Which techniques are most negatively impacted by a patient's anticipation? (Choose 2)

Anticipation can significantly alter a patient's responses in methods used to measure perceptual thresholds. In the context of the ascending and descending limits techniques, anticipation can lead to biased responses.

When utilizing the method of ascending limits, the examiner presents stimuli that gradually increase in intensity. If a patient anticipates the change, they may respond too early or inaccurately, affecting the threshold determination. Similarly, the descending limits method starts with a high-intensity stimulus that is decreased. Again, if the patient expects the intensity to decrease, they may respond prematurely. In both cases, the patient's anticipation disrupts the reliability of the threshold measurements, as their responses do not reflect true perceptual limits but rather their expectations.

On the other hand, the method of constant stimuli presents a fixed set of stimuli, thereby minimizing the influence of anticipation since each stimulus is presented multiple times in a random order. This approach allows for a more consistent and reliable determination of perceptual thresholds, as the patient's previous experiences or anticipatory responses are less influential on any single trial.

Thus, the techniques that are most negatively impacted by a patient's anticipation are indeed the methods of ascending and descending limits, as both are reliant on the patient's immediate responses to gradual changes in stimulus intensity.