The impact of combined heat and noise on short-term retention

Abstract

This thesis reports on the impact of combined heat and noise on the performance of a short-term memory retention task with two levels of difficulty. Thirty-two males, ages 18 - 35, were exposed to four different treatment conditions during four one hour sessions. These four treatment conditions consisted of: a control environment, a noise environment a heat environment, and a combined heat and noise environment. Temperatures during the control and noise conditions were maintained between 68 and 70 degrees Fahrenheit while temperatures during the heat and combined conditions were maintained at 105 degrees Fahrenheit. Sound exposure levels during the noise and combined conditions averaged at 83.7 decibels with peak frequency exposures never exceeding 93.5 decibels for ten seconds. The task to be performed was a computerized version of game "Concentration". Subjects were presented with both a 6 x 8 and an 8 x 8 grid of blank tiles and asked to correctly match as many tile pairs as they could in three minutes. The task was repeated twice for each grid. Results from the 6 x 8 grid showed performance decrements for all three stress conditions with combined heat and noise showing the greatest performance decrement. However, none of these decrements were found to be significantly different from the control environment or from each other at an Alpha level of .05. Further, no significant evidence was found to show that the combined effects of heat and noise exceed the effects of either stressor singularly. Results from the 8 x 8 grid proved to be different. While performance decrements were observed for the heat and noise conditions alone, the greatest overall performance scores were observed during the combined stress condition. Again, none of these scores were found to be significantly different from the control environment or from each other at an Alpha level of .05. It appears, from these results, that heat and noise stress, experienced either singularly or in combination does not have a significant effect on short-term memory or overall performance degradation.