Discrimination learning and stimulus generalization by impulsive and reflective children

The proposition that impulsive children inhibit expressive behavior less than reflective children was investigated by providing third grade impulsive and reflective boys with either differential or nondifferential forms or successive discrimination training prior to tests for stimulus generalization. Consistent with specific predictions derived from Spence's theory on the roles of excitation and inhibition, it was found that: (a) Reflectives acquired the discrimination more rapidly, (b) reflectives achieved a higher level of discriminative performance, (c) impulsives exhibited more variable response reates during the nonreinforced stimulus, and (d) the type of training interacted with the child's conceptual tempo to determine the elevation and shape of the post-discrimination generalization gradients. The results provide support for the construct validity of the Matching Familiar Figures Test of reflectivity-impulsivity.     

Normative location theory: Placement in continuous space

This paper selectively reviews an area of operations research, refered to as normative location theory, that deals with the placement of objects in continuous space. The computational procedures discussed in this literature require initially that a certain set objects be located a priori; the placement of the objects in a second set is then determined in such a way that the total “interaction” among the fixed and variable objects is minimized. A number of strategies appropriate for different distance functions are surveyed and a numerical example is given illustrating one particular iterative algorithm. Although the current versions of these location methods depend upon more than the nonmetric information contained in the proximity measures defined for all pairs of objects, they can be generalized, and consequently, several possible connections to nonmetric multidimensional scaling are pointed out.     

Estimated Intelligence Moderates Cognitive Processing Therapy Outcome for Posttraumatic Stress Symptoms

Although patient intelligence may be an important determinant of the degree to which individuals may comprehend, comply with, and ultimately benefit from trauma-focused treatment, no prior studies have examined the impact of patient intelligence on benefit from psychotherapies for PTSD. We investigated the degree to which educational achievement, often used as a proxy for intelligence, and estimated full scale intelligence quotient (FSIQ) scores themselves moderated treatment outcomes for two effective psychotherapies for PTSD: Cognitive Processing Therapy (CPT) and Written Exposure Therapy (WET). Participants, 126 treatment-seeking adults with PTSD (52% male; mean age = 43.9, SD = 14.6), were equally randomized to CPT and WET; PTSD symptom severity was measured at baseline and 6-, 12-, 24-, 36-, and 60-weeks following the first treatment session. Multilevel models revealed that participants with higher FSIQ scores experienced significantly greater PTSD symptom reduction through the 24-week assessment in CPT but not WET; this effect did not persist through the 60-week assessment. Educational achievement did not moderate symptom change through either 24- or 60-weeks. Individuals with higher FSIQ who are treated with CPT may experience greater symptom improvement in the early stages of recovery.     

Measuring Feeling of Knowing: Comment on Schraw (1995)

Schraw compares two coefficients for the 2×2 contingency tables resulting from many feeling of knowing (FOK) studies: Hamann's coefficient and Goodman and Kruskal's γ. He favours Hamann's coefficient and gives examples where Hamann's coefficient produces what might be considered the more intuitive result. Further scrutiny reveals that these examples are not as convincing as Schraw makes them out to be. Because Hamann's coefficient depends on the row and column marginals, it does not map onto FOK ability as well as Goodman and Kruskal's γ, which is a direct measure of the diagnostic worth of FOK ratings.     

Validity of the multiple-stimulus without replacement preference assessment for edible items

Studies have shown that the multiple-stimulus without replacement (MSWO) preference assessment is an effective assessment format for identifying preferred items. However, it is possible that factors other than reinforcer quality might influence selections by some individuals when the MSWO array consists of edible items. The validity of the MSWO results was evaluated by comparing items identified as most and least preferred by the MSWO assessment in a concurrent-schedule (CS) format. Varying edible items were used in each study. The MSWO format accurately identified the higher quality edible item for most participants across studies (76%); however, the MSWO format did not predict the highest quality edible item in the CS assessment for 20% to 30% of participants in each study.