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Amirhossein Manzouri Foto: Psykologiska institutionen/HD

Amirhossein Manzouri

Forskningsassistent

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Arbetar vid Psykologiska institutionen
E-post amirhossein.manzouri@psychology.su.se
Besöksadress Frescati hagväg 14
Rum 122
Postadress Psykologiska institutionen 106 91 Stockholm

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2018. Amirhossein Manzouri, Ivanka Savic. PLoS ONE 13 (10)

    The neurobiology of sexual preference is often discussed in terms of cerebral sex dimorphism. Yet, our knowledge about possible cerebral differences between homosexual men (HoM), heterosexual men (HeM) and heterosexual women (HeW) are extremely limited. In the present MRI study, we addressed this issue investigating measures of cerebral anatomy and function, which were previously reported to show sex difference. Specifically, we asked whether there were any signs of sex atypical cerebral dimorphism among HoM, if these were widely distributed (providing substrate for more general 'female' behavioral characteristics among HoM), or restricted to networks involved in self-referential sexual arousal. Cortical thickness (Cth), surface area (SA), subcortical structural volumes, and resting state functional connectivity were compared between 30 (HoM), 35 (HeM) and 38 (HeW). HoM displayed a significantly thicker anterior cingulate cortex (ACC), precuneus, and the left occipito-temporal cortex compared to both control groups. These differences seemed coordinated, since HoM also displayed stronger cortico-cortical covariations between these regions. Furthermore, functional connections within the default mode network, which mediates self- referential processing, and includes the ACC and precuneus were significantly weaker in HoM than HeM and HeW, whereas their functional connectivity between the thalamus and hypothalamus (important nodes for sexual behavior) was stronger. In addition to these singular features, HoM displayed 'female' characteristics, with a similar Cth in the left superior parietal and cuneus cortices as HeW, but different from HeM. These data suggest both singular and sex atypical features and motivate further investigations of cerebral midline structures in relation to male homosexuality.

  • 2018. Kristoffer Månsson (et al.). Biological Psychiatry 83 (9), S249-S250

    Background: Amygdala hyper-responsiveness to negative socio-affective stimuli have typically been demonstrated in patients with social anxiety disorder (SAD). Relative to conventional methods, there is emerging evidence that brain signal variability could be a better predictor of behavior than mean neural response.

    Methods: We recruited 46 patients with SAD (mean age 31, 63% females) and 40 matched healthy controls (HC) to undergo 3 Tesla functional magnetic resonance imaging (fMRI) at 2 time-points, totaling 172 MRIsessions. Blood-oxygen level-dependent (BOLD-fMRI) was performed while viewing happy and fearful faces in blocks of 80 seconds. BOLD-fMRI data was reviewed by manually classifying signal from noise. Variability was calculated as each voxel’s standard deviation on signal across scanning-time. Multivariate partial least squares (PLS) estimated patterns of variability that separates patient from controls.

    Results: PLS found one significant latent variable with cross-block covariance on 64%, permutated (x 1000) P<0.001, bootstrapped 95% confidence intervals on each condition, demonstrating less signal variability to happy faces in patients, relative to controls. This pattern of response was spatially located in several regions across the whole-brain, with large clusters appearing in bilateral amygdala, medial prefrontal cortex and posterior cingulate cortex/precuneus.

    Conclusions: We found that neural response variability to positive socio-affective stimuli accurately separated patients from controls. It is likely that less signal variability highlights a deficit in effective emotion processing. We add to the growing literature on healthy individuals suggesting that task-specific brain signal variability contains useful information. The brain signal variability approach opens new avenues to evaluate and better understand brain function in common psychopathology.

Visa alla publikationer av Amirhossein Manzouri vid Stockholms universitet

Senast uppdaterad: 3 december 2018

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