Before revision:  However, these algorithms typically impose other requirements which challenge biological plausibility: for example, requiring complex and precise connectivity schemes (predictive coding) , or multiple sequential backwards phases with information being stored across phases (equilibrium-prop) .
After revision:  However, these algorithms typically impose other requirements which challenge biological plausibility: for example, requiring complex and precise connectivity schemes (predictive coding) , or multiple sequential backwards phases with information being stored across phases .