The Cognitive and Psychomotor Performance of Medical Students Affected by Smartphone Use: A Cross-Sectional Study

Abstract

Background:

The proliferation of smartphones has rendered them essential to contemporary existence, thereby augmenting the duration of exposure to light emitted from screens. This phenomenon engenders significant public health considerations, as sustained usage is correlated with deleterious physical and psychological health outcomes, which include sleep disturbances, visual fatigue, and cognitive deficits, particularly among university students. In light of these hazards, this investigation aims to elucidate the effects of smartphone utilization on cognitive performance, with a specific focus on reaction time.

Aim:

To assess visual reaction time (VRT) and auditory reaction time (ART) among medical students who engage in regular smartphone usage.

Materials and Methods:

A cross-sectional analysis was performed at SRM Medical College and Hospital, Kattankulathur, encompassing participants aged 18–25 years. VRT and ART were quantified before and subsequent to smartphone engagement utilizing a digital chronoscope. Subjects participated in two ART and three VRT assessments. Informed consent was acquired before the commencement of testing.

Results:

Both ART and VRT exhibited a statistically significant increase following smartphone engagement, signifying prolonged reaction times and a potential decline in cognitive function. These outcomes imply that excessive screen exposure may detrimentally affect mental acuity and reaction velocity.

Conclusion:

Extended smartphone engagement adversely influences cognitive performance, as manifested by protracted reaction times. It is imperative that medical students and the broader populace receive education regarding the potential dangers associated with excessive screen exposure. Mitigating usage is essential for the preservation of cognitive health and overall mental well-being.

INTRODUCTION

The rise in smartphone usage among medical students raises questions about its impact on cognitive functions, particularly reaction times (RTs). RT is a crucial indicator of an individual’s alertness and the efficiency of their central nervous system in processing sensory information and executing motor responses.[1] With nearly 70% of internet users, particularly the younger population, increasingly relying on smartphones, the COVID-19 pandemic has amplified this shift. Excessive smartphone use has been linked to increased stress, depression, anxiety, sleep disorders, restlessness, and fatigue, all of which can contribute to cognitive impairment.[2] RT can be classified into three main types: simple reaction time (SRT), recognition reaction time (RRT), and choice reaction time (CRT).[3] Understanding these distinctions is crucial for interpreting the effects of different stimuli on reaction time. This study aims to evaluate the association between smartphone use and visual reaction time (VRT) and auditory reaction time (ART) in medical students using a cross-sectional study design.

MATERIALS AND METHODS

Study design and study participants

A cross-sectional study was conducted among medical students at SRM Medical College Hospital and Research Centre, aged 18–25 years, with the purpose of comparing RTs before and after mobile phone usage, and the study was held from October 2023 to April 2024. Cognitive function was evaluated by Chronoscope–Digital (two ART and three VRT), measuring VRT and ART using the following procedures.

Inclusion criteria

For this study, 182 medical students between the ages of 18–25 years were chosen based on their daily smartphone usage patterns, which included more than 3 h of use. Before testing, informed consent was acquired from each participant after they were briefed on the method of the study.

Exclusion criteria

Students with neurological conditions, pre-existing visual impairments, or those using medications that could impair visual processing were excluded to guarantee the accuracy of the tests.

Data collection procedure

VRT was measured by instructing the subject to press the stop button with their right index finger as soon as a red light appeared, followed by yellow and then green light, which was initiated by the examiner. The RT was recorded and analyzed. For ART, the examiner initiated the Buzzer I and then Buzzer II, and the subject was instructed to press the stop button as soon as they heard the tone. This RT was also recorded and analyzed. After 1 h of mobile phone usage, both VRT and ART were measured again.

Statistical analysis

Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS) version 21. Paired Student’s t-tests were applied to compare VRT and ART before and after mobile usage.

RESULTS

Visual reaction time

A study analyzing mean VRT across three color stimuli showed slight variations in response times. The mean VRTs for the three colors were relatively similar, ranging from 0.005 to 0.017 [Table 1]. However, a significant difference P value of 0.000*** [Table 1] was observed before and after an hour of mobile phone usage for red, yellow, and green stimuli. The overall variation in mean VRTs between the three groups indicated a prolonged RT, indicating a cognitive delay.

Table 1.

Effect of visual reaction time value before and after use of smartphone

VRT	Mean±SD	n	P
Red
Before	0.00502±0.00155	182	0.000***
After	0.01718±0.00353
Yellow
Before	0.00544±0.00174
After	0.01761±0.00344
Green
Before	0.00541±0.00194
After	0.01769±0.00345

VRT=Visual reaction time, SD=Standard deviation. P=0.000. ***Highly significant

Auditory reaction time

The study analyzed the mean ART for two auditory stimuli, BUZZER I and BUZZER II, before and after mobile usage for an hour. Results showed a slight difference in ART for BUZZER I compared to BUZZER II, indicating quicker RTs. The prolonged RTs observed after 1 h of mobile phone usage suggest that cognitive load associated with smartphone use may negatively impact RTs for both visual and auditory stimuli. The color and type of auditory stimulus were critical factors in response efficiency [Table 2].

Table 2.

Effect of auditory reaction time value before and after use of smartphone

ART	Mean±SD	n	P
BUZZER I
Before	0.00629±0.00211	182	0.000***
After	0.01900±0.00365
BUZZER II
Before	0.00683±0.00231
After	0.01966±0.00400

ART=Auditory reaction time, SD=Standard deviation. P=0.000. ***Highly significant

DISCUSSION

The study investigates the impact of smartphone usage on VRT and ART among medical students. It found significant differences in response times across various stimuli, indicating that auditory stimuli are generally faster than visual stimuli. The findings are particularly relevant for medical training, as they highlight the importance of optimizing auditory alerts and notifications to enhance responsiveness in critical situations.[4] The blue light emitted by smartphone screens has been shown to disrupt melatonin production, which regulates sleep–wake cycles, leading to cognitive impairments, including slower RTs.[5] Auditory stimuli reach the brain in approximately 8–10 ms, while visual stimuli take between 20 and 40 ms.[6] The study supports the notion that auditory stimuli are quicker than visual stimuli, even among medical students, when controlling for potential confounding factors.[7] Excessive smartphone use has been linked to reduced sleep duration and increased nocturnal awakenings, impairing cognitive functions, including attention and RT, affecting learning and performance outcomes.[8] The negative effects of smartphone overuse may extend to reaction time tasks in medical students, who rely heavily on these functions for their academic and clinical duties.

Limitations and future directions

The study has limitations, including a cross-sectional design, limited sample size, inability to account for specific smartphone activities, and uncertainty surrounding participant compliance with abstainment instructions, which may affect the generalizability of the findings.

CONCLUSION

Excessive smartphone usage in medical students leads to prolonged RTs, highlighting the need for balanced usage strategies and further research to improve cognitive performance and quick responses.

Data availability

All datasets generated or analyzed during this study are included in the manuscript.

Informed consent

Written informed consent was obtained from the participants before enrolling in the study.

Credit authorship contribution statement

All authors provided substantial contributions to the concept and design of the work, or the acquisition, analysis, or interpretation of data for the word, and drafting of the work or revising it critically for important intellectual content, and gave final approval of the version to be published, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Ethical consideration

The study adhered to ethical guidelines, obtained ethical clearance from the Institutional Ethics Committee before the commencement of the research (Approval No: SRMIEC-ST0723-549), and ensured participant informed consent, confidentiality, and anonymity, with no identifiable information disclosed in any publications or presentations.

Conflicts of interest

The authors declare that there is no conflict of interest.

Funding Statement

The author(s) received no financial support for the research, authorship, and/or publication of this article.