Stellenticket Freie Universität Berlin

For the ana­lysis of cau­sal rela­tion­ships bet­ween time series of dif­fer­ent bio­lo­gical (subs)sys­tems already exist dif­fer­ent meth­ods, which have been deve­lo­ped in the the­or­et­ical frame­work of lin­ear pro­ces­ses and non­lin­ear dynam­ics. Not only in eco­nom­ics, nat­ural sci­ences and bio­logy, but espe­cially in medi­cine, the ques­tion is increas­ingly rai­sed whe­ther cau­sal rela­tion­ships exist bet­ween dif­fer­ent bio­sig­nals (car­di­ores­pir­at­ory-, car­di­ovas­cu­lar-, cent­ral-auto­nomic sys­tems) and whe­ther they are detect­able and quan­ti­fi­able. In detail, howe­ver, there are still large gaps in our know­ledge, espe­cially in elu­cid­at­ing the func­tio­nal sig­ni­fic­ance of the obser­ved effects (sys­tem prop­er­ties). The approach to determ­in­ing caus­al­ity sta­tes that the pre­dic­tion of one time series can be impro­ved by incor­por­at­ing inform­a­tion from ano­t­her (past and pre­sent determ­ine future and not vice versa). The con­cept of Gran­ger caus­al­ity is one of oth­ers enab­ling the descrip­tion of cau­sal depend­en­cies bet­ween dif­fer­ent time series. Sys­tems as diverse as clocks, car­diac pace­makers, fir­ing neur­ons, adjust­ment of heart rate with res­pir­a­tion and/or loco­motory rhythms exhi­bit a tend­ency to oper­ate in syn­chrony. In gen­eral, the adjust­ment of oscil­lat­ory rhythms due to an inter­ac­tion is the essence of syn­chron­iz­a­tion. Invest­ig­a­tion of syn­chron­iz­a­tion in large ensem­bles of neur­ons beco­mes an import­ant part and cent­ral issue in neur­os­cience. Syn­chron­iz­a­tion seems to be a cent­ral mech­an­ism for neur­onal inform­a­tion pro­ces­sing wit­hin a brain area as well as for com­mu­nic­a­tion bet­ween dif­fer­ent brain areas.

The aim of this work focu­ses on the disease-spe­ci­fic descrip­tion of syn­chro­ni­za­tion effects and/or cau­sal cou­plings bet­ween the auto­no­mic and the cen­tral nerve sys­tems in pati­ents suf­fe­ring from fati­gue, bur­nout and dep­res­sion. In par­ti­cu­lar, we will find, select and imple­ment (Mat­Lab) sui­ta­ble algo­rithms in the lite­ra­ture that enable and quan­ti­ta­tively describe the syn­chro­ni­za­tion and/or the cou­plings bet­ween heart rate, blood pres­sure, pulse, respi­ra­tion and cen­tral activity (EEG). In this the­sis a method com­pa­ri­son of dif­fe­rent approa­ches app­lied to simu­la­ted data­sets and real pati­ent data­sets has to be per­for­med. Finally, a new metho­do­lo­gi­cal approach will be deri­ved to describe and quan­tify syn­chro­ni­za­tion and/or cau­sal rela­ti­ons­hips of and bet­ween dif­fe­rent bio­lo­gi­cal sys­tems in fati­gue, bur­nout and dep­res­sion. This inclu­des a com­pre­hen­sive lite­ra­ture rese­arch, the exe­cu­tion of elec­tro­phy­sio­lo­gi­cal mea­su­rements, the collec­tion of ques­ti­onn­aires as well as the sys­te­ma­tic eva­lua­tion and publi­ca­tion of the data. The con­tent and tech­ni­cal super­vi­sion will take place in the working group. There is the pos­si­bi­lity to com­bine the posi­tion with a rese­arch internship.

Dipl.-Ing. Stef­fen Schulz
AG IMO, FB Ana­lysis and Pro­ces­sing of Bio­med­ical Sig­nals and Inform­a­tion
Char­ité - Uni­ver­si­täts­med­izin Ber­lin, CC17, Augus­ten­bur­ger Platz 1, 13353 Ber­lin
Email: steffen.schulz@charite.de