The multitasking myth: the most confident filter the worst

What the studies examined

This area rests on two pillars. The first is the classic Stanford University study (Ophir et al., 2009) in PNAS, comparing cognitive control in light and heavy media multitaskers. The second is a longitudinal study in JAMA Network Open (Nagata et al., 2025) mapping the effects of digital overload on wellbeing.

Heavy multitaskers make more than three times as many errors when filtering irrelevant noise.

Key findings

The multitasking myth

People who claim to be good at multitasking are in fact the worst at it. They chronically fail to ignore irrelevant stimuli, have weaker working memory and struggle to switch between tasks.

Fragmented attention

Instant AI answers and constant notifications train the brain for quick dopamine hits, destroying capacity for focused work.

Link to mental health

Longitudinal data confirm that difficulty sustaining attention and digital overload correlate with rising anxiety and depressive symptoms.

What to do about it

• Practise deep work blocks: 45 minutes, one task, notifications off.
• Use AI in dedicated blocks, not continuously as an interruption.
• Close unnecessary tabs before starting a demanding piece of writing.

Sources

Ophir, E., Nass, C., & Wagner, A. D. (2009). Cognitive control in media multitaskers. PNAS, 106(37), 15583–15587. doi.org/10.1073/pnas.0903620106

Nagata, J. M., et al. (2025). Social Media Use and Depressive Symptoms During Early Adolescence. JAMA Network Open, 8(5). doi.org/10.1001/jamanetworkopen.2025.11704