". . . On the Basis of Velocity Clues Alone": Some Perceptual Themes 1946-1996

Three factors that have transformed perceptual research in the last fifty years are the digital computer, single-unit electrophysiology, and molecular biology. Amongst the developments in which members of the Experimental Psychology Society have been central are: the recognition of the role of optic flow in spatial vision; the demonstration that our perceptual systems contain parallel pathways extracting different information from the sensory array; the identification of specific detectors that can be selectively adapted in psychophysical experiments; and the transfer of the concepts of fourier analysis from audition to vision. The history of Opponent Process Theory offers an example where experimental psychologists have been misled by too simple an interpretation of physiological recordings.     

The Struggle to Prevent and Evaluate: Application of Population Attributable Risk and Preventive Fraction to Suicide Prevention Researach

Population attributable risk (PAR) estimates have been used in suicide research to evaluate the impact of psychosocial and socioeconomic risk factors, including affective disorders, traumatic life events, and unemployment. A parallel concept of preventive fraction (PF), allowing for estimation of the impact of protective factors and effectiveness of preventive interventions, is practically unknown in suicidology. The study authors discuss the application of both concepts to suicide research and prevention, and review literature on the subject. Despite several methodological and conceptual limitations, both PAR and PF are valuable instruments to inform development and evaluation of suicide prevention programs.