P300 is an event-related brain potential (ERP) particularly interesting to the study of cognitive processes in normal subjects and in psychopathology. P300 has been applied in depression with controversial results. A major source for these controversial results could result from the diversity of depressed patients included in the different studies. Supporting this assumption, impulsivity, blunted affect, suicidal behavior and psychotic features significantly influence P300 amplitude. However, no data are available on the possible influences of the personality of depressed patients on P300. Since personality is related to P300 in normal subjects, the aim of the present study is to investigate the relationship between ERPs (P200, N200, and P300) and the Temperament and Character Inventory (TCI) in 54 depressed patients. The main results of the study concern the absence of major correlations between personality dimensions as assessed by the TCI and ERP parameters among depressed patients. Only weak partial positive correlations relate N200 latency with harm avoidance, and P300 amplitude (Pz) with the self-directedness dimension. N200 amplitude is also negatively correlated to persistence. However, the preliminary nature of the presented results with respect to the weak statistical significance should be underlined.

Two different event-related potential (ERP) components were used to investigate the temporal processing of semantic and phonological encoding during implicit picture naming. Participants were shown pictures and carried out a dual choice go/nogo decision based on semantic information (i.e., whether the picture was of an object or an animal) and phonological information (i.e., whether the picture's name starts with a vowel or a consonant). In addition to the already established lateralized readiness potential (LRP; related to response preparation), we introduce the N200 (presumably related to response inhibition) as a tool for measuring online language processing. Both, the LRP and the N200 data indicated that semantic processing began earlier than phonological processing. The data are discussed in the context of language production models. Therein, the LRP and N200 results, taken together, favor a serial or cascaded processing model of language production in contrast to a parallel processing account.