Search bioRxiv⌕ Search

Biology subjects

Rubia, K.

Publications and source records attributed to Rubia, K..

3 recordsLinked to original sources

Where is God? A comparison of the neural correlates of mystical and religious praying

The perception of God can be as a transcendent entity that is infinite and outside of human beings, typical for religious traditions, or as an immanent entity that is outside and inside of human beings, typical for mystical traditions. These different perceptions of God may be associated with different neural correlates depending on which God we pray to. To elucidate the neural correlates of these different perceptions of the divine, we compared fMRI activation during praying between 18 Christians and 16 practitioners of Sahaja Yoga Meditation, characterised by transcendent and immanent perceptions of God, respectively. The thalamus was deactivated during praying in Meditators relative to Christians. Due to the sensory relay function of thalamus, the thalamic deactivation in meditators presumably reflects a reduction in the perception of external stimuli in order to focus on the internal perception of an immanent God, while the activation of the thalamus in Christian prayers could be associated with the dialogue with an externally perceived transcendent God.

neuroscience↗

Increases in whole brain grey matter associated with long-term Sahaja Yoga Meditation: a detailed area by area description

ObjectivesOur previous study showed that long-term practitioners of Sahaja Yoga Meditation (SYM) had around 7% larger grey matter volume (GMV) in the whole brain compared with healthy controls; however, when testing individual regions, only 5 small brain areas were statistically different between groups. Under the hypothesis that those results were statistically conservative, with the same dataset, we investigated in more detail the regional differences in GMV associated with the practice of SYM, with a different statistical approach. DesignTwenty-three experienced practitioners of SYM and 23 healthy non-meditators matched on age, gender and education level, were scanned using structural Magnetic Resonance Imaging. Their GMV were extracted and compared using Voxel-Based Morphometry. Using a novel ad-hoc GLM model, statistical comparisons were made to observe if the GMV differences between meditators and controls were statistically significant. ResultsIn the 16 lobe area subdivisions, GMV was statistically significantly different in 4 out of 16 areas: Right hemispheric temporal and frontal lobes, left frontal lobe and brainstem. In the 116 AAL area subdivisions, GMV difference was statistically significant in 11 areas. The GMV differences were statistically more significant in right hemispheric brain areas. ConclusionsThe study shows that long-term practice of SYM is associated with larger GMV overall, and with significant differences mainly in temporal and frontal areas of the right hemisphere and the brainstem. These neuroplastic changes may reflect emotional and attentional control mechanisms developed with SYM. On the other hand, our statistical ad-hoc method shows that there were more brain areas with statistical significance compared to the traditional methodology which we think is susceptible to conservative Type II errors.

neuroscience↗

An insula-driven network computes decision uncertainty and promotes abstinence in chronic cocaine users

The anterior insular cortex (AIC) and its interconnected brain regions have been associated with both addiction and decision-making under uncertainty. However, the causal interactions in this uncertainty-encoding neurocircuitry and how these neural dynamics impact relapse remain elusive. Here, we used model-based fMRI to measure choice uncertainty in a motor decision task in 61 individuals with cocaine use disorder (CUD) and 25 healthy controls. CUD participants were assessed before discharge from a residential treatment program and followed for up to 24 weeks. We found that choice uncertainty was tracked by the AIC, dorsal anterior cingulate cortex (dACC), and ventral striatum (VS), across participants. Stronger activations in these regions measured pre-discharge predicted longer abstinence after discharge in individuals with CUD. Dynamic causal modelling revealed an AIC-to-dACC directed connectivity modulated by uncertainty in controls, but a dACC-to-AIC connectivity in CUD participants. This reversal was mostly driven by early-relapsers (<30 days). Furthermore, CUD individuals who displayed a stronger AIC-to-dACC excitatory connection during uncertainty encoding remained abstinent for longer periods. These findings reveal a critical role of an AIC-driven, uncertainty-encoding neurocircuitry in protecting against relapse and promoting abstinence.

neuroscience↗