Keywords: speech production; model; fMRI; Broca’s area; premotor cortex; motor cortex; speech acquisition; sensorimotor learning; neural transmission delays This paper describes a neural model of speech acquisition and production that accounts for a wide range of acoustic, kinematic, and neuroimaging data concerning the control of speech movements. The model is a neural network whose components correspond to regions of the cerebral cortex and cerebellum, including premotor, motor, auditory, and somatosensory cortical areas. Computer simulations of the model verify its ability to account for compensation to lip and jaw perturbations during speech. Specific anatomical locations of the model’s components are estimated, and these estimates are used to simulate fMRI experiments of simple syllable production. 1 1

structural equation modeling, effective connectivity The neural substrates underlying auditory feedback control of speech were investigated using a combination of functional magnetic resonance imaging (fMRI) and computational modeling. Neural responses were measured while subjects spoke monosyllabic words under two conditions: (i) normal auditory feedback of their speech, and (ii) auditory feedback in which the first formant frequency of their speech was unexpectedly shifted in real time. Acoustic measurements showed compensation to the shift within approximately 135 ms of onset. Neuroimaging revealed increased activity in bilateral superior temporal cortex during shifted feedback, indicative of neurons coding mismatches between expected and actual auditory signals, as well as right prefrontal and Rolandic cortical activity. Structural equation modeling revealed increased influence of bilateral auditory cortical areas on right frontal areas during shifted speech, indicating that projections from auditory error cells in posterior superior temporal cortex to motor correction cells in right frontal cortex mediate auditory feedback control of speech. 1

Psychology “... she encased the substance of the brain, which she had made soft and fluid, with a hard earthen casing. She had decided to employ a soft and transparent material in creating the brain, so that the images of things might impress themselves more easily upon it. Then, dividing the whole cavity of the skull into three chambers, she assigned these to the three functions of the soul. In the frontal chamber provision was made for imagination to receive the shapes of things, and transmit all that it beheld to reason. Memory’s chamber was set at the very back of the head, lest, dwelling at the threshold of perception, she should be troubled by a continual invasion of images. Reason dwelt between these two, to impose its firm judgment on the workings of the others. She also set the organs of sensory perception close about the palace of the head, that judging intellect might maintain close contact with the messenger senses. [...] Sound emerges from the windpipe and stirs the still air. Once aroused, the agitation spreads, until the last wave of motion slackens, having attained its limit and been drawn out to its full extent. Air provides the substance, and

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