The transcriptional underpinnings of brain development remain poorly understood, particularly in humans and closely related non-human primates. We describe a high resolution transcriptional atlas of rhesus monkey brain development that combines dense temporal sampling of prenatal and postnatal periods with fine anatomical parcellation of cortical and subcortical regions associated with human neuropsychiatric disease. Gene expression changes more rapidly before birth, both in progenitor cells and maturing neurons, and cortical layers and areas acquire adult-like molecular profiles surprisingly late postnatally. Disparate cell populations exhibit distinct developmental timing but also unexpected synchrony of processes underlying neural circuit construction including cell projection and adhesion. Candidate risk genes for neurodevelopmental disorders including primary microcephaly, autism spectrum disorder, intellectual disability, and schizophrenia show disease-specific spatiotemporal enrichment within developing neocortex. Human developmental expression trajectories are more similar to monkey than rodent, and approximately 9% of genes show human-specific regulation with evidence for prolonged maturation or neoteny.

Most studies to date on the ability of English speakers to produce the Spanish approximants [β̞ ,ð̞ ,ɣ̞ ] have impressionistically looked at the stop-spirant contrast of English-speaking learners of Spanish (e.g. Zampini 1994, Díaz-Campos 2004, Face & Menke 2009), but no known study has empirically studied the degree to which these learners are able to spirantize when compared to native speakers. The current study looks at two groups of learners: one group composed of learners who had studied four semesters of university Spanish and another group composed of learners who spent 2 years abroad in a Spanish-speaking country. Intervocalic tokens of [β̞ ,ð̞ ,ɣ̞ ] were taken and were measured for degree of oral occlusion using the intensity curve in PRAAT. Additionally, a multiple regression analysis was run to determine the relationship that oral occlusion had with speech task type formality, motivational intensity, level of instruction/time abroad, phoneme type, and phoneme word position.

While traditional studies on Spanish vowels have agreed that it is a stable system with very little variation, Varela (1992) claims to have observed English transfer phenomena in the vowel system of Miami Cuban Spanish (i.e. schwa in unstressed position, diphthongization of mid-vowels, and the use of English vowels in place of Spanish vowels: e.g. [æ] for /o/, [æk.tú.b?e] for octubre). The current study empirically tests Varela’s claims of English transfer in the Spanish vowel system of three generations of Miami Cuban bilinguals. Speech is analyzed acoustically with Praat and vowel formant values (F1 and F2) are normalized with NORM. No evidence of English vowels replacing Spanish vowels is discovered but the existence of vowel centralization of unstressed vowels in Miami Cuban Spanish is confirmed. The current study discusses the stability of the Miami Cuban Spanish vowel system as compared to Spanish in general.

One of the more characteristic features of Spanish is the process of articulatory reduction, known as spirantization, which affects the voiced stops /b,d,g/ resulting in the voiced approximants [β̞, ð̞, ɣ̞]. While studies have shown variation with respect to the phonetic environments in which /b,d,g/ undergo spirantization, the general consensus has been that they are always realized as approximants between vowels in most varieties of Spanish. Likewise, several studies have found that spirantization relates to different social factors in different varieties of Spanish. However, these studies have been impressionistic and/or qualitative in their analyses of the voiced obstruents and have not examined the varying degrees to which intervocalic /b,d,g/ spirantize. The current study analyzes more than 4,500 tokens of intervocalic /b,d,g/ from the spontaneous speech of 31 speakers from the province of Concepción, Chile. Likewise, the present paper examines and compares the phonetic behavior of traditional intervocalic /b,d,g/ with that of /b,d,g/ in non-traditional intervocalic contexts created by /s/ elision. Results indicated that both linguistic and social factors had an influence on the degree to which speakers realized [β̞, ð̞, ɣ̞], and that while speakers still lenite and delete /b,d,g/ in non-traditional intervocalic environments created by /s/ elision, generally they do so at a much lower rate than when in traditional intervocalic contexts.