Figure 3. Morph Images used for Generalization.
Figure 3 Legend: Several types of stimuli may be used to assess generalization gradients. A) Circles. The circles at the extremes are the images used in the fear conditioning procedure. Circles of varying size created a continuum of stimuli between these two extremes. [79]. B) Faces. The faces at the extremes are the pure images of the light-haired and dark-haired women with neutral facial expressions used in the fear conditioning procedure. The light-haired woman is morphed into the dark-haired woman using 10% increments, providing a continuum of similarity between the two women. The continuum of circles or faces can be used to assess fear generalization gradients following conditioning.