Awareness predicts the magnitude of single-cue trace eyeblink conditioning

Studies of differential eyeblink conditioning (CS+ and CS-) have demonstrated that successful conditioning requires awareness of the stimulus contingencies and that delay conditioning does not. Two experiments were carried out to determine whether awareness is also important for single-cue trace eyeblink conditioning. In experiment 1, participants who performed a secondary, attention-demanding task emitted significantly fewer conditioned eyeblink responses than participants who watched a silent movie during the conditioning session. In experiment 2, participants who became aware of the stimulus contingencies early in the conditioning session emitted significantly more conditioned responses during the remainder of the session than participants who became aware later in the session or who never became aware. These results indicate that awareness is important for single-cue trace eyeblink conditioning, just as it is for differential trace conditioning. The relationship between awareness and trace eyeblink conditioning is discussed in the light of these and other recent findings.