Mismatch negativity in young children of alcoholics from high-density families.

O compoñente dos potenciais evocados (PE) denominado ‘negatividade de disparidade’ ou MMN, do acrónimo en inglés de ‘mismatch negativity’ rexistrouse nun grupo de rapaces fillos de alcohólicos (n = 19, 8 mulleres) con historia familiar de alcoholismo de alta densidade e un grupo de control (n = 23, 12 mulleres), entre 8 e 15 anos de idade. Usouse unha tarefa de escoita dicótica, e os participantes tiñan que prestar atención a un ‘paradigma oddball’ en un ouvido e ignorar os estímulos presentados no outro. Os PE provocados polos tons estándar non atendidos substraeuse dos provocados polos tons desviantes infrecuentes non atendidos, e o MMN medíuse en 10 localizacións frontais e centrais. Non se observaron diferenzas entre os grupos na latencia de pico, na amplitude de pico nin na amplitude media do MMN. Estes resultados indican que los mecanismos preatentivos reflectidos no MMN non están afectados en rapaces con alto risco ao alcoholismo. Os resultados discútense en relación ás diferenzas nos índices electrofisiolóxicos de procesamento da información automático versus controlado e en relación coas características da mostra.The mismatch negativity (MMN) component of event-related potentials was recorded from a group of young children of alcoholics (n= 19, 8 females) with a high-density family history of alcoholism and from a control group (n= 23,12 females), between 8 and 15 years of age. A dichotic listening task was used, and subjects had to pay attention to an oddball paradigm in one ear and ignore the stimuli in the other ear. The event-related potentials elicited by the standard unattended tones were subtracted from those elicited by the infrequent deviant unattended tones, and the MMN was measured at 10 frontal and central electrodes. No group differences were observed in peak latency, peak amplitude, and mean amplitude of the MMN. These results indicated that preattentive mechanisms of mismatch detection were not impaired in young subjects at high risk for alcoholism. Results are discussed in relation to differences in electro-physiological indexes of automatic versus controlled information processing and in relation to the characteristics of the sample.