| The number of air conditioners installed in campus buildings in hot summer and cold winter areas is increasing,making air conditioning system become a major user of energy in the operation and maintenance process in China.According to statistics,When indoor air conditioning is raised 1℃ in summer,energy consumption can be saved by 5%.At present,The General Office of the State Council requires that indoor air conditioning temperature in public buildings should not be lower than 26℃ in summer.However,it remains to be seen whether this measure is universally applicable due to the huge differences in students’ age,individual level and learning process.Different attributes of building thermal environment and learning task have significant influence on learners’ cognitive ability and cognitive load.At present,most studies focus on the effects of thermal environment on thermal comfort and cognitive performance,while there are few studies on the cross-effects of thermal environment,task type and task difficulty on cognitive load.Therefore,clarifying this cross-influence mechanism and setting appropriate thermal environment parameters according to different task types and difficulties can not only reduce individual cognitive load to a certain extent,but also explore new strategies for energy conservation and emission reduction.The effects of indoor temperature and cognitive task on thermal comfort,cognitive ability and cognitive load in summer were investigated.College students were selected as experimental subjects to conduct experiments at 24℃（T24）,26℃（T26）and 28℃（T28）.The results of subjective evaluation questionnaire,such as thermal sensation vote,thermal satisfaction vote and other environmental quality satisfaction vote,were used as the evaluation of indoor environmental quality.In addition,participants’ cognitive performance was quantitatively measured by memory task（N-back task）and decision task（Hannotta task）.Cognitive load was assessed by NASA Mission Load Index（NASATLX）and time-transient fatigue questionnaire.The physiological parameters were Heart Rate Variability（HRV）and Electroencephalogram（EEG）to support the experimental results.The main research results of this paper are as follows:（1）In the study of the influence of thermal environment on thermal comfort,comparing the thermal acceptability of the three temperatures before and after the experiment,it was found that after completing all tasks,the thermal acceptability of the three temperatures all increased,while the increase of slightly cool and slightly warm environment was similar,and the increase of neutral environment was less.At the same time,the air flow speed in a slightly warmer environment made the subjects feel most comfortable.（2）For the low-difficulty memory task,there was no significant difference in the cognitive performance of the participants under the three thermal environment conditions,but with the increase of the task difficulty,the cognitive performance of the participants in the slightly cool environment was better.It can be inferred that participants prefer to perform memory-challenging tasks in the slightly cool environment.For the lowdifficulty decision-making task,the participants had better cognitive performance in the slightly warmer environment.There was no significant difference in the cognitive performance of the moderate-difficulty decision task under the three temperature conditions.For the difficult decision-making task,the subjects had better cognitive performance in the slightly cool environment.Interestingly,with the increase of the difficulty of the decision-making task in the slightly cool and neutral environment,the cognitive performance of the subjects first decreased,then increased,and then decreased.（3）The effects of three kinds of thermal environment and memory task difficulty on cognitive load mainly depended on task difficulty.The effects of the three thermal environments on the cognitive load of memory task tended to be zero.In the lowdifficulty decision task,the cognitive load was the same;In the moderate difficulty decision task,the participants had lower cognitive load in the slightly warm environment.In the high-difficulty decision task,the subjects had lower cognitive load in the slightly cool environment.（4）HRV and EEG energy can be extracted from ECG and EEG signals.HRV andβ/ α can reliably classify the cognitive load level at task difficulty level.The cognitive load of the low-difficulty task was not affected by temperature;In slightly warmer environments,the cognitive load of moderately difficult tasks could be accurately distinguished.In colder environments,we can accurately distinguish cognitive load during difficult tasks.Figure [28] table [32] reference [64]... |
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