Attentional processes facilitate cognitive and behavioral performance in several ways. Attention serves to reduce the amount of information to receive. Attention enables humans to direct themselves to appropriate aspects of external environmental events and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Attention is not a unitary process that can be localized to a single neuroanatomical region. Before the cortical registration of sensory information, activation of important subcortical structures occurs, which is called as an orienting response. Once sensory information reaches the sensory cortex, a large number of perceptual processes occur, which provide various levels of perceptual resolution of the critical features of the stimuli. After this preattentional processing, information is integrated within higher cortical(heteromodal) systems in inferior parietal and temporal lobes. At this stage, the processing characteristics can be modified, and the biases of the system have a direct impact on attentional selection. Information flow has been traced through sensory analysis to a processing stage that enables the new information to be focused and modified in relation to preexisting biases. The limbic and paralimbic system play significant roles in modulating attentional response. It is labeled with affective salience and is integrated according to ongoing pressures from the motivational drive system of the hypothalamus. The salience of information greatly influences the allocation of attention. The frontal lobe operate response selection system with a reciprocal interaction with both the attention system of the parietal lobe and the limbic system. In this attentional process, the search with the spatial field is organized and a sequence of attentional responses is generated. Affective, motivational and appectitive impulses from limbic system and hypothalamus trigger response intention, preparation, planning, initiation and control of frontal lobe on this process. The reticular system, which produces ascending activation, catalyzes the overall system and increases attentional capacity. Also additional energetic pressures are created by the hypothalamus. As psychophysiological measurement, skin conductance, pupil diameter, muscle tension, heart rate, alpha wave of EEG can be used. Event related potentials also provide physiological evidence of attention during information process. NI component appears to be an electrophysiological index of selective attention. P3 response is developed during the attention related to stimulus discrimination, evaluation and response.

This paper first reviewed the definition, criteria, and neurological theories concerning the etiology of AD/HD, and the empirical studies dealing with the comorbidity of AD/HD with other psychiatric disorders. Secondly, results of studies using various neuropsychological tests for assessing the cognitive and behavioral problems in AD/HD children were examined, which suggest the possibility that dysfunction may exist in neural pathways involving many areas of the brain in AD/HD. However, because most of neuropsychological test used in Korea for ADHD children had been developed abroad, further study involving AD/HD, normal control, and other psychiatric control groups is needed to obtain developmental norms for interpreting the results, and to make more accurate diagnosis, and to clarify comorbidity of AD/HD with other disorders.

Attentional dysfunction is considered as one of the core deficits in schizophrenic process. The findings, pathophysiological mechanisms, and their clinical implications of clinical and experimental neurocognitive tests for the attentional impairment in schizophrenics are reviewed. The influences of psychopathology, antipsychotic treatment, and chronic institutionalization are also included in the review. In contrast, there are only a few evidences that attentional dysfunction would be a core deficit of depressive, manic, and anxiety disorders. Some recent findings of attentional impairment in these disorders are reviewed.

Nowadays light therapy is accepted practice in the treatment for Seasonal Affective Disorder. The author reviewed the practical aspects of light therapy, latest treatment research on optimal parameters of light therapy and the mechanisms of action of light therapy. Therapeutic efficacy of light therapy using light visors & dawn simulators has been suggested but further studies are needed to clarify the efficacy. The treatment most strongly supported by research studies is light therapy using a light box to administer bright white light (2500 lux for 2 hours or 10000 lux for 30 minutes). Although some patients may be selective responders to morning light exposure, the optimal timing of light exposure still remains controversial. In practice, generally the duration of exposure can be increased or decreased as necessary and also the timing of exposure can be splitted (e.g. AM/PM usage) if optimal response is obtained. For most, a positive response of light therapy is usually noted within $4{\sim}5\;days$ and optimal response is obtained within 2 weeks. Generally the relapse of symptom occurs within days of discontinuation of light therapy, so to prevent relapse, light therapy should be continued throughout the winter season for typical seasonal affective disorder. Side effects of light therapy appear to be mild and well tolerated. Several theories for the mechanisms of action of light therapy at the basis of seasonal affective disorder had been suggested but remain still controversial. Further studies on the optimal parameters and the mechanisms of light therapy help us to better understand and treat not only seasonal affective disorders but also chronobiological disorders and nonseasonal affective disorders.

Objectives : Disturbance of sleep with or without sleep apnea may impair the memory function. Sleep deficiency, sleepiness, sleep apnea and emotional problem in sleep disorders can induce an impairment of memory function. Methods : In this study, the polysomnographies were administered to 58 sleep apnea patients and 38 sleep disorder patients without sleep apnea. Their clinical symptoms were quantitatively evaluated. Short term and long term memory were evaluated before and after polysom no graphy with Digit symbol test and Rey-Osterrieth complex figure test. And correlations among various sleep, repiratory and clinical variables were statistically studied in order to explore which variables may influence on memory function. Results and Conclusions : Results are as follows. Depth of sleep cis positively correlated with memory function. As sleep apnea increases and average saturation of blood oxygen decreases, memory function is more impaired. Emotional depression, high blood pressure, obesity or alcohol impaired memory function. However, daytime sleepiness was not significantly correlated with memory function. The possible mechanisms how above factors influence on the memory function were discussed.

연구배경 : 양성 및 음성 정신분열병 환자간의 뇌파를 비선형적으로 분석하고 그 결과를 대조군과 비교하여 뇌파의 비선형 분석을 통한 정신분열병의 병태생리를 이해하기 위하여 양성 정신분열병 환자 8명, 음성 정신분열병 환자 9명과 정상 대조군 8명을 대상으로 하여 16전극에서 뇌파를 기록하여 비선형 분석을 시행하였다. 결과 : 좌측측두부 최대 양수 리아프노프 지수 값이 음성 정신분열병군에서 양성 정신분열병군과 정상 대조군에 비하여 유의하게 낮았으며, 일부 전극에서 양성증상은 좌측 두뇌의 카오스적 성상과 정상관이 있었으며 우측두뇌의 카오스적 성상과는 역상관이 있었다. 결론 : 본 연구결과를 통하여 정신분열병 환자의 두뇌 기능을 조사하는 데에 있어서 카오스적 역동을 응용한 뇌파분석이 임상적 유용성이 있음을 알 수 있었으며, 임상적 변인을 잘 통제한 연구가 필요하다는 것을 확인할 수 있었다.

목적 : 저자들은 강박장애 환자의 대뇌기능을 알아보기 위해 신경심리검사 바테리를 이용하여 정상대조군과 비교하였다. 방법 : 강박장애군(12명)과 연령 및 교육을 짝짓기한 정상대조군(17명)에게 신경심리검사 바테리를 시행하였다. 결과 : K-WAIS 검사상 전체지능은 강박장애군 115.2(${\pm}9.9$), 정상대조군 111.8(${\pm}8.4$)로 양군간에 유의한 차이가 없었다. 그러나 언어성 지능의 경우 강박장애 환자군($118.0{\pm}10.6$)이 정상대조군($110.3{\pm}9.4$)보다 유의하게 높았으나(P=0.049), 동작성 지능은 강박장애군($108.4{\pm}11.7$)이 정상대조군($114.4{\pm}11.2$)보다 낮은 경향을 보였다. 양군간의 소검사 항목점수를 비교하면 tactual performance test의 전체시간에서 강박장애군(15.26분)이 정상대조군(9.56분) 보다 유의하게 길었으며(P=0.028), 양손 수행에서도 강박장애군(0.16)의 수행이 정상대조군(0.38) 보다 유의하게 떨어졌다(P=0.047). 전체적인 Halsted Reitan 손상지수도 강박장애군($3.17{\pm}2.1$)이 정상대조군($1.31{\pm}1.8$) 보다 유의하게 높았다(P=0.019). 웨슬러 기억검사의 시각회상에서도 강박장애군($12.3{\pm}1.6$)이 정상대조군($13.4{\pm}0.9$)에 비해 기능이 유의하게 떨어졌다. 결론 : 강박장애 환자는 정상대조군에 비해 공간구조 인지기능의 장애, 과잉된 언어 및 집중력을 보이고 있고, 이는 강박장애 환자의 언어기능과 공간구조 인식기능의 불균형이 강박장애 환자의 정신병리와연관 될 수 있음을 시사한다. 향후 강박장애 환자에서 신경 심리 검사상 보이는 이상소견이 강박장애의 특정적인 소견인가, 치료경과에 따라 선경 심리검사상의 이상소견이 영향을 받는가에 대한 연구가 이어져야할 것으로 생각된다.

Authors report the findings of nocturnal polysomnography and multiple sleep latency test(MSLT) before and after morning light treatment in a winter depressive patient with hypersomnia. On polysomnographic recordings, the sleep pattern of this case before light treatment was similar to that of narcolepsy exhibited, sleep onset REM period(SOREMP). After treatment, the shortened REM latency changed to normal condition, but, deep sleep percentage did not changed, and stage 4 sleep percentage was decreased. Depressive symptoms were improved on clinical interview with Hamilton Depressive Rating Scale. Sleep log showed shortened sleep latency and reduced sleep duration. These findings suggest that although light treatment could alter the sleep structure in seasonal affective disorder with hypersomnia, it does not necessarily imply that antidepressant response of light treatment is result of change of sleep structure.

OSA(Obstructive Sleep Apnea) is a condition with repeated obstruction of the upper airway while sleeping. This obstruction of the upper airway may result if sleep-induced physiologic change in muscle activity is superimposed on various structural defects of the upper airway. Macroglossia, micrognathia, retrognathia, and decreased airway lumen have all been implicated in OSA. There are a variety of surgical and nonsurgical treatment modalities currently available for OSA. Recently the uvulopalatopharyngoplasty has achieved widespread use, but success rates vary and long-term effects are still unknown. Current nonsurgical treatment methods can be cumbersome and uncomfortable with variable responses. For this case. we diagnosed as OSA by using polysomnographic analysis and cephalometric analysis, and delivered intraoral removable appliance which is more conservative, reversible and easy to use for patient. And we got results that Apnea Index(AI) decreased from 14.4 to 3.1, Total Respiratory Disturbance Index(Total RDI) decreased from 18.1 to 7.0 and removal of chronic headache in daytime.