Evaluation of Cognitive Function When Hearing One's Own Name in Patients With Brain Injuries in Early Developmental Stages.

PURPOSE: The level of residual cognitive function in patients with early brain injury is a key factor limiting rehabilitation and the quality of life. Although understanding residual function is necessary for appropriate rehabilitation, the extent of its effects on cognitive improvement remains unknown. This study evaluated cognitive function in patients with severe motor and intellectual disabilities after early brain injuries due to cerebral hemorrhage or periventricular leukomalacia. We focused on neural responses to hearing the subject's own name (SON). According to previous studies, differences in response to SON are associated with several types of cognitive dysfunction. METHODS: We examined healthy subjects (aged 21.4 ± 1.10 years; control) and patients with a previous brain injury (aged 13-27 years at the time of our analysis) resulting in periventricular leukomalacia or a cerebral hemorrhage during the perinatal period or childhood. We recorded EEG responses to the SON and to other Japanese words, obtaining EEG-evoked potentials with wavelet transformations. RESULTS: Compared with healthy controls, beta power (not alpha power) revealed differences in response to SON by patients with brain injury, especially those with cerebral hemorrhage. CONCLUSIONS: We suggest that alpha and beta power differences reflect different cognitive functions and that the SON response reveals more than one process. Beta powers may reflect the intellectual disability of cognitive function in response to self-relevant stimuli, especially in patients with cerebral hemorrhage. Meanwhile, alpha powers did not differ from those of the healthy controls, suggesting that the patients perhaps paid attention to their own names.

Hearing subject's own name induces the late positive component of event-related potential and beta power suppression.

The neuronal response to hearing a subject's own name (SON) has been often investigated using event-related potential (ERP) or time-frequency analysis, but seldom by a combination of these methods. Using this combination of approaches would allow the relationship between memory processes engaged by SON and the neuronal responses to be studied in more detail. Thus, the present study used both ERP and time-frequency analysis to investigate memory process for SON by comparing the responses to SON and to unfamiliar names. Specifically, the SON condition was compared with two control conditions: repeated unfamiliar names and singly presented unfamiliar names. This experimental design allowed us to determine the differences in memory processes between hearing one's own name and hearing unrelated but repeatedly heard names. ERP analysis showed that SON elicited a late positive component in parietal areas, while unfamiliar names elicited no positivity. Beta power suppression was observed in response to SON at 0.4-0.6s after stimulus onset at right central sites, but not in response to unfamiliar names. These results are indicative of an involvement of episodic memory processes on hearing SON, which corresponds to the recognition of one's own name. Further, the ERP results suggest the presence of a "new" stimulus recognition process that is activated by singly presented unfamiliar names but not by repeated unfamiliar names.

Phase-locked theta activity evoked in patients with severe motor and intellectual disabilities upon hearing own names.

BACKGROUND: Severe motor and intellectual disability (SMID) patients cannot express their feelings with language. Understanding what they are thinking about or how they feel is thus difficult. This study focused on brain responses to hearing their own names to clarify the situation in these patients. METHODS: We performed and analyzed electroencephalography (EEG) for six patients with SMID and eleven healthy subjects. All subjects were presented with auditory stimuli including calling the subject's own name (SON) and reading words. EEG was analyzed by time-frequency analysis, event-related spectral perturbation (ERSP) to detect EEG power changes caused by EEG amplitude, and inter-trial coherence (ITC) to investigate phase-locked changes. RESULTS: ERSP results from healthy subjects showed significant theta power increases as a specific response to SON. While we could not identify a similar pattern in the responses of patients with SMID, analysis of ITC revealed that theta phase-locked activity increased in response to SON not only in all healthy subjects, but also in four patients. DISCUSSION: These results indicate that theta phase-locked activity in some patients with SMID was strongly associated with SON, as in healthy subjects. Our study suggests the existence of specific neural markers that signal an attentional shift in patients upon hearing SON.

Measurement of brain activity responded by subjects'own name using EEG.

Sever motor and intellectual disabilities (SMID) patients can't express their feelings with languages. That's why it is important to measure and analyze their brain activity. In this study, we tried to investigate the brain response to hearing subject's own name of healthy people and one patient with SMID by analyzing EEG. The results of time frequency analysis showed the inter trial coherence of a patient with SMID at theta oscillation was higher in response to SON specifically. On the other hand, that of healthy subjects was not so different with that in response to control condition. These results might reflect of the difference of lexical semantic process between the patient and healthy subjects.