Absence of neural speech discrimination in preterm infants at term-equivalent age

Children born preterm are at higher risk to develop language deficits. Auditory speech discrimination deficits may be early signs for language developmental problems. The present study used functional near-infrared spectroscopy to investigate neural speech discrimination in 15 preterm infants at term-equivalent age compared to 15 full term neonates. The full term group revealed a significantly greater hemodynamic response to forward compared to backward speech within the left hemisphere extending from superior temporal to inferior parietal and middle and inferior frontal areas. In contrast, the preterm group did not show differences in their hemodynamic responses during forward versus backward speech, thus, they did not discriminate speech from non-speech. Groups differed significantly in their responses to forward speech, whereas they did not differ in their responses to backward speech. The significant differences between groups point to an altered development of the functional network underlying language acquisition in preterm infants as early as in term-equivalent age

Supplementary Material for: Are All Amplitude-Integrated Electroencephalogram Systems Equal?

<p><b><i>Background:</i></b> Filter and peak detection algorithms implemented in amplitude-integrated electroencephalogram (aEEG) systems are not standardized. New aEEG systems are continuously enriching the market and clinicians are faced with different aEEG devices whose tracings may vary. <b><i>Objectives:</i></b> The aim of this work was to determine the role of different aEEG systems on quantitative measurements of the aEEG. <b><i>Methods:</i></b> In this observational study, a single-channel aEEG recording (Olympic CFM 6000) with corresponding EEG signal was obtained from 32 infants at a gestational age of 36-44 weeks. The signals were split into 334 episodes of 4 h. New aEEG tracings were generated using the NicoletOne Reader Software and aEEG emulations with varying filter profiles and peak detection settings. The aEEG amplitude margins and automated annotation of continuous normal voltage (CNV) were compared. <b><i>Results:</i></b> The output of the Olympic and the NicoletOne systems are very similar but not identical; the Spearman rank correlations of the aEEG amplitude margins exceeded 0.9 and the differences in the lower and upper amplitude margins were 1.55 μV (SD 1.47) and -2.12 μV (SD 1.44) on average (<i>n</i> = 309), respectively. The aEEG emulation showed that the differences between the output of the Olympic and the NicoletOne system could be primarily ascribed to the peak detection algorithm. The differences in output can affect automated analyses with agreement rates in CNV detection of 76% (<i>n</i> = 32, positive) and 92% (<i>n</i> = 32, negative) when comparing the Olympic to the NicoletOne outputs. <b><i>Conclusions:</i></b> Commercial aEEG systems have similar but not identical outputs. Care is advised when interpreting automated aEEG classifications across different devices.</p

Accent discrimination abilities during the first days of life: An fNIRS study

Humans are biologically endowed with the faculty of language. However, the way neonates can crack this complex communicative code is yet not totally understood. While phonetic discrimination has been widely investigated in neonates, less is known about the role of supra-segments patterns in the recognition of native language. Therefore, the aim of this study was to evaluate accent discrimination abilities in newborns in a sentential prosody paradigm. We used near-infared spectroscopy to investigate accent discrimination in 21 full-term born infants within the first days of life. Sentential prosody was used to investigate: (a) native accent, (b) foreign accent, and (c) flattened accent. Neonates revealed a significantly smaller hemodynamic response to native accent compared to flattened accent and foreign accent, respectively. Cluster-based permutation analysis revealed two clusters with a significant difference between the two conditions native accent and foreign accent. The first cluster covered the middle and superior frontal, middle and superior temporal, central, and parietal areas within the left hemisphere. The second cluster, located in the right hemisphere, covered inferior, middle, and superior frontal, central, middle and superior temporal areas. We therefore conclude that neonates can differentiate prosodic features like accents within the same language a few days after birth