Naturally occurring language as a source of evidence in suicide prevention

We discuss computational language analysis as it pertains to suicide prevention research, with an emphasis on providing non‐technologists with an understanding of key issues and, equally important, considering its relation to the broader enterprise of suicide prevention. Our emphasis here is on naturally occurring language in social media, motivated by its non‐intrusive ability to yield high‐value information that in the past has been largely unavailable to clinicians.     

On assessing verbal stimulus hierarchies1

Typical word-association procedures result in verbal response hierarchies for a specific stimulus word. The problem of assessing corresponding stimulus hierarchies is discussed Three approaches are entertained: obtaining associations to all of the words in the dictionary, clerical cross-indexing of existing response-hierarchy data, and obtaining backward associations which are then used in forward association. A comparison of data obtainable by the last two methods is presented.     

Treatment recommendations for mentally disordered offenders: More than roulette?

Clinical judgments on the treatability and prognosis of mentally disordered offeenders (MDO) may strongly influence legal dispositions and the availability of treatment resources. This study examined 1,238 discharge summaries for MDOs referred for court assessments. Psychiatrists evidenced marked variability in how often they recommended treatment and how frequently they judged patients to have a poor prognosis. Two logit analyses suggested that diagnosis and consultation by other clinicians were associated with (a) treatment recommendations (i.e., Axis I diagnosis and social work consultations) and (b) prognosis (i.e., Axis II diagnosis and psychology consultations).     

General slowing alone cannot explain age-related search effects: reply to Cerella (1991)

Cerella (1991) has argued that the performance of older adults in the Fisk and Rogers (1991) study is a linear function of the performance of younger adults that is independent of task-specific cognitive requirements. We demonstrate that this is not the case. First, we show that the scatter plot analyses used by Cerella can hide the very task-specific age-related slowing they were designed to reveal. Second, we demonstrate that the percentage of variance explained by such analyses can be misleading. Third, we show that there are reliable differences across tasks in the parameters relating younger and older adults' performance. Finally, we argue that the general, task-independent proportionate slowing that Cerella suggested explains so much of the variance in age-related performance is actually an average slowing that is a function of a relatively small task-independent and a relatively large task-dependent factor.     

The linkage between stimulus frequency and covert peak areas as it relates to monaural localization

Head-related transfer functions for differently centered narrow noise bands were obtained on 6 subjects. Derived from these measurements were covert peak areas (CPAs), defined as the spatial constellation of loudspeakers that generates maximal sound pressure at the entrance of the ear canal for specific bands of frequency. On the basis of previous data, we proposed that different frequency bands served as important spectral cues for monaural localization of sounds from different loci and that location judgments were directed toward the CPAs associated with the different bands. In the first study, the stimuli were bandpass filtered so that they contained only those frequencies whose associated CPAs occupied either the monaural listener’s “upper” or “lower” spatial regions. Loudspeakers, separated by 15°, were stationed in the left hemifield, ranging from 0° to 180° azimuth and ?45° to 60° elevation. Subjects reported the loudspeaker from which the sound appeared to originate. Judgments of the sound’s elevation were in general accord with the CPAs associated with the different frequency segments. In the second study, monaural localization tests were administered in which different 2.0-kHz-wide frequency bands linked with specific CPAs were notch filtered from a 3.5-kHz highpass noise band. For the control condition, the highpass noise was unfiltered. The data demonstrated that filtering a frequency segment linked with specific CPAs resulted in significantly fewer location responses directed toward that particular spatial region. These results demonstrate in greater detail the relation between the directional filtering properties of the pinna and monaural localization of sound.