David Nussbaum

Domains of Competency to Stand Trial

Attempts to improve the clinical rigor of competency to stand trial evaluations have resulted in the development of several psycholegal measures. Among the most widely used of these measures are the Competency Screening Test (CST), the Fitness Interview Test (FIT), and the Georgia Court Competency Test—Mississippi State Hospital Revision (GCCT-MSH). To examine the theoretical domains of the competency construct as assessed by these measures, a series of exploratory factor analyses were performed combining previously reported data on the FIT and GCCT-MSH with a new outpatient sample of 353 court referrals. For the CST, data from a previous sample were compared to the original validation study. Of the three measures, only the GCCT-MSH showed evidence of stable, independent factors. A comparison of the GCCT-MSH to theDusky standard suggested a need to further develop empirical measures to better represent underlying constructs related to the defendant-attorney relationship and defendants participation in his or her defense.

Neuropsychological and Personality Characteristics of Predatory, Irritable, and Nonviolent Offenders: Support for a Typology of Criminal Human Aggression

This article represents an initial attempt to adapt the three most relevant components of Moyer’s animal aggression typology to humans. These include predatory (unemotional, goal-directed), irritable (anger-based), and defensive (fear-based) aggression. As different brain networks are likely involved, the authors hypothesized that executive function and personality tests could differentiate violent from nonviolent criminals and discriminate the types originally classified on the basis of criminal history. Discriminant analyses correctly classified 80% of the violent and nonviolent groups and 74% of the predatory and irritable groups. Of theoretical salience, the predatory group resembled the unimpaired nonviolent group only on the cognitive Integrated Visual and Auditory Continuous Performance Test but was indistinguishable from the impaired irritable aggression group on the Iowa Gambling, suggesting inhibitory deficits primarily in the face of reward opportunity. Implications for the theory and application to risk assessment are discussed.

Development of a Novel, Ecologically Oriented Virtual Reality Measure of Executive Function: The Multitasking in the City Test

A novel virtual reality executive function task (Multitasking in the City Test [MCT]) was developed with the aim of investigating planning and multitasking with ecological validity in mind in a normal population. Thirty healthy participants (21 females) completed a neuropsychological test battery that included the MCT along with standardized tests of executive and other cognitive functions. The sample performed within normal limits on the standardized tests. The MCT was performed successfully, although specific types of errors occurred frequently. Spearman correlation coefficients were computed between the various test measures. Only the plan score from the MCT was significantly associated with one of the executive function tests administered (Modified Six Elements Test), suggesting that both variables may be measuring a similar construct. Statistically significant correlations were also found between the MCT and the Trail-Making Test Part A and Judgment of Line Orientation, suggesting that “basic” cognitive functions such as information-processing speed and visuospatial skills are being tapped on the MCT. Preliminary evidence from this study suggested that the MCT may be an ecologically valid method of evaluating executive functioning. The clinical implications of these findings are discussed.

Ecologically Valid Assessment of Executive Dysfunction Using a Novel Virtual Reality Task in Patients with Acquired Brain Injury

The current investigation sought to further establish the psychometric properties and ecological validity of the Multitasking in the City Test (MCT) in a clinical population. Ecological validity was addressed via correlational analyses between performance on this test and a subjective measure of everyday executive functioning (Frontal Systems Behavior Scale; FrSBe). The sample was composed of 13 individuals (11 males) who suffered a stroke or traumatic brain injury. A neuropsychological test battery consisting of the MCT and common executive and nonexecutive measures was administered. The only executive function tests that were significantly related to the FrSBe were the MCT and a semantic fluency test. Compared with a sample of normal participants, the patient group produced better plans but completed fewer tasks on the MCT. Patients made similar types of errors as normals, although some of these errors occurred more frequently in the patient sample. This study demonstrated the ecological validity of the MCT and suggested that patients can be differentiated from healthy individuals by quantitative (i.e., number of errors) rather than qualitative (i.e., type of errors) aspects of performance. Further interpretation of MCT performance and comparison with existing executive function tests is discussed.

An Eight Component Decision-Making Model for Problem Gambling:A Systems Approach to Stimulate Integrative Research

Problem Gambling (PG) represents a serious problem for affected individuals, their families and society in general. Previous approaches to understanding PG have been confined to only a subset of the psychobiological factors influencing PG. We present a model that attempts to integrate potential causal factors across levels of organization, providing empirical evidence from the vast literature on PG and complimentary literatures in decision-making and addiction. The model posits that components are arranged systematically to bias decisions in favor of either immediately approaching or avoiding targets affording the opportunity for immediate reward. Dopamine, Testosterone and Endogenous Opioids favor immediate approach, while Serotonin and Cortisol favor inhibition. Glutamate is involved in associative learning between stimuli and promotes the approach response through its link to the DA reward system. GABA functions to monitor performance and curb impulsive decision-making. Finally, while very high levels of Norepinephrine can induce arousal to an extent that is detrimental to sound decision-making, the reactivity of the Norepinephrine system and its effects of Cortisol levels can shift the focus towards long-term consequences, thereby inhibiting impulsive decisions. Empirical evidence is provided showing the effects of each component on PG and decision-making across behavioural, neuropsychological, functional neuroimaging and genetic levels. Last, an effect size analysis of the growing pharmacotherapy literature is presented. It is hoped that this model will stimulate multi-level research to solidify our comprehension of biased decision-making in PG and suggest pharmacological and psychological approaches to treatment.

Neuronal function is necessary but not sufficient for consciousness: consciousness is necessary for will

Behavioral neuroscience has presented philosophers with the task of clarifying the relationship between neural determinism and free will. If neural functions encode information and govern decision-making, are the constructs of will, agency and indeed morality illusions of pre-scientific ignorance? This article will argue that neuronal function is necessary for representing distinct sensory-perceptual, cognitive, motivational, emotional states, and motor functions. However, neural transmission and action potentials are simply chemical-physical representations of these informational states but are not the embodiment of consciousness itself. By some yet undiscovered mechanism, consciousness “reads” the neuronal events into conscious experience. Absent a particular specialized brain region or sufficient relevant transmitters and receptors, relevant information cannot be processed and the individual cannot be conscious of that informational state. In natural and many artificial communication systems, communications proceed bi-directionally. By an argument of symmetry, if neuronal activity can communicate with consciousness, there is no reason to preclude consciousness from communicating back and influencing neuronal function. In the intervening conscious moment, information from diverse perceptual, motivational, cognitive, and emotional sources is weighted and will results. This process then biases resultant neural processes to actualize the willed target. This approach is limited in terms of operationalization into an experimental study because at present, there is no method to measure consciousness-independent of neuronal function and subjective report.