diff --git a/source/Layer.cpp b/source/Layer.cpp
index 695850c..5271824 100644
--- a/source/Layer.cpp
+++ b/source/Layer.cpp
@@ -102,12 +102,22 @@ Json::Value Layer::toJson() const
 
 }
 
-void Layer::up_pass(const arma::mat& v)
+arma::mat Layer::up_pass(const arma::mat &hidden)
 {
-
+	arma::mat reconstruction = rbm().toVisibleProbs(hidden);
+	if (upper)
+	{
+		return upper->up_pass(reconstruction);
+	}
+	return rbm().toHiddenProbs(reconstruction);
 }
 
-void Layer::down_pass(arma::mat& dst, const arma::mat& src)
+arma::mat Layer::down_pass(const arma::mat &visible)
 {
-
+	arma::mat hidden = rbm().toHiddenProbs(visible);
+	if (lower)
+	{
+		return lower->down_pass(hidden);
+	}
+	return rbm().toVisibleProbs(hidden);
 }
diff --git a/source/Layer.hpp b/source/Layer.hpp
index b6607e5..287bbdd 100644
--- a/source/Layer.hpp
+++ b/source/Layer.hpp
@@ -35,8 +35,8 @@ public:
 	Rbm& rbm();
 	void saveWeights();
 
-	void up_pass(const arma::mat& v);
-	void down_pass(arma::mat& dst, const arma::mat& src);
+	arma::mat up_pass(const arma::mat& hidden);
+	arma::mat down_pass(const arma::mat& visible);
 
 	size_t id()
 	{