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1.
Eur J Appl Physiol ; 124(3): 775-781, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37864008

RESUMO

A common practice for those operating in cold environments includes repetitive glove doffing and donning to perform specific tasks, which creates a repetitive cycle of hand cooling and rewarming. This study aimed to determine the influence of intraday repeated hand cooling on cold-induced vasodilation (CIVD), sympathetic activation, and finger/hand temperature recovery. Eight males and two females (mean ± SD age: 28 ± 5 year; height: 181 ± 9 cm; weight: 79.9 ± 10.4 kg) performed two 30-min hand immersions in cold (4.3 ± 0.92 °C) water in an indoor environment (18 °C). Both immersions (Imm1; Imm2) were performed on the same day and both allowed for a 10-min recovery. CIVD components were calculated for each finger (index, middle, ring) during each immersion. CIVD onset time (index, p = 0.546; middle, p = 0.727; ring, p = 0.873), minimum finger temperature (index, p = 0.634; middle, p = 0.493; ring, p = 0.575), and mean finger temperature (index, p = 0.986; middle, p = 0.953; ring, p = 0.637) were all similar between immersions. Recovery rates generally demonstrated similar responses as well. Findings suggest that two sequential CIVD tests analyzing the effect of prior cold exposure of the hand does not impair the CIVD response or recovery. Such findings appear promising for those venturing into cold environments where hands are likely to be repeatedly exposed to cold temperatures.


Assuntos
Temperatura Baixa , Imersão , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Vasodilatação/fisiologia , Temperatura Cutânea , Mãos , Dedos/fisiologia
2.
Int J Circumpolar Health ; 82(1): 2236777, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37469312

RESUMO

Cold-weather military operations can quickly undermine warfighter readiness and performance. Specifically, accidental cold-water immersion (CWI) contributes to rapid body heat loss and impaired motor function. This study evaluated the prevalence of hypothermia and critical hand temperatures during CWI. One-hundred seventeen (N = 117) military personnel (mean ± SD age: 27 ± 6 yr, height: 176 ± 8 cm, weight: 81.5 ± 11.6 kg) completed CWI and rewarming during cold-weather training, which included a 10-min outdoor CWI (1.3 ± 1.4°C) combined with cold air (-4.2 ± 8.5°C) exposure. Following CWI, students removed wet clothing, donned dry clothing, and entered sleeping systems. Core (Tc) and hand (Thand) temperatures were recorded continuously during the training exercise. Tc for 96 students (mean ± SD lowest Tc = 35.6 ± 0.9°C) revealed that 24 students (25%) experienced Tc below 35.0°C. All of 110 students (100%) experienced Thand below 15.0°C, with 71 students (65%) experiencing Thand at or below 8.0°C. Loss of hand function and hypothermia should be anticipated in warfighters who experience CWI in field settings. Given the high prevalence of low Thand, focus should be directed on quickly rewarming hands to recover function.


Assuntos
Hipotermia , Militares , Humanos , Adulto Jovem , Adulto , Temperatura , Prevalência , Imersão , Temperatura Baixa , Água
3.
Sci Rep ; 11(1): 13313, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172769

RESUMO

Stress can impact perception, especially during use-of-force. Research efforts can thus advance both theory and practice by examining how perception during use-of-force might drive behavior. The current study explored the relationship between perceptual judgments and performance during novel close-combat training. Analyses included perceptual judgments from close-combat assessments conducted pre-training and post-training that required realistic use-of-force decisions in addition to an artificially construed stress-inoculation event used as a training exercise. Participants demonstrated significant reductions in situational awareness while under direct fire, which correlated to increased physiological stress. The initial likelihood of firing upon an unarmed person predicted the perceptual shortcomings of later stress-inoculation training. Subsequently, likelihood of firing upon an unarmed person was reduced following the stress-inoculation training. These preliminary findings have several implications for low or zero-cost solutions that might help trainers identify individuals who are underprepared for field responsibilities.

4.
Acta Psychol (Amst) ; 198: 102863, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31252157

RESUMO

The notion that individuals adapt their behaviors in ways that are sensitive to the effortfulness of cognitive processing is pervasive in psychology. In the current set of experiments, we provide a test of a cue-utilization account of how individuals decide which course of action is more or less effortful. In particular, we contrast the influences of time costs and demands on executive control with the influence of an available effort cue. Using a variant of the demand selection task (DST) that specifically focused on making effort-based decisions, we provide evidence that effort-based decisions can be dissociated from both time costs and demands on executive control in a manner predicted by a cue-utilization account.


Assuntos
Cognição/fisiologia , Sinais (Psicologia) , Tomada de Decisões/fisiologia , Função Executiva/fisiologia , Humanos , Esforço Físico
5.
Psychol Res ; 83(5): 1033-1056, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29134281

RESUMO

Why are some actions evaluated as effortful? In the present set of experiments we address this question by examining individuals' perception of effort when faced with a trade-off between two putative cognitive costs: how much time a task takes vs. how error-prone it is. Specifically, we were interested in whether individuals anticipate engaging in a small amount of hard work (i.e., low time requirement, but high error-likelihood) vs. a large amount of easy work (i.e., high time requirement, but low error-likelihood) as being more effortful. In between-subject designs, Experiments 1 through 3 demonstrated that individuals anticipate options that are high in perceived error-likelihood (yet less time consuming) as more effortful than options that are perceived to be more time consuming (yet low in error-likelihood). Further, when asked to evaluate which of the two tasks was (a) more effortful, (b) more error-prone, and (c) more time consuming, effort-based and error-based choices closely tracked one another, but this was not the case for time-based choices. Utilizing a within-subject design, Experiment 4 demonstrated overall similar pattern of judgments as Experiments 1 through 3. However, both judgments of error-likelihood and time demand similarly predicted effort judgments. Results are discussed within the context of extant accounts of cognitive control, with considerations of how error-likelihood and time demands may independently and conjunctively factor into judgments of cognitive effort.


Assuntos
Cognição , Julgamento , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , Probabilidade , Desempenho Psicomotor , Fatores de Tempo , Adulto Jovem
6.
Neuropsychologia ; 123: 77-91, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-29772220

RESUMO

Based on a recent metacognitive account, cognitive effort is the result of an inferential evaluation made over explicitly available cues. Following from this account, we present here a pre-registered experiment that tested the specific hypothesis that explicit awareness of cues that are aligned with cognitive demand is a prerequisite in avoiding effortful lines of action. We attempted to modulate levels of effort avoidance behavior by introducing an incentive (between-subjects) to monitor two lines of action that, unbeknownst to individuals, varied in the probability of a task switch. Importantly, previous research has demonstrated that the difference in these probabilities is relatively opaque to individuals. We did not find strong evidence for our incentive manipulation having an effect on demand avoidance as indexed by individuals' choices in a block of the task where avoiding effort was instructed. However, we do find that being aware of the task-switching cue appears to increase the likelihood of demand avoidance. We consider these results within the context of the metacognition of cognitive effort.


Assuntos
Aprendizagem da Esquiva , Sinais (Psicologia) , Tomada de Decisões/fisiologia , Metacognição , Teorema de Bayes , Feminino , Humanos , Masculino , Motivação
7.
J Exp Psychol Hum Percept Perform ; 42(9): 1372-87, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27123679

RESUMO

In the current set of experiments our goal was to test the hypothesis that individuals avoid courses of action based on a kind of metacognitive evaluation of demand in a Demand Selection Task (DST). Individuals in Experiment 1 completed a DST utilizing visual stimuli known to yield a dissociation between performance and perceived demand. Patterns of demand avoidance followed that of perceived demand. Experiment 2 provided a replication of the aforementioned results, in addition to demonstrating a second dissociation between a peripheral physiological measure of demand (i.e., blink rates) and demand avoidance. Experiment 3 directly tested the assumption that individuals make use of a general metacognitive evaluation of task demand during selections. A DST was utilized in a forced-choice paradigm that required individuals to either select the most effortful, time demanding, or least accurate of 2 choices. Patterns of selections were similar across all rating dimensions, lending credit to this notion. Findings are discussed within a metacognitive framework of demand avoidance and contrasted to current theories. (PsycINFO Database Record


Assuntos
Comportamento de Escolha/fisiologia , Metacognição/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Adulto , Percepção de Cores/fisiologia , Humanos , Adulto Jovem
8.
Cogn Sci ; 40(5): 1080-127, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26306555

RESUMO

Individuals frequently make use of the body and environment when engaged in a cognitive task. For example, individuals will often spontaneously physically rotate when faced with rotated objects, such as an array of words, to putatively offload the performance costs associated with stimulus rotation. We looked to further examine this idea by independently manipulating the costs associated with both word rotation and array frame rotation. Surprisingly, we found that individuals' patterns of spontaneous physical rotations did not follow patterns of performance costs or benefits associated with being physically rotated, findings difficult to reconcile with existing theories of strategy selection involving external resources. Individuals' subjective ratings of perceived benefits, rather, provided an excellent match to the patterns of physical rotations, suggesting that the critical variable when deciding on-the-fly whether to incorporate an external resource is the participant's metacognitive beliefs regarding expected performance or the effort required for each approach (i.e., internal vs. internal + external). Implications for metacognition's future in theories of cognitive offloading are discussed.


Assuntos
Cognição , Metacognição , Feminino , Humanos , Masculino , Modelos Psicológicos , Teoria Psicológica , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia
9.
Conscious Cogn ; 36: 61-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26092219

RESUMO

We often store to-be-remembered information externally (e.g., written down on a piece of paper) rather than internally. In the present investigation, we examine factors that influence the decision to store information in-the-world versus in-the-head using a variant of a traditional short term memory task. In Experiments 1a and 1b participants were presented with to-be-remembered items and either had to rely solely on internal memory or had the option to write down the presented information. In Experiments 2a and 2b participants were presented with the same stimuli but made metacognitive judgments about their predicted performance and effort expenditure. The spontaneous use of external storage was related both to the number of items to be remembered and an individual's actual and perceived short-term-memory capacity. Interestingly, individuals often used external storage despite its use affording no observable benefit. Implications for understanding how individuals integrate external resources in pursuing cognitive goals are discussed.


Assuntos
Comportamento de Escolha/fisiologia , Memória de Curto Prazo/fisiologia , Metacognição/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Percepção Auditiva/fisiologia , Humanos , Individualidade , Adulto Jovem
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