Publications

Blue care, a therapeutic approach utilizing natural aquatic environments, has emerged as a promising nature-based intervention (NBI) to enhance well-being. This literature review explored the concept of blue care as well as its relevance to recreational therapy (RT) practices. Supported by Ulrich's Stress Reduction Theory, this review discusses the restorative effects of water that support physical, emotional, and psychological health. Studies demonstrated that proximity to and engagement with blue spaces was associated with increased physical activity, improved mood, reduced symptoms of anxiety and depression, enhanced body image, and greater life satisfaction. These benefits were observed across diverse populations including children, older adults, and veterans. Interventions ranged from direct immersion activities, such as swimming and surfing, to passive methods, such as viewing aquatic environments or practicing guided imagery.

Recreational therapists work in a broad field with numerous service settings for individuals with disabilities. Students' learning may be enhanced by providing opportunities during class time to implement services for more unfamiliar populations. Therefore, the purpose of this study was to investigate students' reflections from a class time fieldwork experience (CTFE) in a recreational therapy (RT) class with adolescents who engage in health-risk behaviors. A retrospective, qualitative content analysis of 111 RT students' perspectives was used for this study, and two main themes emerged: exposure to an unfamiliar community population and identifying personal biases and judgments. Implications are identified for RT educators and practitioners to apply these findings to future CTFEs, internships, and employment opportunities.

Density information is a possible primitive for the perception of numerosity. It has been argued, however, that the perception of numerosity is more precise than density perception at low numbers, whereas density is more precise for high numbers. An interpretive problem with the stimuli used to make those claims is that actual stimulus density was often mis-specified owing to an ambiguity regarding the idealized versus actual filled area. This ambiguity had the effect of underestimating density precision at low numerosities. Here we used a novel method of stimulus generation that allows us to accurately specify stimulus density independent of patch size and number, while varying patch size from trial to trial to dissociate numerosity and density. For both numerosity discrimination and density discrimination, we presented single stimuli in central vision for comparison with an internal standard. Feedback was given after each judgment. Using well-defined densities, density discrimination was more precise than numerosity perception at all densities and showed no evidence of varying as a function of density, as previously hypothesized. This was found with 8 practiced observers, and then replicated in a pre-registered study with 32 observers. As expected, feedback nullified size biases on number judgments, showing that observers were adaptively combining density and size. Reanalysis of data from a recent investigation of downward sloping Weber fractions for numerosity showed that the square root-like effects in those sorts of studies were most likely owing to reductions in patch size variance that were correlated with increases in density.

PURPOSE: The purpose of this study was to investigate the morphological and hemodynamic characteristics of the ophthalmic artery (OA) in ocular ischemic syndrome (OIS) and identify features potentially associated with disease pathogenesis.

METHODS: This retrospective case-control study included 33 patients with OIS, 22 patients with internal carotid artery stenosis (ICAS), and 29 healthy controls. Clinical data and ophthalmic examinations were collected. The morphology and hemodynamics of the OA were quantified using three-dimensional (3D) reconstruction and computational fluid dynamics (CFD). Particle image velocimetry provided a qualitative consistency check for the CFD results.

RESULTS: The OA diameter in the OIS group was significantly smaller than that in the control and ICAS groups. Compared with the control group, the OIS group showed lower blood flow velocity and wall shear stress (8.25 ± 5.34 Pa vs. 13.50 ± 6.24 Pa; P = 0.004) at the OA origin. A smaller OA diameter and lower wall shear stress at the OA origin were significantly associated with the presence of OIS. A low wall shear stress was observed at the OA origin regardless of the flow direction in the OIS. Patients with high-velocity retrograde OA flow present severe ocular ischemic manifestations.

CONCLUSIONS: Low wall shear stress may be a consistent hemodynamic characteristic of eyes with OIS. This hemodynamic feature may induce inward remodeling of the OA, leading to further luminal narrowing and exacerbation of ocular ischemia. The presence of high-velocity retrograde OA flow may indicate a severe degree of ocular ischemia, highlighting the potential of OA hemodynamics for improving risk stratification and guiding management.

How stimulus properties are processed in the human brain over time is critical to how we engage in dynamic everyday environments. To understand how changes in basic stimulus properties relate to changes in human electrical brain activity over time, previous work has estimated the brain's temporal response function (TRF) by cross-correlating random luminance sequences with electroencephalogram (EEG) signals at various lags to approximate the brain's response to temporal changes in luminance. Using this technique, it was found that luminance changes produce long-lasting "echoes" in the alpha frequency range. However, the neural origin of these echoes and the precise stimulus features that induce them have not been extensively studied. We measured TRFs in response to luminance and contrast changes. Additionally, the fact that EEG responses generated in the primary visual cortex (V1) have a unique pattern of polarity reversal depending on the visual field location (with upper stimuli projecting negatively and lower projecting positively) allowed us to test whether the TRFs generated from upper or lower visual field stimulation were counter-phased, as would be expected if the echoes were generated within V1. We found a luminance echo lasting ∼1 s in the alpha frequency and contrast echoes lasting only around 300 ms. For both stimuli, the TRF was initially counter-phased between upper and lower visual fields but quickly became in phase after ∼100 ms. Our findings demonstrate the existence of contrast (in addition to luminance) echoes in the alpha band, which appear to emerge from V1, perhaps as a traveling wave.

PURPOSE: To evaluate the 1-year progression of retinal capillary nonperfusion in eyes with mild to severe nonproliferative diabetic retinopathy (NPDR) using noninvasive retinal imaging.

METHODS: The CHART study (Clinicaltrials.gov: NCT04636307) is a multicenter, observational, longitudinal study involving five European research centers and included 202 eyes from 155 participants with type 2 diabetes and mild to severe NPDR. Participants underwent comprehensive ophthalmologic examinations at baseline and 3, 6, and 12 months, including best-corrected visual acuity, color fundus photography (Early Treatment Diabetic Retinopathy Study [ETDRS] severity scale), optical coherence tomography (OCT), and OCT angiography (OCTA). Disease progression was evaluated using mixed-effects models.

RESULTS: Of the 202 eyes, 81 eyes were graded as ETDRS level 35, 63 eyes as level 43, 46 eyes as level 47, and 12 eyes as level 53. At baseline, significant differences were observed in OCTA metrics between diabetic retinopathy severity groups. A total of 169 eyes (84%) completed the 1-year follow-up. Over 1 year, eyes with ETDRS levels 35 and 43 showed significant increases in capillary nonperfusion, identified by decreases in skeletonized vessel density in the superficial capillary plexus (rates of progression: β = -0.217 mm-1/y, P = 0.006 and β = -0.310 mm-1/y, P = 0.002, respectively). Eyes with level 47 showed only a borderline statistically significant decrease (P = 0.074), while eyes with level 53 remained stable. Microaneurysm turnover (MAT), formation, and disappearance rates increased in more severe NPDR stages (levels 47 and 53).

CONCLUSIONS: Retinal capillary nonperfusion progresses significantly over 1 year in mild to moderate NPDR, identified by changes in rates of progression of vessel and perfusion densities. In more severe stages (levels 47 and 53), capillary nonperfusion stabilizes, and a hyperperfusion response is identified by increases in MAT associated with the development of intraretinal microvascular abnormalities.

TRANSLATIONAL RELEVANCE: This study provides quantitative data on 1-year progression of retinal capillary nonperfusion in NPDR using noninvasive imaging, offering the basis for future interventional trials.

For goal-directed movements like throwing darts or shooting a soccer penalty, the optimal location to aim depends on the endpoint variability of an individual. Currently, there is no consensus on whether people can optimize their movement planning based on information about their motor variability. Here, we tested the role of different types of feedback for movement planning under risk. We measured saccades toward a bar that consisted of a reward and a penalty region. Participants either received error-based feedback about their endpoint or reinforcement feedback about the resulting reward. We additionally manipulated the feedback schedule to assess the role of feedback frequency and whether feedback focusses on individual trials or a group of trials. Participants with trial-by-trial reinforcement feedback performed best. They were less loss-aversive, had the least endpoint deviation from optimality, and showed more consistent performance at the group level. This combination of reduced between-participant variability and the improved alignment with optimality suggests that reinforcement feedback about a single movement is particularly effective to optimize movement planning under risk.

PURPOSE: This study aimed to investigate whether 40-Hz light flicker could modulate the expression of major histocompatibility complex class II (MHC-II) and enhance the clearance of amyloid-β (Aβ) deposition.

METHODS: We examined retinal MHC-II expression via RNA sequencing, immunofluorescence, and western blotting in mice 8 weeks, 9 months, and 18 to 20 months old. Retinal metabolic waste accumulation was induced by intravitreal and subretinal injections of Aβ oligomers. The impact of 40-Hz flicker on MHC-II expression, microglial activation, and retinal function was evaluated using immunofluorescence, western blotting, dot immunobinding assay, electroretinography, and optokinetic reflex (OKR) testing. Minocycline was used to inhibit microglial activity.

RESULTS: The 40-Hz light flicker upregulated MHC-II expression in the retinas of aged mice. MHC-II⁺ microglia accumulated along retinal veins and exhibited increased numbers and enlarged morphology in the subretinal space. Following intravitreal or subretinal Aβ injection, 40-Hz flicker enhanced microglial activation, further upregulated MHC-II expression, promoted Aβ clearance, and improved electroretinogram responses and OKR performance. These effects were abolished by minocycline treatment.

CONCLUSIONS: We observed that 40-Hz light flicker enhances retinal microglial clearance of Aβ oligomers by upregulating MHC-II expression. These findings support 40-Hz light flicker as a non-invasive therapeutic strategy for age-related retinal disorders by promoting metabolic waste clearance.

PURPOSE: Early lesions caused by age-related macular degeneration (AMD) are imaged by optical coherence tomography (OCT) in unprecedented detail. Most probably, however, the sampling plane of an OCT scan meets a given lesion noncentrally, and the observed sizes of its diameter, cross-sectional area, and volume must be stereologically corrected.

METHODS: Stereological corrections are obtained by a simulation procedure, which is applied to the leading scans in a consecutive sample of 100 early AMD participants.

RESULTS: Mean corrections for lesion diameter, cross-sectional area and volume amount to +9.1%, +32.0%, and +46.6%, respectively. After correction, AMD stage classifications with respect to the 125-µm diameter cutpoint had to be changed for seven participants.

CONCLUSIONS: Simulation results confirm that for lesions pictured and measured in OCT scans - regardless of the accuracy of OCT imaging - stereological correction of observed sizes is compelling and unavoidable.

TRANSLATIONAL RELEVANCE: Categorial AMD classifications based on observed OCT data must be reexaminated after stereological correction.

Los síntomas mixtos, que combinan elementos maníacos e hipomaníacos con características depresivas, constituyen una dimensión central y frecuente de los trastornos del ánimo. Desde las primeras descripciones de Kraepelin y Weygandt hasta las formulaciones actuales, las definiciones diagnósticas han oscilado entre criterios muy restrictivos y aproximaciones dimensionales más amplias. La introducción del especificador "con síntomas mixtos" en el DSM-5 representó un avance, aunque persisten limitaciones notables, como la exclusión de síntomas solapados (irritabilidad, distracción, agitación psicomotora). Revisiones sistemáticas recientes estiman que la prevalencia de características mixtas alcanza al 18 % de los episodios depresivos mayores, al 33 % de los episodios depresivos bipolares y al 35 % de los episodios maníacos o hipomaníacos. Estos cuadros se asocian con mayor riesgo suicida, evolución más grave y menor respuesta terapéutica. En los últimos años, la evidencia farmacológica más robusta proviene de ensayos con antipsicóticos de segunda generación, destacándose lumateperona, lurasidona, ziprasidona, cariprazina y olanzapina/fluoxetina. En contraste, litio, valproato y lamotrigina carecen de estudios específicos en episodios depresivos con características mixtas, y la monoterapia antidepresiva sigue sin respaldo suficiente. Esta revisión integra los antecedentes históricos, los hallazgos epidemiológicos y la evidencia terapéutica más reciente, subrayando la necesidad de consensos diagnósticos más sensibles y de ensayos controlados a largo plazo que orienten la práctica clínica.