of code-switching (see Chapters 5 and 6) and for our understanding of the
costs involved in the co-activation and juxtaposition of languages within
education (see Chapters 7 and 8).
Taken together, there is converging evidence for non-selective activation
behaviorally although there is a debate over the manner and locus of lan-
guage selection. In the following section, we briefly review the principles of
ERPs and experimental paradigms used to study speech production with
ERPs.
ERP Studies on Bilingual Speech Production
Principles of ERPs
Electroencephalography (EEG) is the monitoring (and recording) of sig-
nals produced by the brain by means of highly conductive electrodes set on
the scalp (see Figure 9.2 for a schematic representation of an EEG system).
Brain electrical variations at the surface of the scalp are in the order of the
206 Part 5: The Bilingual Brain
Figure 9.2 Electroencephalography (EEG) system and principles of event-related poten-
tial recording