This hypothesis was based on studies

This phorbol myristate acetate was based on studies that suggest that linguistic experience with “difficult to discriminate” durational cues alters ERP response to this feature (e.g., Nenonen et al., 2003; Tervaniemi et al., 2006) and that this enhanced processing extends to the non-speech domain (Kirmse et al., 2008). In the Kirmse et al. (2008) study, adult native-speakers of two languages were tested: Finnish, where vowel (and consonant) duration is crucial for phoneme distinctions, and German, where vowel duration is still important but of lower relevance as a phonetically distinctive cue with respect to Finnish. The results showed that Finnish ERP responses were characterized by shorter MMN latency for duration changes in both vowels and non-speech tones. Although this study demonstrates that populations where durational cues are relevant to speech discrimination are faster in detecting variations in duration cues in both speech and non-speech stimuli, it is important to note that these abilities are set up very early in life and are based on pre-linguistic shaping of language representations (Benasich et al., 2014; Kuhl et al., 1992). Thus, within populations where duration cues are important for speech segmentation, any variability in setting up the auditory system that disadvantages the processing of such cues could lead to atypical language acquisition. For this reason, we expected that language experience with durational cues in Italian, specifically the ability to process non-speech durational cues, could be a marker of familial risk and predictive of language acquisition in Italian infants.
Method
Results
Discussion The main aim of this study was to investigate RAP skills in an Italian sample of 6-month-old infants with and without family history of LLI. This is the first study in such a sample and provides evidence for the importance of fine-grained auditory processing skills, such as RAP, in a language different from English. Specifically, two critical acoustic features that have been shown to be systematically impaired in individuals with dyslexia (for review, Hämäläinen et al., 2013) were assessed using a multi-feature paradigm: fundamental frequency and sound duration. Both acoustic features were embedded in a rapidly-presented acoustic environment (i.e., 70ms ISI) in order to maximize differences between groups and specifically test Rapid Auditory Processing (RAP) abilities. The changes in fundamental frequency closely replicate previous paradigms (Benasich et al., 2006; Choudhury and Benasich, 2011) and thus provide a compelling cross-linguistic comparison. The results for discrimination of frequency change will be discussed and compared below to analogous results from the earlier American studies. This direct comparison allows us to examine the influence of differing native language experience on the discrimination of non-speech frequency changes. The change in sound duration included here represents a novel addition to the paradigm and have been included in order to assess particular characteristics of Italian, where sound duration is a critical phonemic difference and thus must recruit attention.
Conclusion Such insights also suggest that investigation of core underlying deficits or “intermediate phenotypes” is likely to be a more successful strategy than relying on complex diagnostic phenotypes. In particular, it highlights the advantage of examining early patterns of processing in infants at familial risk of LLI in order to take advantage of their shorter exposure to cultural and environmental confounders. These bellwether results have strong implications for the future implementation of early intervention programs (for a recent example of early intervention see Benasich et al., 2014), which may need to be both specific to Italian populations and early enough in life, to take advantage of the period when infants are still constructing cortical sensory maps, thus facilitating maximal neural plasticity before clinical traits stabilize.