Biological components of sex differences in color preference

examined in this task: two were the same animals providing data shown in Figure 1B (cats 1 and 2), and the third (cat 4) was only tested in this task. The results for the three animals are shown in Figure 2B. With cat 1, the maximum step height remained higher than control values and usually higher than the rod height for all time durations we tested. With cat 2, the maximum step height was quite variable during longer pause durations (over 5 seconds) but remained higher than control step height in the majority of trials. With cat 4 there was also some variability, but on most trials the maximum hind leg step height was also higher than the height of the rod and well above control values. By comparing the step heights when cats pause either immediately in front of an obstacle or straddling an obstacle, we have shown that stepping over an obstacle with the forelegs is necessary to create long-lasting memories to guide the hind legs (Figure 1). We have also shown that visual signals related to the obstacles are not essential for this process (Figure 2). This is strong evidence that a neural signal related to the stepping of the forelegs is responsible for the activation or enhancement of additional structures of the nervous system to produce a long-lasting memory. There are two possible sources of such a signal: the feedback from cutaneous, muscle, and joint afferents which can signal the position of the limb [8]; and the output of motor systems which enhance foreleg flexor activity when stepping over obstacles [9]. We consider the latter hypothesis the most likely as it is consistent with theories of movement control in which motor control signals are used to predict the resulting movement and the associated sensory feedback [10–13]. The significance of this finding is that it clearly provides an example of a signal related to the movement of the limbs (forelegs in this case) being used to update the representation of the location of obstacle close to the body. We believe that the activity from the motor and/or sensory systems provides a positive signal that an obstacle is located between the fore and hind legs, and thus extends the duration of the neural representation of this obstacle until the hind legs step over. This simple behavior provides a convincing example of movement signals being used to update the …