An event-related potential study of attention and recognition memory in infants with iron-deficiency anemia

Abstract

Objectives: The purpose of this work was to determine whether iron-deficiency anemia in infancy represents a risk factor for deficits in attention and memory development using event-related potentials.

Methods: Artifact-free event-related potential data were obtained at 9 and/or 12 months from 15 infants with iron-deficiency anemia and 19 who were iron sufficient during a test of the infant's ability to discriminate a highly familiar stimulus, the mother's face, from a stranger's face.

Results: A midlatency negative component associated with attention and a late-occurring positive slow wave associated with memory updating were identified at both ages in the iron-deficiency anemia and iron-sufficient groups. Consistent with the age-appropriate pattern of development at 9 months, the iron-sufficient group showed a greater attentional response (negative component) to the mother and a greater updating of memory for the stranger (positive slow wave). This pattern of responses was not evident in the iron-deficiency anemia group until 12 months, suggesting a delay in cognitive development.

Conclusions: These data suggest that iron-deficiency anemia adversely affects the allocation of neurophysiologic resources to attention and recognition memory during the processing of information about familiar and unfamiliar stimuli. This delay in cognitive development may reflect alterations in efficiency of central nervous system functions that seem related to early iron deficiency.

Figures

FIGURE 1

Mean NC maximum negative amplitude for repeated measures at 9 and 12 months for subgroups IDA(n = 7) and IS (n = 7).

FIGURE 2

Mean PSW area under curve (arbitrary units) for repeated measures at 9 and 12 months for subgroups IDA (n = 7) and IS (n = 7).

FIGURE 3

Grand means at 9 months for frontocentral electrodes for IDA (gray lines; n = 13) and IS (black lines; n = 15). Thick lines represent mother; thin lines represent stranger; 1500 millisecond recording, ±35 µV.

FIGURE 4

Grand means at 12 months for frontocentral electrodes for IDA (gray lines; n = 9) and IS (black lines; n = 11). Thick lines represent mother; thin lines represent stranger; 1500-millisecond recording, ±35 µV.