Is XXXX a particularly right hemispheric disorder? A study of P3a using single trial analysis.

@entity14377 @entity1 @entity4225 @entity3493
OBJECTIVE: To test the hypothesis that @entity4225 is a manifestation of a particularly right hemispheric disturbance, involving @entity14377 , and to consider the therapeutic implications of the findings. METHODS: A cohort of 17 medication free borderline @entity1 were compared with 17 age and sex matched controls by means of a study of p3a, which reflects the activity of one of the two main generators of the @entity3493 (P3) of the event-related-potential. P3b reflects the output of the other generator. P3a, an aspect of the attentional system, depends upon prefrontally connected neurocircuitry. P3b is underpinned by a particularly parietally connected neural system. Using an oddball paradigm, P3a was extracted from the responses to targets using a novel single trial analysis. RESULTS: In borderline @entity1 , over homologous electrode sites, p3a amplitudes, but not latencies, were significantly larger in the right hemisphere compared with the left. The differences were most marked fronto-centrally. No such difference was shown in the control subjects. P3a at right hemisphere sites was significantly larger in borderline compared with control @entity1 . There was no significant difference between the groups for the left hemisphere sites. CONCLUSIONS: The abnormally large amplitudes of P3a at right hemisphere sites in borderline @entity1 together with the failure of habituation of P3a, are consistent with deficient inhibitory activity. Discussion of the findings suggest that they may reflect impeded maturation of the fronto-medial processing systems which, it is argued, may be a consequence of the typical early environment of those with the borderline condition. This suggestion leads to a consideration of optimal therapeutic behaviour in this condition, in particular for 'matching' or 'analogical' responsiveness.
