Association between cannabis use disorder and greater apathy in adults with HIV.

BACKGROUND: Apathy is prevalent among people with HIV (PWH) and is associated with poor clinical outcomes. Cannabis use and Cannabis Use Disorder (CUD) are also disproportionately prevalent among PWH. CUD and younger onset of cannabis use may be linked to apathy in the general population; however, patterns of use most strongly associated with apathy have not been firmly established, and it is unclear whether cannabis use is linked to apathy in PWH. METHODS: We examined associations in 311 adult PWH between Apathy Evaluation Scale-Self (AES-S) scores and CUD history (current/past/no CUD/no cannabis use) and between AES-S scores and age of CUD onset (adolescent-onset/adult-onset). We also examined robustness of associations to adjustment for depressive symptoms (which may overlap with apathy symptoms) and alcohol use. RESULTS: Current CUD was associated with greater AES-S scores relative to cannabis users with no CUD history (ß = 2.13, 95 % CI = 0.37-3.90, p = 0.018). Adolescent-onset CUD was not associated with greater apathy relative to adult-onset CUD (ß = 0.56, 95 % CI = -2.57 - 3.68, p = 0.7). Associations became nonsignificant after adjustment for depressive symptoms, but not after adjustment for alcohol use. Alcohol use was correlated with apathy (r = 0.19, 95 % CI: 0.076-0.29, p = 0.001). CONCLUSIONS: Cannabis Use Disorder and at-risk alcohol use are associated with apathy among PWH; this finding highlights the need for substance use disorder prevention and treatment among PWH.

Change in medial frontal cerebral metabolite concentrations following bariatric surgery.

Obesity is associated with adverse effects on brain health, including an increased risk of neurodegenerative diseases. Changes in cerebral metabolism may underlie or precede structural and functional brain changes. While bariatric surgery is known to be effective in inducing weight loss and improving obesity-related medical comorbidities, few studies have examined whether it may be able to improve brain metabolism. In the present study, we examined changes in cerebral metabolite concentrations in participants with obesity who underwent bariatric surgery. Thirty-five patients with obesity (body mass index ≥ 35 kg/m2 ) were recruited from a bariatric surgery candidate nutrition class. They completed single voxel proton magnetic resonance spectroscopy at baseline (presurgery) and within 1 year postsurgery. Spectra were obtained from a large medial frontal brain region using a PRESS sequence on a 3-T Siemens Verio scanner. The acquisition parameters were TR = 3000 ms and TE = 37 ms. Tissue-corrected metabolite concentrations were determined using Osprey. Paired t-tests were used to examine within-subject change in metabolite concentrations, and correlations were used to relate these changes to other health-related outcomes, including weight loss and glycated hemoglobin (HbA1c ), a measure of blood sugar levels. Bariatric surgery was associated with a reduction in cerebral choline-containing compounds (Cho; t [34] = - 3.79, p < 0.001, d = -0.64) and myo-inositol (mI; t [34] = - 2.81, p < 0.01, d = -0.47) concentrations. There were no significant changes in N-acetyl-aspartate, creatine, or glutamate and glutamine concentrations. Reductions in Cho were associated with greater weight loss (r = 0.40, p < 0.05), and reductions in mI were associated with greater reductions in HbA1c (r = 0.44, p < 0.05). In conclusion, participants who underwent bariatric surgery exhibited reductions in cerebral Cho and mI concentrations, which were associated with improvements in weight loss and glycemic control. Given that elevated levels of Cho and mI have been implicated in neuroinflammation, reduction in these metabolites after bariatric surgery may reflect amelioration of obesity-related neuroinflammatory processes. As such, our results provide evidence that bariatric surgery may improve brain health and metabolism in individuals with obesity.

Motivated suppression of value- and threat-modulated attentional capture.

Attention prioritizes stimuli previously associated with reward or punishment. The present study examined whether this attentional bias, widely considered to be involuntary and automatic, could be suppressed with sufficient motivation. Participants performed visual search for a shape-defined target. One color-singleton distractor predicted the possibility of receiving a reward and another an electric shock, with each outcome occurring infrequently. Participants were informed that the likelihood to earn a reward or avert punishment depended on fast and accurate performance, thus providing strong motivation to resist distraction by reward- and shock-related stimuli. Results revealed a reduction in the magnitude of attentional capture by reward- and threat-associated distractors, relative to neutral distractors, that persisted into extinction. In a second experiment, we replicated the suppression of value-modulated attentional capture in the absence of the shock condition, thus confirming that the suppression did not result from the presence of threat. Finally, in a third experiment, we replicated the typical pattern of attentional capture by reward cues using a more conventional procedure in which the motivation to suppress valent stimuli was low (the likelihood to be rewarded was high and not contingent on fast performance). This study demonstrates that signals for reward and threat can be actively suppressed with sufficient motivation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Reduced Working Memory is Associated with Heavier Alcohol Consumption History, Role Impairment and Executive Function Difficulties.

Both HIV status and heavy alcohol use have been associated with reduced cognitive function, particularly in the domains of working memory and executive function. It is unclear what aspects of working memory and executive function are associated with HIV status and heavy alcohol use and whether performance on these measures are associated with functional impairment. We examined the relationship between HIV, history of heavy alcohol consumption, and HIV/alcohol interaction on speeded tests of frontal inhibitory abilities, a working memory task related to mental manipulation of letters and numbers, cognitive flexibility, and measures of functional impairment. Study participants included 284 individuals (151 HIV +) recruited from two different studies focusing on HIV associated brain dysfunction, one specific to the effects of alcohol, the other specific to the effects of aging. HIV status was not independently associated with working memory and executive function measures. Higher level of alcohol consumption was associated with reduced performance on Letter Number Sequencing. Poorer Letter Number Sequencing performance was associated with role impairment (an inability to do certain kinds of work, housework, or schoolwork) and executive function difficulties. Future studies should examine causal associations and interventions targeting working memory abilities.

RESUMEN: Tanto el estado del VIH como el consumo excesivo de alcohol se han asociado con una función cognitiva reducida, particularmente en los dominios de la memoria de trabajo y la función ejecutiva. No está claro qué aspectos de la memoria de trabajo y la función ejecutiva están asociados con el estado del VIH y el consumo excesivo de alcohol y si el desempeño en estas medidas está asociado con un deterioro funcional. Examinamos la relación entre el VIH, el historial de consumo excesivo de alcohol y la interacción VIH / alcohol, en pruebas aceleradas de capacidades inhibitorias frontales, tareas de memoria de trabajo relacionadas con la manipulación mental de letras y números, flexibilidad cognitiva y medidas de deterioro funcional. Los participantes del estudio incluyeron 284 personas (151 VIH +) reclutadas de dos estudios diferentes que se centran en la disfunción cerebral asociada al VIH, uno específico de los efectos del alcohol y el otro específico de los efectos del envejecimiento. El estado del VIH no se asoció de forma independiente con las medidas de memoria de trabajo y función ejecutiva. Un mayor nivel de consumo de alcohol se asoció con un rendimiento reducido en la secuenciación de números de letras. Un desempeño deficiente en la secuenciación de números de letras se asoció con un deterioro de los roles (una incapacidad para realizar ciertos tipos de trabajo, tareas domésticas o escolares) y dificultades en las funciones ejecutivas. Los estudios futuros deben examinar las asociaciones causales y las intervenciones dirigidas a las capacidades de la memoria de trabajo.

Neuroimaging and Cognitive Evidence for Combined HIV-Alcohol Effects on the Central Nervous System: A Review.

Alcohol use disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and EtOH are directly neurotoxic and exacerbate each other's neurotoxic effects; EtOH reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol's damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity, and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.

Attentional avoidance of threatening stimuli.

Aversive conditioning has been shown to influence the control of attention, such that aversively conditioned stimuli receive elevated priority. Although aversively conditioned but task-irrelevant distractors are known to capture attention during speeded search in rapid orienting tasks, it is unclear whether this bias extends to situations where orienting can be more deliberate. We demonstrate that punishment, via electric shock, does not give rise to oculomotor capture by shock-associated stimuli during a foraging task; rather, such aversively conditioned stimuli are actively avoided when searching through a display. On the other hand, even during a foraging task, we found some evidence for a covert attentional bias to threat. Our findings indicate that the previously described effects of aversive conditioning on visual search may not generalize beyond the initial glance and can be suppressed when conditions allow for more deliberate search strategies. More generally, our findings reveal that sustained attentional avoidance of aversively conditioned stimuli is possible during active search.

Selection history is relative.

Visual attention can be tuned to specific features to aid in visual search. The way in which these search strategies are established and maintained is flexible, reflecting goal-directed attentional control, but can exert a persistent effect on selection that remains even when these strategies are no longer advantageous, reflecting an attentional bias driven by selection history. Apart from feature-specific search, recent studies have shown that attention can be tuned to target-nontarget relationships. Here we tested whether a relational search strategy continues to bias attention in a subsequent task, where the relationally better color and former target color both serve as distractors (Experiment 1) or as potential targets (Experiment 2). We demonstrate that a relational bias can persist in a subsequent task in which color serves as a task-irrelevant feature, both impairing and facilitating visual search performance. Our findings extend our understanding of the relational account of attentional control and the nature of selection history effects on attention.

Specificity and persistence of statistical learning in distractor suppression.

Statistical regularities in distractor location trigger suppression of high-probability distractor locations during visual search. The degree to which such suppression reflects generalizable, persistent changes in a spatial priority map has not been examined. We demonstrate that suppression of high-probability distractor locations persists after location probabilities are equalized and likely reflects a genuine reshaping of the priority map rather than more transient effects of selection history. Statistically learned suppression generalizes across contexts within a task during learning but does not generalize between task paradigms using unrelated stimuli in identical spatial locations. These findings suggest that stimulus features do play a role in learned spatial suppression, potentially gating the weights applied to a spatial priority map. However, the binding of location to context during learning is not automatic, in contrast to the previously reported interaction of location-based statistical learning and stimulus features. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

On the automaticity of attentional orienting to threatening stimuli.

Attention is biased toward stimuli that have been associated with aversive outcomes in the past. This bias has previously been interpreted as reflecting automatic orienting toward threat signals. However, in many prior studies, either the threatening stimulus provided valuable predictive information, signaling the possibility of an otherwise unavoidable punishment and thereby allowing participants to brace themselves, or the aversive event could be avoided with fast and accurate task performance. Under these conditions, monitoring for threat could be viewed as an adaptive strategy. In the present study, fixating a color stimulus immediately resulted in a shock on some trials, providing a direct incentive not to look at the stimulus. Nevertheless, this contingency resulted in participants fixating the shock-associated stimulus more frequently than a neutral distractor matched for physical salience. Our findings demonstrate that threatening stimuli are automatically attended even when attending such stimuli is actually responsible for triggering the aversive event, providing compelling evidence for automaticity. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Measuring attention to reward as an individual trait: the value-driven attention questionnaire (VDAQ).

Reward history is a powerful determinant of what we pay attention to. This influence of reward on attention varies substantially across individuals, being related to a variety of personality variables and clinical conditions. Currently, the ability to measure and quantify attention-to-reward is restricted to the use of psychophysical laboratory tasks, which limits research into the construct in a variety of ways. In the present study, we introduce a questionnaire designed to provide a brief and accessible means of assessing attention-to-reward. Scores on the questionnaire correlate with other measures known to be related to attention-to-reward and predict performance on multiple laboratory tasks measuring the construct. In demonstrating this relationship, we also provide evidence that attention-to-reward as measured in the lab, an automatic and implicit bias in information processing, is related to overt behaviors and motivations in everyday life as assessed via the questionnaire. Variation in scores on the questionnaire is additionally associated with a distinct biomarker in brain connectivity, and the questionnaire exhibits acceptable test-retest reliability. Overall, the Value-Driven Attention Questionnaire (VDAQ) provides a useful proxy-measure of attention-to-reward that is much more accessible than typical laboratory assessments.

Selection history in context: Evidence for the role of reinforcement learning in biasing attention.

Attention is biased towards learned predictors of reward. The influence of reward history on attentional capture has been shown to be context-specific: When particular stimulus features are associated with reward, these features only capture attention when viewed in the context in which they were rewarded. Selection history can also bias attention, such that prior target features gain priority independently of reward history. The contextual specificity of this influence of selection history on attention has not been examined. In the present study, we demonstrate that the consequences of repetitive selection on attention robustly generalize across context, such that prior target features capture attention even in contexts in which they were never seen previously. Our findings suggest that the learning underlying attention driven by outcome-independent selection history differs qualitatively from the learning underlying value-driven attention, consistent with a distinction between associative and reinforcement learning mechanisms.