NeuroImage
August 15, 2024
Marta Lapo Pais, Marta Teixeira, Carla Soares et al.
8 citations
Inhaled DMT, a psychedelic acting on 5-HT2A serotonin receptors, increases the size of neural population receptive fields (pRFs) in the peripheral visual field of the primary visual cortex (V1). This change, measured with MRI and pRF mapping in a within-subject design, occurred during visual effects documented by the Hallucinogen Rating Scale and was not explained by differences in eye or head movements. The enlarged pRFs may underlie perceptual distortions such as field blurring, tunnel vision, and enlargement of nearby visual space. The findings suggest that 5-HT2A receptor activation controls gain in visual cortex, linking neural population responses to psychedelic visual phenomena.
Social cognitive and affective neuroscience
January 31, 2026
Carla Soares, Gisela Lima, Marta Teixeira et al.
1 citation
A pharmacoimaging study examined how ayahuasca affects a brain region involved in social perception, the posterior superior temporal sulcus (pSTS), which is part of the third visual pathway. Twelve healthy volunteers received two doses of ayahuasca (0.5 mg/kg and 0.8 mg/kg DMT) or a placebo in a crossover design. The higher dose increased connectivity of the right pSTS with visual and mirror-neuron brain regions. This enhanced connectivity correlated with stronger perspective-taking experiences. Participants also reported improved social relationships one week later, even though acute effects were minimal. The findings suggest ayahuasca strengthens early social information processing through the third visual pathway and mirror-neuron systems, offering a basis for its prosocial therapeutic effects.
Scientific Reports
December 12, 2025
Gisela Lima, Carla Soares, Marta Teixeira et al.
Reward processing involves learning, liking, and wanting, and its disruption in mesolimbic and mesocortical pathways underlies many disorders. In a preliminary pharmacoimaging study, 11 healthy participants with prior psychedelic experience self-administered inhaled DMT immediately before MRI scanning, with a no-administration control condition. DMT decreased connectivity between the right nucleus accumbens and left ventral tegmental area, increased connectivity between the right nucleus accumbens and anterior cingulate cortex, and increased connectivity between medial prefrontal cortex and anterior cingulate cortex. These connectivity changes correlated with altered volition and perception. Reduced midbrain-NAc connectivity, often increased in addiction, suggests potential therapeutic value for reward-related disorders.
Research Square
September 17, 2025
Gisela Lima, Carla Soares, Marta Teixeira et al.
Reward processing involves learning, liking, and wanting, and its disruption in mesolimbic and mesocortical pathways underlies many disorders. In a within-subject pharmacoimaging study with 11 healthy participants experienced with psychedelics, inhaled N,N-dimethyltryptamine (DMT) altered connectivity within the mesocorticolimbic circuitry. Connectivity decreased between the right nucleus accumbens and left ventral tegmental area, while it increased between the right nucleus accumbens and anterior cingulate cortex, and between the medial prefrontal cortex and anterior cingulate cortex. These changes correlated with shifts in volition and perception. The findings suggest DMT may have therapeutic potential for disorders affecting reward processing.