Habituation of visual evoked potentials in healthy infants and in infants with periventricular leukomalacia.
OBJECTIVE
To investigate whether habituation of flash visual evoked potentials is already present during the first 3 months of life, and to explore differences between healthy infants, term infants with periventricular leukomalacia (PVL), and preterm infants with PVL.


METHODS
Referential recordings to stimuli consisting of photic stimulation presented in blocks were obtained. A total of 25 blocks, 15-stimuli each, were presented. Intrablock and interblock habituation effects were analyzed.


RESULTS
In healthy infants of 42-50 and 51-58 weeks of post-conceptional age (PCA), a negative central component (NCC) showed a significant decrease in amplitude due to stimulus repetition. NCC habituation was also observed in term infants with PVL at 51-58 weeks of PCA, but not in term infants with PVL at 42-50 weeks of PCA. NCC habituation was not apparent in preterm infants with PVL.


CONCLUSIONS
These results suggest that the neural mechanisms of visual habituation are normally present during the first month of life, but the presence of PVL delays the emergence of these mechanisms, particularly in preterm infants.


CONCLUSIONS
The habituation of flash visual evoked potentials may be developed into a reliable tool to examine normal and abnormal development of early neural processes.
Unidad de Investigación en Neurodesarrollo, Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-UAQ Juriquilla, Boulevard Juriquilla 3001, CP 76230 Querétaro, México.
Berta
B
González-Frankenberger
Thalía
T
Harmony
Josefina
J
Ricardo-Garcell
Eneida
E
Porras-Kattz
Antonio
A
Fernández-Bouzas
Efraín
E
Santiago
Gloria
G
Avecilla-Ramírez
D000704:Analysis of Variance; D003265:Contingent Negative Variation / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007969:Leukomalacia, Periventricular / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000503:physiopathology*