Self-injury behavior (SIB) is one of the most excruciating and costly behaviors of people with developmental disabilities. According to needs assessments by professionals, parents, and caregivers, SIB is near the top of the priority list (National Institutes of Health, 199 1). Historically, family members, doctors, psychologists, teachers, and others who are responsible for providing care and services for people with developmental disabilities have been stymied in their attempts to understand the causes and to develop treatments for this refractory behavior problem. The notion that people could intentionally injure their bodies day after day for years at a time-and sometimes even cause life-threatening damage-defies common sense.For centuries, self-injury has been recognized as an integral part of the human condition, including the condition of people with mental disabilities. From the 13th to the 16th centuries, a fanatical sect of people known as Flagellants flourished in Italy and then spread beyond the Alps to Alsace, Bavaria, Bohemia, Poland, and Germany (Toke, 1909/1999). Despite condemnation by the official Catholic Church, Flagellants proceeded through the streets of towns throughout central Europe as the church bells sounded at 6 a.m. and 6 p.m., beating their backs with bundles of twigs until they bled. Although their purpose was religious mortification, other psychological, physiological, and neurochemical factors may have played a role in sustaining this practice as well. In his Rake's Progress paintings (1732)(1733), which depicted the deplorable conditions in the Bethlehem Hospital at Bishopsgate, William Hogarth painred the figure of Thomas Rakewell. Rakewell wore a bandage where he had injured himself, suggesting that self-Supported in part by POlHD30329 from the National Institute of Child Health and Human Development to Vanderbilt University and P30HD02528 and R01HD3029 to the University of Kansas. Thanks to Frank Symons, Craig Kennedy, and Rachel Freeman for their helpful suggestions during the preparation of this chapter.

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Robots are used for many different applications including underwater recovery, welding, inspection, pick-and-place operations, space exploration, and assembly. Each task im parts different functional demands on the robot topology including the gripper. An improper choice of the basic kine matic chain may demand sophisticated control algorithms to undo poor type selection. This paper suggests techniques of type synthesis based on graph theory and expert systems that will aid in proper kine matic topology. This new area of kinematic research has high potential for aiding the robot designer.

One of the problems encountered in attempting to computerize type synthesis of mechanisms is that of automatically generating a computer graphics display of candidate kinematic chains or mechanisms. This paper presents the development of a computer algorithm for automatic sketching of kinematic chains as part of the computer-aided type synthesis process. Utilizing concepts from graph theory, it can be shown that a sketch of a kinematic chain can be obtained from its graph representation by simply transforming the graph into its line graph, and then sketching the line graph. The fundamentals of graph theory as they relate to the study of mechanisms are reviewed. Some new observations are made relating to graphs and their corresponding line graphs, and a novel procedure for transforming the graph into its line graph is presented. This is the basis of a sketching algorithm which is illustrated by computer-generated examples.

Research in the past decade concerning the effects of pharmacological agents on emotional behavior has concentrated on three basic experimental procedures: escape, avoidance, and conditioned emotional response. These designs are said to measure "fear" and "anxiety." The present study proposes to examine the effects of a pharmacological agent on another class of emotional behavior, the increased rate of operant responding with the onset of extinction following a regular reinforcement schedule. This type of behavior has been discussed by several writers within the framework of "frustration-aggression" theory (Bollard, Doob, Miller, Mowrer, & Sears, 1939), generalized drive theory (Amsel, 1952), or as simply a state of aggression (Keller & Schoenfeld, 1950) or emotion (Skinner, 1938) produced by nonreinforcement. The behavior resulting from withholding positive reinforcement can be characterized as having a markedly increased operant level followed by a depression of the operant curve. It is suggested here that the relative amount of increase in rate of responding is a measure of the amount of emotional arousal. As an index of the degree of "aggression," an extinction inflection ratio is used, modified from the inflection ratio introduced by Hunt, Jernberg, and Brady (1952). The formula used here is: lever presses during 3 min. immediately following the onset of extinction -lever presses during an equivalent period preceding extinction -i-lever presses during the prc-extinction period:Ext. -Pre.Pre.A drug which is effective in reducing "aggression" or interfering with its expression should tend to decrease the inflection ratio of treated animals as compared with saline