diff --git a/src/layer/fully_connected_layer.rs b/src/layer/fully_connected_layer.rs
index 9e2dbcf..476c6eb 100644
--- a/src/layer/fully_connected_layer.rs
+++ b/src/layer/fully_connected_layer.rs
@@ -4,17 +4,20 @@ use layer::weights_matrix::WeightsMatrix;
 use layer::traits::{
 	ProcessInputSignal,
 	CalculateOutputErrorSignal,
+	PropagateErrorSignal,
+	ApplyErrorSignalCorrection,
 	HasOutputSignal,
 	HasErrorSignal,
 };
 use errors::{Result};
+use utils::{LearnRate, LearnMomentum};
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct FullyConnectedLayer {
-	weights  : WeightsMatrix,
-	deltas   : WeightsMatrix,
-	outputs  : SignalBuffer,
-	gradients: ErrorSignalBuffer
+	weights     : WeightsMatrix,
+	deltas      : WeightsMatrix,
+	outputs     : SignalBuffer,
+	error_signal: ErrorSignalBuffer
 }
 
 impl FullyConnectedLayer {
@@ -22,9 +25,9 @@ impl FullyConnectedLayer {
 		let (inputs, outputs) = (weights.inputs(), weights.outputs());
 		Ok(FullyConnectedLayer{
 			weights,
-			deltas   : WeightsMatrix::zeros(inputs, outputs)?,
-			outputs  : SignalBuffer::zeros(outputs)?,
-			gradients: ErrorSignalBuffer::zeros(outputs)?,
+			deltas      : WeightsMatrix::zeros(inputs, outputs)?,
+			outputs     : SignalBuffer::zeros(outputs)?,
+			error_signal: ErrorSignalBuffer::zeros(outputs)?,
 		})
 	}
 
@@ -35,28 +38,43 @@ impl FullyConnectedLayer {
 }
 
 impl ProcessInputSignal for FullyConnectedLayer {
-	fn process_input_signal(&mut self, signal: &SignalBuffer) {
-		if self.output_signal().len() != signal.len() {
-			panic!("Error: unmatching signals to layer size") // TODO: Replace this with error. (Needs to change trait.) 
+	fn process_input_signal(&mut self, input_signal: &SignalBuffer) {
+		if self.output_signal().len() != input_signal.len() {
+			panic!("Error: unmatching signals to layer size") // TODO: Replace this with error.
 		}
 		use ndarray::linalg::general_mat_vec_mul;
-		general_mat_vec_mul(1.0, &self.weights.view(), &signal.biased_view(), 1.0, &mut self.outputs.view_mut())
+		general_mat_vec_mul(1.0, &self.weights.view(), &input_signal.biased_view(), 1.0, &mut self.outputs.view_mut())
 	}
 }
 
 impl CalculateOutputErrorSignal for FullyConnectedLayer {
 	fn calculate_output_error_signal(&mut self, target_signal: &SignalBuffer) {
 		if self.output_signal().len() != target_signal.len() {
-			panic!("Error: unmatching signals to layer size") // TODO: Replace this with error. (Needs to change trait.) 
+			panic!("Error: unmatching signals to layer size") // TODO: Replace this with error.
 		}
 		use ndarray::Zip;
-		Zip::from(&mut self.gradients.view_mut())
+		Zip::from(&mut self.error_signal.view_mut())
 			.and(&self.outputs.view())
 			.and(&target_signal.view())
-			.apply(|g, &t, &o| {
-				*g = t - o
+			.apply(|e, &o, &t| {
+				*e = t - o
 			}
-		);
+		)
+	}
+}
+
+impl PropagateErrorSignal for FullyConnectedLayer {
+	fn propagate_error_signal<P>(&mut self, _propagated: &mut P)
+		where P: HasErrorSignal
+	{
+		unimplemented!()
+	}
+}
+
+impl ApplyErrorSignalCorrection for FullyConnectedLayer {
+	fn apply_error_signal_correction(&mut self, _signal: &SignalBuffer, _lr: LearnRate, _lm: LearnMomentum) {
+		// Nothing to do here since there are no weights that could be updated!
+		unimplemented!()
 	}
 }
 
@@ -72,10 +90,10 @@ impl HasOutputSignal for FullyConnectedLayer {
 
 impl HasErrorSignal for FullyConnectedLayer {
 	fn error_signal(&self) -> &ErrorSignalBuffer {
-		&self.gradients
+		&self.error_signal
 	}
 
 	fn error_signal_mut(&mut self) -> &mut ErrorSignalBuffer {
-		&mut self.gradients
+		&mut self.error_signal
 	}
 }