Today, college students often perform several tasks while using their cell phones or watching television. Researchers questioned the effects multiple distractors can have on working memory retention. 139 students from Stanford University were quantitatively separated into two groups, light media multitaskers (LMMs) and heavy media multitaskers (HMMs), based on their responses to a media usage questionnaire. Both groups observed an image of everyday objects with distracting objects arranged circularly. After a brief white screen, a similar image was shown, and subjects were asked if the arrangement had been altered. Answers were scored through a formula to determine a value for working memory capacity (K). The results indicate HMMs have lower working memory retention capacity compared to LMMs.
The LMM and HMM groups were both shown the same sequence of images, then asked if a change had occurred. After each trial, the number of distractors in the image would increase by two. Overall, the HMMs had lower working memory capacity scores than LMMs. The data indicate their brains were less efficient in storing relevant information to working memory, suggesting a negative correlation between frequency of media multitasking and cognitive retention abilities. However, the graph also depicts an overall decreasing trend in K scores of LMMs and HMMs, indicating memory capacity in both groups worsened. While this may be true, this was expected because the number of distractors increased across the four trials. Although the error bars overlap, the p-value of 0.02 demonstrates that the difference in scores between the LMMs and HMMs was statistically significant. There was only a 2% chance similar differences could be due to random chance. The data demonstrate that working memory mechanisms of HMMs were less effective in storing pertinent information.
Students often use social media or stream Netflix while carrying out everyday tasks. As indicated by the lower K values in the HMM group, this habit of media multitasking correlates with reduced working memory storage. With the rising number of HMMs in younger generations, it has become critically important to raise awareness of the cognitive consequences simultaneous media usage has on working memory retention.
* Uncapher, Melina R et al., Psychonomic Bulletin & Review Vol. 23.2 (2016)