Energy & focus

Can ions sharpen the mind?

A handful of studies have looked at attention, memory and reasoning in ion-rich air. The results are interesting and early, and not all of them agree.

1 hour

after adding ions, 40 students scored higher on reasoning, short-term memory and verbal tasks in poorly ventilated, high-CO₂ air (Guo et al., 2023).

39 people

responded faster and more accurately on a Stroop task, with matching changes in brain activity, in a 2019 crossover study (Chu et al.).

12 students

showed a smaller rise in a stress marker during a 40-minute computer task in a small 2002 study.

The studies

  1. Early

    The effects of negative air ions on cognitive function: an event-related potential (ERP) study

    Chu C-H, et al. · International Journal of Biometeorology 63(10):1309–17 · 2019

    Crossover, n = 39 young adults

    Participants were faster and more accurate on a Stroop task under negative ions, with EEG changes. A single small, unreplicated study.

  2. Early

    Effect of negative air ions on computer operation, anxiety and salivary chromogranin A-like immunoreactivity

    Nakane H, Asami O, Yamada Y, Ohira H · International Journal of Psychophysiology 46:85–9 · 2002

    Crossover, n = 12 female students

    A stress marker rose less during a 40-minute computer task with negative ions, with slightly better task performance. Very small study.

  3. Listeddetails to confirm

    Effect of negative ion atmospheric loading on cognitive performance in human volunteers

    Andrade AC, Fernandes C, Verghese L, Andrade C · Indian Journal of Psychiatry 34(3):253–9 · 1992

    Human volunteer study (design and size to confirm)

    Looked at cognitive performance under negative-ion “loading”. A summary of its results is still to be added.

  4. Early

    Effects of increasing indoor negative air ions on cognitive performance and health of high pure CO₂ level-exposed college students

    Guo, et al. · Indoor Air · 2023

    Experiment, 40 college students, four conditions (500 or 2,500 ppm CO₂, with and without negative ions)

    After one hour, adding negative ions was linked to better reasoning, short-term memory and verbal scores, including at 2,500 ppm CO₂. There was no significant effect after three hours.