Neural Correlates of Processing Syntax in Music and ... - PubMan

Experiment II 111
tion of objects; only for 5-year-olds). “Gestalt closure” did not conform to a normal
distribution and for “Face recognition” only few measurements were acquired. These
variables were therefore not included in the evaluation.
EEG recording and processing
The configuration of the channels used for EEG recording did slightly differ from that
in Experiment I: 22 EEG data were recorded from 23 scalp locations (FP1, FP2, F7, F3,
FZ, F4, F8, FC3, FC4, T7, C3, CZ, C4, T8, CP5, CP6, P7, P3, PZ, P4, P8, O1, O2) and
5 further locations on the head (NOSE, H+, H�����������������������������������xactly
the same as in Experiment I.
Statistical evaluation
For the statistical evaluation of the ERPs, four regions of interest (ROIs) were computed:
left-anterior (F3, F7, FC3), right-anterior (F4, F8, FC4), left-posterior (P3, T7,
CP5), and right-posterior (P4, T8, CP6). To guarantee that both groups did not differ in
their primary auditory processing, the onset of the first chord of the sequence was
evaluated. Two time windows were used in this analysis: [1] 0 to 100 ms, and [2] 100 to
200 ms. Statistical evaluation was performed with mixed-model ANOVAs for repeated
measurements containing the within-subject factors time window (0 to 100 ms vs. 100
to 200 ms), anterior-posterior distribution, and hemisphere (left vs. right) and the between-subjects
factor subgroup (TLD vs. SLI).
For the comparison of the irregular supertonics and the regular tonics four time windows
were used (relative to stimulus onset): [1] 230 to 350 ms (ERAN), [2] 500 to 700
ms (N5), [3] 100 to 180 ms (early difference in the SLI group around 100 to 200 ms;
due to an overlap with the beginning of the ERAN the time window was set to 100 to
180 ms), and [4] 800 to 1000 ms (late difference in the SLI group). All time windows
were centred on the peak of the components. Two time windows were set to the peak of
ERP components, consistently elicited by violations of musical syntax (see, e.g.,
Koelsch et al., 2003; Koelsch et al., 2000): the ERAN [1] and the N5 [2]. Two other
time windows ([3], [4]) were suggested by visual inspection of the ERPs.
Outliers in the data were detected and removed (by means of the SPSS procedure EXAM-
INE) in order to guarantee for normality of the data. Thereafter, a Kolmogorov-Smirnov
test revealed that the variables in the analyses did not deviate from a standard normal
distribution (0.383 ��p ����������edian = 0.853).
22 The children in Experiment I participated in the German Language Devleopment (GLaD) study. Their
EEG measurements were, thus, performed in Berlin. The measurement of the older age groups (Experiment
II to IV) took place at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig.