Dense-array ERPs were recorded in response to a set of fear emo-tional facial expression and neutral faces using an incidental taskduring event related potential recording. The paradigm was builtusing frequently presented faces depicting neutral expression, ran-domly mixed with fear emotional facial expression that appearedto a smaller frequency. Underlying brain sources were estimatedusing Bayesian Model Averaging (BMA). The ERPs showed astrong modulation in the amplitude of an early negative compo-nent in the temporal region (N170) and a positive one at frontalsites in the same latency range by emotional facial expression.BMA analysis suggested the existence of a specific emotional neu-ral system involved in the processing of emotional facial expres-sion. This finding stands in contrast to previous modelssuggesting that N170 processes linked to structural analysis offaces precede analysis of emotional expression. In fact, it mayreflect early top-down modulation from neural systems involvedin automatic emotional processing.

doi:10.1016/j.clinph.2008.04.250

235. Dysfunctional attentional networks in children with

attention deficit hyperactivity disorder—T.M. Bravo, M.

Martın, S. Guerra (Cuba)

Recent research in attention has involved three networks ofanatomical areas that carry out the functions of orienting, alertingand executive control (including conflict monitoring). Studies ofADHD children using tasks somewhat similar to the AttentionNetwork Test (ANT) have shown some evidence of abnormalitiesin alerting and/or conflict. The objective of the present study wasto investigate these three particular aspects of attention in chil-dren with ADHD. Twenty-five medication-naive boys withADHD and 25 healthy controls, aged 8 to 12 years, were studied.A child-friendly version of the ANT was used to measure the effi-ciency of the three networks. Three subtractions where computedto obtain the alerting, orienting and conflict score for each partic-ipant. Across all trials, children with ADHD showed significantlylonger reaction times (RTs) and more errors than healthy con-trols. Children with ADHD had a significant impairment in theirconflict system. Children with ADHD showed a numerically butnot significantly larger alerting and orienting effect. This studysuggested that the dysfunction in executive control system is thestrongest deficits in children with ADHD. These findings supportthe notion that ADHD patients have a specific attentional deficit,rather than a global one.

doi:10.1016/j.clinph.2008.04.251

236.‘‘Hot” and ‘‘Cool” executive dysfunction in children with

attention deficit hyperactivity disorder (ADHD)—T.M.

Bravo, M. Martın, M. Domınguez (Cuba)

ADHD is regarded as a construct that subsumes multiplepotentially dissociable but overlapping cognitive profiles. Theobjective of the current study was to reconsider the impairmenton executive function (EF) in ADHD on the light of distinctionbetween affective/motivational (‘‘hot”) and more purely cognitiveaspects (‘‘cool”) of EF, examining the performance on a neuro-

psychological battery. Twenty-five children with ADHD and 25healthy controls were administered measures of estimated intellec-tual ability, sustained attention, set shifting, inhibitory control,delay aversion, and decision-making. Behavioural ratings wereobtained. The controls were matched in gender, age and IQ withthe ADHD group. ADHD children performed worse than con-trols in all tasks. A discriminant analysis was conducted, the com-bination of the entire measures discriminated correctly the 88% ofboth groups. There was an overlapping distribution of impair-ment based on percentage of individuals in each group‘‘impaired” (>1.5 SD). Twenty percent of children with ADHDshowed dysfunction only in ‘‘hot” EF, 8% in ‘‘cool” EF, and60% had dysfunction in both. The probability of impairment in‘‘hot” and ‘‘cool” EF was independent. The presence of impair-ments in incentive, motivational and reward-related processingsuggests that both ‘hot’ and ‘cool’ EF deficits are present in chil-dren with ADHD.

doi:10.1016/j.clinph.2008.04.252

237. Application of the event related potential contingent

negative variation in the evaluation of the cognitive functions

of patients affected by endogenous depression monopolar—T.

Acosta, A. Montoya, C. Acosta (Cuba)

We studied variations in CNV in monopolar endogenousdepression. 18 depressed patients (30–66 years) and a controlpaired sample of healthy subjects were evaluated using CNV.The analysis of the morfological type of CNV was sensitive to dif-ferentiate among patients and controls, with a highest prevalenceof slow CNV (Type B) in patients. There was a significantdecrease of the width of the CNV at Cz. The extent and the aver-age area of the CNV are not different in the patients and in thecontrols, which suggests that in the depressed patients don’t exista global cortical activation. The CNV showed significant decreaseof the extent in anterior regions in patients, which might be due tothe sleep disorders associated with depression.

doi:10.1016/j.clinph.2008.04.253

238. Attentional network task (Ant) performance in schizo-

phrenic patients and their unaffected first degree relatives:

Potential endophenotypes—S. Guerra Lopez, T.M. Bravo

Collazo, J. Iglesias Fuster, A. Reyes Berazaın, M.A. Pedr-

oso Rodrıguez, R. Mendoza, M. Domınguez, M. Martın

Reyes (Cuba)

We studied family association in attentional performanceusing the Posner‘s paradigm (ANT) in 26 schizophrenic patients,30 unaffected first degree relatives and 30 healthy controls. Weexamine the efficiency of the segregated executive control, alertingand orienting networks by measuring how response latencies(reaction time) were modified by the cue position and the flankingstimuli. We also explore if these alteration attentionals are presentin unaffected family members at a higher rate than in the generalpopulation (family association). The ANOVA reveals main effectsof flanker and cue condition and a significant interaction effectbetween flanker and study groups. The schizophrenic patients

Society Proceedings / Clinical Neurophysiology 119 (2008) e99–e164 e157