Subvocalization: Aural and Emg Feedback in Reading

Abstract

Speech is a complex skill with auditory and kinesthetic components—sensory and motor—coordinated inter- and intramodally. In reading, vision joins these modalities. Functional relations of variables in reading for arithmetic problem-solving were explored for individuals who show much (HVs) compared with those who show little (LVs) speech-muscle activity (subvocalization) during silent reading. Higher relative sound intensities were used by LVs than by HVs in normal reading aloud but not when reading with delayed auditory feedback (DAF). Feedback training for the self-regulated reduction of electromyographic activity of speech muscle during silent reading was effective for both HVs and LVs. After feedback training the difference in relative sound intensities between HVs and LVs was eliminated in normal reading aloud and HVs showed smaller increases than LVs when reading with DAF. Latency to correct answer in silent problem-solving was shorter for LVs than for HVs before but not after feedback training. Variations in heart rate, eye-movement rate, regressive eye movements, reading speed, rate of integrated speech peaks, syllable rate, eye-voice span, eye movements per syllable, and correct answers were related to experimental conditions but not different for HVs and LVs. Data on the interrelations of variables are presented to suggest some tentative hypotheses. The correlation of eye-voice span with speech-muscle activity was related to levels of subvocalization in normal reading aloud but modified by DAF and feedback training. The measurement of speech-muscle activity, feedback training, general and developmental differences in the use of auditory versus kinesthetic cues by HVs and LVs, and implications of subvocalization for speech, memory, thought, and reading are discussed.