BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:BOLD signal changes can oppose oxygen metabolism across the human 
 cortex - Samira M. Epp\, Friedrich-Alexander University\, Erlangen\, Germa
 ny
DTSTART:20260216T123000Z
DTEND:20260216T133000Z
UID:TALK242887@talks.cam.ac.uk
CONTACT:Dace Apšvalka
DESCRIPTION:*Speaker:* Samira M. Epp\, Friedrich-Alexander University\, Er
 langen\, Germany.\n\n*Title:* BOLD signal changes can oppose oxygen metabo
 lism across the human cortex\n\n*Abstract:*\nFunctional magnetic resonance
  imaging measures brain activity indirectly by monitoring changes in blood
  oxygenation levels\, known as the blood-oxygenation-level-dependent (BOLD
 ) signal\, rather than directly measuring neuronal activity. This approach
  crucially relies on neurovascular coupling\, the mechanism that links neu
 ronal activity to changes in cerebral blood flow. However\, it remains unc
 lear whether this relationship is consistent for both positive and negativ
 e BOLD responses across the human cortex. In our recent paper (https://doi
 .org/10.1038/s41593-025-02132-9)\, we found that about 40% of voxels with 
 significant BOLD signal changes during various tasks showed reversed oxyge
 n metabolism\, particularly in the default mode network. These ‘discorda
 nt’ voxels differed in baseline oxygen extraction fraction and regulated
  oxygen demand via oxygen extraction fraction changes\, whereas ‘concord
 ant’ voxels depended mainly on cerebral blood flow changes. \nI will tal
 k about the main findings of our recent work and give a short outlook on c
 urrent work. \n\n*Bio:* \n* I am currently working as a *PostDoc at the FA
 U* (Friedrich-Alexander University) in Nürnberg-*Erlangen* (Neuroradiolog
 y)\, in the working group of Prof. Valentin Riedl ("Neuroimaging of immuno
 logical and metabolic processes") \n* I finished my *PhD in 'systemic neur
 osciences' in 2023 in Munich*\, at the Graduate School of Systemic Neurosc
 iences\, a collaboration between LMU (Ludwig-Maximilians-University) and T
 UM (Technical University\, Munich)\, also in the working group of Prof. Ri
 edl (Neuroimaging Center\, Neuroradiology) \n* *Graduated 2018 at the HU (
 Humboldt University) in Berlin*\, Masters in Psychology \n* During my stud
 ies\, I have been working as a research assistant for 4 years at the MPI (
 Max-Planck-Institute) for Human Development in Berlin\, working mainly wit
 h fMRI BOLD data \n\n*Venue*: MRC CBU West Wing Seminar Room and Zoom http
 s://us02web.zoom.us/j/82385113580?pwd=RmxIUmphQW9Ud1JBby9nTDQzR0NRdz09 (Me
 eting ID: 823 8511 3580\; Passcode: 299077)\n
LOCATION: MRC-CBU\, 15 Chaucer Road\, Cambridge
END:VEVENT
END:VCALENDAR