A study on rats has shown that caffeine may help to make lazy rats work harder but it can have the opposite effect on already hard-working animals. Does the same effect apply to people?
Caffeine addicts are reliant upon their morning cups of coffee, not only due to the addiction to caffeine but because they also believe that the morning mocha helps them to concentrate harder and it ups productivity.
Correct? Maybe not, according to Science News. Research on rats their reaction to psychostimulants has produced more varied results.
A research paper published in the journal Neuropsychopharmacology has shown that lackadaisical rats concentrate harder if given a stimulant (be that caffeine or an amphetamine), the stimulants actually leads to harder working rats easing off.
The research was led by Jay Hosking of the University of British Columbia in Vancouver.
Drug Policy Central notes that the study was different from more traditional laboratory behavioral tests, where the animals’ willingness to exert physical effort is studied. The new research looked at the animals’ inclinations for mental effort.
The study used twenty rats. For the tests, each rat was presented with five food dispensers. Each food dispenser had a light. One of the dispensers contained a sugar pellet (which was the reward for completing the activity). When the light flashed, if the rat was fast enough, it could release the sugar pellet. There were two parts to the trial. With the first, the food reward flash lasted for one second; with the second it lasted for only a fifth of a second.
With the second study, the rats were required to concentrate harder, although they were rewarded with two sugar pellets. At the beginning of each session the rat chose which part of the study they wished to undertake by pressing one of two levers.
In many ways like people, the rats displayed a range of attitudes. Some rats wanted to work ‘hard’ and wanted the bigger reward, and thus always opted for the harder trial; whereas others always opted for the lower effort (and lower rewarded) trials.
Live Science notes that the study was re-run using stimulants. When both the hard-working and lazy groups of rats were dosed with psychostimulants, it was shown that stimulants made the lazy rats more motivated to work hard, but it had the opposite effect on harder-working rats who slackened off.
It is unknown why the hard-working rats reacted one way to the stimulants and the lazier group of rats the other way. It may be that there are similar reactions with people to stimulants like caffeine. For some people it makes them concentrate more and to work harder, whilst for other people it is not such a good idea and it could have the opposite effect. To test this, further studies would be require using human volunteers.
The paper reference is:
Cocker et al., “Sensitivity to cognitive effort mediates psychostimulant effects on a novel rodent cost/benefit decision-making task,” Neuropsychopharmacology, 2012.