Cognitive epidemiology: With emphasis on untangling cognitive ability and socioeconomic status

This commentary touches on practical, public policy, and social science domains informed by cognitive epidemiology while pulling together common themes running through this important special issue. As is made clear in the contributions assembled here, and others (Deary, Whalley, & Starr, 2009; Gottfredson, 2004; Lubinski & Humphreys, 1992, 1997), social scientists and practitioners cannot afford to neglect cognitive ability when modeling epidemiological and health care phenomena. However, given the dominant concern about the confounding of general cognitive ability (GCA) and socioeconomic status (SES), and the extent to which SES is frequently seen as the primary cause of health disparities (while GCA is neglected as a possible influence in epidemiology and health psychology), some methodological applications for untangling the relative influences of GCA and SES are reviewed. In addition, cognitive epidemiology is placed in a broader context: Just as cognitive epidemiology facilitates an understanding of pathology (“at risk” populations, and ways to attenuate undesirable personal and social conditions), it may also enrich our understanding of optimal functioning (“at promise” populations, and ways to identify and nurture the human and social capital needed to develop innovations for saving lives, economies, and perhaps even our planet). Finally, while GCA is likely the most important dimension in the study of individual differences for modeling healthy behaviors and outcomes, other relatively independent dimensions of psychological diversity do add value (Krueger, Caspi, & Moffitt, 2000). For example, compliance has at least two psychological components: a “can do” competency component (ability) and a “will do” motivational component (conscientiousness). Ultimately, developing and modeling healthy behaviors, interpersonal environments, and medical maladies are best accomplished by teaming multiple dimensions of human individuality.     

USING PARENTS TO MAINTAIN IMPROVED DENTAL FLOSSING SKILLS IN CHILDREN

An experimenter-administered intervention involving prompts, self-monitoring, permanent product collection, rewards for plaque reduction, and corrective feedback was used to improve the flossing skills of four 7- to 11-year-old children. Parents were subsequently trained in the reward and feedback procedures to facilitate maintenance. In a multiple baseline across subjects design, all four subjects snowed improvement in plaque between teeth during experimenter-administered intervention. Three subjects maintained low plaque levels during the 3- to 4-month parent-administered rewards and feedback follow-up condition. Improved plaque levels on nontargeted tooth surfaces also were observed. Pediatric dentistry applications are discussed.     

SEPARATE AND COMBINED EFFECTS OF METHYLPHENIDATE AND A BEHAVIORAL INTERVENTION ON DISRUPTIVE BEHAVIOR IN CHILDREN WITH MENTAL RETARDATION

We investigated the separate and combined effects of a behavioral intervention and methylphenidate (Ritalin®) on disruptive behavior and task engagement in 3 children with severe to profound mental retardation. The behavioral intervention involved differential reinforcement of appropriate behavior and guided compliance. All 3 children demonstrated decreased disruptive behavior and improved task engagement in response to the behavioral intervention. Two of the 3 children demonstrated similar improvement in response to methylphenidate. Although both interventions were highly effective for these 2 participants, the relative efficacy of the interventions varied between the 2 children. There was no evidence of an additive or synergistic effect of the two interventions, but the high efficacy of each intervention alone limited our ability to detect such effects.     

Teacher Use Of Interventions In General Education Settings: Measurement And Analysis Of The Independent Variable

This study examined the integrity with which 4 general education teachers implemented an intervention designed to improve the academic performance of elementary school students. Treatment integrity was measured daily using permanent products. The results showed that the 4 teachers markedly increased the integrity of the delivered treatment when they were provided with performance feedback. The results suggest that academic performance improved for the group of students as integrity improved.     

The relaxation word of the day: A simple technique to measure adherence to relaxation

A new procedure of assessing adherence to home practice of relaxation is presented. The technique involved the subject identifying one of four possible relaxation words of the day at the end of a taped relaxation session. The method was employed to assess the relationship between adherence to relaxation and decline of blood pressure during a 10-session/8-week relaxation program involving 17 hypertensive subjects. No statistically significant relationship was found on either a short-term or a long-term basis. An advantage of the assessment technique is that it appears easily integrated into the overall therapeutic objective for relaxation therapy; a disadvantage is that the subject needs to comply not only with the relaxation schedule but also with the monitoring procedure.This research study was funded by NIH Grant HL27159.     

Central auditory processing : IV. Ear dominance—Spatial and temporal complexity

Ear dominance for dichotically presented tones was measured in 63 right-handed subjects when the frequency difference (Δf) was small compared to the center frequency (f_c) and again when it was large. Although two-thirds of the population exhibited a left-ear dominance in both conditions, a shift toward right-ear dominance occurred when the Δf was increased. An additional study, employing the alternating tone illusion described by Deutsch, revealed the same general effect, i.e., a shift toward right-ear dominance with increasing values of Δf/f_c. The results of these experiments, coupled with a review of previously published data of other dichotic experiments, indicate that as the ratio of Δf/f_c increases, the subjective complexity of the sound image increases, and there is a progressive emergence of a “right-ear advantage” (or ear dominance). A tentative explanation relates these results to the effects of anatomical asymmetries of primary and auditory association cortex and the efferent temporal lobe enhancement mechanism described by R. Efron, P. H. Crandall, B. Koss, P. L. Divenyi, and E. W. Yund (Brain and Language, 1983, 19, 254–263.     

Central auditory processing: I. Ear dominance—A perceptual or an attentional asymmetry?

The phenomenon of ear dominance for pitch described by Efron and Yund has been attributed by them to an asymmetry of sensory origin in the binaural integration of dichotic tone pairs. An explanation of this phenomenon in terms of an attentional bias is rejected on the basis of two experiments where the possibility of such bias was excluded. These and other experiments indicate that a simple explanation of this ear dominance in terms of a hemispheric specialization in the processing of tonal stimuli also must be rejected.     

Carbon monoxide levels and rates of consumption after changing to low tar and nicotine cigarettes

Studies which have examined low tar and nicotine (LT/LN) cigarette smoking have failed, for the most part, to assess adequately the long-term effects of these cigarettes. Most studies have been short-term laboratory investigations of nicotine regulation. More practical strategies for changing to LT/LN cigarettes have largely been ignored. The present study examined long-term changes in smoking patterns following the gradual introduction of LT/LN cigarette smoking. Predicted increases in reported rates of consumption as well as carbon monoxide (CO) levels were not found for most smokers following changes to LT/LN cigarettes. Generally, smokers showed decreased rates of consumption, and a majority had lower CO levels at the end of treatment and during follow-up. Thus, LT/LN cigarette smoking would appear to be an alternative treatment goal for risk reduction in individuals who cannot stop smoking.     

Fixed and optional stopping models for two-choice discrimination times

Several current models for choice- or discrimination-time experiments represent the stimulus as a sequence of independent and identically distributed observations. This paper develops and compares models based on two different stopping rules that a subject might use to terminate his sampling process and convert his perceptual evidence into an observable response. The fixed and optional stopping rules yield different predicted forms for the speed/accuracy tradeoff function and for the relation between mean and variance of response times. These predictions are developed in the general case and then specialized for certain conditions of symmetry, so that the expressions are easier to apply and to compare between models. A later section considers how changes in stopping criteria (either between or within experimental trials) affect predictions about mean response times for correct responses and errors, and then uses these ideas to relate the optional stopping rule for the Random Walk models to those of the Accumulator models. A final section considers specialized models for stimulus detection and intensity discrimination that assume Poisson-distributed sensory input, and relates these models to the present fixed stopping model.