The species-specific organizational property of speech is a continual mouth open-close alternation, the two phases of which are subject to continual articulatory modulation. The cycle constitutes the syllable, and the open and closed phases are segments framescontent displays that are prominent in many nonhuman primates. The new role of Broca's area and its surround in human vocal communication may have derived from its evolutionary history as the main cortical center for the control of ingestive processes. The frame and content components (...) of speech may have subsequently evolved separate realizations within two general purpose primate motor control systems: (1) a motivation-related medial system, including anterior cingulate cortex and the supplementary motor area, for self-generated behavior, formerly responsible for ancestral vocalization control and now also responsible for frames, and (2) a lateral system, including Broca's area and surround, and Wernicke's area, specialized for response to external input (and therefore the emergent vocal learning capacity) and more responsible for content. (shrink)

The Frame/Content theory deals with how and why the first language evolved the present-day speech mode of programming syllable “Frame” structures with segmental “Content” elements. The first words are considered, for biomechanical reasons, to have had the simple syllable frame structures of pre-speech babbling, and were perhaps parental terms, generated within the parent–infant dyad. Although all gestural origins theories have iconicity as a plausible alternative hypothesis for the origin of the meaning-signal link for words, they all share the problems of (...) how and why a fully fledged sign language, necessarily involving a structured phonology, changed to a spoken language. (shrink)

Head stabilization is fundamental for balance during locomotion but can be impaired in elderly or diseased populations. Previous studies have identified several parameters of head stability with possible diagnostic value in a laboratory setting. Recently, the ecological validity of measures obtained in such controlled contexts has been called into question. The aim of this study was to investigate the ecological validity of previously described parameters of head stabilization in a real-world setting. Ten healthy subjects participated in the study. Head and (...) trunk movements of each subject were recorded with inertial measurement units (IMUs) for a period of at least ten hours. Periods of locomotion were extracted from the measurements and predominant frequencies, root mean squares (RMSs) and bout lengths were estimated. As parameters of head stabilization, attenuation coefficients (ACs), harmonic ratios (HRs), coherences and phase differences were computed. Predominant frequencies were distributed tightly around 2 Hz and ACs, HRs and coherences exhibited the highest values in this frequency range. All head stability parameters exhibited characteristics consistent with previous reports, although higher variances were observed. These results suggest that head stabilization is tuned to the 2 Hz fundamental frequency of locomotion and that previously described measures of head stability could generalize to a real-world setting. This is the first study to address the ecological validity of these measures, highlighting the potential use of head stability parameters as diagnostic tools or outcome measures for clinical trials. The low cost and ease of use of the IMU technology used in this study could additionally be of benefit for a clinical application. (shrink)

Words denoting “mother” in baby talk and in languages usually include nasal sounds, supporting Falk's suggestion that infant nasalized demand vocalizations might have motivated a first word. The linguistic contrast between maternal terms and paternal terms, which favor oral consonants, and the simple phonetic patterns of parental terms in both baby talk and languages also suggest parental terms could have been first words.

Arbib's gestural-origins theory does not tell us why or how a subsequent switch to vocal language occurred, and shows no systematic concern with the signalling affordances or constraints of either medium. Our frame/content theory, in contrast, offers both a vocal origin in the invention of kinship terms in a baby-talk context and an explanation for the structure of the currently favored medium.

Hurford presents a much-needed lowly origins scenario for the evolution of conceptual precursors to lexical items. But more is still needed on action, regarding both the message level of lexical concepts and the medium. We summarize our complementary action-based lowly origins (frame/content) scenario for the vocal auditory medium of language, which, like Hurford's scenario, is anchored in a phylogenetically old neurological dichotomy.

Corballis argues that language underwent two modality switches – from vocal to manual, then back to vocal. Speech has evolved a frame/content mode of organization whereby consonants and vowels (content) are placed into a syllable structure of frames (MacNeilage 1998). No homologue to this mode is present in sign language, raising doubt as to whether the proposed modality switches could have occurred.

Joseph apparently does not understand the main purpose of my target article and how different it is from any purpose underlying his work. In addition, most of the neurological ideas of the target article for which he claims unacknowledged priority are not original to him, but instead predate the work of both of us.

There was little disagreement among commentators about whether speech production involves a frame/content mode of organization, but there was some disagreement with the contention that frames evolved from ingestive cyclicities and were mediated via a medial “intrinsic” system.