Self-selection refers to the fact that certain kinds of people may be drawn to certain kinds of lifestyles or practices (including participation in human research). When the effects of those lifestyles/practices are observed scientifically, they are confounded with myriad other factors which also characterize that group. For example, in the context of meditation studies, it is possible that meditation in the realm of 10-50,000 hours has beneficial effects, but is also difficult to prove the important factor is not all other characteristics of such avid meditators (for example, their tendency to sleep soundly or to drink green tea, etc).
A recent study in PNAS by Tang et al. begins to address this concern by reporting results from the random assignment of 40 subjects to an active control group learning stress-reduction techniques, and another 40 subjects to an experimental group undergoing 5 daily 20-minute sessions of a "integrative body-mind training" program targeting the same "body relaxation, breathing practice, mental imagery and mindfulness" abilities as meditation, absent attentional control, known to be distractingly difficult for novice meditators.
Outcomes on intelligence, attention, mood, and stress were assessed (with Raven's progressive matrices, Posner et al's attentional network test, a scale called the Profile of Mood States, and cortisol & secretory IgA, respectively).
Despite a lack of pre-training differences between groups, the meditation training was associated with:
- significantly greater improvements in attention than the control group, only in terms of the ability of subjects to quickly resolve conflict; the ability to maintain alertness or to orient attention was unimproved;
- marginally larger improvements in intelligence, as assessed by Raven's (p=.086)
- reduction in the stress evoked by a cognitive challenge (as evaluated after 3 minutes of mental arithmetic and then another 20 minute session of training)
- broad improvements in mood, including increased positive mood and decreased negative moods.
Whereas the current study found improvements only in conflict resolution on the ANT, work by Jha et al with expert meditators found improvements only on the other two components of the ANT. Critically, however, Jha et al included subjects who were interested in meditation; maybe this capacity is resistant to training among those with a prior interest in meditation, perhaps because they are already quite good at it (a ceiling effect). Alternatively, meditation's effects on conflict resolution could be more immediate but also more impermanent than those on the other subsystems, yielding an effect here but not in the longer term study of Jha et al.
See also the coverage at MindUpdate.
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Chris, I love your blog, but at this point I have to ask...
Do you meditate?
Best,
Jeff
lol, actually I don't. my interest was piqued only because meditation research seems to be the best documented form of attention training (disappointingly enough, perhaps). i keep finding new papers on it which address various questions of interest, so the posts keep on coming...
The closest thing I've ever done to meditation is use the "brainwave generator" (which works very well, btw).
http://bwgen.com
I haven't used bwgen.com, but I have listened to various audio tracks that use binaural beats (e.g. pzizz for sleep, holosync for poor man's meditation).
Part of me has been skeptical about how an auditory signal can significantly influence brainwave frequency, but I do admit that binaural beat audio tracks do make me feel different... so maybe I should read up more :)
I'll download bwgen and test it out.
Chris, have you seen any papers on the effectiveness of binaural beats?
looks like there's only a little interesting stuff and no coherent literature review. i'm searching under "Frequency following response" "entrainment" and "binaural beats" or "combination tone".
some results:
http://www.ncbi.nlm.nih.gov/pubmed/10911677
http://www.ncbi.nlm.nih.gov/pubmed/16115248
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JA…
i guess you might find something under steady state auditory or visual evoked potential as well. interestingly most of the work I'm skimming suggests the bwgen might have its effects primarily in the brainstem. strange...
somewhat related; visual flicker at appropriate frequencies has been reported to enhance attention:
http://develintel.blogspot.com/2006/06/enhancing-memory-with-visual-fli…
I haven't used bwgen.com, but I have listened to various audio tracks that use binaural beats (e.g. pzizz for sleep, holosync for poor man's meditation).
the brain wave machine thing is like changing the time on your wristwatch by moving the hands .. there is a better way.
and how a researcher in this field cannot practice meditation is a complete mystery to me .. it totally speeds up the investigation you are involved in ... it is so ridiculous to me that i consider the scientific research into consciousness to be an elaborate and skillfully constructed avoidance mechanism ... like, you don't really want to know.
the first thing it will do is flip your model. so much more can be discovered if you even hypothetically consider that matter is a condensation of consciousness, from subtle to gross, rather than consciousness being a by-product of biochemical activity in meat.
you have it backwards, but i never met a neuroscientist who could buy into that. it would be like killing your self-identity.
hey greg- love your art!
nice metaphor for the brainwave generator. I agree it is not an ideal method for brainwave entrainment, but it is a low-barrier-to-entry method with consequences that have not been explored scientifically.
i personally really like the idea that "matter is a condensation of consciousness" but I see no proof of it! And plenty of awful stuff masquerading as proof (e.g., what the bleep do we know).
how could it be proven?
when people die, we assume they are no longer conscious, and yet their physical matter remains (e.g., postmortem anatomical investigations of brains reveal similar structures as MRI of living brains).
yes, the proof thing is an obstacle for science ...
interesting article on this from a couple of years ago .. not long .. http://www.seedmagazine.com/news/2005/10/what_buddhism_offers_science.p… what buddhism offers science
another you might find interesting .. http://www.seedmagazine.com/news/2008/06/the_reality_tests_1.php A team of physicists in Vienna has devised experiments that may answer one of the enduring riddles of science: Do we create the world just by looking at it?
apologies, one more, from "what is enlightenment" http://www.wie.org/j29/consciousness.asp?ifr=hp-edt is god all in your head
I agree it is not an ideal method for brainwave entrainment, but it is a low-barrier-to-entry method with consequences that have not been explored scientifically.