling a certain level of arousal affects performance of complex tasks beneficially. ...
Diss. -- Oulun yliopisto.
... The effects of temperature on maximal grip strength have been investigated more extensively, but these showed ambiguous results. Some found no change in maximal grip strength (Flouris et al., 2006;Imamura et al., 1998;Immink et al., 2012;Wiggen et al., 2011;Zander and Morrison, 2008), while others found a reduced maximal grip strength in the cold (Bowen, 1968;Chi et al., 2012;O'Connor et al., 2009;Vincent and Tipton, 1988). Identifying the cause of the differences in these results is difficult because of large differences in cooling methods, cooling rates, level of body cooling, and task protocols. ...
Prolonged exposure to cold can impair manual performance, which in turn can affect work task performance. We investigated whether mild whole-body cold stress would affect isometric force control during submaximal hand grip and key pinch tasks. Twelve male participants performed isometric hand grip and key pinch tasks at 10% and 30% of maximal voluntary contraction (MVC) for 30 and 10 s respectively, in cold (8 °C) and control (25 °C) conditions. Finger temperature decreased significantly by 18.7 ± 2.1 °C and continuous low-intensity shivering in the upper trunk increased significantly in intensity and duration during cold exposure. Rectal temperature decreased similarly for the 8 °C and 25 °C exposures. Force variability (FCv) was <2% for the hand grip tasks, and <3% for the key pinch tasks. No significant changes in FCv or force accuracy were found between the ambient temperatures. In conclusion, isometric force control during hand grip and key pinch tasks was maintained when participants experienced mild whole-body cold stress compared with when they were thermally comfortable.
... At core temperatures between 34.0 and 35.0°C, concentration is significantly impaired and complex tasks are 175% slower compared with performance on tasks that are performed at non-hypothermic body temperatures (Hoffman, 2001). Research suggests that, when thermal protection is used and whole body cooling is prevented, cognitive impairments may be limited to those previously described by the distraction theory (Bowen, 1968). Diminished attention (Spitznagel et al., 2009;Solianik et al., 2014;Solianik et al., 2015), reduced accuracy (Shurtleff et al., 1994), worsened short-term memory Davis et al., 1975;Patil et al., 1995;Muller et al., 2012;Solianik et al., 2014;Solianik et al., 2015), longer reaction times (Stang and Wiener, 1970;Makinen et al., 2006;Muller et al., 2012;Solianik et al., 2014;Solianik et al., 2015), and decreased efficiency of cognitive tasks (Lockhart et al., 2005;Makinen et al., 2006) are all likely to occur if cold exposure is severe enough to cause distraction from the task or result in whole body cooling that could slow neuronal and synaptic activity. ...
Athletes, occupational workers, and military personnel experience cold temperatures through cold air exposure or cold water immersion, both of which impair cognitive performance. Prior work has shown that neurophysiological pathways may be sensitive to the effects of temperature acclimation and, therefore, cold acclimation may be a potential strategy to attenuate cold-induced cognitive impairments for populations that are frequently exposed to cold environments. This review provides an overview of studies that examine repeated cold stress, cold acclimation, and measurements of cognitive performance to determine whether or not cold acclimation provides beneficial protection against cold-induced cognitive performance decrements. Studies included in this review assessed cognitive measures of reaction time, attention, logical reasoning, information processing, and memory. Repeated cold stress, with or without evidence of cold acclimation, appears to offer no added benefit of improving cognitive performance. However, research in this area is greatly lacking and, therefore, it is difficult to draw any definitive conclusions regarding the use of cold acclimation to improve cognitive performance during subsequent cold exposures. Given the current state of minimal knowledge on this topic, athletes, occupational workers, and military commands looking to specifically enhance cognitive performance in cold environments would likely not be advised to spend the time and effort required to become acclimated to cold. However, as more knowledge becomes available in this area, recommendations may change.
... Typically lower visibility is present in subtropical locations during winter when cold-water upwelling occurs (Barton et al., 1998). Therefore divers are managing the feelings of colder water, which causes distraction and reduced comfort levels (Bowen, 1968) combined with dealing with the effects of low visibility. ...
Understanding the underlying causes of SCUBA diver contact with sensitive benthic organisms is critical for designing targeted strategies to address and manage diver impacts. For the marine tourism industry to maintain or expand current levels of recreational diving practices, ecologically sustainable management of dive sites is required. This study surveyed 400 SCUBA divers engaged in recreational diving in the subtropical reefs off eastern Australia. A combination of in-water observational research was conducted, with post-dive questionnaires. Linear regression techniques were employed to identify the variables that correlate the frequency of diver contacts with reef biota. Of the 17 variables tested, nine were found to significantly influence contact frequency. These were: the number of days since a diver's last dive, location of original certification, awareness and understanding of marine park zoning (3 variables), site selection, use of photographic equipment, total number of dives logged and diving depth. These results show that while a diver's long-term and recent experience can play a role, awareness of marine park regulations and unidentified differences in prior training (related to location) are also important, suggesting that education and training may provide viable alternatives to limiting diver access at sensitive locations.
... Además del estudio de los cambios de rendimiento y conducta bajo presión aumentada y de los efectos de los estresores ambientales, también se desarrolló una línea de trabajo interesada en la capacidad de adaptación humana en el medio submarino, analizando la base psicológica del entrenamiento y la formación del buceador, la evaluación de aptitud psicológica, la personalidad y actitudes del buceador o la importancia de la ansiedad en buceo [6][7][8][9][10][11][12][13][14][15][16] . ...
Antecedentes: Las demandas y estresores ambientales del medio subacuático imponen al buceador la necesidad de desarrollar un riguroso programa de formación y un meticuloso proceso adaptativo de naturaleza psicofisiológica. Método: Con el fin de verificar el papel de los rasgos cognitivos y de personalidad en el ambiente extremo del buceo, se han analizado con un diseño ex post facto datos psicológicos de una muestra de personal que realiza cursos militares de buceo autónomo, comprobando las diferencias existentes en su capacidad para adaptarse a las demandas ambientales y en sus posibilidades para realizar actividades subacuáticas, determinando la validez predictiva de las diferencias individuales y elaborando un modelo psicológico de la adaptación subacuática. Resultados: Los datos obtenidos indican la existencia de variables psicológicas que diferencian entre quienes superan o no el curso de buceo y entre buceadores con niveles claramente distintos de rendimiento subacuático. Además, estas variables correlacionan con el rendimiento y la adaptación bajo el agua y permiten anticipar el resultado de la formación de los buceadores. Las medidas de inteligencia, personalidad y ansiedad utilizadas se han reducido, mediante modelos de análisis factorial exploratorio y confirmatorio, a un modelo de medida con dos factores relacionados, Ajuste emocional y Capacidad mental, que permite representar de forma adecuada y significativa la adaptación subacuática. Conclusión: Los resultados apoyan la hipótesis de que estos factores pueden ser componentes psicológicos de la adaptación subacuática y pueden facilitar el aprovechamiento de la formación de los buceadores y la adaptación a las demandas del medio subacuático.
... Conversely, with increasing water depth, the solar heating of oceans and lakes is reduced and divers can be exposed to very stressful conditions. For example, while the majority of diving takes place at water temperatures between 8 and 14°C (Bowen 1968), the temperature of northern waters may be 4-6°C (Mekjavic et al. 2001), and as low as −2°C in Arctic waters (Morrison and Zander 2007;Chapter 23). Beyond the surface layer, and regardless of its temperature, deep water temperatures approach 5°C at 1000 m, with a seabed temperature of approximately 3°C. ...
... In addition, during heavy surge the observer may find it difficult concentrate on data recording because at least part of their attention must be devoted to avoiding contact with the bottom as surge whips them back and forth. Diver hypothermia, whether caused by relatively short exposure to very cold water or by improper thermal protection on long tropical dives, can cause divers to suffer loss of body movement, concentration, or even mental acuity, which makes their data highly suspect in regard to accuracy (Bowen 1968, Ebeling and Hixon 1991, personal observation). Because of reduced visibility, water temperature, and storm surge, visual surveying is very difficult to do on many temperate reefs during a substantial portion of the year (Ebeling and Hixon 1991). ...
... Central Nervous System (CNS) decrements, such as amnesia and unconsciousness associated with hypothermia. Moreover some authors defend that even exposure to less severe cold may affect cognitive performance (Palinkas, 2001;Mäkinen, Palinkas, Dennis, Pääkkönen, Rintamäki, Leppäluoto & Hassi, 2006;Baddeley, Cuccaro, Egstrom, Weltman & Willis, 1975;Bowen, 1968). Mäkinen et al. (2006) found that a rigorous enough cold exposure, causing whole body cooling, resulted in impaired cognitive performance. ...
In education we also have to consider the performances obtained and the conditions where they are obtained.
‘Preparing for life’ is about having knowledge and, sometimes, being able to use it in difficult conditions.
Traditional classroom can be occasionally misguiding, but through sport it’s possible to understand phenomena that can be transferred to education. The aim of our study was to investigate the influence of cold and rain in outdoor sports on the cognitive performances of amateur hikers. Cognitive performance of 40 amateur hikers was tested (arithmetical operations test) in a comfortable surrounding with mild temperature and outdoors on a rainy and mildly windy day. Significant differences in the time to solve the test was found in different environments (p<0.0001), taking longer outdoors, as well as the number of faults (p<0.0001). We can conclude that even a mild change in weather environment can influence the cognitive performance.
... The "water effect" could have distracted the subjects so that their level of attention directed toward the task underwater was less than on the surface. Bowen (1968) discusses this rationale in his explanation of a performance decrement in manual dexterity and psychomotor tasks in cold water. ...
... Cognitive function in divers submerged at various temperatures is of interest both in military and some civilian settings. Underwater cognitive testing has sometimes been done using waterproof paper and pencils (e.g., Bowen, 1968; Davis et al., 1975) or auditory problem presentation with manual signals for responses (e.g., Stang and Wiener, 1970). Some simple testing devices have been constructed (e.g.; Biersner, 1976; Stang and Wiener, 1970). ...
A waterproof keyboard has been developed. This allows collection of cognitive performance data from divers submerged in a tank. Cognitive tasks are presented to the divers on a computer screen placed at the tank viewing window. The four button keyboard can be easily manipulated while wearing standard diving gloves. Software techniques for adapting various types of tasks to the four- button response format are discussed. (Author)
... Of particular interest is the impairment of short-term memory reported in individuals during cold stress when hypothermia is not present (Pozos, 1986 ). Several investigators have described cold-induced memory degradation in humans, often with relatively brief, apparently nonhypothermic, cold exposures (Baddeley, Cuccaro, Egstrom, Weltman, & Willis, 1975; Bowen, 1968; Coleshaw, VanSomeren, Wolff, Davis, & Keatinge, 1983; Davis, Baddeley, & Hancock, ' This report was supported by Naval Medical Research and Development Command Research and Technology Work Units 61153N.MR04120.00B.1058 and 61152N.MR00001. ...
Exposure to moderate, nonhypothermic cold temperature has been reported to affect a variety of behavioral and neural functions. To elucidate the effects of mild cold stress on short-term (working) memory, Long-Evans rats were exposed to an ambient temperature of either 2 degrees or 23 degrees C while performing a delayed matching task. At the beginning of each trial, rats were required to respond on one of two levers cued by a light. Following a delay of 2, 8, or 16 s, a response on the lever previously cued produced food reinforcement. Relative to performance at 23 degrees C, exposure to 2 degrees C occasioned no change in matching accuracy at the 2-s delay, a modest decrement at the 8-s delay, and a larger decrement at the 16-s delay. The cold exposure did not decrease colonic temperature. In addition to accuracy decrements, matching response times were consistently shorter during cold exposures. Cold-induced impairments were absent during removal of the memory component from the task, indicating the observed cold effects on memory were not due to impaired attentional, sensory, or motor processes. These data suggest that mild cold stress may impair active maintenance of information in working memory but not processes related to reference memory.
... Thus there would appear to be a genuine local cold limiting factor on dexterity which is additional to any central effect. The precise mechanism of this local effect is likely to be multifactorial and models describing a direct vascular response, 4 a neuro-muscular pathway, 11 and physical changes in the viscosity of synovial fluid 12 have all been proposed. The end result is a reduction in performance at HST's above those required to produce cold injury. ...
Objective: In this review we detail the impact of environmental stress on cognitive and military task performance and highlight any individual characteristics or interventions which may mitigate any negative effect.
Background: Military personnel are often deployed in regions markedly different from their own, experiencing hot days, cold nights and trips both above and below sea level. In spite of these stressors, high-level cognitive and operational performance must be maintained.
Methods: A systematic review of the electronic databases Medline (PubMed), EMBASE (Scopus), PsychINFO and Web of Science was conducted from inception up to September 2018. Eligibility criteria included a healthy human cohort, an outcome of cognition or military task performance and assessment of an environmental condition.
Results: The search returned 113,850 records, of which 124 were included in the systematic review. Thirty-one studies examined the impact of heat stress on cognition; twenty of cold stress; fifty-nine of altitude exposure; and eighteen of being below sea level.
Conclusion: The severity and duration of exposure to the environmental stressor affects the degree to which cognitive performance can be impaired, as does the complexity of the cognitive task and the skill or familiarity of the individual performing the task.
Application: Strategies to improve cognitive performance in extreme environmental conditions should focus on reducing the magnitude of the physiological and perceptual disturbance caused by the stressor. Strategies may include acclimatisation and habituation, being well skilled on the task, and reducing sensations of thermal stress with approaches such as head and neck cooling.
Even though breathing under increased ambient pressure is a recent development in man’s history, there is now ample reason and need to put man at the greatest possible depth consistent with his ability to do useful work. Respiratory variables are of crucial importance in determining both the capacity and the safety of working at depth and under high pressure.
Six experienced male SCUBA divers performed a test of manual dexterity in the open ocean underwater environment. Each was timed on the assembly of ten bolt combinations at a shallow (4.6m) and deeper (15.3m) ocean depth. Performance efficiency, as measured by the time to complete the task, declined 25.8% at 4.6m and 36.8% at 15.3m underwater, when compared to equivalent dry land performance. The synthesis of results from the current study and data adduced from previous experimental work concerning manual dexterity underwater, suggests that percentage increase in task completion time is linearly related to the depth of ocean performance. This observation implicates the major role of physical factors in performance decrement with increasing depth and attributes a lesser influence to situational anxiety than has previously been apportioned. In addition, task skill level is identified as a potent interactive variant of performance underwater. The proposed function permits calculation of completion times of simple manual dexterity tasks over the range of ocean depths in which air breathing divers may operate. In consequence, it holds potential importance in setting temporal constraints on performance and safety standards for the submerged operator.
Besides providing man a wide range of information about his environment, the visual sense provides confirmatory data for information received through the other senses. In an underwater environment certain changes take place in the visual process due to the change of the visual medium from air to water. Understanding these changes is relevant to the effective engineering of underwater tools and equipment and the orientation of the underwater worker who must perform in a strange environment.
The purpose of this chapter is to present information about man’s performance in an ocean environment, particularly as it contrasts with performance in a normal, dry-land, 1-atm, air environment. The kind of information selected for presentation is that based on experimentation as opposed to that from less formal sources. The strength of this choice is that information obtained by the scientific method can be assessed for confidence, reliability, and generality; the weakness is the piecemeal character of the information. Research results typically are not about holistic job performance by operational divers working in the ocean, but about a dimension of performance as affected by a characteristic of the ocean environment. Most often, several performance dimensions are measured as effects of variations in a single environmental characteristic. Researchers tend to work by varying an environmental characteristic, such as cold or atmospheric pressure, and recording a range of performance dimensions, such as manual dexterity, reaction time, and memory. The principal challenge of preparing this chapter, therefore, was to develop a framework for organizing the fragments of performance-oriented research information relevant to man in the sea.
The human hand is designed as a mechanical tool but it is also an important sensory organ. The normal hand of a diver in arctic water must be protected against the cold and also against injuries of different kinds. The aim of this experiment was to study as a matter of principle thermal and functional properties of a thin and flexible glove system for divers. Two prototypes were evaluated, one with an inner layer of polyester and one with a double inner layer of natural silk. Subjective ratings of perceived hand temperature, hand moisture, difficulty in performing the manual dexterity test and degree of exertion in the test of grip strength were obtained. Both were warmer than a previously tested five-fingered prototype but colder than previously tested conventional deep-diver gloves.
Work-related injuries, such as back injuries and carpal tunnel syndrome, are the most prevalent, most EXPENSIVE, and most preventable workplace injuries, accounting for more than 647,000 lost days of work annually (according to OSHA estimates). Such injuries, and many others, can be prevented in your facility by establishing an ergonomic design. This book shows you how to apply simple Ergonomic tools and procedures in your plant. Challenging worldwide regulations are forcing some companies to spend thousands of dollars per affected employee in order to comply. This book shows you how to comply with these regulations at a fraction of the cost, in the most timely, efficient method possible. Learn how to use the Human Factors/Ergonomics tools in process industries. Identify and prioritize Ergonomic issues, develop interventions, and measure their effects. Apply Ergonomics to the design of new facilities
This chapter discusses thermal physiology of man in the aquatic environment. The physical properties of water are very different from those of air. Accordingly, the environmental stress easily becomes severe and may even threaten life. On immersion, heat exchange between the body and its environment is enhanced. Water has a volumetric specific heat 4000 times greater than that of air and conductivity 25 times that of air. Water, therefore, serves as a gigantic heat sink around the body. As a consequence, a nude man will have difficulty reducing heat loss enough to prevent body cooling, even in water at a moderate temperature (20–25 °C). The chapter presents the review of the thermal responses and energy exchanges of swimming man, with special reference to his physical work capacity and various kinds of water activity. Body cooling will activate cold receptors in the skin and in the central nervous system, causing the body to respond in an attempt to retain a normal temperature. Thus, heat loss is decreased by vasoconstriction and heat production is increased by shivering. The magnitude of the shivering response is a function of skin and core temperatures, the former being the more important stimulus. If both skin and core temperatures are low, the shivering response is greater than if one of these stimuli is present. These effects occur at rest, as well as during exercise. One effect of shivering is that the energy cost of a given rate of work—for example, by swimming—will increase.
Scientific diving is an extremely useful tool for supporting research in environments with restricted access, where remotely operated or autonomous underwater vehicles cannot be used. However, these environments tend to be close to the surface and require the application of advanced
diving techniques to ensure that the research is conducted within acceptable safety parameters. The two main techniques discussed are under-ice and cave diving; for each environment the specific hazards are reviewed and methods for mitigating the concomitant risks are detailed. It is concluded
that scientific diving operations in these environments can be conducted to acceptable risk levels; however, risk management strategies must outline precisely when and where diving operations are to be prohibited or terminated.
The purpose is to create an evaluation system for the working psychic capacity, directly conditioned by the exigencies of divers'and frogmen's tasks, with the object of establishing their aptitude to accomplish their missions, and as an indicator of the prognostic and perspective level of the said specialists. A battery of psychological and psychophysiological tests was suited, oriented to the assessment of the mobility of the psychic processes, the operative thought, the psychomotor activity process, the time of reaction, the profoundness vision, and the commutation, volume, and distribution of the attention. These tests were validated and standardized for the studied population. The data were processed by central measure staticians, and by a test of matrix correlation with a p = 0,05. The results revealed significant differences in age, time of reaction, operative thought, psychomotor activity, and in the distribution, commutation and volumen of the attention; due to these factors, independent qualification standards were established for divers and frogmen.
Five experienced divers and 15 novice divers completed a complex underwater assembly task and sets of written problems in a water-filled tank and in the ocean. Performance measurements included subtask completion times, problem-solving accuracy, activity analysis, and basic physiological variables. Experienced divers showed essentially unchanged performance between tank and ocean. Novice divers performed slower than the experienced divers in the tank and showed a marked decrement in both assembly time and problem-solving accuracy in the ocean. The results suggest that diving experience improves underwater motor skills rather than work strategy, and that psychological stress was a significant factor even at shallow ocean depths for novices.
An experiment was conducted to measure apparent distance of a target within arm's length above water and under water. Eight experienced divers and eight novice divers wearing facemasks indicated apparent distances by reaching responses. The viewing conditions were (1) a target and a subject in air environment, (2) a target in water but a subject in air, and (3) a target and a subject under water. Apparent distances were smaller in conditions (2) and (3) than in (1). This difference is interpreted as being due to the dissimilar convergence and accommodation requirements in the various conditions. There was little difference between the experienced and novice divers.
This study investigated the effects of cold and exercise in the cold on the physiological and cognitive responses of 11–12-year-old boys. Children were dressed in sweat suits and exposed to cold (CD, 7°C), cool (CL, 13°C), and neutral (N, 22°C) environments for 110 minutes, with 10 minutes of light exercise (1 watt · kg body wt−1) midway through the exposure. A 30-minute “recovery” in neutral conditions followed each session. Session order was randomized. Rectal temperature (Tre) decreased significantly more in CD compared to CL and N, and continued to decrease during the recovery period. Chest skin temperature (Tch) was significantly different between conditions and remained stable even in CD, despite the decrease in Tre. Tch returned to prechamber values during the recovery period. Hand temperature (Th) decreased during CL and CL, and remained significantly lower than prechamber values following the recovery. Exercise heart rate was lower in the CD and CL(115 ± 13 and 119 ± 20 beats · min−1) compared to N (130 ± 17 beats · min−1). No differences were observed in oxygen consumption between sessions. No differences were also observed between sessions in cognitive performance on language and math tests. It was concluded that while the study conditions did not appear to affect cognitive capacity in boys, they proved sufficient to disturb core temperature. This disturbance was not corrected 30 minutes following cold exposure. Am. J. Hum. Biol. 9:39–49 © 1997 Wiley-Liss, Inc.
Germany's climate and geographical location have historically played an important role in the outcome of many military campaigns. Modern climatic conditions will likewise effect exposed military personnel. Exposed soldiers respond physiologically and behaviorally to extreme cold depending on their energy stores, sex, build, race, and metabolic activity. These responses are reviewed in terms of the energy balance of the human body, the factors which limit thermogenesis, and the various means of measuring and assessing the impact of temperature. A value of O C, the temperature at which human tissue freezes, is used as a threshold at which the adverse effects of cold become significant to military operations to include decreased resistance to infection and levels of performance. German winter temperature can be characterized by large intraseasonal and interannual variability and a general lack of persistence of climatic elements.
The thermal stress of cold water diving limits the amount of dive time available for the completion of mission tasks. Heat loss resulting from immersion in cold water also degrades progressively diver psychomotor performance before tolerance limits are reached that necessitate rewarming of the diver. This report is a review of current research efforts aimed at quantifying mechanisms of heat loss, the physiological and psychomotor responses to varying degrees of heat loss, and protective systems to extend diving times and performance under thermally adverse conditions.
As an assessment of adequacy of current Navy diving guidelines for thermal protection, the performance and physiology of three wet-suited SCUBA divers were measured over a series of 36 dives in water temperatures ranging from 5 C to 25 C. The divers performed cognitive and motor tasks during dives lasting up to 50 min at a depth of 3.35 m; heart rate, respiration rate, and skin temperatures were recorded at 5-min intervals. Results indicated that despite substantial decreases in skin temperatures, diver performance on cognitive tasks was not significantly affected; motor performance was impaired only when water temperature reached 5 C. These results indicate that the standard neoprene wet suit provides adequate protection during dives in shallow water at temperatures as low as 10 C and for exposure times as long as 50 min. (Author)
Cold exposure is present to significant amounts in the everyday occupational and leisure time activities of circumpolar residents. A cross-sectional population study demonstrated that Finns reported being exposed to cold on average 4% of their total time. Factors modifying cold exposure are: age, gender, employment, education, health, and amount of physical exercise. Several symptoms and complaints are associated with wintertime cold exposure and start to appear more commonly when temperatures decrease below À108C. Urban circum-polar people do not evidently demonstrate cold acclimatization responses in terms of changes in thermoregulation, probably due to behavioral factors (adequate protective clothing, short cold exposures, and high housing temperatures). With regard to performance, we observed that moderate cold exposure, which may occur in everyday life, affects cognition negatively through the mechanisms of distraction and both positively and negatively through the mechanism of arousal (increased vigilance). It seems that especially simple cognitive tasks are adversely affected by cold, while in more complex tasks performance may even improve in mild or moderate cold. Repeated, short cold exposures in the laboratory, causing cold habituation responses, do not markedly improve neuromuscular or cognitive performance. The article discusses the functional significance of cold exposure, adaptation, and the specific environmental conditions and physiological mechanisms that affect behavior and performance in high latitude environments. Am. J.
This paper examines the influence of neighbourhood deprivation on older adults’ preferences for and perceptions of active leisure participation using an original research approach. A mixed‐methods procedure, incorporating Q methodology and semi‐structured interviews, was undertaken with 63 elderly residents from high‐ and low‐deprivation neighbourhoods in Christchurch, New Zealand. Analysis of Q sort data and interview transcripts revealed that residents of a high‐deprivation neighbourhood had diverse preferences for leisure settings and generally perceived their neighbourhood as a constraint to active leisure participation. In contrast, residents of a low‐deprivation neighbourhood showed distinct preferences for attractive, natural leisure settings and perceived that their neighbourhood facilitated active leisure participation. Leisure providers are encouraged to consider how environmental characteristics influence individual perceptions and preferences and potentially affect active leisure participation in high‐ and low‐deprivation neighbourhoods when providing recreational facilities and resources for older adults. As a research tool for leisure studies, Q methodology provides a novel means for researchers to appraise preferences for neighbourhood leisure environments and may be useful in determining the accessibility and efficacy of community leisure provision.
Performance impairments attributed to the effects of nitrogen narcosis have been reported to be significantly larger in studies conducted underwater compared to in hyperbaric chambers. One suggestion is that the larger impairment results from higher levels of anxiety in the underwater environment. The current study aimed to investigate the impact of anxiety and narcosis, in isolation and in combination, on a measure of psychomotor performance.
The effects of self-reported anxiety (anxious vs. not anxious) and depth (surface vs. underwater) on performance on the digit letter substitution test (DLST) were measured in 125 divers.
Change from baseline scores indicated that divers performed significantly worse on the DLST underwater (mean = 3.35; SD = 4.2) compared to the surface (mean = 0.45-0.73; SD = 4.0-4.2). This decrement was increased when divers reported they were also anxious (mean = 7.11; SD = 6.1). There was no difference on DLST performance at the surface between divers reporting they were anxious and those reporting they were not anxious.
The greater decrement in performance at depth in divers reporting anxiety compared to those not reporting anxiety and the lack of this effect on the surface suggested that anxiety may magnify performance deficits presumed to be caused by narcosis.
A substantial body of work has considered the role and impact of constraints on the leisure experience. Recent research in leisure constraints theory, however, has moved beyond a preoccupation with barriers to access and identified the importance of in situ constraints and their impact on the leisure experience itself. New directions in constraints research are needed to expand our understanding of in situ constraints in leisure segments like adventure recreation. This paper presents the findings of an interpretive, qualitative study of how in situ (or 'in-water') constraints impacted on the experiences of 27 recreational scuba divers in Australia. The notion of comfort as it applies to adventure leisure and diving is also explored. Using a grounded approach to analysis, it was revealed that divers' comfort was constrained in physical, psychological, social, and visual contexts. This suite of constraints worked to limit, disrupt, or impede divers' in-water comfort, bringing discomfort or uncertainty into a dive. The implications and application of these findings for adventure leisure research and practical management of the scuba dive experience are discussed.
This thesis explores the role of comfort in adventure leisure and in recreational SCUBA diving in particular. In this chapter the study’s central elements of comfort, constraints and negotiation will be introduced. Human engagement with marine locations provides background to the evolution of SCUBA diving as a leisure activity. The concept of comfort is then introduced, with attention given to what comfort means from a range of disciplines. Following this, the use of the term comfort in adventure, leisure and tourism research is reviewed. Divers’ constraints to comfort are also briefly examined here in this introduction, to build understanding of how comfort can be experienced during adventure, and SCUBA diving. Leisure constraints-negotiation research is discussed briefly and linked to SCUBA diving experiences. The objectives of this study are then presented prior to introducing the qualitative research paradigm that guides the research, and the thesis outline.
Previous experiments have shown that, in warm water, subjects adapt to the reduction of weight in water: after 10 min immersion their weight discrimination improves, and on leaving the water they suffer an after-effect when discrimination is impaired in air. The present experiment investigated changes in discrimination when immersing the arm in warm (27C) or cold (11C) water. Twenty-four subjects were tested at each temperature. All subjects showed a deterioration of similar magnitude between air and the first water lest. The cold group showed a further deterioration between the first and second water test, in contrast to the slight improvement of the warm group. They also show a deterioration between the first and second air tests, while the warm group showed none. It is argued that the relative deterioration of the cold group was probably due to numbing of the tactile senses, or perhaps to the distracting effects of cold pain.
The cognitive efficiency of 14 divers was studied during 1-hour exposure to water of 40°F (4.4°C) and 78°F (25.6°C). Reasoning ability was tested using a sentence comprehension task presented at the beginning and end of each test session. Vigilance was tested by requiring subjects to detect the onset of a faint peripheral light during the performance of a two-man pipe assembly task. Memory was tested by requiring subjects to learn a number of “facts” during the dive, with retention tested by recall and recognition on land, after a 40-min delay. Despite a mean drop in rectal temperature of 1.3°F (0.72°C), neither reasoning nor vigilance was impaired. Memory performance did deteriorate, though it is suggested that this may reflect a peripheral context-dependent memory effect. It is concluded that a well-motivated subject may be cognitively unimpaired despite a marked drop in deep body temperature.
To assess the effects of nitrogen narcosis 16 male divers were tested on a digit. copying and o mental task. After a surface testing, the divers were tested under water; 8 started at 3 m followed by 30 m (Group A), and the other 8 at 30 m followed by 3 m (Group B). For all the divers, performance at 3 m and 30 m was compared and it was found that at 30 m the digit-copying was significantly impaired by 2L% (p0.2). For digit-copying there was no significant difference between the impairment of Group A (19%) and that of Group B (23%). However, in the mental task analysis of variance revealed a significant Groups x Conditions interaction (p
In order to study the effects of temperature changes induced by cold stress on working memory, telemetry thermistor probes were implanted into the hippocampal region of the brain and into the peritoneal cavity of rats. Temperatures in these regions were monitored while rats performed on a delayed matching-to-sample (DMTS) task at ambient temperatures of 23 degrees C and 2 degrees C. Matching accuracy was significantly decreased during exposure to 2 degrees C, indicating a marked impairment of short-term or working memory. Temperature in the hippocampus increased 2 degrees C during exposure to 23 degrees C, but only 1 degrees C when the environmental temperature was 2 degrees C. Body temperature showed a similar but less pronounced pattern in that cold exposure attenuated the increase in temperature observed when animals performed the DMTS task. These results suggest that cold-induced impairment of working memory may be associated with subtle temperature changes in the brain.
4 manual tasks were performed under 4 temperature conditions (25°, 50°, 75°, 100°F) and 3 exposure durations (40, 80, 120 minutes), under gloved and bare hand conditions. Temperature condition and duration of exposure had no significant effect on dexterity, which was, however, significantly affected by wearing a glove. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
12 soldiers put their hands in a refrigerated box and tried to tie knots. "Performance was severely hindered when hand skin temperature fell to 55° F… . becoming asymptotoic after about 40 minutes." From Psyc Abstracts 36:04:4LG93C. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
12 U.S. Army enlisted men were tested on 3 manual tasks (knot-tying, block-stringing, and block-packing) under 1 control and 3 experimental conditions involving Cold Hand and/or Cold Body temperatures. The 3 cooling conditions had a differential effect across the 3 tasks. Cold Body was the only condition that did not result in significant decrements for all tasks. Knot-tying was unaffected by body cooling. The results were interpreted in terms of the differential effect of cooling the hand or body on various aspects of complex manual performance.
Eight divers performed an addition test and a screwplate test of manual dexterity in the open sea under four conditions—-breathing either air or an oxy-helium mixture and working at a depth of either 10 or 200 ft. Speed of addition was impaired at depth for both air (19.9 per cent) and helium (14.8 per cent), while errors increased only on air (from 5.9 to 21.1 per cent). The manual dexterity test also showed a decrement in speed for both air (46.7 per cent) and helium (31.8 per cent), and air divers lost more screws at depth (11.1 per cent) than at 10 ft (4.7 per cent). While a decrement at depth was expected in the air dives, the considerable impairment shown on oxy-helium dives was not. A further experiment was therefore run in a dry pressure chamber to study the effects of breathing oxy-helium at pressure when the additional stresses associated with deep diving in the open sea were absent. At a pressure equivalent to 200 ft of water, there was a 10 per cent impairment in speed on both the screwplate (p
The literature dealing with human performance in the cold is reviewed. Seven major areas are discussed: a) tactile sensitivity, b) manual performance, c) tracking, d) reaction time, e) complex behaviors, f) maintaining hand skin temperature (HST) as a means of maintaining operator effectiveness, and g) adaptation and acclimatization to low ambient temperatures. Performance decrements at low ambient temperatures appear to result principally from lowered HST and competing stimuli provided by the cold environment.
The study examines the performance capabilities of divers. Trials were conducted at various water temperatures to assess the effects of cold. Dry land trials provided control performance scores. The capabilities tested were; tactile sensitivity, manual dexterity, manual movement, reasoning(arithmetic), problem solving, memory, and a multi-task capability requiring simultaneous manual tracking and attention to an audio channel. The data indicates that diving in warm water causes loss in motor functions due, it is thought, to the changes and hindrances experienced in the diving condition. Diving in cold water increases the motor loss and causes distraction and disruption in mental tasks; 'blocking' in attention and lowered memory capability were found. Impairment of performance on the multi-task was considerable. It is hypothesized that cold water stress, in addition to causing specific sensory and motor losses, causes increasing losses of capability as the task becomes more complex and is more dependent on sustained attention and memory functions. (Author)
Increased complexity in organisms narrows the range of body temperature within which effective function is found. The organism responds to this problem by developing both internal and external mechanisms for keeping a steady body temperature independent of the environment. However, there comes a point at which these protective devices break down; the study of the response to arctic conditions involves the study of these three aspects, namely, external protection, internal changes, and the nature of the failure to resist the cold. Bodily functions fail, as does the protective mechanism, from the outside inwards, the vital functions naturally being the last to fail. Recent advances in engineering, particularly developments in aviation, have tended to draw attention to the fact that the limits to arctic activities are usually set by the extent to which man can adapt himself rather than his machines. The adjustments made by people living in very cold regions include a whole number of changes in behaviour which can be grouped under the general heading of the techniques of arctic living. Such changes in behaviour are obviously of the first importance for success and survival, especially when directed to the provision of a satisfactory private climate by the use of special clothing and shelter. Adjustments of a rather different kind from these can also be found in human beings attempting to adapt to arctic surroundings, and it is these other changes in human beings that are being considered here—the physiological and psychological changes that help men to meet the challenge of a cold environment.(Received July 25 1955)
The restricted visual fields available to SCUBA divers were examined by means of an under-water perimetry apparatus. Measurements were obtained for three standard partial masks (covering only the eyes and nose), one atypical “wrap-round” partial mask, and one full-face mask. Data are presented along with some consideration of the interactions between mask design and visual field, and a brief resumé of procedural variables affecting human factors experimentation underwater.
Field studies of the three 10 men teams of divers participating in the SEALAB II project were undertaken. During each team's 15 day submergence at 205 feet, psychomotor tests and a vision test were conducted in the water, and a mental arithmetic test in the habitat. Compared to base line performance (dry-land and shallow water conditions), performance on the mental arithmetic test showed no deterioration while performance on the psychomotor tests showed considerable deterioration. Many divers found that their in-water work activities proceeded slowly; among other causes of a more physical nature, concern for one's safety may detract from the amount of attention one gives to the task at hand. The most active divers in the SEALAB group were those who indicated that they were least fearful and least aroused by the conditions and who were helpful, gregarious, and made least telephone contact with the outside world.
An experiment was conducted for the purpose of learning a) whether or not performance decrement in monitoring and controlling a complex visual display is related to body heat loss and b) whether or not such an impairment can be forestalled by glycine administration. Following extensive training on the experimental task, 72 subjects were independently and randomly assigned to the 9 combinations of 3 ambient temperature conditions (70°, 55° and 40℉) and 3 glycine treatments (0, 20 and 40 gm), then required to execute a performance sequence lasting 3 hours and 20 minutes. Statistical analyses established that the mathematical function relating performance to temperature was a parabola having a maximum near 55°. No significant glycine effects were observed.
Submitted on September 25, 1958
The latency of cold-induced vasodilatation of the hand was found to be sensitive to the threat of shock and related to individual differences in performance on a task involving a conflict between a gain in money and a risk of shock.
Efficiency of signal corps operators
- E A Blair
- C W Gottschalk
A review of thermal protection relative to safety and saturation diving. Paper presented at Exhibit and Conference of the Marine Technology Society
- H R Frey
Philosophy of man-in-the-sea.
- R C Mosby
- D C Pauli
- G P Clapper
The effect of temperature on serial discriminative responses
- F H Rohles
Toward a behavior a support system for divers.
- H Bowen
Effects of cold on hand activities with special reference to joints and fluid viscosities. Protection and functioning of hands in cold climates
- J Hunter
Man in a cold environment
- O G Edholm
- A C Burton
Tactile sensitivity in the cold. Protection and functioning of hands in cold climates
- A W Mills
Size and distance judgments underwater and on land
- H E Ross
Hydropsychotherapy and the corrective therapist. Paper presented at the Tri-Organization Scientific and Clinical Rehabilitation Conference
- L G Wiener