Is it about speech or about prediction? Testing between two accounts of the rhythm-reading link

The mechanisms subtending the positive association between reading and rhythmic skills, remain unclear. Our goal was to perform a systematic test between two major explanations: the Temporal Sampling Framework (TSF), which highlights the relation between rhythm and speech encoding, and a competitor explanation based on the enhancing role of rhythm in prediction within visual and auditory sequences. We compared beat vs. duration perception for their associations with encoding and sequence learning tasks, using both visual and auditory sequences. We also compared these associations for Portuguese vs. Greek participants, since Portuguese stress-timed rhythm is more compatible with music-like beats, lasting around 500 ms, than Greek, syllable-timed rhythm (faster). If rhythm acts via speech encoding, it should be more salient in Portuguese. Consistent with TSF’s proposal, we found a significant association between beat perception and auditory encoding in Portuguese but not Greek participants. Correlations of time perception with visual and auditory sequence learning were either null or insufficiently supported in both groups. Altogether, the evidence favored TSF-related predictions in detriment of the rhythm-as-prediction-enhancer hypothesis.