Cognitive Neuropsychology of HIV-Associated Neurocognitive Disorders

Advances in the treatment of the human immunodeficiency virus (HIV) have dramatically improved survival rates over the past 10 years, but HIV-associated neurocognitive disorders (HAND) remain highly prevalent and continue to represent a significant public health problem. This review provides an update on the nature, extent, and diagnosis of HAND. Particular emphasis is placed on critically evaluating research within the realm of cognitive neuropsychology that aims to elucidate the component processes of HAND across the domains of executive functions, motor skills, speeded information processing, episodic memory, attention/working memory, language, and visuoperception. In addition to clarifying the cognitive mechanisms of HAND (e.g., impaired cognitive control), the cognitive neuropsychology approach may enhance the ecological validity of neuroAIDS research and inform the development of much needed novel, targeted cognitive and behavioral therapies. The research described was supported by MH73419 and MH62512 from the National Institutes of Health. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the United States Government.     

Large sex difference in adolescents on a timed line judgment task: attentional contributors and task relationship to mathematics

Visuospatial performance, assessed with the new, group-administered Judgment of Line Angle and Position test (JLAP-13), varied with sex and mathematical competence in a group of adolescents. The JLAP-13, a low-level perceptual task, was modeled after a neuropsychological task dependent upon functioning of the posterior region of the right hemisphere [Benton et al, 1994 Contributions to Neuropsychological Assessment: A Clinical Manual (New York: Oxford University Press)]. High-school boys (N = 52) performed better than girls (N = 62), with a large effect for sex (d = 1.11). Performance increased with mathematical competence, but the sex difference did not vary significantly across different levels of mathematics coursework. On the basis of earlier work, it was predicted that male, but not female, performance in line judgment would decline with disruptions to task geometry (page frame), and that the sex difference would disappear with disruptions to geometry. These predictions were supported by a number of univariate and sex-specific analyses, although an omnibus repeated-measures analysis did not detect the predicted interaction, most likely owing to limitations in power. Thus, there is partial support for the notion that attentional predispositions or strategies may contribute to visuospatial sex differences, with males more likely than females to attend to, and rely upon, internal or external representations of task geometry. Additional support for this hypothesis may require development of new measures or experimental manipulations with more powerful geometrical disruptions.     

Conditioned fear extinction and reinstatement in a human fear-potentiated startle paradigm

The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h after fear conditioning. Upon presentation of unsignaled USs after extinction, participants displayed significant fear reinstatement. In summary, these procedures produced robust fear-potentiated startle, significant CS+/CS- discrimination, within-session extinction, and significant reinstatement. This is the first demonstration of fear extinction and reinstatement in humans using startle measures.     

Skill training,retention, and transfer: The effects of a concurrent secondary task

In two experiments, we examined training, retention, and transfer of a duration production skill in a prospective paradigm. Participants were trained with feedback and then were either tested immediately for transfer without feedback or retrained with feedback 1 week later. There were three training and retraining conditions, two involving secondary tasks. Retention of the duration production skill was perfect across the 1-week delay when the secondary task condition was unchanged, but there was no skill transfer when that condition was changed. These findings demonstrate specificity of training, with the assumption that the cognitive operations learned during duration production training incorporate requirements of the secondary task. More generally, this study challenges the current practice in which training conditions often do not match eventual testing conditions.     

Interoceptive fear conditioning and panic disorder: the role of conditioned stimulus-unconditioned stimulus predictability

Interoceptive fear conditioning is at the core of contemporary behavioral accounts of panic disorder. Yet, to date only one study has attempted to evaluate interoceptive fear conditioning in humans (see Acheson, Forsyth, Prenoveau, & Bouton, 2007). That study used brief (physiologically inert) and longer-duration (panicogenic) inhalations of 20% CO(2)-enriched air as an interoceptive conditioned (CS) and unconditioned (US) stimulus and evaluated fear learning in three conditions: CS only, CS-US paired, and CS-US unpaired. Results showed fear conditioning in the paired condition, and fearful responding and resistance to extinction in an unpaired condition. The authors speculated that such effects may be due to difficulty discriminating between the CS and the US. The aims of the present study are to (a) replicate and expand this line of work using an improved methodology, and (b) clarify the role of CS-US discrimination difficulties in either potentiating or depotentiating fear learning. Healthy participants (N=104) were randomly assigned to one of four conditions: (a) CS only, (b) contingent CS-US pairings, (c) unpaired CS and US presentations, or (d) an unpaired "discrimination" contingency, which included an exteroceptive discrimination cue concurrently with CS onset. Electrodermal and self-report ratings served as indices of conditioned responding. Consistent with expectation, the paired contingency and unpaired contingencies yielded elevated fearful responding to the CS alone. Moreover, adding a discrimination cue to the unpaired contingency effectively attenuated fearful responding. Overall, findings are consistent with modern learning theory accounts of panic and highlight the role of interoceptive conditioning and unpredictability in the etiology of panic disorder.     

Using I³ theory to clarify when dispositional aggressiveness predicts intimate partner violence perpetration

Deriving hypotheses from I3 theory (pronounced "I-cubed theory"), the authors conducted 4 studies to clarify the circumstances under which dispositional aggressiveness predicts intimate partner violence (IPV) perpetration. Consistent with the hypothesis that this link would be stronger when inhibitory processes are weak rather than strong, Studies 1 and 2 demonstrated that dispositional aggressiveness was an especially robust predictor of IPV perpetration among people experiencing self-regulatory strength depletion. Consistent with the hypothesis that this Dispositional Aggressiveness × Inhibition interaction effect would be stronger when instigating triggers are strong rather than weak, Studies 3 and 4 demonstrated that dispositional aggressiveness was an especially robust predictor of IPV perpetration among people characterized by both weak inhibition (poor executive control in Study 3, depletion in Study 4) and strong instigation (provocation in both studies). These effects were robust in studies employing experimental and nonexperimental designs, cross-sectional and longitudinal methods, dating and married participants, self-report and behavioral measures of IPV perpetration, and diverse operationalizations of all constructs. Discussion emphasizes the importance of incorporating instigating, impelling, and inhibiting processes into theoretical and empirical analyses of IPV perpetration.