ACTIVITY AND ATTENTION IN ZINC-DEPRIVED ADOLESCENT MONKEYS

Lethargy is characteristic of malnourished populations, but little is known about the biologic mechanism or consequences for cognitive perfo rmance. In the current experiment, 24-h activity patterns and performa nce of an attention task were studied in adolescent female monkeys (18 -33 mo of age, n = 10/group) under conditions of moderate dietary zinc deprivation (2 mu g Zn/g diet) and adequate dietary zinc (50 mu g Zn/ g). There were progressive decreases in daytime activity levels in the zinc-deprived group followed by slowing of growth around the time of the growth spurt. Attention performance was also impaired before the o nset of growth retardation. Zinc-deprived monkeys failed to show the s hift to later initiation of the rest phase of the diurnal cycle seen i n controls in late adolescence. These data support previous findings t hat activity and attention can be affected during early stages of zinc deprivation before the onset of growth retardation.