Scientists Prove Stoned Rats Really Don’t Care About Much

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Craig Boudreau Vice Reporter
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A new study on rats has confirmed what humans have long known: Smoking pot makes you lazy.

Researchers from the University of British Columbia found that giving THC, the psychoactive ingredient in marijuana, to rats made them “cognitively lazy,” UBC News reported Tuesday.

The rats were given two tasks involving levers that operated lights. One lever turned on a light that would stay on for one second, and if the rats “nose poked” a button within the time frame allotted, one sugar cube would come out as a reward. The other lever turned a light on for .2 seconds, but would yield the rodents two sugar cubes. These were dubbed low risk/low reward (LR) and high risk/high reward (HR), respectively. If the rats didn’t poke the button within the allotted time, or prematurely poked it, no reward was given.

Researchers found that after injecting the rats with THC, rats that would normally use the HR lever opted to use the LR lever instead — evidence of cognitive laziness.

“Perhaps unsurprisingly, we found that when we gave THC to these rats, they basically became cognitively lazy,” lead author of the study, Mason Silveira, told UBC News. “The rats could still do the task— they just didn’t want to.”

Interestingly, THC did not have an effect on their accuracy in completing either of the tasks, nor did it affect the timing needed to gain the reward.

The scientists also administered cannabidiol (CBD), a non-psychoactive ingredient in marijuana, to the rats. They found rats who had CBD in their system still opted to use the HR lever and get the two sugar cubes.

Catharine Winstanley, senior author of the study, said this has implications for humans, as it shows those under the influence of THC may exert less cognitive effort and stay away from hard tasks.

When given both THC and CBD, rats’ cognitive laziness diminished, albeit only slightly.

“This was surprising, as it had been suggested that high concentrations of CBD could modulate or reduce the negative effects of THC,” Winstanley told UBC News. “Unfortunately, that did not appear to be the case.”

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