A review and critique of the process approach in neuropsychological assessment

This paper surveys the process approach literature with an emphasis on higher level cognitive functions like attention and concentration, learning and memory, and problem solving and executive functioning. In particular, it discusses organizational strategies and kinds of errors found on a variety of tests as well as behavioral, situational, and interpersonal issues as they relate to test procedures. It critiques the process approach and suggests future directions.     

“How dare you sport thus with life?”: Frankensteinian fictions as case studies in scientific ethics

Fictional scenarios involving "hard" science offer what are in effect case studies of scientific ethics. From his analysis of Shelley's novel, biologist Leonard Isaacs constructed a model of a "Frankenstein scenario," applicable to the dilemmas posed by the advancement of science in our time, as well as to fiction about science by such contemporary writers as Robin Cook and Michael Crichton. The special contribution of fiction to the study of ethics is that it both reflects and evaluates reality's infinite permutations. In reflecting and judging, the fictional scenarios engage our moral imagination and compel us to confront our personal ethos in relation to the evolving ethos of science.     

The ombudsman for research practice

We propose that institutions consider establishing a position of “Ombudsman for Research Practice”. This person would assume several roles: as asounding board to those needing confidential consultation about research issues — basic, applied or clinical; as afacilitator for those wishing to pursue a formal grievance process; and as aneducator to distribute guidelines and standards, to raise the consciousness regarding sloppy or irregular practices in order to prevent misconduct and to promote the responsible conduct of research. While there are compelling features to this position, many complex issues need to be considered and resolved. We invite readers to respond to questions we raise in the text.     

Extraction of relief from visual motion

We quantified the ability of human subjects to discriminate the relative distance of two points from a slanted plane when viewing the projected velocities of this scene (orthographic projection). The relative distance from a plane (called relief) is a 3-D property that is invariant under linear (affine) transformations. As such, relief canin principle be extracted from the instantaneous projected velocity field; a metric representation, which requires the extraction of visual acceleration, is not required. The stimulus consisted of a slanted planeP (specified by three points) and two pointsQ ₁ andQ ₂ that are non-coplanar withP. This configuration of points oscillated rigidly around the vertical axis. We have measured thesystematic error andaccuracy with which human subjects estimate the relative distance of pointsQ ₁ andQ ₂ from planeP as a function of the slant of_P. The systematic error varies with slant: it is low for small slant values, reaches a maximum for medium slant values, and drops again for high slant values. The accuracy covaries with the systematic error and is thus high for small and large slant values and low for medium slant values. These results are successfully modeled by a simple relief-from-motion computation based on local estimates of projected velocities. The data are well predicted by assuming (1) a measurement error in velocity estimation that varies proportionally to velocity (Weber’s law) and (2) an eccentricity-dependent underestimation of velocity.     

Are microsaccades responsible for the gap effect?

Extinguishing a fixation point shortly before, or concurrently with, the onset of a peripheral visual target reduces the latency of saccades to that target. Saslow (1967) hypothesized that thisgap effect might occur because fixation point offsets reduce the incidence of corrective microsaccades with an associated saccadic refractory period. In the present study, a robust gap effect was obtained. However, using a Purkinje image eyetracker with 1 arcmin of resolution, we found that fixation point offsets had no effect on the occurrence of microsaccades and that the occurrence of microsaccades had no impact on the magnitude of the gap effect. Microsaccades therefore do not appear to play any part in the production of the gap effect.     

A behavioral link between the oculomotor and cardiovascular systems

Although the eyes and the heart serve very different purposes, each receives autonomic innervation. Capitalizing on recent theoretical and technological innovations in the understanding and assessment of oculomotor and cardiovascular behavior, three experiments measured behavioral covariation between the oculomotor and cardiovascular systems. Measures of dark focus and dark vergence indexed oculomotor tone, and the spectral decomposition of variations in heart rate indexed cardiovascular control mechanisms. In Experiment 1, individual differences in cardiovascular parameters could predict individuals’ dark vergence (R²=.806) but not their dark focus (R²=.404). In Experiment 2, the same parameters were measured from subjects who experience either panic attacks (n=11) or blood phobia (n=9). Heart rate was positively correlated with dark vergence and the two subject groups were separable based on both oculomotor and cardiovascular variables. Using a within-subjects approach, Experiment 3 found that both dark vergence and dark focus tended to be nearer during sympathetic dominance of the heart than during parasympathetic dominance, within-subjects variations in cardiovascular parameters could predict dark focus, and between-subjects variations in interbeat intervals could predict dark vergence. Shared patterns of autonomic activation may be responsible for this eye-heart link.     

Book reviews

Integrative Psychological and Behavioral Science -     

An affordable computer-aided method for conducting Morris water maze testing

A relatively inexpensive and reliable computer-aided method for assessing Morris water maze performance is described. The procedure uses SigmaScan digitizing software (Jandel Scientific, San Rafael, CA) to collect distance swum data, while escape latencies are measured with a hand-held stopwatch. Swim paths are videotaped for subsequent viewing and saved on disk as data sets ofx,y coordinates. At a later time,x,y data files are printed and analyzed to obtain additional performance measures (e.g., distance swum in previous reinforced quadrant, heading angle, etc.). Intra- and interrater reliabilities associated with this method are presented. Correlation coefficients in ther = .85?.90 and above range are reported for both reliability types. Given its approximate cost of $1,500 (excluding the price of an IBM-compatible computer), the present procedure potentially can aid in performing instructional and research activities at small colleges which typically lack extensive equipment budgets.     

Aggressivity,inattention, hyperactivity,and impulsivity in boys at high and low risk for substance abuse

Aggressivity, inattention, hyperactivity, and impulsivity are cardinal dimensions of externalizing behavior problems of childhood. They are diagnostic and clinical features of childhood disorders, and are thought to be linked to the subsequent development of adult disorders such as substance abuse (SA). Little is known, however, about the convergent and discriminant validity of these four constructs. We used multiple measures to develop indices of aggressivity, inattention, hyperactivity, and impulsivity in a sample of 10- to 12-year-old boys (N=183) with and without a family history of SA. Data were taken from mother reports, child reports, teacher reports, and laboratory tasks. The study aims were (1) to test the convergent and discriminant validity of aggressivity, inattention, hyperactivity, and impulsivity; (2) to examine whether the data were consistent with a model specifying the four constructs as indicators of one superordinate factor; and (3) to differentiate boys with and without a family history of SA in construct scores. The results supported the convergent and discriminant validity of the four constructs. Although discriminable, the constructs covaried strongly and were consistent with a model specifying them as indicators of a single superordinate factor. Boys with a family history of substance abuse scored higher than control boys on aggressivity, inattention, and impulsivity scores, but the groups did not differ on hyperactivity scores. The results are discussed in terms of the role of childhood behavior problems in vulnerability to SA.This work was supported by the National Institute on Drug Abuse grant No. DA 05605.