The neuroscience behind why our brains will need time to adjust to ‘un-social distancing’

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With COVID-19 vac­cines work­ing and restric­tions lift­ing across the coun­try, it’s final­ly time for those now vac­ci­nat­ed who’ve been hun­kered down at home to ditch the sweat­pants and reemerge from their Net­flix caves. But your brain may not be so eager to dive back into your for­mer social life.

Social dis­tanc­ing mea­sures proved essen­tial for slow­ing COVID-19’s spread world­wide – pre­vent­ing upward of an esti­mat­ed 500 mil­lion cas­es. But, while nec­es­sary, 15 months away from each oth­er has tak­en a toll on people’s men­tal health.

In a nation­al sur­vey last fall, 36% of adults in the U.S. – includ­ing 61% of young adults – report­ed feel­ing “seri­ous lone­li­ness” dur­ing the pan­dem­ic. Sta­tis­tics like these sug­gest peo­ple would be itch­ing to hit the social scene.

But if the idea of mak­ing small talk at a crowd­ed hap­py hour sounds ter­ri­fy­ing to you, you’re not alone. Near­ly half of Amer­i­cans report­ed feel­ing uneasy about return­ing to in-per­son inter­ac­tion regard­less of vac­ci­na­tion status.

So how can peo­ple be so lone­ly yet so ner­vous about refill­ing their social calendars?

Well, the brain is remark­ably adapt­able. And while we can’t know exact­ly what our brains have gone through over the last year, neu­ro­sci­en­tists like me have some insight into how social iso­la­tion and reso­cial­iza­tion affect the brain.

Too much time alone can make your social ther­mo­stat feel on the fritz.

Social homeostasis – the need to socialize

Humans have an evo­lu­tion­ar­i­ly hard­wired need to social­ize – though it may not feel like it when decid­ing between a din­ner invite and rewatch­ing “Schitt’s Creek.”

From insects to pri­mates, main­tain­ing social net­works is crit­i­cal for sur­vival in the ani­mal king­dom. Social groups pro­vide mat­ing prospects, coop­er­a­tive hunt­ing and pro­tec­tion from predators.

But social home­osta­sis – the right bal­ance of social con­nec­tions – must be met. Small social net­works can’t deliv­er those ben­e­fits, while large ones increase com­pe­ti­tion for resources and mates. Because of this, human brains devel­oped spe­cial­ized cir­cuit­ry to gauge our rela­tion­ships and make the cor­rect adjust­ments – much like a social thermostat.

Social home­osta­sis involves many brain regions, and at the cen­ter is the meso­cor­ti­col­im­bic cir­cuit – or “reward sys­tem.” That same cir­cuit moti­vates you to eat choco­late when you crave some­thing sweet or swipe on Tin­der when you crave … well, you get it.

And like those moti­va­tions, a recent study found that reduc­ing social inter­ac­tion caus­es social crav­ings – pro­duc­ing brain activ­i­ty pat­terns sim­i­lar to food deprivation.

So if peo­ple hunger for social con­nec­tion like they hunger for food, what hap­pens to the brain when you starve socially?

Your brain on social isolation

Sci­en­tists can’t shove peo­ple into iso­la­tion and look inside their brains. Instead, researchers rely on lab ani­mals to learn more about social brain wiring. Luck­i­ly, because social bonds are essen­tial in the ani­mal king­dom, these same brain cir­cuits are found across species.

One promi­nent effect of social iso­la­tion is – you guessed it – increased anx­i­ety and stress.

Many stud­ies find that remov­ing ani­mals from their cage bud­dies increas­es anx­i­ety-like behav­iors and cor­ti­sol, the pri­ma­ry stress hor­mone. Human stud­ies also sup­port this, as peo­ple with small social cir­cles have high­er cor­ti­sol lev­els and oth­er anx­i­ety-relat­ed symp­toms sim­i­lar to social­ly deprived lab animals.

Evo­lu­tion­ar­i­ly this effect makes sense – ani­mals that lose group pro­tec­tion must become hyper­vig­i­lant to fend for them­selves. And it doesn’t just occur in the wild. One study found that self-described “lone­ly” peo­ple are more vig­i­lant of social threats like rejec­tion or exclusion.

Anoth­er impor­tant region for social home­osta­sis is the hip­pocam­pus – the brain’s learn­ing and mem­o­ry cen­ter. Suc­cess­ful social cir­cles require you to learn social behav­iors – such as self­less­ness and coop­er­a­tion – and rec­og­nize friends from foes. But your brain stores tremen­dous amounts of infor­ma­tion and must remove unim­por­tant con­nec­tions. So, like most of your high school Span­ish – if you don’t use it, you lose it.

Sev­er­al ani­mal stud­ies show that even tem­po­rary adult­hood iso­la­tion impairs both social mem­o­ry – like rec­og­niz­ing a famil­iar face – and work­ing mem­o­ry – like recall­ing a recipe while cooking.

And iso­lat­ed humans may be just as for­get­ful. Antarc­tic expe­di­tion­ers had shrunk­en hip­pocampi after just 14 months of social iso­la­tion. Sim­i­lar­ly, adults with small social cir­cles are more like­ly to devel­op mem­o­ry loss and cog­ni­tive decline lat­er in life.

So, human beings might not be roam­ing the wild any­more, but social home­osta­sis is still crit­i­cal to sur­vival. Luck­i­ly, as adapt­able as the brain is to iso­la­tion, the same may be true with resocialization.

Your brain on social reconnection

Though only a few stud­ies have explored the reversibil­i­ty of the anx­i­ety and stress asso­ci­at­ed with iso­la­tion, they sug­gest that reso­cial­iza­tion repairs these effects.

One study, for exam­ple, found that for­mer­ly iso­lat­ed mar­mosets first had high­er stress and cor­ti­sol lev­els when reso­cial­ized but then quick­ly recov­ered. Adorably, the once-iso­lat­ed ani­mals even spent more time groom­ing their new buddies.

Social mem­o­ry and cog­ni­tive func­tion also seem to be high­ly adaptable.

Mouse and rat stud­ies report that while ani­mals can­not rec­og­nize a famil­iar friend imme­di­ate­ly after short-term iso­la­tion, they quick­ly regain their mem­o­ry after resocializing.

And there may be hope for peo­ple emerg­ing from social­ly dis­tanced lock­down as well. A recent Scot­tish study con­duct­ed dur­ing the COVID-19 pan­dem­ic found that res­i­dents had some cog­ni­tive decline dur­ing the harsh­est lock­down weeks but quick­ly recov­ered once restric­tions eased.

Unfor­tu­nate­ly, stud­ies like these are still sparse. And while ani­mal research is infor­ma­tive, it like­ly rep­re­sents extreme sce­nar­ios since peo­ple weren’t in total iso­la­tion over the last year. Unlike mice stuck in cages, many in the U.S. had vir­tu­al game nights and Zoom birth­day par­ties (lucky us).

So pow­er through the ner­vous ele­va­tor chats and pesky brain fog, because “un-social dis­tanc­ing” should reset your social home­osta­sis very soon.

– Kareem Clark, PhD, is a post­doc­tor­al asso­ciate work­ing in the Pan Lab at the Fralin Bio­med­ical Research Insti­tute at Vir­ginia Tech. This arti­cle was orig­i­nal­ly pub­lished on The Con­ver­sa­tion.

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