Exploring the role of genetics and environment on the neural substrates of word and rule learning

Basora Marimon, Anna

Exploring the role of genetics and environment on the neural substrates of word and rule learning

Document Type

Doctoral thesis
Published Version

Author

Basora Marimon, Anna

Director

Sebastián Gallés, Núria
Burgaleta Díaz, Miguel

Publication Date

2015-03-17

Pages

164 p.

Citation

Basora Marimon, A. Exploring the role of genetics and environment on the neural substrates of word and rule learning. Universitat Pompeu Fabra; 2015. handle: http://hdl.handle.net/10803/384711

This citation was generated automatically.

Doctoral program

Programa de doctorat en Biomedicina

Abstract

L’origen ambiental i genètic de les diferències individuals en l’aprenentatge de paraules i regles gramaticals és desconegut. Per aquest motiu es van realitzar dos estudis. En el primer, dos grups de bessons, monozigòtics i dizigòtics, varen desenvolupar una tasca d’aprenentatge de paraules i regles. Es va mesurar la similitud entre bessons en l’activitat cerebral i els resultats indicaren que els factors genètics eren poc rellevants. En el segon estudi es va mesurar la diferència entre bessons monozigòtics en la integritat de la matèria blanca i en el nivell d’aprenentatge de paraules i es van correlacionar ambdues mesures. Els resultats mostraren que els factors ambientals que afecten als fascicles arcuat i front-occipital esquerres explicarien, en part, les diferències individuals en l’aprenentatge de paraules. Ambdós estudis suggereixen que les experiències juguen un paper central en el modelatge dels substrats neuronals associats a l’aprenentatge de paraules i regles.
The genetic and environmental origin of individual differences in word and grammar learning is unknown. Two separate studies addressed this issue. In the first study, monozygotic and dizygotic twins were exposed to a word and rule learning task while event-related potentials were recorded. Brain signal similarity between twins was measured, and indicated a weak influence of genetics in both processes. In the second study, white matter integrity estimates were obtained for language-relevant connections in a sample of monozygotic twins that also underwent a statistical word learning task. Twin differences in both white matter integrity and word learning performance were computed and correlated. Significant results in the left arcuate and inferior fronto-occipital fasciculus revealed that the environmental pressures affecting the integrity of these two structures partially explain individual differences in word learning. Taken together, both studies suggest that life experiences play a pivotal role in shaping the neural substrates of word and rule learning.

Keywords

Word learning, Rule learning, Twins, Heritability, Neural substrates, Aprenentatge de paraules, Aprenentatge de regles, Bessons, Heretabilitat, Substrats neuronals