Mind Blanking
The term ‘absent-mindedness’ usually refers to a lapse in attention and memory, perhaps losing the thread of a task or forgetting someone’s name at an awkward moment.
It’s a common and normal occurrence, and though often inconvenient, it’s not generally cause for alarm: sometimes it’s the consequence of hyper-focus on something else, sometimes it’s the result of rumination about something we’re stressed or anxious about, and sometimes it’s an indication of physical tiredness or psychological exhaustion.
“Mind blanking,” which is also not generally something to worry about, refers to a mental state in which our brains seem to be void of any conscious content.
We’re not distracted by something else, we’re not doing the equivalent of a mental crouch or swoon due to overwork, we’re just not doing anything—our brains are not producing the usual background computation or foreground babble that we might otherwise take for granted.
Recent research has attempted to formalize the study of mind blanking (or MB) in part by assessing existing literature on mindfulness, meditation, drowsiness, and yes, absent-mindedness, eventually concluding that there are a slew of similar states, but that moments in which our brains don’t seem to be doing anything (no thought, no noise, no cognition seeming to occur) are meaningfully distinct from adjacent states and thus worthy of further research.
One of the tricky aspects of dealing with this sort of experience, of course, is that test subjects can’t report it until afterward; their mind is blank, and perhaps not even conscious of its own blankness, so the idea of telling someone or taking a note or pressing a button to indicate what they’re experiencing wouldn’t bubble to the surface as usable cognition.
That said, it’s currently estimated (based on attempts to utilize both self-caught and probe-caught means of ‘catching’ MB moments, the latter being assessments that try to determine if a subject has been MBing without realizing it) that we have blank minds (for some value of that concept) somewhere between 5% and 20% of our wakeful lives.
This strongly suggests there’s an evolutionary benefit to this mental state, but we don’t have a sense of what that might be, currently, beyond speculation that it may be related to our state of arousal (our level of biological stimulation), a blank mind either helping us calm ourselves so we can relax and recharge, or perhaps being a consequence of other processes that cause our brains and bodies to meander through up and down cycles of arousal.
It’s also possible mind blanking is part of the same (theorized) brain-cleansing process we experience while sleeping, these little shut-downs (which are perhaps more frequent that we previously understood) helping our glymphatic system remove some of the proteins and metabolic waste that’s built up throughout the day, keeping things somewhat tidy between deeper cleaning cycles at night.