Edmund S. Crelin

Computed tomography in the study of the development of the skull base: 2. Anencephaly, the aberrant skull form

Surgicalhe application of various radiographic modalitieis in the analysis of the paradigm aberrant skull of anencephalics is reported. Again, we found high resolution CT to be the most valuable modality. A detailed description of the skull base changes in anencephaly is presented, and the appropriate embryologic explanation is offered.

The skulls of our ancestors: Implications regarding speech, language, and conceptual thought evolution

Summary Anatomical studies compared the vocal tracts and skulls of immature and mature humans with those of other species and with the fossil skulls of ancestral human forms. The results offered an explanation of human vocal tract evolution and its possible relationship to the evolution of speech, language, and conceptual thought.

Oxonic acid and fetal development: I. Embryotoxicity in mice.

Feeding the uricase inhibitor potassium oxonate (K Ox) as 3( of the diet to pregnant mice during days 8-10 postconception caused a 95-98% incidence of embryonic mortality with resorption. The same treatment during days 10-13 of gestation caused no changes in litter size and fetal weight; however, if in addition to feeding K Ox, three concurrent i.v. injections of 2.5 mg/day of Na urate (Na UR) were given then 47% of the mouse fetuses were killed and resorbed. Intravenous Na urate alone during the same stages of early and middle pregnancy had no effect on fetal survival or development. A 3.6% incidence of cleft palate was caused in mice treated with the combination of K Ox and Na UR during middle pregnancy. In groups of mature nonpregnant female mice exposed to the same treatment regimens, serum uric acid, potassium and sodium were elevated in a treatment-related manner. Serum urea levels were unchanged. K Ox is lethal to mouse fetuses during early embryonic development. Hyperuricemia, hyperkalemia or hypernatremia are maternal alterations which may be responsible for, or contribute to this effect.

Speech Producing Abilities of Primates and Human Evolution

Comparative anatomic and acoustic studies of the supralaryngeal vocal tracts of living and extinct primates indicate that speech production has been an important factor in human evolution. The sounds of human speech make human language a rapid medium of communication through a process of speech “encoding.” The presence of the human vowels /a/, /i/, and /u/ facilitates this process. The supralaryngeal vocal tracts of newborn Homo sapiens and the living nonhuman primates are similar and resemble the reconstructed vocal tracts of fossil Australopithecine and Neanderthaloid hominids. Vocal tract area functions that were directed towards making the best possible approximations to the human vowels /a/, /i/, and /u/, as well as certain consonantal configurations, were modeled by means of a computer program. The lack of these vowels in the phonetic repertoires of these creatures, who lack a pharyngeal region like that of adult Homo sapiens, may be concomitant with the absence of speech encoding and a consequent l...

Anatomical Constraints on Speech in Chimpanzee, Newborn Homo sapiens and Neanderthal man

The cross‐sectional area function of the supralaryngeal vocal tract of chimpanzee and the muscular and anatomical constraints on possible variation, were determined by sectioning the cadaver of a young adult on the midsaggital plane. Vocal tract area functions that were directed towards making best possible approximations to the human vowels /a/, /i/, and /u/, as well as certain consonantal configurations, were modeled by means of a computer program. The chimpanzee vocal tract could not produce these extreme vowels since it lacked a supralaryngeal pharyngeal region like that of adult Homo sapiens. The vocal tracts of newborn Homo sapiens and chimpanzee are similar and resemble the reconstructed vocal tract of the fossil La Chappelle‐aux‐Saints Neanderthal man (Lieberman and Crelin, 1971). The lack of the vowels /a/, /i/, and /u/ in the phonetic repertories of these creatures may be concomitant with the absence of consonantal encoding and decoding and consequently a linguistic ability inferior to that of m...