Frontotemporal neural systems supporting semantic processing in Alzheimer’s disease

We hypothesized that semantic memory for object concepts involves both representations of visual feature knowledge in modality-specific association cortex and heteromodal regions that are important for integrating and organizing this semantic knowledge so that it can be used in a flexible, contextually appropriate manner. We examined this hypothesis in an fMRI study of mild Alzheimer’s disease (AD). Participants were presented with pairs of printed words and asked whether the words matched on a given visual–perceptual feature (e.g., guitar, violin: SHAPE). The stimuli probed natural kinds and manufactured objects, and the judgments involved shape or color. We found activation of bilateral ventral temporal cortex and left dorsolateral prefrontal cortex during semantic judgments, with AD patients showing less activation of these regions than healthy seniors. Moreover, AD patients showed less ventral temporal activation than did healthy seniors for manufactured objects, but not for natural kinds. We also used diffusion-weighted MRI of white matter to examine fractional anisotropy (FA). Patients with AD showed significantly reduced FA in the superior longitudinal fasciculus and inferior frontal-occipital fasciculus, which carry projections linking temporal and frontal regions of this semantic network. Our results are consistent with the hypothesis that semantic memory is supported in part by a large-scale neural network involving modality-specific association cortex, heteromodal association cortex, and projections between these regions. The semantic deficit in AD thus arises from gray matter disease that affects the representation of feature knowledge and processing its content, as well as white matter disease that interrupts the integrated functioning of this large-scale network.     

The Effects of Social and Physical Functioning and Self-Management Abilities on Well-Being Among Patients with Cardiovascular Diseases,Chronic Obstructive Pulmonary Disease,and Diabetes

To increase our understanding of relationships between well-being and social/physical functioning and self-management abilities (SMAs) among chronically ill patients. The cross-sectional questionnaire-based study included 1,254 patients with cardiovascular diseases, 725 with chronic obstructive pulmonary disease, and 253 with diabetes (total, 2232/4200; 53 % response rate). Social and physical functioning correlated significantly with SMAs and well-being (all p?≤?0.001). After controlling for background characteristics, multiple regression showed that social and physical functioning were still related to SMAs (β?=?0.32–0.12; both p?≤?0.001) and well-being (β?=?0.39–0.14; both p?≤?0.001). The strengths of relationships between well-being and social (β?=?0.39 vs. 0.20) and physical (β?=?0.14 vs. 0.07) functioning declined significantly (both p?≤?0.001) when the SMA mediator was included in the equation. SMAs of chronically ill are related to their social and physical functioning. We found indications that chronically ill patients reporting lower levels of social and physical functioning are worse self-managers than are those with higher levels of functioning. Furthermore, SMAs may mediate the relationships between social and physical functioning and well-being. Self-management interventions aiming to enhance SMAs more broadly than traditional interventions aiming only to prevent functional decline are expected to improve SMAs and enhance well-being among chronically ill patients.     

Spatial coordinates and reading: Comments on Monk (1985)

Subjects are able to process some texts when they are presented, word-by-word, in a single physical location. As differential spatial information is not available in this task, Monk (1985a) argues that it need not be derived in normal reading. We suggest this conclusion is unwarranted, because subjects make large and very accurate regressive saccades to regions of previously fixated text. Without a representation of spatial coordinates this should not occur.     

Colour Relations in Form

The orthodox monadic determination thesis holds that we represent colour relations by virtue of representing colours. Against this orthodoxy, I argue that it is possible to represent colour relations without representing any colours. I present a model of iconic perceptual content that allows for such primitive relational colour representation, and provide four empirical arguments in its support. I close by surveying alternative views of the relationship between monadic and relational colour representation.     

Positive Mental Health as a Predictor of Problematic Internet and Facebook Use in Adolescents and Young Adults

Recent research on Problematic Internet Use and Problematic Facebook Use (PIU and PFU) has focused on the idea that people who engage in PIU or PFU are more likely to present with mental health problems. The goal of the present study was to examine the contribution of positive mental health (PMH) to PIU and PFU among adolescents and young adults. A total of 1927 Italian adolescents and young adults participated in the study. Structural equation modeling showed that PMH is negatively linked to both PIU and PFU, indicating that PMH may be an important antecedent for both PIU and PFU among adolescents and young adults. In conclusion, dimensions of PMH may be taken into account by researchers and educational practitioners in preventing both PIU and PFU.     

Suicidal–Homicidal Ideation in Mass Killers and Transcendence

This article examines the role that suicidal–homicidal ideation plays in influencing mass killers and draws on the author’s concept of transcendent fantasy theory. Although numerous researchers touch on the fact that 50% of mass killers commit suicide, few have traced and compared the suicidal person’s fantasy process with that of the suicidal–homicidal killer’s fantasy process. Suicidal individuals tend to be intropunitive. They internalize the blame for real or imagined failures, and they seek to escape from such failures, or to inflict punishment on him- or herself for the same reasons. Mass killers externalize the blame for their real or imagined losses. Due to their mordant bitterness toward self and others, these suicidal–homicidal individuals often fantasize not only about escaping, but transcending their feelings of inadequacy, self-doubt, and worthlessness by having society see them as powerful, clever, and superior for pulling off a massacre and making (in their view) oppressive people pay.