From my congress chair lecture I gave at the 47th Annual Meeting of the Japanese Neuropsychological Society on September 7, 2023, I summarized my medical and research activities on idiopathic normal pressure hydrocephalus (iNPH), which began with neuropsychology. Among them, I introduced our research on cognitive impairment and apathy in patients with iNPH. I also described my current work with a number of neuropsychological experts to clarify the relationship between behavioral and psychological symptoms of dementia (BPSD) and the results of neuroimaging and blood biomarker tests, and to examine the relationship between the results of these tests and the effects of non-pharmacological measures on BPSDs.

Interoception is sensation for the internal state of the body. Changes in the internal state of the body, such as the activity of internal organs and associated sensations and pain, are the instances of this sensation. It has been rapidly recognized over the past two decades and has come to attract attention as one of the elements underlying various mental functions. This paper outlines the definition of interoception, the systems of manifestation and dynamic regulation of interoception, the neural basis of interoception and methods of assessment.

This is a review paper about neuropsychological data during ictal as well as postictal periods in patients with epilepsy, which we have investigated on-site at Utano Reginal Epilepsy Center. After a brief summary of Kyoto-school of neuropsychology, our research there is summarized into 3 parts, that is, recovery processes of non-fluent types of aphasia during postictal periods, an interpretation of neologisms during postictal periods following focal impaired awareness seizures in patients with temporal lobe epilepsy based on Brown's theory of paraphasia, and a finding of developmental and micro-genetic (Brown) parallelism of aura-sensations. While brain researches, nowadays, are overwhelmingly done on the basis of localistic viewpoints, psychiatric and holistic ones may invite clinicians into a window leading to a new world where we afford to relish neuropsychology by way of apparently old-fashioned, but actually still active method.

Neuropsychology plays a crucial role in rehabilitation medicine. It thoroughly assesses patients' cognitive functions and behavioral issues, revealing the characteristics of pathologies or impairments. This enables the rehabilitation team to accurately understand patients' needs and devise appropriate plans. Specifically, the test results allow for individualized training and interventions tailored to each patient. Neuropsychological examinations also prove valuable in evaluating and determining the effectiveness of training, tracking patients' changes, and adjusting plans accordingly. In terms of providing information and support to patients and their families, neuropsychology serves to offer concrete details through test results, alleviating anxiety and dispelling misunderstandings. Furthermore, the progress in research and knowledge contributes to the advancement of rehabilitation strategies and intervention methods.

The increase in the number of patients with Alzheimer's disease (AD) in recent years and advances in brain imaging technology have made AD a major target for neuropsychology. The purposes of applying neuropsychology to AD include: 1) to help in the early and differential diagnosis of AD, 2) to clarify impaired cognitive functions and to use it to help care for and support patients with AD, 3) to utilize neuropsychology to clarify the pathophysiology of AD, and 4) to clarify the mechanisms of human psychological phenomena through patients with AD. This article discusses the neuropsychology for AD, focusing on how neuropsychology is utilized in the treatment and research of AD.

Neuropsychological research and schizophrenia research are research areas in close proximity, but in some aspects they differ in conception. The following suggestions are made with an awareness of both similarities and differences between the two research fields.

From the perspective of 'applying neuropsychological research to schizophrenia research', the following three points are proposed: 1. a 'paradigm shift' is needed to be able to diagnose schizophrenia on neuroimaging, rather than just increasing the diagnostic accuracy; 2. use the principle of 'double divergence' for clinical-anatomical correlations; 3. be careful in interpreting the neural basis of psychological states influenced by social factors.

On the other hand, from the perspective of 'applying schizophrenia research to neuropsychology', the following three points are proposed: 1. use global indicators in a generous way, 2. take a bold step in 'understanding', and 3. focus on the patient and life perspectives.

Posterior cortical atrophy is a neurodegenerative syndrome characterized by a progressive decline in visuospatial processing and other posterior cognitive functions, relatively preserved memory and language in the early stages, and atrophy of posterior brain regions. Atypical Alzheimer's disease accounts for more than half of the cases, but dementia with Lewy bodies and corticobasal degeneration are also known. The symptoms are based on impairment of the bilateral dorsal/ventral visual pathways. Diagnosis may be delayed by ophthalmological consultation due to subjective visual complaints or overlooking abnormalities on routine cognitive screening. Early diagnosis can be achieved by detecting visuospatial cognitive impairment through appropriate examination and testing. With advances in neuroimaging and other diagnostic methods, it is becoming possible to diagnose underlying diseases. It is important to make an early diagnosis that leads to adequate treatment and management.

An overview of the free energy principle (FEP) was introduced. FEP is a unifying theory of the brain that was first published in 2006 and has developed rapidly. Next we presented new models of several neuropsychological disorders based on FEP. The most important aspect of the theory is precision control. This is a top-down optimisation of precision (or confidence) of the signal. Neuromodulators are responsible for this precision control. The paper introduced several neuropsychological models, emphasising this point.

Recently, sensory cognitive deficits of autism spectrum disorder (ASD) are gaining increased attention. Sensory cognitive deficits of ASD are known to affect a variety of comorbid symptoms and behaviors that are problematic in ASD. This paper outlines how to recognize, understand and care for sensory cognitive deficits of ASD, especially auditory characteristics, which affect communication, with some personal opinions based on recent domestic and international research findings. Future research is expected to investigate the pathophysiology for developmental changes and novel interventions for sensory cognitive deficits, leading to a more sensory-friendly (or autism-friendly) society.