"Long before it's in the papers"
June 15, 2015


Green space may make city kids smarter

June 15, 2015
Courtesy of PNAS
and World Science staff

Ex­po­sure to green spaces may help boost chil­dren’s cog­ni­tive de­vel­op­ment, ac­cord­ing to a stu­dy, which at­trib­ut­ed part of the ef­fect to low­er pol­lu­tion.

Re­search­ers mon­i­tored changes in cog­ni­tive meas­ures eve­ry three months be­tween Jan­u­ary 2012 and March 2013 among 2,593 grade-school age chil­dren ages 7 to 10 in Bar­ce­lona, Spain.

Over the course of a year, ex­po­sure to green­ness with­in and around schools—as de­ter­mined by sat­el­lite data—was linked with en­hanced men­tal abil­ity to con­tin­u­ously ma­ni­pu­late and up­date in­forma­t­ion, ac­cord­ing to the in­ves­ti­ga­tors. These abil­i­ties are called work­ing mem­o­ry and su­pe­ri­or work­ing mem­o­ry, re­spec­tive­ly.

Re­duced in­at­ten­tive­ was an­oth­er ben­e­fit, ac­cord­ing to the stu­dy.

The re­sults were in­de­pend­ent of eth­ni­city, ma­ter­nal educa­t­ion, and pa­ren­tal em­ploy­ment, said the re­search­ers, Payam Dad­vand of the Cen­ter for Re­search in En­vi­ron­men­tal Ep­i­de­mi­ology in Bar­ce­lona and col­leagues.

The re­sults linked eve­ry in­crease in to­tal sur­round­ing green­ness by a quar­tile to a 5 per­cent in­crease in work­ing mem­o­ry, 6 per­cent in­crease in su­pe­ri­or work­ing mem­o­ry, and 1 per­cent re­duc­tion in in­at­ten­tive­ness. 

A com­put­er mod­el­ing anal­y­sis sug­gested that elemen­tal car­bon, a com­mon traffic-related air pol­lu­tant, might ac­count for 20 per­cent to 65 per­cent of the es­ti­mat­ed links be­tween school green­ness and cog­ni­tive de­vel­op­ment. 

No sig­nif­i­cant link turned up be­tween ex­po­sure to green­ness at home and cog­ni­tive meas­ures, the re­search­ers said. Giv­en the soar­ing rates of glob­al ur­ban­iz­a­tion, ex­pand­ing green spaces at schools might be a step to­ward im­prov­ing ac­a­dem­ic at­tain­ment among chil­dren, ac­cord­ing to the au­thors. 

Dad­vand and col­leagues said pre­vi­ous stud­ies had linked green space to bet­ter men­tal health, but wheth­er this might in­flu­ence cog­ni­tive de­vel­op­ment spe­cif­ic­ally was un­clear.

“Con­tact with na­ture is thought to play a cru­cial and ir­re­place­a­ble role in brain de­vel­op­ment,” the re­search­ers wrote, re­port­ing their find­ings this week in the early on­line edi­tion of the re­search jour­nal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­en­ces

“Nat­u­ral en­vi­ron­ments in­clud­ing green spaces pro­vide chil­dren with un­ique op­por­tun­i­ties such as in­cit­ing en­gage­ment, risk tak­ing, dis­cov­ery, cre­ati­vity, mas­tery and con­trol, strength­en­ing sense of self, in­spir­ing bas­ic emo­tion­al states in­clud­ing sense of won­der, and en­hanc­ing psy­cho­log­i­cal restora­t­ion, which are sug­gested to in­flu­ence pos­i­tively dif­fer­ent as­pects of cog­ni­tive de­vel­op­ment.”

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Exposure to green spaces may help boost children’s cognitive development, according to a study, which attributed part of the effect to lower pollution. Researchers monitored changes in cognitive measures every three months between January 2012 and March 2013 among 2,593 grade-school age children ages 7 to 10 in Barcelona, Spain. Over the course a year, exposure to greenness within and around schools—as determined by satellite data—was linked with enhanced mental ability to continuously manipulate and update information, according to the investigators. These abilities are called working memory and superior working memory, respectively. Reduced inattentiveness was another benefit, according to the study. The results were independent of ethnicity, maternal education, and parental employment, said the researchers, Payam Dadvand of the Centre for Research in Environmental Epidemiology in Barcelona and colleagues The results linked every increase in total surrounding greenness by a quartile to a 5% increase in working memory, 6% increase in superior working memory, and 1% reduction in inattentiveness. A computer modeling analysis suggested that elemental carbon, a common traffic-related air pollutant, might account for 20 percent to 65% of the estimated links between school greenness and cognitive development. No significant link turned up between exposure to greenness at home and cognitive measures, the researchers said. Given the soaring rates of global urbanization, expanding green spaces at schools might be a step toward improving academic attainment among children, according to the authors. Dadvand and colleagues said previous studies had linked green space to better mental health, but whether this might influence cognitive development specifically was unclear. “Contact with nature is thought to play a crucial and irreplaceable role in brain development,” the researchers wrote, reporting their findings this week in the early online edition of the research journal pnas. “Natural environments including green spaces provide children with unique opportunities such as inciting engagement, risk taking, discovery, creativity, mastery and control, strengthening sense of self, inspiring basic emotional states including sense of wonder, and enhancing psychological restoration, which are suggested to influence positively different aspects of cognitive development.”