Reading only secondary material, I had memorized (clenching my right fist) that recall is enhanced by clenching my left fist (if I recall that correctly). The paper is here:

“Getting a grip on memory” by Propper et al. in PLOS ONE.

I considered selecting this for my next journal club presentation, and now read this fascinating commentary:
     Hot stuff! “Fist-clenchingly poor science”, “If you can't stand the heat, don't go into the kitchen“, but –emotions scaled down– deeply interesting discussion, as science should be. And emotion is also fine, people who know me will recall how agitated I can get when “begging to differ”. Scientists are humans, but truth will out.

  At this point, I myself don't know yet what to think, the low sample size (n=9 for some comparisons) bothers me. Further, as mentioned in the discussion, “the bottom line is that none of the conditions significantly improved recall compared to the no-clench control”. Without any doubt, replication will be attempted, and we will know.

  I take another learning lesson from this: only a real peer, that is an expert in THAT field, can assess a manuscript well.