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Fig. 10.6. Response to schematic images by Goren et al. (1975) and Johnson et al. (1991). The activations of the retina, LGN, V1, and FSA levels are shown using the plotting conventions from Figures 10.4 and 10.5. The top row shows a set of input images as they are drawn on the retina. These patterns were presented to newborn human infants on head-shaped paddles moving at a short distance (about 20 cm) from the eyes, against a light-colored ceiling. The newborn's preference was determined by measuring the average distance his or her eyes or head tracked each pattern, compared with other patterns. Below, x > y indicates that image x was preferred over image y under those conditions. Goren et al. (1975) measured infants between 3 and 27 minutes after birth. They found that b > f > i and b > e > i. Similarly, Johnson et al. (1991), in one experiment measuring within 1 hour after birth, found b > e > i. In another, measuring at an average of 43 minutes, they found b > e, and b > h. Finally, Johnson and Morton (1991), measuring newborns an average of 21 hours old, found that a > (b,c,d), c > d, and b > d. The HLISSOM model has the same preference for each of these patterns, as shown in the images above. The second row shows the model LGN activations resulting from the patterns in the top row. The third row shows the V1 activations, with the numerical sum of the activities shown underneath. If only one unit were active at half strength, the sum would be 0.5; higher values indicate more activation. The bottom row displays the settled responses of the FSA, again with the numerical sum underneath. This sum represents the strength of the response of the model. The images are sorted left to right according to the preferences of the model. The strongest V1 response by nearly a factor of three is to the checkerboard pattern (a), which explains why the newborn would prefer that pattern over the others. The facelike patterns (b-d) are preferred over patterns (e-i) because of activation in the FSA. The details of the facelike patterns do not significantly affect the results -- all of the facelike patterns (b-d) lead to FSA activation, generally in proportion to their V1 activation levels. The remaining patterns are ranked by their V1 activity alone, because they do not activate the FSA. In all conditions tested, the HLISSOM model shows behavior remarkably similar to that of the newborns, and provides a detailed computational explanation for why these behaviors occur. Reprinted from Bednar and Miikkulainen (2003a).