I would like to summarize some of my thoughts on the theme of this congress, "Learning, Utilizing, and Enjoying Neuropsychology," and would like to express my encouragement to our junior members and express my gratitude for all member's support during my time as president. Looking back on my work as a clinical researcher, I realized that if I study the issues in front of me slowly and without rushing to achieve results while accumulating day-to-day clinical work, it might be possible that I will be able to give back to clinical practice eventually. I would like to convey this message especially to young people. If you are too strong in your desire to quickly achieve results and apply them to the clinical practice in front of you, you may end up not enjoying your research, and you may find yourself unsure of your career path. I would like you to continue to conduct research from a neuropsychological perspective step by step in your daily clinical practice.

In neuropsychology, symptomatology has traditionally developed through the study of lesion localization and symptom mapping, mainly in patients with focal brain lesions. Since the 1980s, however, primary progressive aphasia (PPA) caused by neurodegenerative disorders has regained attention and numerous studies are currently underway. At the same time, neuroimaging research has shown that language functions as a complex network involving various cortical areas and white matter fibers. Against this background, recent research on lesion-symptom associations has entered new phases, using techniques such as disconnectome analysis and longitudinal analyses with linear mixed-effects models. On the other hand, there are notable differences in the quality and frequency of symptoms between focal brain lesions and neurodegenerative disorders. These differences may be due to differences in the spatial distribution of lesions, temporal progression, and resulting patterns of functional compensation.

Two-way anomia, which is the core symptom of semantic dementia (SD), is a condition in which naming and word comprehension are simultaneously impaired. Naming is a most vulnerable language function and is impaired after lesions in the anterior temporal lobe (ATL) or in basal temporal regions of the dominant cerebral hemisphere. Compared to naming, word comprehension is more robust to brain damage and is only impaired after extensive damage to basal temporal and posterior temporal lobes and occipital lobes. In SD, ATL is damaged from the early stages of the disease, while the basal and posterior temporal lobes are affected in the later stages. Naming impairment is a predominant, often an isolated symptoms in the early stages of the disease, while two-way anomia develops with additional word comprehension impairment as the disease progresses. Two-way anomia may reflect extensive damage to the anterior half of the ventral visual pathway, which consists of the ATL, basal and posterior temporal cortex.

Autism Spectrum Disorder (ASD) has core symptoms of persistent deficits in social communication and social interaction and restricted, repetitive patterns of behavioral interests. On the other hand, the core symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) are age-inappropriate inattention, hyperactivity, and impulsivity. Although the core symptoms of these two developmental disorders are completely different, it is known that people diagnosed with ASD exhibit ADHD traits/symptoms more frequently than those with typical development and that people diagnosed with ADHD are more likely to have ASD traits/symptoms. Furthermore, it is known that attention is related not only to ADHD, where inattention is a core symptom but also to social communication and social interaction and restricted, repetitive patterns of behavior interests, which are core symptoms of ASD. However, different aspects of attention are associated with ASD and ADHD. In other words, ASD and ADHD are different but overlap, and both are closely related to attention.

Therefore, while introducing the results of brain imaging research, we would like to deepen our consideration of the similarities and differences between the brains of ASD and ADHD and their relationship with attention.

The purpose of the study was to conduct an acoustic analysis of speech duration characteristics in Japanese speakers with apraxia of speech (Apraxia of Speech: AOS) and to identify an assessment index for AOS. Seventeen participants in the AOS group and twenty healthy controls undertook a task involving continuous recitation of 3-mora words. An acoustic analysis was conducted on parameters related to speech duration. The results showed that the AOS group exhibited significantly longer durations in total speech, speech onset, vowel duration, and syllable transition times compared to the healthy group. Furthermore, vowel duration was associated with the prolongation of total speech duration. The cut-off values for 3-mora words calculated based on those results were 586 msec for total speech duration and 491 msec for speech onset time, and which were shown to be the criteria for discriminating AOS speech from healthy speech.

We describe a case of progressive supranuclear palsy (PSP) presenting with progressive dynamic aphasia. A 71-year-old, right-handed, male patient visited our hospital complaining of forgetfulness, speech disturbance, and walking difficulties. Ten days later, he fell down and fractured his left femoral neck; this injury was treated at the orthopedics ward. Neurologically, he displayed downward vertical gaze limitations, bradykinesia in the left upper and lower extremities, and postural instability leading to frequent falls. Brain magnetic resonance images revealed atrophy of the bilateral frontal lobes and the tegmentum of the midbrain. Therefore, we diagnosed his condition as PSP-Richardson syndrome in accordance with the diagnostic criteria of the Movement Disorder Society. His spontaneous speech was highly sparse, but he had no disturbance in naming, repetition, reading or comprehension; these features were highly consistent with dynamic aphasia. His verbal condition deteriorated gradually, displaying the features of prosodic-type apraxia of speech as well as worsening of dynamic aphasia. Single-photon emission computed tomography (SPECT) images of the head performed at this time showed decreased blood flow in the predominant right side of the frontal lobes and basal ganglia.

Recently, several cases of progressive dynamic aphasia have been reported, most of which have been diagnosed as frontotemporal lobar degeneration including PSP. We speculate that functional disorders in the bilateral frontal cortical and subcortical areas, including the basal ganglia, might contribute to the emergence and evolution of dynamic aphasia and apraxia of speech. Accumulation and chronological examinations of similar cases to ours could elucidate the pattern of the pathological progression in the speech disorders associated with PSP.