Transcranial Focused Ultrasound to the Right Prefrontal Cortex
frontiersin.org
frontiersin.org
Providing precisely the evidence you have, as OP did, is perfectly intellectually hygenic, and is not slandering.
Anyway, my personal sense, as a former scientist, is that most journals have systematic problems.
This is the kind of study you could very easily do 20 times with 20 different "Ultrasound to the X" experiments and then publish the 1 which has p>0.05 results.
Maybe interesting if you're a researcher, but not at all something that should have any public attention.
“ Experiments investigating tFUS in rodents have recently found that induced excitability changes in the brain can be, at least partially, due to an indirect effect of auditory stimulation, which was eliminated by removal of the cochlear fluid (Guo et al., 2018). Additionally, Sato et al. (2018) found that temporary chemical deafness could reduce the effects of tFUS on the brain. These studies show that important confounds can lead to brain activation through indirect pathways, but do not negate the notion that tFUS can also influence the brain directly. Experiments with organisms that lack auditory systems, like Xenopus oocyte (the “clawed frog”), show the effects of tFUS on neural activity (Kubanek et al., 2016), and ultrasound also influences neural activity and causes spike trains in slice preparations (Tyler et al., 2008). In humans, tFUS has produced tactile sensations (Lee et al., 2016a) and visual phosphenes (Lee et al., 2016b) with corresponding focal tissue activation that is hard to explain by activation through ascending auditory activation. Future experiments will need to better control unconscious and conscious auditory effects for ultrasound neuromodulation experiments on mood.”
I was going to go into detail about how absurd this intervention is in terms of scale of number of impacted neurons but really this sentence tells you everything you need to know about the quality and rigor of this work.
Why do you consider the composition of the participant group important and therefore insufficient? Stimulating the brain by ultrasound sounds like such a low level intervention that it is hard to believe that age or sex could matter a lot.
At my school volunteers were recruited for course credit. So it could be due to the elation of getting it over with.
I could also argue that the effect is due to the excitement of participating in a study. If the declared interest of the students is Psychology they might simply be excited to do the study.
There may also be a novelty component where the change in routine produces arousal.
Even n=1 can give a statistically relevant result (for the hypothesis that a given event never happens)
I haven’t read the paper, but n=51 can be more than high enough to get significant results for more realistic null hypotheses, if the effect is large enough.
Having said that, effects rarely are large. If you have a weaker effect, you need more subjects (picking a somewhat random paper from a google search: https://www.journalofcognition.org/articles/10.5334/joc.72/)
I’m surprised by the fraction of male subjects they managed to recruit. A well-known joke is that the typical experiment in psychology is either done with mice or with teenage girls as participants.
The magnetic method seemed much safer.