Infant discrimination of rapid auditory cues predicts later language impairment

The hemodynamic response to acoustically modified syllables in premature and full term newborn infants acquired by near infrared spectroscopy

This research assesses, in newborns, the hemodynamic response to acoustically modified syllables (pronounced in a prolonged manner), versus the response to unmodified syllables (pronounced at a normal rate). The aim was to assess which of these stimulation conditions produced better syllable discrimination in two groups of neonates: 13 preterm (mean gestational age 30 weeks, SD 3 weeks), and 13 full term newborns (mean age 38 weeks, SD 1 week). Syllable discrimination, in each condition, was assessed by using an oddball paradigm (equal syllable trials vs. different syllable trials). The statistical analysis was based on the comparison between the hemodynamic response [oxyHbO] obtained by Near Infrared Spectroscopy (NIRS) to different syllable trials vs. equal syllable trials, in each condition. The modified syllable condition was better in producing trial discrimination in both groups. The amplitude of the hemodynamic response to the different syllable trials was greater than the one to the equal syllable trials: for term infants, t = 2.59, p = 0.024, and for preterm t = 2.38, p = 0.035. This finding occurred in the left temporal lobe. These data suggest that the modified syllables facilitate processing of phonemes from birth.

Influence of memory, attention, IQ and age on auditory temporal processing tests: preliminary study

PURPOSE

To investigate the existence of correlations between the performance of children in auditory temporal tests (Frequency Pattern and Gaps in Noise--GIN) and IQ, attention, memory and age measurements.

METHOD

Fifteen typically developing individuals between the ages of 7 to 12 years and normal hearing participated in the study. Auditory temporal processing tests (GIN and Frequency Pattern), as well as a Memory test (Digit Span), Attention tests (auditory and visual modality) and intelligence tests (RAVEN test of Progressive Matrices) were applied.

RESULTS

Significant and positive correlation between the Frequency Pattern test and age variable were found, which was considered good (p<0.01, 75.6%). There were no significant correlations between the GIN test and the variables tested.

CONCLUSIONS

Auditory temporal skills seem to be influenced by different factors: while the performance in temporal ordering skill seems to be influenced by maturational processes, the performance in temporal resolution was not influenced by any of the aspects investigated.

Age, dyslexia subtype and comorbidity modulate rapid auditory processing in developmental dyslexia

The nature of Rapid Auditory Processing (RAP) deficits in dyslexia remains debated, together with the specificity of the problem to certain types of stimuli and/or restricted subgroups of individuals. Following the hypothesis that the heterogeneity of the dyslexic population may have led to contrasting results, the aim of the study was to define the effect of age, dyslexia subtype and comorbidity on the discrimination and reproduction of non-verbal tone sequences. Participants were 46 children aged 8–14 (26 with dyslexia, subdivided according to age, presence of a previous language delay, and type of dyslexia). Experimental tasks were a Temporal Order Judgment (TOJ) (manipulating tone length, ISI and sequence length), and a Pattern Discrimination Task. Dyslexic children showed general RAP deficits. Tone length and ISI influenced dyslexic and control children's performance in a similar way, but dyslexic children were more affected by an increase from 2 to 5 sounds. As to age, older dyslexic children's difficulty in reproducing sequences of 4 and 5 tones was similar to that of normally reading younger (but not older) children. In the analysis of subgroup profiles, the crucial variable appears to be the advantage, or lack thereof, in processing long vs. short sounds. Dyslexic children with a previous language delay obtained the lowest scores in RAP measures, but they performed worse with shorter stimuli, similar to control children, while dyslexic-only children showed no advantage for longer stimuli. As to dyslexia subtype, only surface dyslexics improved their performance with longer stimuli, while phonological dyslexics did not. Differential scores for short vs. long tones and for long vs. short ISIs predict non-word and word reading, respectively, and the former correlate with phonemic awareness. In conclusion, the relationship between non-verbal RAP, phonemic skills and reading abilities appears to be characterized by complex interactions with subgroup characteristics.

Association between language development and auditory processing disorders1

Introduction

It is crucial to understand the complex processing of acoustic stimuli along the auditory pathway; comprehension of this complex processing can facilitate our understanding of the processes that underlie normal and altered human communication.

Aim

To investigate the performance and lateralization effects on auditory processing assessment in children with specific language impairment (SLI), relating these findings to those obtained in children with auditory processing disorder (APD) and typical development (TD).

Material and methods

Prospective study. Seventy-five children, aged 6-12 years, were separated in three groups: 25 children with SLI, 25 children with APD, and 25 children with TD. All went through the following tests: speech-in-noise test, Dichotic Digit test and Pitch Pattern Sequencing test.

Results

The effects of lateralization were observed only in the SLI group, with the left ear presenting much lower scores than those presented to the right ear. The inter-group analysis has shown that in all tests children from APD and SLI groups had significantly poorer performance compared to TD group. Moreover, SLI group presented worse results than APD group.

Conclusion

This study has shown, in children with SLI, an inefficient processing of essential sound components and an effect of lateralization. These findings may indicate that neural processes (required for auditory processing) are different between auditory processing and speech disorders.

Developmental changes in mismatch responses to mandarin consonants and lexical tones from early to middle childhood

The purpose of this study was to use mismatch responses (MMRs) to explore the dynamic changes of Mandarin speech perception abilities from early to middle childhood. Twenty preschoolers, 18 school-aged children, and 26 adults participated in this study. Two sets of synthesized speech stimuli varying in Mandarin consonant (alveolo-palatal affricate vs. fricative) and lexical tone features (rising vs. contour tone) were used to examine the developmental course of speech perception abilities. The results indicated that only the adult group demonstrated typical early mismatch negativity (MMN) responses, suggesting that the ability to discriminate specific speech cues in Mandarin consonant and lexical tone is a continuing process in preschool- and school-aged children. Additionally, distinct MMR patterns provided evidence indicating diverse developmental courses to different speech characteristics. By incorporating data from the two speech conditions, we propose using MMR profiles consisting of mismatch negativity (MMN), positive mismatch response (p-MMR), and late discriminative negativity (LDN) as possible brain indices to investigate speech perception development.

Auditory temporal structure processing in dyslexia: processing of prosodic phrase boundaries is not impaired in children with dyslexia

Reading disability in children with dyslexia has been proposed to reflect impairment in auditory timing perception. We investigated one aspect of timing perception--temporal grouping--as present in prosodic phrase boundaries of natural speech, in age-matched groups of children, ages 6-8 years, with and without dyslexia. Prosodic phrase boundaries are characterized by temporal grouping of functionally related speech elements and can facilitate syntactic processing of speech. For example, temporary syntactic ambiguities, such as early-closure structures, are processed faster when prosodic phrase boundaries are present. We examined children's prosodic facilitation by measuring their efficiency of sentence processing for temporary syntactic ambiguities spoken with (facilitating) versus without (neutral) prosodic phrase boundaries. Both groups of children benefited similarly from prosodic facilitation, displaying faster reaction times in facilitating compared to neutral prosody. These findings indicate that the use of prosodic phrase boundaries for speech processing is not impaired in children with dyslexia.

Cell size anomalies in the auditory thalamus of rats with hypoxic-ischemic injury on postnatal day 3 or 7

Children born prematurely (<37 weeks gestational age) or at very low birth weight (VLBW; <1500g) are at increased risk for hypoxic ischemic (HI) brain injuries. Term infants can also suffer HI from birth complications. In both groups, blood/oxygen delivery to the brain is compromised, often resulting in brain damage and later cognitive delays (e.g., language deficits). Literature suggests that language delays in a variety of developmentally impaired populations (including specific language impairment (SLI), dyslexia, and early HI-injury) may be associated with underlying deficits in rapid auditory processing (RAP; the ability to process and discriminate brief acoustic cues). Data supporting a relationship between RAP deficits and poor language outcomes is consistent with the "magnocellular theory," which purports that damage to or loss of large (magnocellular) cells in thalamic nuclei could underlie disruptions in temporal processing of sensory input, possibly including auditory (medial geniculate nucleus; MGN) information This theory could be applied to neonatal HI populations that show subsequent RAP deficits. In animal models of neonatal HI, persistent RAP deficits are seen in postnatal (P)7 HI injured rats (who exhibit neuropathology comparable to term birth injury), but not in P1-3 HI injured rodents (who exhibit neuropathology comparable to human pre-term injury). The current study sought to investigate the mean cell size, cell number, and cumulative probability of cell size in the MGN of P3 HI and P7 HI injured male rats that had previously demonstrated behavioral RAP deficits. Pilot data from our lab (Alexander, 2011) previously revealed cell size abnormalities (a shift toward smaller cells) in P7 but not P1 HI injured animals when compared to shams. Our current finding support this result, with evidence of a significant shift to smaller cells in the experimental MGN of P7 HI but not P3 HI subjects. P7 HI animals also showed significantly fewer cells in the affected (right) MGN as compared P3 HI and shams animals. Moreover, cell number in the right hemisphere was found to correlate with gap detection (fewer cells=worse performance) in P7 HI injured subjects. These findings could be applied to clinical populations, providing an anatomic marker that may index potential long-term language disabilities in HI injured infants and possibly other at-risk populations.

Sex differences in behavioral outcome following neonatal hypoxia ischemia: insights from a clinical meta-analysis and a rodent model of induced hypoxic ischemic brain injury

Hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) is one of the most common injuries among preterm infants and term infants with birth complications. Both populations show cognitive/behavioral deficits, including impairments in sensory, learning/memory, and attention domains. Clinical data suggests a sex difference in HI outcomes, with males exhibiting more severe cognitive/behavioral deficits relative to matched females. Our laboratory has also reported more severe behavioral deficits among male rats with induced HI relative to females with comparable injury (Hill et al., 2011a,b). The current study initially examined published clinical studies from the past 20years where long-term IQ outcome scores for matched groups of male and female premature infants were reported separately (IQ being the most common outcome measure). A meta-analysis revealed a female "advantage," as indicated by significantly better scores on performance and full scale IQ (but not verbal IQ) for premature females. We then utilized a rodent model of neonatal HI injury to assess sham and postnatal day 7 (P7) HI male and female rats on a battery of behavioral tasks. Results showed expected deficits in HI male rats, but also showed task-dependent sex differences, with HI males having significantly larger deficits than HI females on some tasks but equivalent deficits on other tasks. In contrast to behavioral results, post mortem neuropathology associated with HI was comparable across sex. These findings suggest: 1) neonatal female "protection" in some behavioral domains, as indexed by superior outcome following early injury relative to males; and 2) female protection may entail sex-specific plasticity or compensation, rather than a reduction in gross neuropathology. Further exploration of the mechanisms underlying this sex effect could aid in neuroprotection efforts for at-risk neonates in general, and males in particular. Moreover, our current report of comparable anatomical damage coupled with differences in cognitive outcomes (by sex) provides a framework for future studies to examine neural mechanisms underlying sex differences in cognition and behavior in general.

Effect of maturation on suprasegmental speech processing in full- and preterm infants: a mismatch negativity study

Infants born prematurely are at higher risk for later linguistic deficits present in delayed or atypical processing of phonetic and prosodic information. In order to be able to specify the nature of this atypical development, it is important to investigate the role of early experience in language perception. According to the concept of Gonzalez-Gomez and Nazzi (2012) there is a special intrauterine sensitivity to the prosodic features of languages that should have a special role in language acquisition. Therefore, we may also assume that pre- and full-term infants having months difference in intrauterine experience show different maturation patterns of processing prosodic and phonetic information present at word level. The aim of our study was to investigate the effect of these differences on word stress pattern vs. phoneme information processing. Two age groups of infants (6 and 10 month-olds) were included in our study. 21 of 46 of the total of infants investigated were prematurely born with low birth weight. We used the mismatch negativity (MMN) event related brain potential (ERP) component, a widely used electrophysiological correlate of acoustic change detection, for testing the assumed developmental changes of phoneme and word stress discrimination. In a passive oddball paradigm we used a word as standard, a pseudo-word as phoneme deviant, and an illegally uttered word as stress deviant. Our results showed no differences in MMN responses in the phoneme deviant condition between the groups, meaning a relatively intact maturation of phoneme processing of preterm infants as compared to their contemporaries. However, the mismatch responses measured in the stress condition revealed significant between-group differences. These results strengthen the view that the total length of intrauterine experience influences the time of emergence of prosodic processing.

Physiologic discrimination of stop consonants relates to phonological skills in pre-readers: a biomarker for subsequent reading ability?(†)

Reading development builds upon the accurate representation of the phonological structure of spoken language. This representation and its neural foundations have been studied extensively with respect to reading due to pervasive performance deficits on basic phonological tasks observed in children with dyslexia. The subcortical auditory system - a site of intersection for sensory and cognitive input - is exquisitely tuned to code fine timing differences between phonemes, and so likely plays a foundational role in the development of phonological processing and, eventually, reading. This temporal coding of speech varies systematically with reading ability in school age children. Little is known, however, about subcortical speech representation in pre-school age children. We measured auditory brainstem responses to the stop consonants [ba] and [ga] in a cohort of 4-year-old children and assessed their phonological skills. In a typical auditory system, brainstem responses to [ba] and [ga] are out of phase (i.e., differ in time) due to formant frequency differences in the consonant-vowel transitions of the stimuli. We found that children who performed worst on the phonological awareness task insufficiently code this difference, revealing a physiologic link between early phonological skills and the neural representation of speech. We discuss this finding in light of existing theories of the role of the auditory system in developmental dyslexia, and argue for a systems-level perspective for understanding the importance of precise temporal coding for learning to read.

Training in rapid auditory processing ameliorates auditory comprehension in aphasic patients: a randomized controlled pilot study

Experimental studies have often reported close associations between rapid auditory processing and language competency. The present study was aimed at improving auditory comprehension in aphasic patients following specific training in the perception of temporal order (TO) of events. We tested 18 aphasic patients showing both comprehension and TO perception deficits. Auditory comprehension was assessed by the Token Test, phonemic awareness and Voice-Onset-Time Test. The TO perception was assessed using auditory Temporal-Order-Threshold, defined as the shortest interval between two consecutive stimuli, necessary to report correctly their before-after relation. Aphasic patients participated in eight 45-minute sessions of either specific temporal training (TT, n=11) aimed to improve sequencing abilities, or control non-temporal training (NT, n=7) focussed on volume discrimination. The TT yielded improved TO perception; moreover, a transfer of improvement was observed from the time domain to the language domain, which was untrained during the training. The NT did not improve either the TO perception or comprehension in any language test. These results are in agreement with previous literature studies which proved ameliorated language competency following the TT in language-learning-impaired or dyslexic children. Our results indicated for the first time such benefits also in aphasic patients.

From temporal processing to developmental language disorders: mind the gap

The 'rapid temporal processing' and the 'temporal sampling framework' hypotheses have been proposed to account for the deficits in language and literacy development seen in specific language impairment and dyslexia. This paper reviews these hypotheses and concludes that the proposed causal chains between the presumed auditory processing deficits and the observed behavioural manifestation of the disorders are vague and not well established empirically. Several problems and limitations are identified. Most data concern correlations between distantly related tasks, and there is considerable heterogeneity and variability in performance as well as concerns about reliability and validity. Little attention is paid to the distinction between ostensibly perceptual and metalinguistic tasks or between implicit and explicit modes of performance, yet measures are assumed to be pure indicators of underlying processes or representations. The possibility that diagnostic categories do not refer to causally and behaviourally homogeneous groups needs to be taken seriously, taking into account genetic and neurodevelopmental studies to construct multiple-risk models. To make progress in the field, cognitive models of each task must be specified, including performance domains that are predicted to be deficient versus intact, testing multiple indicators of latent constructs and demonstrating construct reliability and validity.

Behavioral and histological outcomes following neonatal HI injury in a preterm (P3) and term (P7) rodent model

Hypoxia-ischemia (HI) occurs when blood and/or oxygen delivery to the brain is compromised. HI injuries can occur in infants born prematurely (<37 weeks gestational age) or at very low birth weight (<1500 g), as well as in term infants with birth complications. In both preterm and term HI populations, brain injury is associated with subsequent behavioral deficits. Neonatal HI injury can be modeled in rodents (e.g., the Rice-Vannucci method, via cautery of right carotid followed by hypoxia). When this injury is induced early in life (between postnatal day (P)1-5), neuropathologies typical of human preterm HI are modeled. When injury is induced later (P7-12), neuropathologies typical of those seen in HI term infants are modeled. The current study sought to characterize the similarities/differences between outcomes following early (P3) and late (P7) HI injury in rats. Male rats with HI injury on P3 or P7, as well as sham controls, were tested on a variety of behavioral tasks in both juvenile and adult periods. Results showed that P7 HI rats displayed deficits on motor learning, rapid auditory processing (RAP), and other learning/memory tasks, as well as a reduction in volume in various neuroanatomical structures. P3 HI animals showed only transient deficits on RAP tasks in the juvenile period (but not in adulthood), yet robust deficits on a visual attention task in adulthood. P3 HI animals did not show any significant reductions in brain volume that we could detect. These data suggest that: (1) behavioral deficits following neonatal HI are task-specific depending on timing of injury; (2) P3 HI rats showed transient deficits on RAP tasks; (3) the more pervasive behavioral deficits seen following P7 HI injury were associated with substantial global tissue loss; and (4) persistent deficits in attention in P3 HI subjects might be linked to neural connectivity disturbances rather than a global loss of brain volume, given that no such pathology was found. These combined findings can be applied to our understanding of differing long-term outcomes following neonatal HI injury in premature versus term infants.

Cerebellar function in developmental dyslexia

Developmental dyslexia is a genetically based neurobiological syndrome, which is characterized by reading difficulty despite normal or high general intelligence. Even remediated dyslexic readers rarely achieve fast, fluent reading. Some dyslexics also have impairments in attention, short-term memory, sequencing (letters, word sounds, and motor acts), eye movements, poor balance, and general clumsiness. The presence of "cerebellar" motor and fluency symptoms led to the proposal that cerebellar dysfunction contributes to the etiology of dyslexia. Supporting this, functional imaging studies suggest that the cerebellum is part of the neural network supporting reading in typically developing readers, and reading difficulties have been reported in patients with cerebellar damage. Differences in both cerebellar asymmetry and gray matter volume are some of the most consistent structural brain findings in dyslexics compared with good readers. Furthermore, cerebellar functional activation patterns during reading and motor learning can differ in dyslexic readers. Behaviorally, some children and adults with dyslexia show poorer performance on cerebellar motor tasks, including eye movement control, postural stability, and implicit motor learning. However, many dyslexics do not have cerebellar signs, many cerebellar patients do not have reading problems, and differences in dyslexic brains are found throughout the whole reading network, and not isolated to the cerebellum. Therefore, impaired cerebellar function is probably not the primary cause of dyslexia, but rather a more fundamental neurodevelopmental abnormality leads to differences throughout the reading network.

Visual attentional engagement deficits in children with specific language impairment and their role in real-time language processing

In order to become a proficient user of language, infants must detect temporal cues embedded within the noisy acoustic spectra of ongoing speech by efficient attentional engagement. According to the neuro-constructivist approach, a multi-sensory dysfunction of attentional engagement - hampering the temporal sampling of stimuli - might be responsible for language deficits typically shown in children with Specific Language Impairment (SLI). In the present study, the efficiency of visual attentional engagement was investigated in 22 children with SLI and 22 typically developing (TD) children by measuring attentional masking (AM). AM refers to impaired identification of the first of two sequentially presented masked objects (O1 and O2) in which the O1-O2 interval was manipulated. Lexical and grammatical comprehension abilities were also tested in both groups. Children with SLI showed a sluggish engagement of temporal attention, and individual differences in AM accounted for a significant percentage of unique variance in grammatical performance. Our results suggest that an attentional engagement deficit - probably linked to a dysfunction of the right fronto-parietal attentional network - might be a contributing factor in these children's language impairments.

Word stress processing in specific language impairment: auditory or representational deficits?

Word stress processing has repeatedly been reported to be affected in specific language impairment (SLI) with potential consequences for various aspects of language development. However, it still remains unresolved whether word stress impairments in SLI are due to deficits in basic auditory processing or to a degraded phonological representation or both. We addressed this question examining an unselected sample of 10 children with SLI and 11 typically developing (TD) children, aged about 8 years, with respect to their basic auditory processing (duration and skewness discrimination) and phonological representation of prosodic (word stress) and segmental (consonant) contrasts. Our results show lower performance of the SLI group compared to the TD group in all tasks. Crucially, two subgroups of children with SLI emerged from our analyses: While one group was impaired in basic auditory perception, particularly affecting duration discrimination, the other showed no significant auditory processing deficits but a representational impairment.

Musical, language, and reading abilities in early Portuguese readers

Early language and reading abilities have been shown to correlate with a variety of musical skills and elements of music perception in children. It has also been shown that reading impaired children can show difficulties with music perception. However, it is still unclear to what extent different aspects of music perception are associated with language and reading abilities. Here we investigated the relationship between cognitive-linguistic abilities and a music discrimination task that preserves an ecologically valid musical experience. 43 Portuguese-speaking students from an elementary school in Brazil participated in this study. Children completed a comprehensive cognitive-linguistic battery of assessments. The music task was presented live in the music classroom, and children were asked to code sequences of four sounds on the guitar. Results show a strong relationship between performance on the music task and a number of linguistic variables. A principle component analysis of the cognitive-linguistic battery revealed that the strongest component (Prin1) accounted for 33% of the variance and Prin1 was significantly related to the music task. Highest loadings on Prin1 were found for reading measures such as Reading Speed and Reading Accuracy. Interestingly, 22 children recorded responses for more than four sounds within a trial on the music task, which was classified as Superfluous Responses (SR). SR was negatively correlated with a variety of linguistic variables and showed a negative correlation with Prin1. When analyzing children with and without SR separately, only children with SR showed a significant correlation between Prin1 and the music task. Our results provide implications for the use of an ecologically valid music-based screening tool for the early identification of reading disabilities in a classroom setting.

Altered neuronal response during rapid auditory processing and its relation to phonological processing in prereading children at familial risk for dyslexia

Developmental dyslexia (DD) is a learning disability affecting 5-17% of children. Although researchers agree that DD is characterized by deficient phonological processing (PP), its cause is debated. It has been suggested that altered rapid auditory processing (RAP) may lead to deficient PP in DD and studies have shown deficient RAP in individuals with DD. Functional neuroimaging (fMRI) studies have implicated hypoactivations in left prefrontal brain regions during RAP in individuals with DD. When and how these neuronal alterations evolve remains unknown. In this article, we investigate functional networks during RAP in 28 children with (n = 14) and without (n = 14) a familial risk for DD before reading onset (mean: 5.6 years). Results reveal functional alterations in left-hemispheric prefrontal regions during RAP in prereading children at risk for DD, similar to findings in individuals with DD. Furthermore, activation during RAP in left prefrontal regions positively correlates with prereading measures of PP and with neuronal activation during PP in posterior dorsal and ventral brain areas. Our results suggest that neuronal differences during RAP predate reading instruction and thus are not due to experience-dependent brain changes resulting from DD itself and that there is a functional relationship between neuronal networks for RAP and PP within the prereading brain.

The epigenetics of maternal cigarette smoking during pregnancy and effects on child development

The period of in utero development is one of the most critical windows during which adverse intrauterine conditions and exposures can influence the growth and development of the fetus as well as the child's future postnatal health and behavior. Maternal cigarette smoking during pregnancy remains a relatively common but nonetheless hazardous in utero exposure. Previous studies have associated prenatal smoke exposure with reduced birth weight, poor developmental and psychological outcomes, and increased risk for diseases and behavioral disorders later in life. Researchers are now learning that many of the mechanisms whereby maternal smoke exposure may affect key pathways crucial for proper fetal growth and development are epigenetic in nature. Maternal cigarette smoking during pregnancy has been associated with altered DNA methylation and dysregulated expression of microRNA, but a deeper understanding of the epigenetics of maternal cigarette smoking during pregnancy as well as how these epigenetic changes may affect later health and behavior remain to be elucidated. This article seeks to explore many of the previously described epigenetic alterations associated with maternal cigarette smoking during pregnancy and assess how such changes may have consequences for both fetal growth and development, as well as later child health, behavior, and well-being. We also outline future directions for this new and exciting field of research.

Knockdown of the candidate dyslexia susceptibility gene homolog dyx1c1 in rodents: effects on auditory processing, visual attention, and cortical and thalamic anatomy

The current study investigated the behavioral and neuroanatomical effects of embryonic knockdown of the candidate dyslexia susceptibility gene (CDSG) homolog Dyx1c1 through RNA interference (RNAi) in rats. Specifically, we examined long-term effects on visual attention abilities in male rats, in addition to assessing rapid and complex auditory processing abilities in male and, for the first time, female rats. Our results replicated prior evidence of complex acoustic processing deficits in Dyx1c1 male rats and revealed new evidence of comparable deficits in Dyx1c1 female rats. Moreover, we found new evidence that knocking down Dyx1c1 produced orthogonal impairments in visual attention in the male subgroup. Stereological analyses of male brains from prior RNAi studies revealed that, despite consistent visible evidence of disruptions of neuronal migration (i.e., heterotopia), knockdown of Dyx1c1 did not significantly alter the cortical volume, hippocampal volume, or midsagittal area of the corpus callosum (measured in a separate cohort of like-treated Dyx1c1 male rats). Dyx1c1 transfection did, however, lead to significant changes in medial geniculate nucleus (MGN) anatomy, with a significant shift to smaller MGN neurons in Dyx1c1-transfected animals. Combined results provide important information about the impact of Dyx1c1 on behavioral functions that parallel domains known to be affected in language-impaired populations as well as information about widespread changes to the brain following early disruption of this CDSG.

Neuroplasticity-based cognitive and linguistic skills training improves reading and writing skills in college students

This study reports an evaluation of the effect of computer-based cognitive and linguistic training on college students' reading and writing skills. The computer-based training included a series of increasingly challenging software programs that were designed to strengthen students' foundational cognitive skills (memory, attention span, processing speed, and sequencing) in the context of listening and higher level reading tasks. Twenty-five college students (12 native English language; 13 English Second Language), who demonstrated poor writing skills, participated in the training group. The training group received daily training during the spring semester (11 weeks) with the Fast ForWord Literacy (FFW-L) and upper levels of the Fast ForWord Reading series (Levels 3-5). The comparison group (n = 28) selected from the general college population did not receive training. Both the training and comparison groups attended the same university. All students took the Gates MacGinitie Reading Test (GMRT) and the Oral and Written Language Scales (OWLS) Written Expression Scale at the beginning (Time 1) and end (Time 2) of the spring college semester. Results from this study showed that the training group made a statistically greater improvement from Time 1 to Time 2 in both their reading skills and their writing skills than the comparison group. The group who received training began with statistically lower writing skills before training, but exceeded the writing skills of the comparison group after training.

Early gamma oscillations during rapid auditory processing in children with a language-learning impairment: changes in neural mass activity after training

Children with language-learning impairment (LLI) have consistently shown difficulty with tasks requiring precise, rapid auditory processing. Remediation based on neural plasticity assumes that the temporal precision of neural coding can be improved by intensive training protocols. Here, we examined the extent to which early oscillatory responses in auditory cortex change after audio-visual training, using combined source modeling and time-frequency analysis of the human electroencephalogram (EEG). Twenty-one elementary school students diagnosed with LLI underwent the intervention for an average of 32 days. Pre- and post-training assessments included standardized language/literacy tests and EEG recordings in response to fast-rate tone doublets. Twelve children with typical language development were also tested twice, with no intervention given. Behaviorally, improvements on measures of language were observed in the LLI group following completion of training. During the first EEG assessment, we found reduced amplitude and phase-locking of early (45-75 ms) oscillations in the gamma-band range (29-52 Hz), specifically in the LLI group, for the second stimulus of the tone doublet. Amplitude reduction for the second tone was no longer evident for the LLI children post-intervention, although these children still exhibited attenuated phase-locking. Our findings suggest that specific aspects of inefficient sensory cortical processing in LLI are ameliorated after training.

Evaluation of the therapeutic benefit of delayed administration of erythropoietin following early hypoxic-ischemic injury in rodents

Hypoxia-ischemia (HI) and associated brain injuries are seen in premature as well as term infants with birth complications. The resulting impairments involve deficits in many cognitive domains, including language development. Poor rapid auditory processing is hypothesized to be one possible underlying factor leading to subsequent language delays. Mild hypothermia treatment for HI injuries in term infants is widely used as an intervention but can be costly and time consuming. Data suggest that the effectiveness of hypothermia treatment following HI injury declines beyond 6 h following injury. Consequently, the availability of a therapeutic alternative without these limitations could allow doctors to treat HI-injured infants more effectively and thus reduce deleterious cognitive and language outcomes. Evidence from both human studies and animal models of neonatal HI suggests that erythropoietin (Epo), an endogenous cytokine hormone, may be a therapeutic agent that can ameliorate HI brain injury and preserve subsequent cognitive development and function. The current study sought to investigate the therapeutic effectiveness of Epo when administered immediately after HI injury, or delayed at intervals following the injury, in neonatal rodents. Rat pups received an induced HI injury on postnatal day 7, followed by an intraperitoneal injection of Epo (1,000 U/kg) immediately, 60 min, or 180 min following induction of injury. Subjects were tested on rapid auditory processing tasks in juvenile (P38-42) and adult periods (P80-85). Ventricular and cortical size was also measured from post mortem tissue. Results from the current study show a therapeutic benefit of Epo when given immediately following induction of HI injury, with diminished benefit from a 60-min-delayed injection of Epo and no protection following a 180-min-delayed injection. The current data thus show that the effectiveness of a single dose of Epo in ameliorating auditory processing deficits following HI injury decreases precipitously as treatment is delayed following injury. These data may have important implications for experimental human neonatal intervention with Epo.

Fast ForWord®: the birth of the neurocognitive training revolution

In 1996, I cofounded Scientific Learning Corporation (SLC) with Drs Michael Merzenich, William Jenkins, and Steve Miller. I coined the term "Cogniceutical" to describe the new type of company we envisioned. SLC was the first company cofounded by academic scientists with the mission of building neurocognitive interventions. Fast ForWord® is the registered trade name of the platform SLC built to translate basic neuroplasticity-based training research into clinical and educational products. Fast ForWord® was the first cognitive neurotherapeutic intervention, the first to be individually adaptive in real time, the first "brain fitness" program that collected data over the Internet, and the first to use computer gaming technologies to change brains and enhance human potential. We included lofty goals in our first business plan for SLC. These included: using neuroplasticity-based training to improve language, literacy, and other academic skills; helping seniors maintain and recover function; helping people learn English as a second language; helping patient populations with neurological or mental disorders. SLC's first focus became improving language and literacy. Mike, Bill, Steve, and I began this journey together in 1994 with a laboratory-based research study that included seven children. To date, over two million children in 46 countries have used Fast ForWord® products. On any given school day, approximately 60,000 children log in to train on 1 of 10 Fast ForWord Language, Literacy, or Reading programs. We did not know at the time that we were creating what became a "disruptive innovation." This chapter chronicles this transformational journey.

Developmental trends in auditory processing can provide early predictions of language acquisition in young infants

Auditory processing capabilities at the subcortical level have been hypothesized to impact an individual's development of both language and reading abilities. The present study examined whether auditory processing capabilities relate to language development in healthy 9-month-old infants. Participants were 71 infants (31 boys and 40 girls) with both Auditory Brainstem Response (ABR) and language assessments. At 6 weeks and/or 9 months of age, the infants underwent ABR testing using both a standard hearing screening protocol with 30 dB clicks and a second protocol using click pairs separated by 8, 16, and 64-ms intervals presented at 80 dB. We evaluated the effects of interval duration on ABR latency and amplitude elicited by the second click. At 9 months, language development was assessed via parent report on the Chinese Communicative Development Inventory - Putonghua version (CCDI-P). Wave V latency z-scores of the 64-ms condition at 6 weeks showed strong direct relationships with Wave V latency in the same condition at 9 months. More importantly, shorter Wave V latencies at 9 months showed strong relationships with the CCDI-P composite consisting of phrases understood, gestures, and words produced. Likewise, infants who had greater decreases in Wave V latencies from 6 weeks to 9 months had higher CCDI-P composite scores. Females had higher language development scores and shorter Wave V latencies at both ages than males. Interestingly, when the ABR Wave V latencies at both ages were taken into account, the direct effects of gender on language disappeared. In conclusion, these results support the importance of low-level auditory processing capabilities for early language acquisition in a population of typically developing young infants. Moreover, the auditory brainstem response in this paradigm shows promise as an electrophysiological marker to predict individual differences in language development in young children.

Language and motor abilities of preschool children who stutter: evidence from behavioral and kinematic indices of nonword repetition performance

Stuttering is a disorder of speech production that typically arises in the preschool years, and many accounts of its onset and development implicate language and motor processes as critical underlying factors. There have, however, been very few studies of speech motor control processes in preschool children who stutter. Hearing novel nonwords and reproducing them engages multiple neural networks, including those involved in phonological analysis and storage and speech motor programming and execution. We used this task to explore speech motor and language abilities of 31 children aged 4-5 years who were diagnosed as stuttering. We also used sensitive and specific standardized tests of speech and language abilities to determine which of the children who stutter had concomitant language and/or phonological disorders. Approximately half of our sample of stuttering children had language and/or phonological disorders. As previous investigations would suggest, the stuttering children with concomitant language or speech sound disorders produced significantly more errors on the nonword repetition task compared to typically developing children. In contrast, the children who were diagnosed as stuttering, but who had normal speech sound and language abilities, performed the nonword repetition task with equal accuracy compared to their normally fluent peers. Analyses of interarticulator motions during accurate and fluent productions of the nonwords revealed that the children who stutter (without concomitant disorders) showed higher variability in oral motor coordination indices. These results provide new evidence that preschool children diagnosed as stuttering lag their typically developing peers in maturation of speech motor control processes.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) discuss why performance on nonword repetition tasks has been investigated in children who stutter; (b) discuss why children who stutter in the current study had a higher incidence of concomitant language deficits compared to several other studies; (c) describe how performance differed on a nonword repetition test between children who stutter who do and do not have concomitant speech or language deficits; (d) make a general statement about speech motor control for nonword production in children who stutter compared to controls.

Music and early language acquisition

Language is typically viewed as fundamental to human intelligence. Music, while recognized as a human universal, is often treated as an ancillary ability - one dependent on or derivative of language. In contrast, we argue that it is more productive from a developmental perspective to describe spoken language as a special type of music. A review of existing studies presents a compelling case that musical hearing and ability is essential to language acquisition. In addition, we challenge the prevailing view that music cognition matures more slowly than language and is more difficult; instead, we argue that music learning matches the speed and effort of language acquisition. We conclude that music merits a central place in our understanding of human development.

Infant word segmentation and childhood vocabulary development: a longitudinal analysis

Infants begin to segment novel words from speech by 7.5 months, demonstrating an ability to track, encode and retrieve words in the context of larger units. Although it is presumed that word recognition at this stage is a prerequisite to constructing a vocabulary, the continuity between these stages of development has not yet been empirically demonstrated. The goal of the present study is to investigate whether infant word segmentation skills are indeed related to later lexical development. Two word segmentation tasks, varying in complexity, were administered in infancy and related to childhood outcome measures. Outcome measures consisted of age-normed productive vocabulary percentiles and a measure of cognitive development. Results demonstrated a strong degree of association between infant word segmentation abilities at 7 months and productive vocabulary size at 24 months. In addition, outcome groups, as defined by median vocabulary size and growth trajectories at 24 months, showed distinct word segmentation abilities as infants. These findings provide the first prospective evidence supporting the predictive validity of infant word segmentation tasks and suggest that they are indeed associated with mature word knowledge. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=jxzLi5oLZQ8.

Contribution of temporal processing skills to reading comprehension in 8-year-olds: evidence for a mediation effect of phonological awareness

This study tested whether the association between temporal processing (TP) and reading is mediated by phonological awareness (PA) in a normative sample of 615 eight-year-olds. TP was measured with auditory and bimodal (visual-auditory) temporal order judgment tasks and PA with a phoneme deletion task. PA partially mediated the association between both auditory and bimodal TP and reading, above nonverbal abilities, vocabulary, and processing speed. PA explained a larger proportion of the association between auditory TP and reading (56% vs. 39% for bimodal TP), and most of the association between bimodal TP and reading was direct. This finding is consistent with a dual-phonological and visual-pathway model of the association between TP and reading in normative reading skills.

Subcortical representation of speech fine structure relates to reading ability

Impaired perception of consonants by poor readers is reflected in poor subcortical encoding of speech timing and harmonics. We assessed auditory brainstem representation of higher harmonics within a consonant-vowel formant transition to identify relationships between speech fine structure and reading. Responses were analyzed in three ways: a single stimulus polarity, adding responses to inverted polarities (emphasizing low harmonics), and subtracting responses to inverted polarities (emphasizing high harmonics). Poor readers had a reduced representation of higher speech harmonics for subtracted polarities and a single polarity. No group differences were found for the fundamental frequency. These findings strengthen the evidence of subcortical encoding deficits in poor readers for speech fine structure and delineate effective strategies for capturing these neural impairments in humans.

Auditory stimulation of opera music induced prolongation of murine cardiac allograft survival and maintained generation of regulatory CD4+CD25+ cells

BACKGROUND

Interactions between the immune response and brain functions such as olfactory, auditory, and visual sensations are likely. This study investigated the effect of sounds on alloimmune responses in a murine model of cardiac allograft transplantation.

METHODS

Naïve CBA mice (H2k) underwent transplantation of a C57BL/6 (B6, H2b) heart and were exposed to one of three types of music--opera (La Traviata), classical (Mozart), and New Age (Enya)--or one of six different single sound frequencies, for 7 days. Additionally, we prepared two groups of CBA recipients with tympanic membrane perforation exposed to opera for 7 days and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment). An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Immunohistochemical, cell-proliferation, cytokine, and flow cytometry assessments were also performed.

RESULTS

CBA recipients of a B6 cardiac graft that were exposed to opera music and Mozart had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to a single sound frequency (100, 500, 1000, 5000, 10,000, or 20,000 Hz) or Enya did not (MSTs, 7.5, 8, 9, 8, 7.5, 8.5 and 11 days, respectively). Untreated, CBA mice with tympanic membrane perforations and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment) rejected B6 cardiac grafts acutely (MSTs, 7, 8 and 8 days, respectively). Adoptive transfer of whole splenocytes, CD4+ cells, or CD4+CD25+ cells from opera-exposed primary allograft recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and > 100 days, respectively). Proliferation of splenocytes, interleukin (IL)-2 and interferon (IFN)-γ production was suppressed in opera-exposed mice, and production of IL-4 and IL-10 from opera-exposed transplant recipients increased compared to that from splenocytes of untreated recipients. Flow cytometry studies showed an increased CD4+CD25+ Forkhead box P3 (Foxp3)+ cell population in splenocytes from those mice.

CONCLUSION

Our findings indicate that exposure to opera music, such as La traviata, could affect such aspects of the peripheral immune response as generation of regulatory CD4+CD25+ cells and up-regulation of anti-inflammatory cytokines, resulting in prolonged allograft survival.

Maturational changes in the human envelope-following responses

INTRODUCTION

The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. Human envelope-following responses (EFRs) are useful for objective measurement of temporal auditory processing in subjects who are unable to give accurate behavioural responses (e.g., young children).

OBJECTIVE

To evaluate age-dependent changes in EFRs during the first 2 years of life.

METHODS

The EFRs were recorded in a sample of 16 well babies distributed into 2 age groups (G1: 12 newborns; G2: 4 babies of 2 years). The EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200 Hz presented at 50 dB HL.

RESULTS

The age-related changes affected both morphology and EFR detectability. The main morphological differences were at the expense of frequencies below 50 Hz, where the first component P1 was not well defined in either of the 2 age groups. For all modulation frequencies, age significantly affected EFR amplitude and detectability.

CONCLUSIONS

The present study provides the first evidence on EFR maturation. Some understanding of normal EFR development would facilitate a better use of this technique in clinically-objective measurement of auditory temporal processing in infants who cannot provide reliable behavioural responses.

Assessing speech perception in children with language difficulties: effects of background noise and phonetic contrast

Deficits in speech perception are reported for some children with language impairments. This deficit is more marked when listening against background noise. This study investigated the speech perception skills of young children with and without language difficulties. A speech discrimination task, using non-word minimal pairs in an XAB paradigm, was presented to 20 5-7-year-old children with language difficulties and 33 typically-developing (TD) children aged between 4- to 7-years. Stimuli were presented in quiet and in background noise (babble), and stimuli varied in phonetic contrasts, differing in either place of articulation or presence/absence of voicing. Children with language difficulties performed less well than TD children in all conditions. There was an interaction between group and noise condition, such that children with language difficulties were more affected by the presence of noise. Both groups of children made more errors with one voicing contrast /s z/ and there was some indication that children with language difficulties had proportionately greater difficulty with this contrast. Speech discrimination scores were significantly correlated with language scores for children with language difficulties. Issues in developing material for assessment of speech discrimination in children with LI are discussed.

Individual differences in lexical processing at 18 months predict vocabulary growth in typically developing and late-talking toddlers

Using online measures of familiar word recognition in the looking-while-listening procedure, this prospective longitudinal study revealed robust links between processing efficiency and vocabulary growth from 18 to 30 months in children classified as typically developing (n = 46) and as "late talkers" (n = 36) at 18 months. Those late talkers who were more efficient in word recognition at 18 months were also more likely to "bloom," showing more accelerated vocabulary growth over the following year, compared with late talkers less efficient in early speech processing. Such findings support the emerging view that early differences in processing efficiency evident in infancy have cascading consequences for later learning and may be continuous with individual differences in language proficiency observed in older children and adults.

Auditory processing in children and adolescents in situations of risk and vulnerability

CONTEXT AND OBJECTIVE

Children and adolescents who live in situations of social vulnerability present a series of health problems. Nonetheless, affirmations that sensory and cognitive abnormalities are present are a matter of controversy. The aim of this study was to investigate aspects to auditory processing, through applying the brainstem auditory evoked potential (BAEP) and behavioral auditory processing tests to children living on the streets, and comparison with a control group.

DESIGN AND SETTING

Cross-sectional study in the Laboratory of Auditory Processing, School of Medicine, Universidade de São Paulo.

METHODS

The auditory processing tests were applied to a group of 27 individuals, subdivided into 11 children (7 to 10 years old) and 16 adolescents (11 to 16 years old), of both sexes, in situations of social vulnerability, compared with an age-matched control group of 10 children and 11 adolescents without complaints. The BAEP test was also applied to investigate the integrity of the auditory pathway.

RESULTS

For both children and adolescents, there were significant differences between the study and control groups in most of the tests applied, with significantly worse performance in the study group, except in the pediatric speech intelligibility test. Only one child had an abnormal result in the BAEP test.

CONCLUSIONS

The results showed that the study group (children and adolescents) presented poor performance in the behavioral auditory processing tests, despite their unaltered auditory brainstem pathways, as shown by their normal results in the BAEP test.

Fetal head circumference growth in children with specific language impairment

OBJECTIVE

To characterise fetal brain growth in children with specific language impairment (SLI).

DESIGN

A nested case-control study.

SETTING

Perth, Western Australia.

PARTICIPANTS

Thirty children meeting criteria for SLI at age 10 years were individually matched with a typically developing comparison child on sex, non-verbal ability, fetal gestational age, maternal age at conception, smoking and alcohol intake during pregnancy.

MAIN OUTCOME MEASURES

Occipitofrontal head circumference (HC) was measured using ultrasonography at approximately 18 weeks gestation. Femur length provided a measure of fetal length. Occipitofrontal HC was measured at birth and at the 1-year postnatal follow-up using a precise paper tape measure, while crown-heel length acted as an index of body length at both time points. Raw data were transformed to z-scores using reference norms.

RESULTS

The SLI group had a significantly smaller mean HC than the typically developing comparison children at birth, but there was no group difference at 18 weeks gestation or at the 1-year postnatal follow-up. Individual analyses found that 12 SLI children had an HC z-score less than -1 at birth, with three of these cases meeting criteria for microcephaly. There was no group difference in the indices of overall body size at any time point.

CONCLUSIONS

Children with SLI are more likely to have a small HC at birth but not at 18 weeks gestation or infancy, suggesting growth asynchrony in brain development during the second half of pregnancy.

Electrophysiological evidence for attenuated auditory recovery cycles in children with specific language impairment

Previous research indicates that at least some children with specific language impairment (SLI) show a reduced neural response when non-linguistic tones were presented at rapid rates. However, this past research has examined older children, and it is unclear whether such deficits emerge earlier in development. It is also unclear whether atypical refractory effects differ for linguistic versus non-linguistic stimuli or can be explained by deficits in selective auditory attention reported among children with SLI. In the present study, auditory refractory periods were compared in a group of 24 young children with SLI (age 3-8 years) and 24 matched control children. Event-related brain potentials (ERPs) were recorded and compared to 100 ms linguistic and non-linguistic probe stimuli presented at inter-stimulus intervals (ISIs) of 200, 500, or 1000 ms. These probes were superimposed on story narratives when attended and ignored, permitting an experimental manipulation of selective attention within the same paradigm. Across participants, clear refractory effects were observed with this paradigm, evidenced as a reduced amplitude response from 100 to 200 ms at shorter ISIs. Children with SLI showed reduced amplitude ERPs relative to the typically-developing group at only the shortest, 200 ms, ISI and this difference was over the left-hemisphere for linguistic probes and over the right-hemisphere for non-linguistic probes. None of these effects was influenced by the direction of selective attention. Taken together, these findings suggest that deficits in the neural representation of rapidly presented auditory stimuli may be one risk factor for atypical language development.

The mismatch negativity (MMN)--a unique window to disturbed central auditory processing in ageing and different clinical conditions

In this article, we review clinical research using the mismatch negativity (MMN), a change-detection response of the brain elicited even in the absence of attention or behavioural task. In these studies, the MMN was usually elicited by employing occasional frequency, duration or speech-sound changes in repetitive background stimulation while the patient was reading or watching videos. It was found that in a large number of different neuropsychiatric, neurological and neurodevelopmental disorders, as well as in normal ageing, the MMN amplitude was attenuated and peak latency prolonged. Besides indexing decreased discrimination accuracy, these effects may also reflect, depending on the specific stimulus paradigm used, decreased sensory-memory duration, abnormal perception or attention control or, most importantly, cognitive decline. In fact, MMN deficiency appears to index cognitive decline irrespective of the specific symptomatologies and aetiologies of the different disorders involved.

Playing Music for a Smarter Ear: Cognitive, Perceptual and Neurobiological Evidence

Human hearing depends on a combination of cognitive and sensory processes that function by means of an interactive circuitry of bottom-up and top-down neural pathways, extending from the cochlea to the cortex and back again. Given that similar neural pathways are recruited to process sounds related to both music and language, it is not surprising that the auditory expertise gained over years of consistent music practice fine-tunes the human auditory system in a comprehensive fashion, strengthening neurobiological and cognitive underpinnings of both music and speech processing. In this review we argue not only that common neural mechanisms for speech and music exist, but that experience in music leads to enhancements in sensory and cognitive contributors to speech processing. Of specific interest is the potential for music training to bolster neural mechanisms that undergird language-related skills, such as reading and hearing speech in background noise, which are critical to academic progress, emotional health, and vocational success.

The role of early auditory development in attachment and communication

Auditory perception and learning take place during the third trimester of gestation. Fetuses and newborns who lack typical auditory experience can go on to develop typical socioemotional attachment and language, given a supportive environment. For hospitalized preterm infants in developmentally sensitive neonatal intensive care units, detrimental effects of deviant early auditory experience may be remediated by later experience, but much is unknown about the causes of language deficits of prematurity. Prenatal auditory stimulation programs that incorporate audio speakers against the maternal belly should be discouraged because of possible overstimulation effects on the developing auditory system and sleep/wake state organization.

Inhibition of X-linked inhibitor of apoptosis with embelin differentially affects male versus female behavioral outcome following neonatal hypoxia-ischemia in rats

Hypoxia-ischemia (HI; concurrent oxygen/blood deficiency) and associated encephalopathy represent a common cause of neurological injury in premature/low-birth-weight infants and term infants with birth complications. Resulting behavioral impairments include cognitive and/or sensory processing deficits, as well as language disabilities, and clinical evidence shows that male infants with HI exhibit more severe cognitive deficits compared to females with equivalent injury. Evidence also demonstrates activation of sex-dependent apoptotic pathways following HI events, with males preferentially activating a caspase-independent cascade of cell death and females preferentially activating a caspase-dependent cascade following neonatal hypoxic and/or ischemic insults. Based on these combined data, the 'female protection' following HI injury may reflect the endogenous X-linked inhibitor of apoptosis (XIAP), which effectively binds effector caspases and halts downstream cleavage of effector caspases (thus reducing cell death). To test this theory, the current study utilized neonatal injections of vehicle or embelin (a small molecule inhibitor of XIAP) in male and female rats with or without induced HI injury on postnatal day 7 (P7). Subsequent behavioral testing using a clinically relevant task revealed that the inhibition of XIAP exacerbated HI-induced persistent behavioral deficits in females, with no effect on HI males. These results support sex differences in mechanisms of cell death following early HI injuries, and suggest a potential clinical benefit from the development of sex-specific neuroprotectants for the treatment of HI.