Objects, raised lines, and the haptic horizontal-vertical illusion

Experiments were conducted to determine whether the haptic horizontal-vertical illusion occurs with solid, three-dimensional objects as well as with tangible lines. The objects consisted of round or square bases, with dowel rods projecting above them at heights equal to the widths of the horizontal bases. A negative illusion, with overestimation of horizontals, was found with free haptic exploration, but not with tracing with the fingertip. The negative illusion occurred when subjects felt wooden Ls and inverted Ts with a grasping, pincers motion of the index finger and thumb. The presence or absence of illusory misperception was dependent upon exploration strategy, since the negative illusion vanished with finger tracing. A negative illusion was also found when subjects adjusted a vertical dowel so that it was judged to be equal in extent to a round or square base. A general overestimation of judged size derived from the pincers response measure, but was not found with the use of a tangible ruler. Comparable illusory results are most likely when drawings and objects promote similar haptic scanning methods. The results were consistent with the idea that the orientation of an edge or line is more important than whether one explores a tangible line or a three-dimensional object.     

Campus Student Suicide Rates: Fact or Artifact?

A review of all English-language studies (14 foreign and 17 American) on campus student suicides was undertaken. Only studies reporting original data and containing sufficient demographic information to compute standard mortality rates (SMR) or crude suicide rates were analyzed and organized into single-site studies. Only 4 single-site studies had a higher suicide rate than the comparable populations. Multiple-site collaborative studies done in the United States since 1960 strongly suggest a campus student suicide rate significantly less than in the matched control population. However, deficiencies in case finding, case definition, sampling bias, and statistical techniques may place these conclusions in doubt. The author outlines research methods that might be applied to future multiple-site studies to resolve questions related to late adolescent and young adult suicidal behavior on campus and in other similar educational settings.     

The Self‐Directed Violence Classification System and the Columbia Classification Algorithm for Suicide Assessment: A Crosswalk

The lack of a standardized nomenclature for suicide‐related thoughts and behaviors prompted the Centers for Disease Control and Prevention, with the Veterans Integrated Service Network 19 Mental Illness Research Education and Clinical Center, to create the Self‐Directed Violence Classification System (SDVCS). SDVCS has been adopted by the Department of Veterans Affairs and the Department of Defense. Another classification system, the Columbia Classification Algorithm for Suicide Assessment, has been recommended by the Food and Drug Administration. To facilitate the use of both systems, this article provides a “crosswalk” between the two classification systems.