Processing Syntactic Relations in Language and Music: An Event-Related Potential Study

line sites. In addition, several non-standard sites over posited language centers were used, including Wernicke’s area (WL, WR: 30% of the interaural distance lateral to a point 13% of the nasion-inion distance posterior to Cz), posterior temporal (PTL, PTR: 33% of the interaural distance lateral to Cz), and anterior temporal (ATL, ATR: one-half the distance between F7-8 and T3 -4). Vertical eye movements and blinks were monitored by means of an electrode placed beneath the left eye, and horizontal eye movements were monitored by an electrode positioned to the right of the right eye. The above 15 channels were referenced to an electrode placed over the left mastoid bone and were amplified with a bandpass of 0.01 to 100 Hz (3db cutoff) by a Grass Model 12 amplifier system. Activity over the right mastoid bone was actively recorded on a sixteenth channel in order to determine if there were lateral asymmetries associated with the left mastoid reference. Data analysis. Continuous analog-todigital conversion of the EEG and stimulus trigger codes was performed on-line by a Data Translation 2801-A board and an ATcompatible computer, at a sampling frequency of 200 Hz. Epochs were comprised of the 100 ms preceding and 1180 ms following stimulus presentation. Trials characterized by excessive eye movement (vertical or horizontal) or amplifier blocking were rejected. For analyses involving words embedded within sentences, less than 10% of the trials were removed per condition. For analyses involving sentenceending words, approximately 15% of the trials in each condition were removed. ERPs were quantified by computer as the mean voltage within a latency range following presentation of words of interest, relative to a baseline of activity (either prestimulus or poststimulus, depending on the words of interest; see below).