Shigeru Toki

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A number of clinical studies in which early adversities were defined retrospectively, demonstrated that early adverse experiences increased the morbidity rate of post-traumatic stress disorder (PTSD) in later life. However, no prospective studies have yet been conducted to elucidate whether early adversity affects the risk or severity of PTSD. Thus, we(More)
We studied the neural activation associated with anticipations of emotional pictures using functional magnetic resonance imaging (fMRI) by directly comparing certain with uncertain anticipation conditions. While being scanned with fMRI, healthy participants (n=18) were cued to anticipate and then perceive emotional stimuli having predictable (i.e., certain)(More)
It is well known that early life events induce long-lasting psychophysiological and psychobiological influences in later life. In rodent studies, environmental enrichment after weaning prevents the adulthood behavioral and emotional disturbances in response to early adversities. We compared the behavioral effect of neonatal isolation (NI) with the effect of(More)
In general, emotion is known to enhance memory processes. However, the effect of emotion on associative memory and the underling neural mechanisms remains largely unexplored. In this study, we explored brain activation during an associative memory task that involved the encoding and retrieval of word and face pairs. The word and face pairs consisted of(More)
Rodent studies have revealed that the early rearing environment plays an important role in the development of stress vulnerability, memory and cognition. Although early lighting conditions (ELC) are involved in these neuronal developments through both maternal and offspring behavior, their influence has not been fully elucidated. Thus, by using(More)
Diagnosis of psychiatric disorders based on brain imaging data is highly desirable in clinical applications. However, a common problem in applying machine learning algorithms is that the number of imaging data dimensions often greatly exceeds the number of available training samples. Furthermore, interpretability of the learned classifier with respect to(More)
AIM Cognitive impairment may account for functional and occupational disability in patients with bipolar disorder even during periods of euthymia. While imaging suggests structural, neurochemical, and functional abnormalities in bipolar disorder patients, the pathophysiology of these deficits has not been elucidated. It was hypothesized that euthymic(More)
BACKGROUND A few studies have used pseudo-continuous arterial spin labeling (pCASL) to assess the regional cerebral blood flow (rCBF) in patients with major depressive disorder (MDD). However, rCBF changes during treatment with escitalopram have not been studied in detail. We used pCASL to investigate the effect of 6-week escitalopram treatment on the rCBF(More)
Pain is a multidimensional phenomenon. Patients with somatoform pain disorder suffer from long-lasting pain, with the pathology being closely associated with cognitive-emotional components. Differences between these patients and controls in cerebral responses to pain stimuli have been reported. However, to our knowledge, no studies of somatoform pain(More)
BACKGROUND It is known that the onset, progression, and prognosis of major depressive disorder are affected by interactions between a number of factors. This study investigated how childhood abuse, personality, and stress of life events were associated with symptoms of depression in depressed people. METHODS Patients with major depressive disorder (N =(More)