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Parkinson's disease (PD) impairs various cognitive functions, including time perception. Dysfunctional time perception in PD is poorly understood, and no study has investigated the rehabilitation of time perception in patients with PD. We aimed to induce the recovery of time perception in PD patients and investigated the potential relationship between recovery and cognitive functions/domains other than time perception. Sixty patients with PD (27 females) and 20 healthy controls (10 females) were recruited. The participants underwent a feedback training protocol for 4 weeks to improve the accuracy of subjective spatial distance or time duration using a ruler or stopwatch, respectively. They participated in three tests at weekly intervals, each comprising 10 types of cognitive tasks and assessments. After duration feedback training for 1 month, performance on the Go/No-go task, Stroop task, and impulsivity assessment improved in patients with PD, while no effect was observed after distance feedback training. Additionally, the effect of training on duration production correlated with extended reaction time and improved accuracy in the Go/No-go and Stroop tasks. These findings suggest that time perception is functionally linked to inhibitory systems. If the feedback training protocol can modulate and maintain time perception, it may improve various cognitive/psychiatric functions in patients with PD. It may also be useful in the treatment of diseases other than PD that cause dysfunctions in temporal processing.

Introduction Pathological abnormalities first appear in the medial temporal regions including entorhinal cortex and parahippocampus in patients with Alzheimer's disease. Previous studies showed that olfactory decline in elderly subjects was associated with volume reductions in the left hippocampus and left parahippocampus without cognitive impairment. The aim of this study is to investigate the link between olfaction and volume reductions in the medial temporal regions including the parahippocampus, entorhinal cortex, and hippocampal subfields. Method 27 elderly subjects and 27 young controls were measured olfaction acuity, cognitive function, and structural magnetic resonance imaging. Image processing and gray matter volumetric segmentation were performed with FreeSurfer. Volume data were analyzed with SPSS Statistics software. Results Interesting results of this study were that volume reduction in the entorhinal cortex was not directly linked with declining olfactory ability. Volume reduction in the left entorhinal cortex was correlated with volume reduction in the left parahippocampus and dentate gyrus. However, left parahippocampus volume reduction had the greatest impact on olfactory decline, and the entorhinal cortex and dentate gyrus might additionally contribute to olfactory decline. Conclusion Our results indicate that olfactory decline may be directly reflected in the medial temporal regions as reduced parahippocampus volumes, rather than as morphological changes in the entorhinal cortex and hippocampus. The parahippocampus may play an important role in the association between memory retrieval and olfactory identification., Left: Visualization of brain segmentation in a single subject with FreeSurfer. The entorhinal cortex (ENT) is indicated in red, and the parahippocampus (para‐HI) is indicated in green. Right: Visualization of hippocampal subfield segmentation in a single subject with each subfield represented by a different color.

Higher wake promotion against sleep drive boosts cognitive processing, but it also seems to increase the risk of insomnia by reinforcing an obsession with sleep in neurotic patients. To explore whether a personality trait of neuroticism simultaneously facilitates wake-promoting ability and sleep devaluation via a common regional prefrontal function under a sleep-restricted condition, working memory tasks were administered to 49 healthy humans after a 2-h sleep restriction. Higher wake-promoting ability demonstrated in a high-load task was correlated with lower bilateral prefrontal activation, as measured by near-infrared spectroscopy. Structural equation modeling revealed that neuroticism predicts sleep devaluation and wake-promoting ability via left and right regional prefrontal efficiency, respectively. Our results indicate that neuroticism-related neural efficiency increases resilience to sleepiness, but decreases sleep satisfaction.

It is well known that a new face studied from one view is often difficult to identify from another. This viewpoint dependence has detrimental implications for forensic practice. To compensate for this problem, we employed synthesized face images in the training session of a standard old/new recognition task. Observers in the experimental conditions learned one or more synthesized face images along with an original photograph of the face in a different view, whereas observers in the control conditions learned only the original photograph of the face. It was found that the experimental conditions consistently produced better recognition accuracy than the control conditions. We conclude that synthesized face views can be used to facilitate person identification in forensic applications. Copyright © 2008 John Wiley & Sons, Ltd.