Cell phones are often criticized for their disruptive impact on attention and cognition. But a recent study published in BMC Psychology has revealed a surprising effect: the presence of a cell phone actually appeared to improve reaction times in a specific cognitive task that required attentional shifts.
Previous research has shown that even the mere presence of a cell phone can affect cognitive tasks by drawing attention away from the task at hand. However, the specifics of how cell phones influence attentional control, the ability to allocate cognitive resources to achieve specific mental goals, remained under-explored.
Attentional control is essential for managing multiple cognitive processes simultaneously and efficiently. It’s linked to working memory, the brain’s system for temporarily holding and processing information. Studies have suggested that individuals with higher working memory capacity perform better on tasks requiring attentional control. However, there’s evidence to suggest that high working memory capacity doesn’t always translate to better control, especially in tasks that require switching attention between different visual features, like the Navon task.
The Navon task requires participants to focus on both global shapes and local details within a visual stimulus, making it an ideal measure of how well someone can shift their attention under different conditions. Previous research has shown that people with higher working memory capacities may not always excel in this task, particularly when frequent shifts in attention are required. This curious outcome led a trio of researchers from China and Japan to investigate further the potential influence of external factors, like the presence of a cell phone, on this task.
The study involved 36 adult participants who performed the Navon task under two conditions: with a cell phone present and with a cell phone absent, replaced by a similarly sized and weighted mobile battery. Participants were not allowed to interact with the phone or the battery during the task, ensuring that any cognitive effects observed were due to the mere presence of these items rather than direct interaction.
The Navon task involved recognizing and responding to letters made up of smaller letters, requiring attentional switches between the global and local levels of the letter configurations. Participants were instructed to press specific keys to indicate whether they recognized certain target letters at the global or local level, with their reaction times and accuracies recorded. The task was structured into blocks, with random assignment to the two experimental conditions to counterbalance potential order effects.
Contrary to the common assumption that cell phones invariably disrupt cognitive processes, the researchers found that participants actually performed better—in terms of reaction time—when a cell phone was present compared to when it was replaced by a mobile battery. This finding was consistent regardless of the type of trial, whether it required sustained attention to a single level (global or local) or involved switching between levels.
However, the study’s findings were not uniformly positive regarding the cell phone’s influence. While reaction times improved, the accuracy of the responses did not show a significant difference between the phone-present and phone-absent conditions. This suggests that while participants could respond more quickly with a cell phone nearby, their ability to correctly identify the target letters in the Navon task was not necessarily enhanced.
But why would the mere presence of a cell phone improve reaction time? The researchers speculate that the cell phone might have caused participants to consciously focus more centrally, potentially to avoid distractions caused by the phone. This reallocation of visual attention could explain the faster reaction times, as more cognitive resources are concentrated where they are most needed for the task.
Additionally, the researchers explored the role of cell phone dependency, assessed via the Problematic Use of Mobile Phones (PUMP) scale. It was found that participants with higher PUMP scores, indicating greater dependency on their mobile devices, showed significantly lower accuracy in completing the task.
This suggests that individuals who are more dependent on their cell phones tend to perform with less precision in tasks requiring attentional control. But this decline in accuracy was not influenced by whether a cell phone was physically present during the task, suggesting that the negative impact of cell phone dependency on cognitive performance is a broader behavioral trait rather than a situational effect.
Despite its intriguing findings, the study has limitations. The sample size was relatively small, and the task-specific nature of the findings may not generalize across other types of cognitive tasks. Additionally, the study did not measure individual differences in working memory capacity, which could influence how attentional control is affected by external factors like cell phone presence.
“Given that the attentional cost of the cell phone presence may negatively affect the efficiency of cognitive activities, some scholars have suggested ensuring restrictions on their presence in the work environment,” the researchers concluded. “This study demonstrates the possibility of refuting the claim that cell phones must always be excluded from the workplace by highlighting the positive effects of the cell phone presence.”
“Cell phones affect our cognitive activities, and it is sometimes useful to remove cell phones to reduce the disruptive effects. However, it is natural for workers to want to have their cell phones nearby. Therefore, future investigations are required to better understand the effects of cell phones and to find optimal usage.”
The study, “Effects of cell phone presence on the control of visual attention during the Navon task,” was authored by Wenjuan Liu, Tomoya Kawashima, and Kazumitsu Shinohara.