Time and Classical Conditioning

[Ready for Fall 2026]

Modified: 2026-08-03 10:48 AM CDST

• What role, if any, does the time between the CS and the UCS play? It plays a very significant role, it turns out.
  • Delayed conditioning is easily established. Delays of around .5 sec. between the CS and the UCS lead to the strongest conditioning.
  • In trace conditioning a period of time is allowed to lapse between the CS and the UCS.
  • It is called trace conditioning, because a memory trace is presumably responsible for the conditioning.
    • Traces of up to 12 sec. can be established in pigeons without a great deal of effort.
    • Longer traces are not likely to lead to conditioning.
    • That is why punishing children hours after they commit some infraction does not lead to learning.
    • Later in the chapter, however, we will see that traces of up to 75 minutes have been established with some pairs of stimuli. (See Taste Aversion)
  • In backwards conditioning, the UCS precedes the CS.
    • Typically, little or no conditioning results, although some have succeeded in demonstrating backwards conditioning when life-threatening shock was used.
  • Simultaneous conditioning leads to little or no conditioning as well.
    • Simultaneous conditioning provides us with a glimpse into the logic of conditioning.
    • A CS that does not predict the UCS is of no value.
  • Temporal conditioning does not use an explicit CS.
    • Rather, the UCS repeats itself on a regular basis.
    • Some animals may use that repetition to achieve conditioning by timing the interval between UCS onset and offset.
    • Example: Think of a curvy road with no signs telling you a curves is coming.
• The "Highway Analogy" graphic provides you with a useful analogy
  • I saw this analogy presented at an APA meeting some years ago, and I created the graphic for it later. I cannot recall who presented it originally.
  • The analogy is useful because it shows how the CS is a signal for the UCS.
    • In this analogy, the sign is the CS, the curve is the UCS.
  • Notice that putting the sign far away from the curve does not lead to conditioning, nor does putting the sign in the curve, or after the curve.