Eyeblink conditioning as a function of CS-US interval

The length of the time interval between the onset of the conditioned stimulus (CS) and that of the unconditioned stimulus (US) has been studied with respect to its effect upon eyelid conditioning in a number of experiments, as was done by Berstein (1934), Kimble (1942), McAllister (1953), etc. But the indices which were used to deal with the experimental data were almost the same, with percentage of CR occurrence to indicate the process of conditioning. This index (J-b) being obtained from group data, we could not make a further investigation using the index as an independent variable, such as investigating the occurrence of physiological changes during conditioned response. The purpose of this experiment was to study the relationship between the conditioning of the eyelid response and the length of the time interval between the onset of the CS (tone) and that of the US (airpuff), using some new indices as measures of the conditioned response in order to have some understanding upon the basic process of conditioning.