The Influence of Physical Activity on Brain Aging and Cognition: The Role of Cognitive Reserve, Thresholds for Decline, Genetic Influence, and the Investment Hypothesis
James M. Rippe in Lifestyle Medicine, 2019
Healthy APOE-ε4 carriers also show altered brain activation under memory challenge tasks.35,122 Sperling reported that ε4 carriers displayed increased hippocampal activation that subsequently converted to hypoactivation as memory became more impaired, possibly forecasting a path toward dementia.35 (see Figure 112.1). Numerous studies have revealed that older adults carrying the APOE-ε4 allele exhibit lower cognitive function in areas of executive function, working memory, episodic memory, and perceptual processing, as well as cognitive deficits in the absence of pathology.123–125 Some findings in younger adults have also shed some new light on possible effects of the ε4 allele. One study that examined postmortem gene transcripts from brain cortical samples of young adults who were either ε3 or ε4 revealed differences in mitochondrial function in ε4 carriers before any evidence of plaque or tangle formation.126 Another study revealed mitochondrial damage post mortem in the posterior cingulate cortex in young adults, again found without plaque.127 Both studies offer support for a theory of mitochondrial dysfunction mediating, at least in part, the role the APOE-ε4 allele in cognitive aging and development of AD. The mitochondrial synthetic effect of exercise reported above may mitigate this process.
What is the self?
Tamara Ownsworth in Self-Identity after Brain Injury, 2014
The ability to perceive changes to self over time is important for identity formation across the lifespan (see Table 2.1). D’Argembeau and colleagues (2008) examined the neural correlates of self-reflection over time, requiring subjects to reflect on their own psychological characteristics for the present and past, and also those of an intimate other for present and past. Although cortical midline structures were recruited for each of the four reflective tasks relative to the control condition, the degree of activity varied significantly within this neural circuitry across the conditions. Specifically, the ventral and dorsal medial prefrontal cortex and posterior cingulate cortex were recruited more when reflecting on the present self than when reflecting on the past self or the other person. These findings suggest that cortical midline structures support the ability to differentiate our present and past selves and thus maturation of self-identity over time.
Choice Impulsivity
Hanna Pickard, Serge H. Ahmed in The Routledge Handbook of Philosophy and Science of Addiction, 2019
We recently reviewed current evidence that personality traits can be used as endophenotypes of SUD, allowing for a better understanding of which individual differences in specific brain circuits provide vulnerability or resilience to SUD (Belcher et al. 2014). In our analysis, we identified Tellegen’s three personality traits, PEM, NEM and CON (the inverse measure of AI), as tied to specific brain circuits and genes (Figure 23.1). Our heuristic model was based on a continuum of three independent variables (constituted by the three main orthogonal personality traits) that interact dynamically and with the environment to determine the degree of vulnerability to the development of SUD. Individuals with low PEM, high NEM and high AI would be most vulnerable (least resilient), and individuals with high PEM, low NEM and low AI would be least vulnerable (most resilient). To our previous analysis we now add CI as an additional personality trait in its own right, which is modulated by a brain circuit that includes the vmPFC, NAc and the posterior cingulate cortex (see above), the function of which is moderated by the COMT and the dopamine D4R genes (see above), as well as the α2A adrenoceptor (α2AR) gene (see below; Figure 23.1).
Hypnotic Automaticity in the Brain at Rest: An Arterial Spin Labelling Study
Published in International Journal of Clinical and Experimental Hypnosis, 2019
Pierre Rainville, Anouk Streff, Jen-I Chen, Bérengère Houzé, Carolane Desmarteaux, Mathieu Piché
Between-subject regression analyses were also performed using individual changes in hypnotic depth and the individual hypnotizability scores as predictors of hypnosis-related rCBF changes (Figure 5). The analysis of hypnotic depth revealed a single positive peak at x = − 2, y = − 56, z = 4 (t = 4.22, p < .001). This effect was difficult to interpret anatomically as the peak fell in the midline, within cerebrospinal fluid (CSF), below the most caudal part of the posterior cingulate cortex and above the cerebellum. The regression performed on hypnotizability scores also revealed a single positive peak at x = 8, y = − 50, z = 26 (t = 4.38, p < .001). This peak was located in the retrosplenial part of the posterior cingulate cortex. No negative regression peak was found on hypnotic depth and hypnotizability.
Self and other body perception in anorexia nervosa: The role of posterior DMN nodes
Published in The World Journal of Biological Psychiatry, 2018
Esther Via, Ximena Goldberg, Isabel Sánchez, Laura Forcano, Ben J. Harrison, Christopher G. Davey, Jesús Pujol, Ignacio Martínez-Zalacaín, Fernando Fernández-Aranda, Carles Soriano-Mas, Narcís Cardoner, José M. Menchón
In recent years, neuroimaging studies have suggested that self-referential and self-evaluative mental activity processes rely on the so-called default mode network (DMN) (Buckner et al. 2008; Davey et al. 2010). The DMN involves a set of areas that show synchronised increased activation during resting periods compared to tasks, and which actively respond to self-related processes such as autobiographical memory recall, prospective thinking and self-judgments (Raichle et al. 2001; Harrison et al. 2008; Preedy 2011), including the evaluation of one’s own body and the sense of body ownership (Northoff et al. 2006; Tsakiris et al. 2010). These areas include the posterior cingulate cortex (PCC) and precuneus, the inferior parietal cortices, the bilateral lateral temporal cortex, the insula, and dorsal and ventral areas of the medial frontal cortex (Raichle et al. 2001). In AN, a few studies have found resting-state alterations in the connectivity of DMN regions, including between the anterior cingulate and the precuneus (Lee et al. 2014; Mcfadden et al. 2014), in the anterior insula (Boehm et al. 2014) and in the frontal and parietal cortices (Cowdrey et al. 2014), which were suggested to imply a dysfunctional self-referential network involved in rumination about body shape, weight and eating (Cowdrey et al. 2014). Other studies exploring the DMN found no differences within this system in AN patients (Gaudio et al. 2015).
Advances in minimally invasive surgery and clinical measurement
Published in Computer Assisted Surgery, 2019
Neural substrates of action to the object or this specific direct route, however, remain unclear, especially for the connection from the visual pathway to the motor cortex. Zijian Wang et al. conducted a study examined this issue by conducting a Functional Magnetic Resonance Imaging (fMRI) experiment, in which two action generation tasks involving pictures of real objects and the object’s nouns were used, with pictures naming and covert noun reading being the control tasks. The result showed that the model predefined for the Posterior Cingulate Cortex (PCC) and precuneus connecting Inferior Parietal Lobule (IPL) to the posterior medial frontal cortex dominated over the others (with 0.45 probability), suggesting that the PCC and the precuneus locate at the neural substrates of action to the object.
Related Knowledge Centers
- Anterior Cingulate Cortex
- Brodmann Area
- Cingulate Cortex
- Cytoarchitecture
- Default Mode Network
- Limbic Lobe
- Precuneus
- Working Memory
- Brain
- Retrosplenial Cortex