RESUMEN
Individuals actively maintain attentional templates to prioritize target-matching inputs. While previous works have established that multiple templates can be held simultaneously, current understanding is limited with respect to the representational quality of such templates. We thus investigated: (a) whether the maintenance of two templates is limited to broad, coarse-grained representations, and if not, (b) whether there is nonetheless a decline in the achievable level of specificity when multiple attentional templates are held simultaneously. Using a spatial cueing procedure, we probed the breadth of attentional templates while participants maintained either one (Experiment 1) or two target colors (Experiment 2) under conditions of low- or high-similarity search and found specific template maintenance during high-similarity search for both single- and dual-target conditions. We then directly compared template specificity during single- and dual-target maintenance in Experiment 3, probing at the point of differentiation between target and nontarget feature values observed during single-target search. Here we found no difference in the selectivity of cue validity effects between single- and dual-target search, suggesting equivalent template specificity regardless of whether one or two features are relevant to search. Lastly, in Experiment 4, we established that such template specificity is dependent on access to visual working memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Asunto(s)
Atención , Memoria a Corto Plazo , Humanos , Señales (Psicología) , Tiempo de Reacción , Percepción VisualRESUMEN
The process by which multiple items within an object grouping are rapidly summarized along a given visual dimension into a single mean value (i.e., perceptual averaging) has increasingly been shown to interact dynamically with visual working memory (VWM). Commonly, this interaction is studied with respect to the influence of perceptual averaging over VWM, but it is also the case that VWM can support perceptual averaging. Here, we argue that, in the presence of memory-matching elements, VWM exerts an obligatory influence over perceptual averaging even when it is detrimental to do so. Over four experiments, we tested our hypothesis by having individuals perform a mean orientation estimation task while concurrently maintaining a colored object in VWM. We anticipated that mean orientation reports would be attracted to the local mean of memory-matching items if such items are prioritized in perceptual average judgments. This was indeed the case as we observed a persistent bias in mean orientation judgments toward the subset mean of items matching the VWM item color, despite color being entirely irrelevant to the mean orientation task. Our results thus highlight a goal-invariant influence of VWM over perceptual averaging, which we attribute to amplification through memory-driven selection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Asunto(s)
Juicio , Memoria a Corto Plazo , Humanos , Motivación , Percepción VisualRESUMEN
Cardiac arrhythmia is a known manifestation of novel coronavirus 2019 (COVID-19) infection. Herein, we describe the clinical course of an otherwise healthy patient who experienced persistent ventricular tachycardia and fibrillation which is believed to be directly related to inflammation, as opposed to acute myocardial injury or medications that can prolong the QT interval.
Asunto(s)
Infecciones por Coronavirus/complicaciones , Cardioversión Eléctrica/métodos , Electrocardiografía/métodos , Neumonía Viral/complicaciones , Fibrilación Ventricular/complicaciones , Fibrilación Ventricular/terapia , Antiarrítmicos/uso terapéutico , COVID-19 , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/terapia , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/terapia , Recuperación de la Función , Medición de Riesgo , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/diagnóstico por imagenRESUMEN
PURPOSE: To ascertain whether offsetting the Descemet membrane endothelial keratoplasty (DMEK) punch can expand the donor pool in conjunction with prepunched and preloaded services by recapturing the corneas otherwise excluded by the conventional central clear zone criteria. METHODS: In this retrospective review of corneas recovered and processed for DMEK by a single eye bank between March 2017 and October 2018, corneas failing to meet the conventional central clear zone requirement during initial evaluation (defined as an area in the central cornea where an 7.5- to 8.0-mm diameter graft can be obtained free of previous surgical scars, Descemet tears, or confined areas of endothelial defects) were further evaluated for offset punching. Corneas with a central endothelial cell density of at least 2000 cells/mm at the initial screening (average of 3 specular images assessed with the center dot method) that had a clear zone of 7.5- to 8.0-mm diameter where a graft could be obtained were designated as eligible for offset punching for either prepunched or preloaded DMEK. RESULTS: A total of 2607 corneas were found to be suitable for DMEK using the conventional central clear zone criteria. An additional 62 corneas were deemed DMEK suitable by offsetting the punch, yielding a 2.4% increase in the availability of DMEK suitable corneas. CONCLUSIONS: Offsetting the DMEK punch can recapture corneas otherwise excluded from the DMEK donor pool because of a failure to meet the conventional central clear zone criteria, and by our estimation may help eye banks meet the growing demand for DMEK tissue while maximizing the transplant potential of every cornea.
Asunto(s)
Córnea , Queratoplastia Endotelial de la Lámina Limitante Posterior/métodos , Bancos de Ojos/métodos , Donantes de Tejidos/provisión & distribución , Obtención de Tejidos y Órganos/provisión & distribución , Anciano , Recuento de Células , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Agudeza VisualRESUMEN
Attentional control processes help to prioritize the storage of information in visual working memory (VWM) by gating what enters the system and influencing how precisely this information is stored. However, the extent to which such prioritization occurs deliberately, opposed to incidentally, is poorly understood. In large part, this is because investigations of this matter have almost exclusively relied on comparisons of memory for exogenously cued items versus uncued items. To understand whether prioritization occurs independent of intention, though, it is essential to examine instances in which attended items are entirely task-irrelevant. Thus, in the current study we used a directed avoidance paradigm to examine VWM performance following the selection of an item known to be task-irrelevant. In Experiment 1, we confirmed that cueing the color of a non-target item paradoxically increases attention to the cued item when the target color is unknown, resulting in longer search times (in line with previous findings). In Experiments 2 and 3, we applied the same cueing procedure to a delayed-estimation task of VWM, but now found a non-target cueing benefit in which the recall of task-relevant items was improved by directed avoidance. We further found that this effect is not solely due to the reprioritization of cognitive resources during maintenance (Exp. 4), but involves additional control processes that 1) reallocate resources to relevant items at encoding, and 2) selectively stabilize such items during the transition from encoding to maintenance (Exp. 5). As such, we suggest that while attentionally selected items may initially be prioritized independent of importance, more controlled mechanisms reallocate resources on the basis of relevance when sufficient time is provided before the sensory information is removed or displaced.
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Memoria a Corto Plazo , Recuerdo Mental , Cognición , Señales (Psicología) , Humanos , Intención , Percepción VisualRESUMEN
Preparing for upcoming events, separating task-relevant from task-irrelevant information and efficiently responding to stimuli all require cognitive control. The adaptive recruitment of cognitive control depends on activity in the dopaminergic reward system as well as the frontoparietal control network. In healthy aging, dopaminergic neuromodulation is reduced, resulting in altered incentive-based recruitment of control mechanisms. In the present study, younger adults (18-28 years) and healthy older adults (66-89 years) completed an incentivized flanker task that included gain, loss, and neutral trials. Event-related potentials (ERPs) were recorded at the time of incentive cue and target presentation. We examined the contingent negative variation (CNV), implicated in stimulus anticipation and response preparation, as well as the P3, which is involved in the evaluation of visual stimuli. Both younger and older adults showed transient incentive-based modulation of CNV. Critically, cue-locked and target-locked P3s were influenced by transient and sustained effects of incentives in younger adults, while such modulation was limited to a sustained effect of gain incentives on cue-P3 in older adults. Overall, these findings are in line with an age-related reduction in the flexible recruitment of preparatory and target-related cognitive control processes in the presence of motivational incentives.
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Envejecimiento , Encéfalo/fisiología , Función Ejecutiva/fisiología , Motivación , Recompensa , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Conducta de Elección , Señales (Psicología) , Electroencefalografía , Potenciales Relacionados con Evento P300 , Femenino , Humanos , Masculino , Desempeño Psicomotor , Adulto JovenRESUMEN
Adaptive gain theory (Aston-Jones & Cohen, 2005) suggests that the phasic release of norepinephrine (NE) to cortical areas reflects changes in the utility of ongoing tasks. In the context of aging, this theory raises interesting questions, given that the motivations of older adults differ from those of younger adults. According to socioemotional selectivity theory (Carstensen, Isaacowitz, & Charles, 1999), aging is associated with greater emphasis on emotion-regulation goals, leading older adults to prioritize positive over negative information. This suggests that the phasic release of NE in response to threatening stimuli may be diminished in older adults. In the present study, younger adults (aged 18-34years) and older adults (60-82years) completed the Attention Network Test (ANT), modified to include an incentive manipulation. A behavioral index of attentional alerting served as a marker of phasic arousal. For younger adults, this marker correlated with the effect of both gain and loss incentives on performance. For older adults, in contrast, the correlation between phasic arousal and incentive sensitivity held for gain incentives only. These findings suggest that the enlistment of phasic NE activity may be specific to approach-oriented motivation in older adults.
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Envejecimiento/fisiología , Atención/fisiología , Motivación/fisiología , Desempeño Psicomotor/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
PURPOSE: This study assessed a novel diabetes mellitus (DM) rating scale in relation to its utility in reducing Descemet membrane endothelial keratoplasty (DMEK) tissue preparation failure. METHODS: A 5-point DM rating scale was defined, in which 1 demonstrated relatively good health associated with DM and 5 represented comorbidities associated with DM. A chart review from consecutive donors who had at least 1 tissue prepared for DMEK was performed. Using the donor profile, the first tissue processed from each donor was categorized according to the DM severity and if the tissue passed or failed the DMEK preparation. Failure rates per rating group were evaluated using logistic regression and odds of preparation failure. RESULTS: A total of 125 tissues prepared for DMEK were categorized based on the defined DM rating scale. Of these, 9 tissues were rated 1 (11.1% failure), 25 were rated 2 (0% failure), 31 were rated 3 (6.5% failure), 24 were rated 4 (16.7% failure), and 36 were rated 5 (30.6% failure). The odds ratios were significant for tissues rated as 5 and 3 (P < 0.05). No other rating categories were found to influence the odds of failure. A χ test comparing categories of low risk (1-3) and high risk (4-5) was also performed (P = 0.001). CONCLUSIONS: The DM rating scale does seem to stratify the risk of preparation failure associated with the severity of DM and associated comorbidities. Inclusion of some diabetic donors for the preparation of DMEK grafts may be warranted given proper screening of the donor history and application of the rating scale.
Asunto(s)
Córnea , Queratoplastia Endotelial de la Lámina Limitante Posterior , Diabetes Mellitus/clasificación , Donantes de Tejidos , Recolección de Tejidos y Órganos , Diabetes Mellitus/etiología , Bancos de Ojos , Humanos , Estudios Retrospectivos , Medición de Riesgo , Donantes de Tejidos/clasificaciónRESUMEN
The Attention Network Test (ANT) is widely used to capture group and individual differences in selective attention. Prior behavioral studies with younger and older adults have yielded mixed findings with respect to age differences in three putative attention networks (alerting, orienting, and executive control). To overcome the limitations of behavioral data, the current study combined behavioral and electrophysiological measures. Twenty-four healthy younger adults (aged 18-29years) and 24 healthy older adults (aged 60-76years) completed the ANT while EEG data were recorded. Behaviorally, older adults showed reduced alerting, but did not differ from younger adults in orienting or executive control. Electrophysiological components related to alerting and orienting (P1, N1, and CNV) were similar in both age groups, whereas components related to executive control (N2 and P3) showed age-related differences. Together these results suggest that comparisons of network effects between age groups using behavioral data alone may not offer a complete picture of age differences in selective attention, especially for alerting and executive control networks.
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Atención/fisiología , Señales (Psicología) , Potenciales Evocados/fisiología , Función Ejecutiva/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Orientación/fisiología , Adulto JovenRESUMEN
BACKGROUND: Several studies have shown that the modulation of fibrotic scar in cardiac diseases has beneficial effects on cardiac arrhythmias. In addition, recent reports suggest a potential role of mineralocorticoid receptor upregulation in atrial fibrillation (AF). The role of spironolactone, a mineralocorticoid receptor blocker and a potent antifibrotic agent, in AF is as yet unexplored. The aim of this study was to determine if spironolactone, a mineralocorticoid receptor blocker with potent antifibrotic properties, has beneficial effects on AF. HYPOTHESIS: Spironolactone therapy in patients with atrial fibrillation provides additional clinical benefits in addition to the current conventional pharmacological agents. METHODS: A comprehensive retrospective analysis was performed on 83 patients with AF, including 23 who were treated with spironolactone for ≥3 months. The combined primary outcome of hospitalization for AF or direct current cardioversion (DCCV) was compared between patients treated with spironolactone in addition to the usual care for AF and those receiving conventional medical therapy alone. RESULTS: Patients receiving spironolactone had significantly fewer primary outcome events (AF-related hospitalizations or DCCV) (22% vs 53%, P = 0.027). CONCLUSIONS: Spironolactone therapy is associated with a reduction in the burden of AF, as reflected by a combination of hospitalizations for AF and DCCV. Larger randomized controlled studies should be performed to evaluate the efficacy and safety of spironolactone as an adjunctive therapy for patients with AF.
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Antiarrítmicos/uso terapéutico , Fibrilación Atrial/tratamiento farmacológico , Cardiopatías/tratamiento farmacológico , Antagonistas de Receptores de Mineralocorticoides/uso terapéutico , Espironolactona/uso terapéutico , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/etiología , Fibrilación Atrial/patología , Fibrilación Atrial/fisiopatología , Distribución de Chi-Cuadrado , Cardioversión Eléctrica , Femenino , Fibrosis , Cardiopatías/complicaciones , Cardiopatías/patología , Cardiopatías/fisiopatología , Hospitalización , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Texas , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Although exercise-associated ventricular arrhythmias are frequently observed during exercise testing, their prognostic significance remains uncertain. Therefore, we aimed to evaluate the clinical correlates and prognostic significance of exercise-associated premature ventricular complexes (PVCs) during and after exercise testing. METHODS: We studied 1847 heart failure-free patients who underwent clinical treadmill testing between March 13, 1997, and January 15, 2004, in the Veterans Affairs Palo Alto Health Care System. Logistic regression was used to evaluate the clinical and exercise test associations of exercise and recovery PVCs. Propensity score-adjusted Cox survival analyses were used to evaluate the prognostic significance of exercise-associated PVCs. RESULTS: Of the 1847 subjects, 850 (46.0%) developed exercise PVCs (median rate, 0.43 per minute) and 620 (33.6%) had recovery PVCs (median rate, 0.60 per minute). Resting PVCs, age, and systolic blood pressure were key predictors of both exercise and recovery PVCs. Whereas exercise PVCs were related to the heart rate increase with exercise, recovery PVCs were related to coronary disease (previous myocardial infarction, coronary revascularization procedure, or pathological Q waves on resting electrocardiogram) and ST-segment depression. During a 5.4-year mean follow-up, 161 subjects (8.7%) died, and 53 of these deaths (32.9%) were due to cardiovascular causes. Recovery PVCs, but not exercise PVCs, were associated with 71% to 96% greater propensity-adjusted mortality rates (hazard ratio, 1.96 [95% confidence interval, 1.31-2.91] for infrequent PVCs; hazard ratio, 1.71 [95% confidence interval, 1.07-2.73] for frequent PVCs compared with subjects without PVCs), and occurrence of recovery PVCs reclassified 33.2% of subjects with intermediate-risk Duke Treadmill Scores into higher-risk subgroups. CONCLUSION: In our heart failure-free population, recovery PVCs were associated with increased mortality and augmented established risk markers.