Left Temporal Sites Research Articles

Neural correlates of response to joint attention in 2-to-5-year-olds in relation to ASD and social-communicative abilities: An fNIRS and behavioral study.

Autism spectrum disorder (ASD) is associated with life-long challenges with social cognition, and one of its earliest and most common manifestations is atypical joint attention, which is a pivotal skill in social-cognitive and linguistic development. Early interventions for ASD children often focus on training initiation of joint attention (IJA) and response to joint attention bids (RJA), which are important for social communication and cognition. Here, we used functional near-infrared spectroscopy and behavioral measures to test typically developing (TD, n = 17) and ASD children (n = 18), to address the relationship between the neural correlates of RJA and social-communicative behavior. Group-level differences were present for RJA-specific activation over right temporal sites, where TD children showed higher levels of activation during RJA than ASD children, whereas the two groups did not differ in the control condition. Correlations between neural activation and behavioral traits suggest that, in ASD children, neural activation during RJA is related to the frequency of RJA behavior when the former is measured over left temporal sites, and to social affect symptoms when considered for right temporal sites. Possible implications of the evidenced correlations are discussed.

Children's Shyness, Frontal Brain Activity, and Anxiety in the Perioperative Context.

Although preoperative anxiety affects up to 75% of children undergoing surgery each year and is associated with many adverse outcomes, we know relatively little about individual differences in how children respond to impending surgery. We examined whether patterns of anterior brain electrical activity (i.e., a neural correlate of anxious arousal) moderated the relation between children's shyness and preoperative anxiety on the day of surgery in 70 children (36 girls, Mage = 10.4 years, SDage = 1.7, years, range 8 to 13 years) undergoing elective surgery. Shyness was assessed using self-report approximately 1 week prior to surgery during a preoperative visit (Time 1), preoperative anxiety was assessed using self-report, and regional EEG (left and right frontal and temporal sites) was assessed using a dry sensory EEG headband on the day of surgery (Time 2). We found that overall frontal EEG alpha power moderated the relation between shyness and self-reported preoperative anxiety. Shyness was related to higher levels of self-reported anxiety on the day of surgery for children with lower average overall frontal alpha EEG power (i.e., higher cortical activity) but not for children with higher average overall frontal alpha EEG power (i.e., lower cortical activity). These results suggest that the pattern of frontal brain activity might amplify some shy children's affective responses to impending surgery. Findings also extend prior results linking children's shyness, frontal brain activity, and anxiety observed in the laboratory to a real-world, ecologically salient environment.

Event related potentials to native speech contrasts predicts word reading abilities in early school-aged children

Speech perception skills have been implicated in the development of phoneme-graphene correspondence, yet the exact nature of speech perception and word reading ability remains unknown. We investigate phonological sensitivity to native (English) and nonnative (Spanish) speech syllables within an auditory oddball paradigm using event related potentials (ERPs) collected from lateral temporal electrode sites in 33 monolingual English-speaking children aged 6–8 years (N = 33). We further explore the relationship between ERPs to English word reading abilities for this group. Results revealed that language stimuli (English, Spanish), ERP condition (standard, deviant), and hemisphere (left, right) all influenced the lateral N1 component. ERPs recorded from deviant English stimuli were significantly more negative within the left hemisphere compared to all other recorded ERPs. Mean amplitude differences within the N1 in left lateral electrode sites recorded in response to English phoneme contrasts significantly predicted English word reading abilities within this sample. Results indicate that speech perception of native contrasts recorded in left temporal electrode sites for the N1 component are linked to English word reading abilities in early school-aged children.

P213 A COMPLICATED STEMI : POISED BETWEEN THROMBOSIS AND HEMORRHAGE

Abstract The introduction of more effective and powerful antithrombotic therapies has allowed the progressive reduction of ischemic events associated however with an increase in haemorrhagic events. What we are describing is an example of how iatrogenic and non–iatrogenic complications can add up, making routine therapeutic management difficult during and after hospital stay.We are talking about a 50–year–old male patient, a smoker and with a history of dyslipidemia under treatment, who arrived at our cath–lab with a diagnosis of anterior SCA–STEMI, after loading ticagrelor 180 mg from the spoke center where he had gone for chest pain. At coronary angiography, evidence of critical disease of the median anterior interventricular artery treated by primary angioplasty and for the high thrombotic load by thromboaspiration, DES and Tirofiban bolus and 18–hour continuous infusion. Approximately 15 hours after the event, the patient appeared confused and aphasic. A brain CT scan with and without contrast agent was performed which documented the presence of a hemorrhagic focus in the atypical left temporal site, in the absence of arteriovenous malformations not susceptible to surgical therapy (BARC–3). Therefore, in view of the high risk of bleeding, de–escalation therapy with cardioaspirin and clopidogrel was practiced. Five days after the event, the clinical picture was complicated again by the finding of apical thrombosis on the transthoracic ultrasound. For this reason, given the stability of the haemorrhagic lesion on CT scans and control MRIs, Enoxaparin sodium 4000 IU was introduced in therapy once, with resolution of the formation in the imaging control after one month. The patient was then discharged with indication for short–DAPT in consideration of the high PRECISE–DAPT score. The arduous task of managing this case led us to reflect on the importance of the pre– and post–PCI clinical picture of the patient in order to seek the appropriate antithrombotic treatment by dynamically balancing the ischemic and haemorrhagic risk during hospitalization through numerous standardized tools at our disposal.

How does experimentally induced pain affect creative ideation and underlying attention-related psychophysiological mechanisms?

While the adverse effect of chronic pain on attention and more complex cognitive abilities is well documented, the findings for experimentally induced pain are inconsistent. These inconsistencies could be attributable to sufficient attentional resources and/or compensatory mechanisms in individuals experiencing experimentally induced pain that are not observable at the behavioral level but could be revealed by psychophysiological measures such as the electroencephalography (EEG). With the current study, we aimed to investigate whether experimentally induced pain affects creative ideation in an adaptation of the Alternate Uses Task (AUT). Performance in the AUT was compared between 39 females in a pain group and 37 females in a pain-free group. While solving the task, EEG was recorded to measure the degree of internally directed attention assessed by means of task-related power (TRP) changes in the upper alpha-frequency band. The results revealed that the pain group and the pain-free group did not differ in AUT performance at the behavioral level. However, TRP increases in the upper alpha band at right (vs. left) temporal, parietal, and occipital electrode sites were significantly more pronounced in the pain group compared to the pain-free group. These results indicate that individuals in the pain group allocated more attention to internal mental processes during creative ideation than individuals in the pain-free group. The necessary inhibition of pain might have caused this additional activation so that the pain group performed similarly well on the behavioral level as the pain-free group.

P107 MULTIMODALITY IMAGING IN ASCENDING AORTA PSEUDO–ANEURYSM COMPLICATED BY MOBILE TROMBUS SYMPTOMATIC FOR RECURRENT ISCHEMIC STROKE

Abstract A 80–year–old male patient was admitted to hospital with a clinical picture of Broca‘s aphasia. The patient had arterial hypertension, diabetes, chronic kidney disease and peripheral vasculopathy. In remote cardiological history he presents long standing persistent atrial fibrillation on OAC and he had a biological aortic valve prosthesis (Medtronic 23). Overall time in the therapeutic range (INR 2.0–2.5) was adequate considering the presence of atrial fibrillation. A CT scan was performed on suspicion of stroke, showing a recent ischemic lesion in the left middle temporal region complicated by same–site subarachnoid blood suffusion. During the hospital stay there was a recurrence of the aforementioned symptoms: at the CT check a new acute ischemic same–site lesion and a new ischaemic lesion at the left temporal site was highlighted. In the suspicion of a cardio–embolic origin of cerebro–vascular events, it was decided to carry out imaging for the study of the aorta and heart cavities to exclude embolic sources. Given the patient‘s comorbidities and the reported allergies (contrast medium with angioedema–like reaction at a previous CT) it was decided to perform transesophageal echocardiography (TEE) first. TEE documented the presence of a saccular aneurysm of probable pseudo–aneurysmatic nature, which extends from 20 mm from the valvular plane, characterized by pedunculated, mobile thrombotic apposition, adhered to the internal collar, projecting into the psueudo–aneurysmatic cavity (image 1). This finding was confirmed and better characterized with the help of the real time three–dimensional echocardiographic method (image 2). To confirm and better characterize the extension of the pseudo–aneurysm and plan any strategy, a CT scan with contrast medium was required. Performing contrast–enhanced CT, after careful preparation with premedication with antihistamine and cortisone, confirmed the finding of pseudo–aneurysm of the ascending aorta, but the pedunculated thrombotic apposition was less clearly evidenced compared with TEE (giving the superior temporal resolution of TEE) (image 3). The case was therefore assessed in Heart Team and the patient was scheduled for surgically exclusion of the pseudo–aneurysm. Conclusion In our case a multimodality imaging approach was used to diagnose and confirm the presence of ascending aorta pseudo–aneurysm complicated by pedunculated thrombotic apposition inside it, symptomatic for recurrent ischaemic stroke.

Physiological comfort evaluation under different airflow directions in a heating environment

BackgroundIndoor airflow and thermal comfort are difficult to assess through subjective evaluations because airflow sensations can differ based on various factors, such as personal characteristics, interests, preferences, and the current state of mind. Thus, subjective evaluations should be combined with objective assessments, such as physiological measurements. This study evaluated airflow and thermal comfort through physiological measurements, including skin temperature, electroencephalography, respiration, and electrocardiography, in addition to subjective evaluations.MethodsTwenty participants entered a test room at 30 °C after staying in an acclimation room at 18 °C for 20 min. They were exposed to indirect and direct airflow toward their faces and performed four tasks under each condition: resting, counting to 10 s following time alerts, counting to 10 s in the mind, and mental calculation. The mean speed of the air directed to the participants’ faces was 0.123 m/s and 0.225 m/s in the indirect and direct conditions, respectively.ResultsThe gamma and beta bands of electroencephalograms taken at the left-temporal (T3) and left-parietal (P7) sites showed significantly lower amplitudes under the indirect condition (gamma, T3: p = 0.034, P7: p = 0.030; beta, T3: p = 0.051, P7: p = 0.028). Similarly, the variability of respiration was lower under the indirect condition (p < 0.010). The amplitudes of gamma and beta waves showed significant correlations with anxiousness levels (gamma, T3: r = 0.41; beta, T3: r = 0.35).ConclusionsOur results suggest that indirect heating airflow causes lower mental stress and fatigue than those induced by direct flow, which is equivalent to more comfort. The results of this study suggest that physiological measurements can be used for the evaluation of unconscious indoor comfort, which cannot be detected by subjective evaluations alone.

Neurophysiological mechanisms of perspective-taking: An MEG investigation of agency

ABSTRACT According to the embodied cognition framework, sensory and motor areas are recruited during language understanding through simulation processes. Behavioral and imaging findings point to a dependence of the latter on perspective-taking (e.g., first person “I” versus third person “s/he”). The current study aims at identifying possible neurophysiological correlates of perspective in a linguistic context. Twenty healthy participants were measured with magnetoencephalography (MEG) while semantically processing visually presented inflected German verbs in the first- and third-person perspective, simple present tense. Results show that the first-person perspective induces stronger beta (15–25 Hz) desynchronization in the right-hemispheric posterior superior temporal sulcus, ventral posterior cingulate gyrus, and V5/MT+ area; no modulation of sensorimotor cortex emerged. Moreover, a stronger event-related field (ERF) was observed for the first-person perspective at about 150 ms after pronoun-verb onset, originating in occipital and moving to central and left temporal cortical sites. No effect of perspective on sensory gating was found when targeting the N1 component related to tones following the linguistic stimuli. Results indicate an effect of linguistic perspective-taking on brain activation patterns. The contribution of the single brain areas and their role in self-other distinction is further discussed.

Imbalance between Emotionally Negative and Positive Life Events Retrieval and the Associated Asymmetry of Brain Activity.

Sustained focusing on a negative assessment of life events can create negative background and changes in the emotional feedback to new information. In this regard, it is important to assess the balance between self-assessment of emotional memories and their reflection in brain activity. The study was aimed at exploring the brain activity using electroencephalographic (EEG) analysis in six frequency ranges from delta to beta2 during the retrieval of positive or negative emotional memory compared with the resting state. According to ANOVA results, the most informative for differentiation of emotions were the alpha2 and beta2 rhythms with greater synchronization effect for positive than for negative emotions. The memory retrieval, regardless of the valence of emotions, was accompanied by alpha1 desynchronization at the posterior cortex. Self-assessment of the memory intensity was not significantly different due to emotion valences. However, the scores of positive emotions were related positively with beta2 oscillations at the left anterior temporal site, whereas for negative emotions, at the right one. Thus, the emotional autobiographical memory is reflected by activation processes in the visual cortex and areas associated with multimodal information processing, whereas differentiation of the valence of emotions is presented by the high-frequency oscillations at the temporal cortex areas.

Spoken word processing in Rett syndrome: Evidence from event-related potentials

This study examined the feasibility of using auditory event-related potentials to evaluate spoken word processing during passive listening in girls with Rett syndrome (n = 11) and typical peers (n = 33), age 4–12 years. The typical group demonstrated the expected pattern of more negative amplitudes within 200–500 ms in response to words than nonwords at left temporal sites. In participants with Rett syndrome, word-nonword differentiation was observed at the right temporal sites. More negative left hemisphere amplitudes in response to words were associated (at trend level) with better receptive language skills and more adaptive behavior. The results indicate that girls with Rett syndrome differentiate known words from novel nonwords, but may do so using potentially atypical neural processes. Brain-behavior correlations support validity of the proposed neural markers of word processing, making passive listening paradigms a promising approach for assessing speech and language processing in participants with limited spoken language skills.

Rigid External Distractor-Aided Advancement After Simultaneously Performed LeFort-III Osteotomy and Fronto-Orbital Advancement.

Due to the complex development of the craniofacial skull, corrective surgery is a major challenge for patients with severe craniofaciostenosis. Although fronto-orbital advancement and simultaneous LeFort-III osteotomy in combination with distraction osteogenesis have been reported as a safe and successful method to obtain good esthetic and functional results, there is a lack of studies evaluating this method.Our retrospective study included 12 patients with syndromic craniofaciostenosis, who were primarily treated at our department in accordance with a standardized treatment protocol, consisting of a simultaneous fronto-orbital advancement with LeFort-III osteotomy in combination with a rigid external distractor (RED-II). Distraction distance, duration of operation, postoperative complications, perioperative hemoglobin concentration, esthetic outcome, and the subjective Whitaker Scale were used to evaluate the success of our surgical method.The esthetic outcome of all of our patients was assessed as good. Furthermore, the surgical outcome was assigned I for 11 patients and II for 1 patient, who suffered from wound healing disturbance at the left temporal site, which required revision 2 weeks postoperatively. The mean skeletal advancement of the midface was 16.4 mm, ranging from 12 to 20 mm.Our standardized treatment protocol, consisting of fronto-orbital advancement in combination with LeFort-III osteotomy and application of a rigid external distractor device (RED-III) for patients with severe syndromic craniofaciostenosis, goes along with low infection rates and more predictable and precise esthetic and functional outcomes than the conventional surgical technique without distraction osteogenesis.

Oscillatory Brain Activity in Morphological Parsing of Complex Words: Information Gain from Stems and Suffixes

In this study, behavioral and EEG measurements were taken while participants performed two priming lexical decision experiments on complex words. In Experiment I stems of high and low family size were used as primes. Behavioral results show an inhibitory effect for stem family size whereas time-frequency responses (TFR) show significant oscillatory brain activity in the range of betaband and theta-band on right and left temporal sites respectively, both related to lexical status of word patterns. In Experiment II, in which suffixes of high and low family size were used as primes, the effect of family size is facilitatory. Concerning ERP analysis on waveform amplitudes, an early significant lexical status effect emerges although it disappears over time. No significant oscillatory brain activity emerges concerning time frequency responses (TFR). According to an informationgain probabilistic model, the participants modulate their responses in terms of the information provided by the different morphemes used as primes.

Electroencephalographic characterization of subgroups of children with learning disorders.

Electroencephalographic alterations have been reported in subjects with learning disorders, but there is no consensus on what characterizes their electroencephalogram findings. Our objective was to determine if there were subgroups within a group of scholars with not otherwise specified learning disorders and if they had specific electroencephalographic patterns. Eighty-five subjects (31 female, 8–11 years) who scored low in at least two subscales -reading, writing and arithmetic- of the Infant Neuropsychological Evaluation were included. Electroencephalograms were recorded in 19 leads during rest with eyes closed; absolute power was obtained every 0.39 Hz. Three subgroups were formed according to children’s performance: Group 1 (G1, higher scores than Group 2 in reading speed and reading and writing accuracy), Group 2 (G2, better performance than G1 in composition) and Group 3 (G3, lower scores than Groups 1 and 2 in the three subscales). G3 had higher absolute power in frequencies in the delta and theta range at left frontotemporal sites than G1 and G2. G2 had higher absolute power within alpha frequencies than G3 and G1 at the left occipital site. G3 had higher absolute power in frequencies in the beta range than G1 in parietotemporal areas and than G2 in left frontopolar and temporal sites. G1 had higher absolute power within beta frequencies than G2 in the left frontopolar site. G3 had lower gamma absolute power values than the other groups in the left hemisphere, and gamma activity was higher in G1 than in G2 in frontopolar and temporal areas. This group of children with learning disorders is very heterogeneous. Three subgroups were found with different cognitive profiles, as well as a different electroencephalographic pattern. It is important to consider these differences when planning interventions for children with learning disorders.

T-complex measures in bilingual Spanish-English and Turkish-German children and monolingual peers.

BackgroundLateral temporal neural measures (Na and T-complex Ta and Tb) of the auditory evoked potential (AEP) index maturation of auditory/speech processing. These measures are also sensitive to language experience in adults. This paper examined neural responses to a vowel sound at temporal electrodes in four- to five-year-old Spanish-English bilinguals and English monolinguals and in five- to six-year-old Turkish-German bilinguals and German monolinguals. The goal was to determine whether obligatory AEPs at temporal electrode sites were modulated by language experience. Language experience was defined in terms of monolingual versus bilingual status as well as the amount and quality of the bilingual language experience.MethodAEPs were recorded at left and right temporal electrode sites to a 250-ms vowel [Ɛ] from 20 monolingual (American)-English and 18 Spanish-English children from New York City, and from 11 Turkish-German and 13 monolingual German children from Ulm, Germany. Language background information and standardized verbal and non-verbal test scores were obtained for the children.ResultsThe results revealed differences in temporal AEPs (Na and Ta of the T-complex) between monolingual and bilingual children. Specifically, bilingual children showed smaller and/or later peak amplitudes than the monolingual groups. Ta-amplitude distinguished monolingual and bilingual children best at right electrode sites for both the German and American groups. Amount of experience and type of experience with the target language (English and German) influenced processing.ConclusionsThe finding of reduced amplitudes at the Ta latency for bilingual compared to monolingual children indicates that language specific experience, and not simply maturational factors, influences development of the neural processes underlying the Ta AEP, and suggests that lateral temporal cortex has an important role in language-specific speech perception development.

Electro-cortical measures during visual and kinesthetic imagery performance following visual- and auditory-guided instructions

Electroencephalography (EEG) measures can provide extensive and detailed knowledge of how the brain works during imagery. Prior to imagery performance, individuals may acquire information on how to imagine the movement through either visual or auditory instructions. The purpose of this study was to determine differences in cerebral cortical activation during kinesthetic and visual imagery performance while following visual- and audio-guided imagery instructions. EEG recordings were collected from 28 participants and guided imagery instructions were given in two versions: audio and visual. The results revealed that lower alpha values (8–10 Hz) were greater when participants were performing kinesthetic imagery following auditory instructions as opposed to following visual instructions. Furthermore, lower alpha values were greater at the right hemisphere than the left hemisphere and greater at the right temporal site than the left temporal site. In the upper alpha band (11–13 Hz), results showed that values were greater at the temporal site in the right hemisphere than the temporal site in the left hemisphere. In addition, upper alpha values were greater at the right hemisphere than the left hemisphere and greater at the right temporal site than the left temporal site. The findings of this study suggest that electro-cortical measures can detect differences of the processes involved during guided imagery performance while following either audio or video instructions. In the applied setting, practitioners can implement neurofeedback techniques to assess the specific mental effort required by individuals following guided instructions to perform imagery.

Hippocampal glutamatergic/NMDA receptor functioning in bipolar disorder: A study combining mismatch negativity and proton magnetic resonance spectroscopy

Disturbances in the hippocampal glutamate (Glu)/N-methyl-d-aspartate (NMDA) system have been implicated in the pathophysiology of bipolar disorder (BD). Here we aim to provide a targeted integration of two measures of glutamatergic functioning in BD; the association between mismatch negativity (MMN) and in vivo hippocampal-Glu measured via proton magnetic resonance spectroscopy (1H MRS). Participants comprised of 33 patients with BD and 23 matched controls who underwent a two-tone passive, duration deviant MMN paradigm and 1H MRS. Levels of Glu/creatine (Cr) in the hippocampus were determined. Pearson׳s correlations were used to determine associations between MMN and Glu/Cr. In controls, MMN amplitude was positively associated with Glu/Cr at the left temporal site. We did not find any significant associations with Glu/Cr and frontocentral MMN nor did we find any significant associations in BD patients. The results provide further insight into the neurophysiology of MMN, with evidence supporting the role of hippocampal-Glu signalling through the NMDA receptor in temporal MMN. Our data also demonstrate that Glu/Cr regulation of MMN is dampened in BD, which may indicate a lack of tightly regulated hippocampal NMDA functioning. These findings provide insight into the underlying basis of glutamatergic transmission disturbances implicated in the disorder.

When "ultrarapid" word-related motor activity is not faster than "early".

When "ultrarapid" word-related motor activity is not faster than "early".

Investigating the role of glutathione in mismatch negativity: An insight into NMDA receptor disturbances in bipolar disorder

ObjectiveWe aim to provide a targeted integration to investigate neuronal mechanisms underlying mismatch negativity (MMN) in bipolar disorder (BD), by looking at the association between temporal MMN and in vivo hippocampal glutathione (GSH) measured via proton magnetic resonance spectroscopy (1H-MRS). MethodsTwenty-eight people with BD and 22 matched controls underwent a two-tone passive, duration deviant MMN paradigm as well as 1H-MRS. GSH concentration in the left hippocampus was determined and Pearson’s correlations were used to identify associations between MMN amplitude and in vivo GSH concentration. ResultsIn controls MMN amplitude was negatively associated with GSH at the left temporal site (r=−0.542, 95% C.I.: −0.810, −0.060), and a similar trend at the right (r=−0.374, 95% C.I.: −0.678, 0.007). There were no significant associations in BD. ConclusionsThe results provide insight into the relationship between MMN and in vivo GSH, and demonstrate that the metabolite system regulating MMN is abnormal in BD, compared to controls. This may indicate a lack of tightly regulated hippocampal NMDA functioning, or that NMDA receptor regulation in BD is mediated by other factors. SignificanceThese results provide insight into the underlying basis of hippocampal NMDA disturbances implicated in BD.

Maturation of cortical auditory evoked potentials (CAEPs) to speech recorded from frontocentral and temporal sites: Three months to eight years of age

The goal of the current analysis was to examine the maturation of cortical auditory evoked potentials (CAEPs) from three months of age to eight years of age. The superior frontal positive–negative–positive sequence (P1, N2, P2) and the temporal site, negative–positive–negative sequence (possibly, Na, Ta, Tb of the T-complex) were examined. Event-related potentials were recorded from 63 scalp sites to a 250-ms vowel. Amplitude and latency of peaks were measured at left and right frontal sites (near Fz) and at left and right temporal sites (T7 and T8). In addition, the largest peak (typically corresponding to P1) was selected from global field power (GFP). The results revealed a large positive peak (P1) easily identified at frontal sites across all ages. The N2 emerged after 6months of age and the following P2 between 8 and 30months of age. The latencies of these peaks decreased exponentially with the most rapid decrease observed for P1. For amplitude, only P1 showed a clear relationship with age, becoming more positive in a somewhat linear fashion. At the temporal sites only a negative peak, which might be Na, was clearly observed at both left and right sites in children older than 14months and peaking between 100 and 200ms. P1 measures at frontal sites and Na peak latencies were moderately correlated. The temporal negative peak latency showed a different maturational timecourse (linear in nature) than the P1 peak, suggesting at least partial independence. Distinct Ta (positive) and Tb (negative) peaks, following Na and peaking between 120 and 220ms were not consistently found in most age groups of children, except Ta which was present in 7year olds. Future research, which includes manipulation of stimulus factors, and use of modeling techniques will be needed to explain the apparent, protracted maturation of the temporal site measures in the current study.

Asymmetry of temporal auditory T-complex: Right ear–left hemisphere advantage in Tb timing in children

ObjectiveTo investigate brain asymmetry of the temporal auditory evoked potentials (T-complex) in response to monaural stimulation in children compared to adults. MethodsTen children (7 to 9years) and ten young adults participated in the study. All were right-handed. The auditory stimuli used were tones (1100Hz, 70dB SPL, 50ms duration) delivered monaurally (right, left ear) at four different levels of stimulus onset asynchrony (700–1100–1500–3000ms). Latency and amplitude of responses were measured at left and right temporal sites according to the ear stimulated. ResultsPeaks of the three successive deflections (Na–Ta–Tb) of the T-complex were greater in amplitude and better defined in children than in adults. Amplitude measurements in children indicated that Na culminates on the left hemisphere whatever the ear stimulated whereas Ta and Tb culminate on the right hemisphere but for left ear stimuli only. Peak latency displayed different patterns of asymmetry. Na and Ta displayed shorter latencies for contralateral stimulation. The original finding was that Tb peak latency was the shortest at the left temporal site for right ear stimulation in children. Amplitude increased and/or peak latency decreased with increasing SOA, however no interaction effect was found with recording site or with ear stimulated. ConclusionOur main original result indicates a right ear–left hemisphere timing advantage for Tb peak in children. The Tb peak would therefore be a good candidate as an electrophysiological marker of ear advantage effects during dichotic stimulation and of functional inter-hemisphere interactions and connectivity in children.