corrected function name and added type checking in proc_meanAcrossTime
corrected function name and added type checking in proc_meanAcrossTime

bsdlab/bbci_public,bsdlab/bbci_public,MarkusWenzel/bbci_public,bbci/bbci_public,MarkusWenzel/bbci_public,IrinaNicolae/bbci_public,svendaehne/bbci_public,drsternburg/bbci_public,IrinaNicolae/bbci_public,IrinaNicolae/bbci_public,drsternburg/bbci_public,svendaehne/bbci_public,bbci/bbci_public,bsdlab/bbci_public,svendaehne/bbci_public,drsternburg/bbci_public,MarkusWenzel/bbci_public,bbci/bbci_public