Artificial language training reveals the neural substrates underlying addressed and assembled phonologies

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Neuroimaging

Background:

• Behavioral studies suggest two reading routes: addressed (whole word) and assembled (grapheme-to-phoneme).
• Neural underpinnings of these distinct phonological access routes remain unclear.

Purpose of the Study:

• To elucidate the neural substrates of addressed versus assembled phonological reading routes.
• To investigate the strategy-shift hypothesis during reading acquisition.

Main Methods:

• An artificial language (Korean Hangul) was created for training.
• Participants were trained in either addressed or assembled phonology conditions over eight days.
• Brain activity was measured using neuroimaging techniques.

Main Results:

• A clear neural dissociation was observed: addressed phonology engaged regions like the anterior cingulate cortex and angular gyrus, while assembled phonology activated the left precentral gyrus/inferior frontal gyrus and supramarginal gyrus.
• Evidence supports the strategy-shift hypothesis, showing a shift from assembled to addressed phonology networks with practice.

Conclusions:

• Provides robust brain-imaging evidence for distinct neural pathways supporting the dual-route model of reading.
• Demonstrates a practice-dependent shift in reading strategy, moving from assembled to addressed phonological processing.