Ihre Suche

Suche zurücksetzen

In authors or contributors

"Ott, Ulrich"

Thema

Attention/*physiology

Ergebnisse 3 Einträge

Abstracts

Reuter, M., Ott, U., Vaitl, D., & Hennig, J. (2007). Impaired executive control is associated with a variation in the promoter region of the tryptophan hydroxylase 2 gene. Journal of Cognitive Neuroscience, 19(3), 401–408. https://doi.org/10.1162/jocn.2007.19.3.401

Current models of attention describe attention not as a homogenous entity but as a set of neural networks whose measurement yields a set of three endophenotypes-alerting, orienting, and executive control. Previous findings revealed different neuroanatomical regions for these subsystems, and data from twin studies indicate differences in their heritability. The present study investigated the molecular genetic basis of attention in a sample of 100 healthy subjects. Attention performance was assessed with the attention network test that distinguishes alerting, orienting, and executive control (conflict) using a simple reaction time paradigm with different cues and congruent and incongruent flankers. Two gene loci on candidate genes for cognitive functioning, the functional catechol-O-methyltransferase (COMT) VAL158MET and the tryptophan hydroxylase 2 (TPH2) -703 G/T promoter polymorphism, were tested for possible associations with attention. COMT is involved in the catabolism of dopamine, and TPH is the rate-limiting enzyme for serotonin synthesis. Results showed no effect of the COMT polymorphism on attention performance. However, the TT genotype of TPH2 -03 G/T was significantly associated with more errors (a possible indicator of impaired impulse control; p = .001) and with decreased performance in executive control (p = .001). This single-nucleotide polymorphism on the TPH2 gene explained more than 10% of the variance in both indicators of attention stressing the role of the serotonergic system for cognitive functions.
Ott, U., Reuter, M., Hennig, J., & Vaitl, D. (2005). Evidence for a common biological basis of the Absorption trait, hallucinogen effects, and positive symptoms: epistasis between 5-HT2a and COMT polymorphisms. American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics : The Official Publication of the International Society of Psychiatric Genetics, 137B(1), 29–32. https://doi.org/10.1002/ajmg.b.30197

Absorption represents a disposition to experience altered states of consciousness characterized by intensively focused attention. It is correlated with hypnotic susceptibility and includes phenomena ranging from vivid perceptions and imaginations to mystical experiences. Based on the assumption that drug-induced and naturally occurring mystical experiences share common neural mechanisms, we hypothesized that Absorption is influenced by the T102C polymorphism affecting the 5-HT2a receptor, which is known to be an important target site of hallucinogens like LSD. Based on the pivotal role ascribed to the prefrontal executive control network for absorbed attention and positive symptoms in schizophrenia, it was further hypothesized that Absorption is associated with the VAL158MET polymorphism of the catechol-O-methyltransferase (COMT) gene affecting the dopaminergic neurotransmitter system. The Tellegen Absorption Scale was administered to 336 subjects (95 male, 241 female). Statistical analysis revealed that the group with the T/T genotype of the T102C polymorphism, implying a stronger binding potential of the 5-HT2a receptor, indeed had significantly higher Absorption scores (F = 10.00, P = 0.002), while no main effect was found for the COMT polymorphism. However, the interaction between T102C and COMT genotypes yielded significance (F = 3.89; P = 0.049), underlining the known functional interaction between the 5-HT and the dopaminergic system. These findings point to biological foundations of the personality trait of Absorption.
Irrmischer, M., Houtman, S. J., Mansvelder, H. D., Tremmel, M., Ott, U., & Linkenkaer-Hansen, K. (2018). Controlling the temporal structure of brain oscillations by focused attention meditation. Human Brain Mapping, 39(4), 1825–1838. https://doi.org/10.1002/hbm.23971

Our focus of attention naturally fluctuates between different sources of information even when we desire to focus on a single object. Focused attention (FA) meditation is associated with greater control over this process, yet the neuronal mechanisms underlying this ability are not entirely understood. Here, we hypothesize that the capacity of attention to transiently focus and swiftly change relates to the critical dynamics emerging when neuronal systems balance at a point of instability between order and disorder. In FA meditation, however, the ability to stay focused is trained, which may be associated with a more homogeneous brain state. To test this hypothesis, we applied analytical tools from criticality theory to EEG in meditation practitioners and meditation-naïve participants from two independent labs. We show that in practitioners-but not in controls-FA meditation strongly suppressed long-range temporal correlations (LRTC) of neuronal oscillations relative to eyes-closed rest with remarkable consistency across frequency bands and scalp locations. The ability to reduce LRTC during meditation increased after one year of additional training and was associated with the subjective experience of fully engaging one's attentional resources, also known as absorption. Sustained practice also affected normal waking brain dynamics as reflected in increased LRTC during an eyes-closed rest state, indicating that brain dynamics are altered beyond the meditative state. Taken together, our findings suggest that the framework of critical brain dynamics is promising for understanding neuronal mechanisms of meditative states and, specifically, we have identified a clear electrophysiological correlate of the FA meditation state.

Custom feed

Last update from database: 11.08.25, 05:41 (UTC)

Ihre Suche

Ergebnisse 3 Einträge

Erkunden

Team

Eintragsart

Sprache

Thema