ERPs reveal individual differences in morphosyntactic processing

• Published in: Neuropsychologia Vol. 56; no. Apr; pp. 289 - 301
• Main Authors: Tanner, Darren, Van Hell, Janet G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2014; Elsevier
• Subjects: Adolescent; Adult; Analysis of Variance; Behavioral psychophysiology; Biological and medical sciences; Brain; Brain Mapping; Comprehension - physiology; Electroencephalography; Electrophysiology; English; ERPs; Event Related Potentials; Evoked Potentials - physiology; Familial sinistrality; Female; Fundamental and applied biological sciences. Psychology; Humans; Individual Differences; Individuality; LAN; Language; Language Processing; Language Proficiency; Male; Miscellaneous; Morphological Processing; Morphosyntax; N400; Neurolinguistics; P600; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Semantics; Syntactic Processing; Young Adult; ERPs; N400; P600; Familial sinistrality; Individual differences; LAN; Morphosyntax; Human; Central nervous system; Electrophysiology; Cognition; Encephalon; English; Verbal ability; Language; Morphology; Interindividual comparison; Syntax; Event evoked potential
• ISSN: 0028-3932; 1873-3514; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2014.02.002

We investigated individual differences in the neural substrates of morphosyntactic processing among monolingual English speakers using event-related potentials (ERPs). Although grand-mean analysis showed a biphasic LAN-P600 pattern to grammatical violations, analysis of individuals׳ ERP responses showed that brain responses varied systematically along a continuum between negativity- and positivity-dominant ERP responses across individuals. Moreover, the left hemisphere topography of the negativity resulted from component overlap between a centro-parietal N400 in some individuals and a right hemisphere-dominant P600 in others. Our results show that biphasic ERP waveforms do not always reflect separable processing stages within individuals, and moreover, that the LAN can be a variant of the N400. These results show that there are multiple neurocognitive routes to successful grammatical comprehension in language users across the proficiency spectrum. Our results underscore that understanding and quantifying individual differences can provide an important source of evidence about language processing in the general population. •Biphasic LAN-P600 to morphosyntactic violations was a spurious result of averaging.•Violations elicited N400s in some individuals and P600s in others.•Dominance of N400 in some individuals was related to familial sinistrality.•Monolinguals differentially engage core language network for morphosyntax.•LAN component can be a variant of the N400.