This paper supports something I've been thinking about...
I'm not sure how convincing this experiment is by itself, but I find the general idea interesting.
I've made the experience that while noradrenergics increase focus and alertness which is good for simple tasks, it sometimes feels like one can't think as "broadly" on them (the anagram task in the paper is a good example).
Goes against the "more catecholamines=better (for cognition)" notion that many people seem to have (me included, up till now).
OTOH, it seems that methylphenidate doesn't impair cognitive flexibility in people with ADHD. (Could this be due to lower baseline catecholamine levels in ADHDers?)
I'd be glad about further papers on this topic, opinions or experiences... Another interesting point is the role of dopamine as opposed to NA.
Full Text as PDF (starts in full screen mode, press Esc)Noradrenergic modulation of cognitive flexibility in problem solving.
Beversdorf DQ, Hughes JD, Steinberg BA, Lewis LD, Heilman KM.
Department of Neurology, Ohio State University Medical Center, Columbus 43210, USA.
Stress causes impaired performance on tests of creativity. Drugs that block beta-adrenergic receptors improve test performance in patients with test anxiety. Furthermore, catecholamine precursors (L-DOPA) reduce the flexibility of semantic networks. Our study investigated the effect of noradrenergic system modulation on cognitive flexibility in problem solving. Eighteen normal subjects undertook three problem solving tasks (number series, shape manipulation and anagrams) 45 min after propranolol, placebo and ephedrine. On the task that appeared to rely most heavily on cognitive flexibility (anagrams), subjects who were most able to solve these problems demonstrated significantly shorter solution times (logarithmic scores) after propranolol than after ephedrine. This suggested that the noradrenergic system exerts a modulatory effect on cognitive flexibility in problem solving.
PMID: 10511436 [PubMed - indexed for MEDLINE]
I'm not sure how convincing this experiment is by itself, but I find the general idea interesting.
I've made the experience that while noradrenergics increase focus and alertness which is good for simple tasks, it sometimes feels like one can't think as "broadly" on them (the anagram task in the paper is a good example).
Goes against the "more catecholamines=better (for cognition)" notion that many people seem to have (me included, up till now).
OTOH, it seems that methylphenidate doesn't impair cognitive flexibility in people with ADHD. (Could this be due to lower baseline catecholamine levels in ADHDers?)
I'd be glad about further papers on this topic, opinions or experiences... Another interesting point is the role of dopamine as opposed to NA.

