Roles of the Default Mode Network in Different Aspects of Self-representation When Remembering Social Autobiographical Memories.

Autobiographical memory (AM) is episodic memory for personally experienced events, in which self-representation is more important than that in laboratory-based memory. Theoretically, self-representation in a social context is categorized as the interpersonal self (IS) referred to in a social interaction with a person or the social-valued self (SS) based on the reputation of the self in the surrounding society. Although functional neuroimaging studies have demonstrated the involvement of the default mode network (DMN) in self-representation, little is known about how the DMN subsystems contribute differentially to IS-related and SS-related AMs.

Age-related changes in the distribution of intravenously administered gadolinium-based contrast agents leaked into the cerebrospinal fluid in patients with suspected endolymphatic hydrops.

Purpose: The purpose of this retrospective study was to investigate the relationship between age and leakage of intravenously administered gadolinium-based contrast agents (GBCAs) into the cerebrospinal fluid (CSF) by volumetric segmentation of the whole-cranium CSF.

Materials And Methods: In 30 patients clinically diagnosed with suspected endolymphatic hydrops, the three-dimensional real inversion recovery (3D-real IR) images were obtained at pre- and 4 h post-intravenous administration of a single dose of GBCA. The volume of interest was set on the whole-cranium CSF in the 3D-real IR image.

Distribution of Gadolinium-based Contrast Agent after Leaking into the Cerebrospinal Fluid: Comparison between the Cerebral Cisterns and the Lateral Ventricles.

Purpose: Leakage of a small amount of intravenously administered gadolinium-based contrast agents (GBCAs) into the cerebrospinal fluid (CSF) space has been reported, even in healthy subjects without blood-brain barrier disruption. Several candidates including the choroid plexus and cortical veins have been proposed as the source of the leakage. The purpose of this study was to evaluate the distribution of intravenously administered GBCA leakage into the CSF by comparing the contrast enhancement of the cerebral cisterns to the lateral ventricles (LVs).

[Time and Self in Episodic Memory and Confabulation].

Confabulation is defined as the production of narrative descriptions of events that never happened, and is often observed in amnesia with basal forebrain lesions. However, little is known about the possible mechanisms related to confabulation. In this review article, we summarized previous neuropsychological and neuroimaging studies associated with confabulation, and proposed a hypothetical mechanism of confabulation.

[Neural Mechanisms Underlying the Processing of Temporal Information in Episodic Memory and Its Disturbance].

Episodic memory is defined as memory for personally experienced events, and includes memory content and contextual information of time and space. Previous neuroimaging and neuropsychological studies have demonstrated three possible roles of the temporal context in episodic memory. First, temporal information contributes to the arrangement of temporal order for sequential events in episodic memory, and this process is involved in the lateral prefrontal cortex.