Learning disabilities and poor motivation to achieve due to prolonged iodine deficiency.
The effect of prolonged iodine deficiency on learning and motivation was studied. One hundred male children--matched for age, socioeconomic status, and formal education--were selected from both severely iodine-deficient (SID) and mildly iodine-deficient (MID) villages. Mean urinary iodine excretion was significantly lower in the SID than in the MID group (219.84 +/- 57.52 compared with 449.14 +/- 32.31 nmol/L, P < 0.001). The serum thyroxine concentration was significantly lower (90.36 +/- 6.46 compared with 123.70 +/- 15.42 nmol/L, P< 0.001) and serum thyroid-stimulating hormone (TSH) was significantly higher in the SID group than in the MID group (6.23 +/- 0.34 compared with 4.85 +/- 0.28 mU/L, P< 0.01). The children were administered maze, verbal, and pictorial learning tasks and a test of motivation. The results showed that SID children are slow learners compared with MID children. In both groups the rate of learning over trials was superior in younger (aged 9-12 y) children although the initial performance of older (aged 12-15 y) children was better (P < 0.01). SID children scored significantly lower than MID children on the achievement motivation scale (P < 0.01). The results are suggestive of neural impairment as well as poor sociopsychologic stimulation, resulting in learning disability and lowered achievement motivation. Unless iodine nutrition is improved in the community as a whole, these abnormalities may prevent millions of children from the SID areas from achieving their full potential even if learning opportunities are made available to them.
Tiwari
B D
BD
Department of Psychology, Kashi Vidyapeeth, Varanasi, India.
Godbole
M M
MM
Chattopadhyay
N
N
Mandal
A
A
Mithal
A
A
D000124:Achievement; D000293:Adolescent; D000375:Aging / Q000378:metabolism; D002648:Child; D004522:Educational Status; D006043:Goiter, Endemic / Q000097:blood / Q000150:complications / Q000453:epidemiology; D006801:Humans; D007194:India / Q000453:epidemiology; D007360:Intelligence; D007455:Iodine / Q000097:blood / Q000172:deficiency* / Q000502:physiology; D007858:Learning; D007859:Learning Disabilities / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D018782:Maze Learning; D009042:Motivation; D012720:Severity of Illness Index; D012923:Social Class; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013997:Time Factors; D014706:Verbal Learning
D013972:Thyrotropin; D007455:Iodine; D013974:Thyroxine