chapter  1
37 Pages

Excitory and Inhibitory Influences on Reflex Responsiveness

ByFrances K. Graham, Barbara D. Strock, Bonnie L Zeigler

The recent work on reflex modification has focused on the polysynaptic startle reflex. Landis and Hunt (1939), in an extensive cinemagraphic study, described the primary component of startle as an inflexibly patterned, flexor contraction beginning with the eyeblink and, in its full manifestation, progressing downward to involve the whole body. Landis and Hunt (1939) drew explicit attention to the fact that startle was not a directional response, involving movement “away from” a stimulus, because they found that the pattern was “in no way changed by the direction from which the stimulus comes [p. 31].” It cannot, therefore, be considered a “flight” reaction and may, as Graham (1979, b) suggested, be more appropriately described as an “interrupt” of ongoing activity.