Research has shown that having a few plants around your office space or work space has a restorative effect on your brain. The study, titled Restorative Elements at the Computer Workstation: A Comparison of Live Plants and Inanimate Objects With and Without Window View, explains that having something on your desk -- a plant or possibly also an inanimate object -- that breaks up the monotony of your view or tasks can have a restorative effect.
The researchers explain it to Fast Company like this:
[M]ost of the research points back to a premise conceived by University of Michigan psychologists Rachel and Stephen Kaplan called "attention restoration theory." The gist of "attention restoration theory" is that our brains expend a lot of energy on tasks that require direct attention. This mental fatigue can only be restored when we give our direct attention a break. Sleep can do the job, but when we're awake, we can also refresh direct attention by shifting our minds to an indirect, or effortless form of engagement. Nature offers just this type of absorbing, restorative distraction... Kaplan hopes this type of research convinces designers and employers to see desk plants as essential office supplies rather than perks or amenities reserved for senior workers.
Glancing up and seeing a plant has a micro-restorative effect on the brain, giving you an opportunity, however brief, to reconnect with nature and refresh your mind. Those moments add up over the course of a day. So, along with taking a walk in the park, having plants around can help you have a better day.