Application of the ATN classification scheme in a population without dementia: Findings from the EPAD cohort.

BACKGROUND: We classified non-demented European Prevention of Alzheimer's Dementia (EPAD) participants through the amyloid/tau/neurodegeneration (ATN) scheme and assessed their neuropsychological and imaging profiles. MATERIALS AND METHODS: From 1500 EPAD participants, 312 were excluded. Cerebrospinal fluid cut-offs of 1000 pg/mL for amyloid beta (Aß)1-42 and 27 pg/mL for p-tau181 were validated using Gaussian mixture models. Given strong correlation of p-tau and t-tau (R2  = 0.98, P < 0.001), neurodegeneration was defined by age-adjusted hippocampal volume. Multinomial regressions were used to test whether neuropsychological tests and regional brain volumes could distinguish ATN stages. RESULTS: Age was 65 ± 7 years, with 58% females and 38% apolipoprotein E (APOE) ε4 carriers; 57.1% were A-T-N-, 32.5% were in the Alzheimer's disease (AD) continuum, and 10.4% suspected non-Alzheimer's pathology. Age and cerebrovascular burden progressed with biomarker positivity (P < 0.001). Cognitive dysfunction appeared with T+. Paradoxically higher regional gray matter volumes were observed in A+T-N- compared to A-T-N- (P < 0.001). DISCUSSION: In non-demented individuals along the AD continuum, p-tau drives cognitive dysfunction. Memory and language domains are affected in the earliest stages.

Toward feeling, understanding, and caring: The development of empathy in young autistic children.

LAY ABSTRACT: Empathy is a highly valued human capacity. Yet, autistic people are often portrayed as lacking in empathy. Recent research, which views empathy as a complex construct emerging from multiple interrelated emotional and cognitive processes, argues that, although many autistic people do have difficulty understanding others' emotions, and this may hinder them from responding to others in a prosocial manner, they are not indifferent to other people's feelings. Hoping to contribute to a better understanding of the unique challenges that autistic children face in their empathy development, we followed the development of four empathy abilities: emotion contagion, attention to others, emotion acknowledgment, and prosocial actions, in 1- to 6-year-old autistic children, in comparison with non-autistic children. Once a year, for 4 consecutive years, children's empathy abilities were evaluated by experimenters who acted out emotional episodes to provoke empathy in children, and by parents who filled out empathy questionnaires. We found that autistic children experienced indeed more difficulty attending to others, acknowledging others' emotions, and initiating prosocial actions toward others. However, according to parents, they did not differ from their non-autistic peers in feeling along with others' negative emotions. This indicates that it might not be the case that autistic children did not want to act empathetically toward others. Rather, they might not know how to do so. Notably, despite these difficulties, when looking at children's developmental trajectories, autistic children showed similar improvements over time as non-autistic children. This provides evidence that autistic children have the potential to learn and to improve their empathy skills.