Psychological Medicine
October 2, 2017
André Schmidt, Felix Müller, Claudia Lenz et al.
62 citations
Activating the serotonin 2A receptor with LSD impairs the brain's ability to stop or inhibit responses, and this breakdown is linked to visual hallucinations. In a double-blind, placebo-controlled experiment with 18 healthy adults, LSD reduced brain activity in regions including the frontal and cingulate cortex, middle temporal gyrus, and cerebellum during a response-inhibition task. Parahippocampal activation related differently to performance under LSD versus placebo. Less activation in the left superior frontal gyrus during LSD exposure was associated with greater cognitive impairment and visual imagery. The findings suggest that 5-HT2A receptor activation disrupts hippocampal-prefrontal circuits, which may promote visual hallucinations.
Neurosignals
January 1, 2017
Davide Zanchi, Marie‐Louise Montandon, Indrit Sinanaj et al.
46 citations
Brain functional changes in the fronto-parietal network and default mode network precede observable cognitive decline in healthy older adults. In a study of 62 elderly individuals, those with stable cognition, those who later deteriorated, and those with mild cognitive impairment showed distinct brain activation patterns during a working memory task. Compared to stable controls, individuals with mild cognitive impairment and those who later declined had lower activation in frontal regions but higher activation in the anterior and posterior cingulate cortex and insula. These neural differences appeared before performance differences on cognitive tests, suggesting they may serve as early markers of cognitive decline.
The International Journal of Neuropsychopharmacology
May 16, 2017
André Schmidt, Felix Müller, Patrick C. Dolder et al.
41 citations
Methylphenidate and modafinil, but not MDMA (ecstasy), improved the ability to stop a motor response in healthy adults. Using brain imaging, methylphenidate broadly activated frontal, temporal, and parietal regions, including the anterior cingulate cortex and presupplementary motor area, more than modafinil did. Modafinil increased activation in the right middle frontal gyrus and parietal lobule, while MDMA activated the right middle/inferior frontal gyrus and superior parietal lobule without improving performance. The findings suggest that methylphenidate may be superior to modafinil and MDMA for enhancing cognitive performance related to response inhibition in healthy people.
The International Journal of Neuropsychopharmacology
November 22, 2017
André Schmidt, Felix Müller, Patrick C. Dolder et al.
25 citations
Modafinil, but not methylphenidate or MDMA, increased brain activity in a limbic-cortical-striatal-pallidal-thalamic circuit and the amygdala when healthy subjects viewed fearful faces. Activation in frontal brain regions correlated with increased feelings of fearfulness and depressiveness after modafinil. Despite modafinil's cognitive enhancement effects, potential adverse effects on emotion processing should be considered.