Handedness a cikin Yara An Haifi Mai Haihuwa

A duniya baki ɗaya, kashi 10.6 cikin ɗari na mutane na hannun hagu, yayin da sauran kashi 89.4 cikin ɗari na hannun dama ne (Papadatou-Pastou et al., 2020). Duk da yake an san cewa hannu da hannu yana shafar duka abubuwan halitta da muhalli, har yanzu ba a fahimci dalilin da yasa wasu mutane ke zama hagu ba wasu kuma suna zama na dama.

Oneaya daga cikin hasashe mai tsawo shine yanayin da ke kewaye da haihuwa na iya shafar ɗaga hannu. An ba da shawarar cewa haifuwa da wuri ko a cikin matsanancin yanayi na iya haɓaka damar zama na hagu ko haɗa hannu-abin da ake kira "farkon zagi" hasashe na hagu (Satz, 1973). Wannan ka'idar ta ɗauka cewa lalacewar kwakwalwa ta farko da ke haifar da rikitarwa na haihuwa na iya haifar da sauyawa a hannun hannu. Da yake akwai mutane da yawa da farko dama-dama, za a sami ƙarin “ɓarna” na hagu fiye da “ɓarna” dama ta wannan sauyawa. Don haka, ka'idar zata ɗauka cewa samun rikitarwa na haihuwa zai haifar da ɓarna mai yawa na kwakwalwa da babban damar zama na hagu.

Amma da gaske haka lamarin yake? Yayin da binciken da ya gabata sau da yawa yakan bincika alaƙar da ke tsakanin rikice -rikicen haihuwa da ba da hannu, galibi suna yin sakaci da samun maƙasudin kwakwalwa don tantance ko akwai lalacewar kwakwalwa. Wani sabon binciken daga Netherlands (wanda ni marubucin marubuci ne) yanzu ya bincika ko an haife shi sosai yana shafar baiwa (van Heerwaarde et al., 2020).

A cikin binciken, masanan sun kimanta ba da hannu a shekarun makaranta (shekaru 4-8) a cikin yara 179 da aka haife su da haihuwa. Matsakaicin shekarun haihuwa (lokacin tsakanin lokacin haila na ƙarshe na mahaifiyar da haihuwar yaron) na yaran shine makonni 26.5, idan aka kwatanta da makonni 38-42 a cikin jariran da aka haifa. Mahimmanci, marubutan sun kuma sami sikirin kwakwalwa don tantance lalacewar kwakwalwa.

Kididdigar mika hannun ta nuna cewa a cikin yaran da aka haifa kafin farkon wa'adin kashi 19.6 cikin ɗari sun kasance masu riƙe hannun hagu, kashi 3.4 cikin ɗari sun kasance masu haɗe-haɗe yayin da sauran kashi 77.1 cikin ɗari na masu hannun dama ne. Wannan yana nuna cewa akwai ƙarin masu riƙe hannun hagu da masu haɗe-haɗe tsakanin yara waɗanda aka haife su da ƙanƙantar da kai fiye da tsakanin yaran da aka haife su na cikakken lokaci (a cikin yawan jama'a, kashi 89.4 cikin ɗari na mutane masu hannun dama).

Amma shin haɗin gwiwar hagu da haɗin gwiwa suma suna da alaƙa da lalacewar kwakwalwa?

Masana kimiyya sunyi amfani da hoton hoton maganadisu don ganowa. Binciken kwakwalwarsu ya nuna cewa kusan kashi 47 cikin ɗari na yara sun nuna raunuka ɗaya ko fiye a cikin kwakwalwa, wanda ya fi na jariran da aka haifa cikakken lokaci. Duk da haka, babu cikakken haɗin ilimin lissafi tsakanin hannun hagu da haɗin kai da lalacewar kwakwalwa. Daga nan sai masanan suka yi amfani da wani nau'in na’urar tantance kwakwalwa don tantance lalacewa a cikin farin abin kwakwalwa. Bugu da ƙari, ba a sami wata alaƙa da mika hannu ba.

A haɗe, binciken da van Heerwaarde et al. (2020) ya nuna a sarari cewa hannun hagu da gauraye sun fi yawa a cikin yaran da aka haife su da wuri fiye da na yaran da aka haife su na cikakken lokaci. Bugu da ƙari, sun kuma nuna cewa yana da wuya cewa lalacewar kwakwalwa yana haifar da hagu kamar yadda ba a sami alaƙa tsakanin raunin da lalacewar kwakwalwa ba. Wannan yana nuna cewa wasu abubuwan da ke da alaƙa da haihuwa kafin haihuwa na iya shafar hannu.

Satz P. (1973). Hagu da hagu na farkon cin mutunci: bayani. Neuropsychologia, 11, 115-117.

van Heerwaarde AA, van der Kamp LT, van der Aa NE, de Vries LS, Groenendaal F, et al. (2020) Rashin hannun dama a cikin yaran da aka haife su da haihuwa: Haɗuwa da farkon neuroimaging da neurodevelopment na dogon lokaci. KASA DAYA 15 (7), e0235311.