Neuroscience and Psychology aren't the only sources of evidence for the negative effects of sleep deprivation. Just think of all the shitty things you feel happening to your mind when you haven't slept in days – the haziness, the ADD, the forgetfulness, the tendency to believe that coffee will make you happy and everything will work out if you just power through it all while blustering about your "3rd wind" or whatever.
Well, the latter effect has recently been studied and a new paper out of Duke University, published in the Journal of Neuroscience, shows pretty strong evidence that sleep deprivation tips our decision-making scales in the optimistic direction, or more specifically, the over-optimistic direction.
Experimental subjects were tested using a computerized gambling task with real monetary rewards and losses. Interestingly, participants that were put through an all-nighter showed a strong propensity to focus on making money rather than avoiding the loss of it, while the well-slept were more balanced gamblers.
Furthermore, brain imagining data showed that sleep-deprived subjects had abnormal brain activity in areas of the brain related to the perception and judgment of environmental outcomes. Lead author Vinod Venkatraman, et al, write:
SD [sleep deprivation] appears to create an optimism bias; for example, participants behave as if positive consequences are more likely (or more valuable) and as if negative consequences are less likely (or less harmful)…it appears that SD biases valuation by bringing about an increased attentional bias toward higher-ranked positive outcomes while concurrently reducing concern for losses.
For most humans, the hurt of losing money usually outweighs the joy of winning it, but the baggy-eyed all-nighters of this study turn that idea on its head. They also perfectly epitomize the Vegas slot-zombie, mindlessly staring at brightly rendered fruits and number 7s for nights on end — sleepless, penniless, hopeful, and, ultimately, screwed.
But what about stimulants? Stimulants (pharmaceutical or otherwise) sharpen our focus and keep us awake, right? There's no doubt they do those things, but, as the authors point out, stimulants may not offset the decision-making effects of sleep deprivation:
Stimulants may improve vigilance but their influence on other aspects of cognition, such as decision making, is less clear (Gottselig et al., 2006; Killgore et al., 2007, 2008; Huck et al., 2008). Our findings that SD shapes decision preferences independent of its effects on vigilance suggest that the traditional countermeasures may be ineffective in ameliorating the decision biases engendered by limited sleep.
Does this mean if we all slept a lot less the world would turn into some kind of wide-eyed optimism-fest where everyone focused on how to achieve the best outcomes all the time and ignored the possible negatives, hippyish smiles and all? More likely, we would all just become slot-spinning dead beats.
image via steadyhealth.com