Scott Alexander conducts an experiment playing a word game 800 times under varying CO2 levels, finding no correlation between indoor carbon dioxide and cognitive performance. Longer summary

Scott Alexander describes his experiment to test the effect of indoor carbon dioxide levels on cognitive performance. He played a word game called WordTwist 800 times over three months, recording his scores and the CO2 levels in his room. The CO2 levels ranged from 445 ppm to 3208 ppm. Scott found no correlation between CO2 levels and his game performance (r = 0.001, p = 0.97). He discusses potential confounding factors but argues that his results strongly suggest that CO2 levels don't affect his cognitive performance on this specific task. Scott encourages others to conduct similar experiments with different cognitive tasks and offers to provide CO2 monitors to interested researchers. Shorter summary

Scott Alexander explores research on how high indoor CO2 levels may impair cognition and sleep, suggesting simple solutions like better ventilation. Longer summary

Scott Alexander discusses recent research on the effects of high indoor carbon dioxide (CO2) levels on cognitive function and sleep quality. He describes how his housemates discovered high CO2 levels in their home and improved their symptoms by increasing ventilation. The post explores studies showing cognitive impairment at high CO2 levels and the potential impact on sleep quality. Scott suggests that nighttime CO2 levels in bedrooms can be particularly high and may affect sleep. He recommends simple solutions like opening windows or using certain plants to reduce CO2 levels. The post ends with a call for readers to participate in an informal experiment on nighttime air quality. Shorter summary

Scott Alexander critiques a study suggesting knowledge of ApoE4 gene status affects memory performance, arguing the results may be due to priming or stereotype threat rather than actual memory decline. Longer summary

Scott Alexander discusses a study by Lineweaver et al. that tested elderly adults for the ApoE4 gene, a risk factor for Alzheimer's. The study found that subjects who knew they had ApoE4 performed worse on memory tests than those who had it but didn't know. Scott critiques the study's methodology and interpretation, suggesting that the results might be due to priming effects or stereotype threat rather than actual memory decline. He expresses concern that the medical community might overinterpret these results and discourage genetic testing without sufficient evidence of harm. Shorter summary