博文

目前显示的是 十一月, 2012的博文

重复是最好的统计

重复是科学研究中重要的组成部分,但实际操作中却很难实现。下面这段话摘自Steven J. Luck的An Introduction to the Event-Related Potential Technique。QCC同学在实验室说过,但 中文书 里翻了很久都没找到。还是直接搜英文比较容易找到。 以下摘自Steven J. Luck的An Introduction to the Event-Related Potential Technique,Box 6.1: Replication is the best statistic. I learned this when I was a graduate student in the Hillyard lab, although no one ever said it aloud. I frequently say it aloud to my students. Replication does not depend on assumptions about normality, sphericity, or independence. Replication is not distorted by outliers. Replication is a cornerstone of science. Replication is the best statistic.  A corollary principle – which Steve Hillyard has said aloud – is that the more important a result is, the more important it is to replicate the result before you publish it. There are two reasons for this, the first of which is obvious: you don’t want to make a fool of yourself by making a bold new claim and being wrong. The second and less obvious reason is that i...

[备忘] fMRI扫描可以缓解抑郁

这是一个经常被问到的问题,MRI扫描对大脑有什么影响?目前没有什么证据表明MRI扫描对大脑有什么损害,除了在高场中快速头动的话可能产生一点头晕 (van Nierop et al., 2012)。而相反,有证据表明fMRI扫描时的脉冲电磁刺激有缓解抑郁的作用 (Rohan et al., 2004)。而最近,这个效应被随机双盲的临床试验重复 (Vaziri-Bozorg et al., 2012)。 Rohan M, Parow A, Stoll AL, Demopulos C, Friedman S, Dager S, Hennen J, Cohen BM, Renshaw PF, 2004. Low-field magnetic stimulation in bipolar depression using an MRI-based stimulator. Am J Psychiatry 161(1):93-8.  Vaziri-Bozorg SM, Ghasemi-Esfe AR, Khalilzadeh O, Sotoudeh H, Rokni-Yazdi H, Ghanaati H, Firouznia K, Sharifi V, Tabatabayee M, Kooraki S, Shakiba M, (2012). Antidepressant effects of magnetic resonance imaging--based stimulation on major depressive disorder: a double-blind randomized clinical trial. Brain Imaging Behav 6(1):70-6. van Nierop LE, Slottje P, van Zandvoort MJ, de Vocht F, Kromhout H, 2012. Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study. Occup Environ M...