Art and the science of generative AI.

Understanding shifts in creative work will help guide AI's impact on the media ecosystem.

Larger visual changes compress time: The inverted effect of asemantic visual features on interval time perception.

Time perception is fluid and affected by manipulations to visual inputs. Previous literature shows that changes to low-level visual properties alter time judgments at the millisecond-level. At longer intervals, in the span of seconds and minutes, high-level cognitive effects (e.g., emotions, memories) elicited by visual inputs affect time perception, but these effects are confounded with semantic information in these inputs, and are therefore challenging to measure and control. In this work, we investigate the effect of asemantic visual properties (pure visual features devoid of emotional or semantic value) on interval time perception. Our experiments were conducted with binary and production tasks in both conventional and head-mounted displays, testing the effects of four different visual features (spatial luminance contrast, temporal frequency, field of view, and visual complexity). Our results reveal a consistent pattern: larger visual changes all shorten perceived time in intervals of up to 3min, remarkably contrary to their effect on millisecond-level perception. Our findings may help alter participants' time perception, which can have broad real-world implications.

Build Your Own Equiluminance Helmet.

A wearable 'helmet' version of the S cone isolating technique was constructed to explore vision at equiluminance. For my high school summer science project, I visited parks and streets while wearing the helmet and report that the helmet appears to have captured the main properties described for the large-scale, more cumbersome stage version.

[Increased sensitivity in bipolar disorder detection with the MDQ and BSDS using Ghaemi-Goodwin's criteria for the bipolar spectrum]. / Aumento de la sensibilidad en la detección de trastornos bipolares combinando el MDQ y/o el BSDS con los criterios de espectro bipolar de Ghaemi-Goodwin.

INTRODUCTION: Many patients with bipolar disorder (BD) spend around 10 years without a diagnosis and appropriate treatment. The difficulty in distinguishing bipolar from unipolar depression, the prevalence of depressive symptoms along the course of BD and patients' bias in recalling their hypomanic symptoms are some of the factors that contribute to this problem. OBJECTIVE: This study compares the efficiency of several screening instruments for BD detection in a group of patients (n=63) with mood disorders, or cluster B personality disorders. METHOD: The diagnoses were made with structured interviews: Mini International Neuropsychiatric Interview (MINI) and Structured Clinical Diagnostic Interview for axis II (SCID-II). The patients completed the Mood Disorder Questionnaire (MDQ) and Bipolar Spectrum Disorder Scale (BSDS) and were assessed with the Bipolar Index-BI and Ghaemi-Goodwin Bipolar Spectrum Criteria. Sensitivity, specifcity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were estimated for each instrument, along with Chi2 and T-tests. Statistical analyses were conducted using the SPSS-v16. RESULTS: The BI had the best global performance with 88% specificity and 0.90 of sensitivity. The MDQ-H had the highest specificity and the MDQ-6 the highest sensitivity. However, when combining the MDQ with Ghaemi's criteria, an ostensible augment was obtained in sensitivity while maintaining good predictive values. CONCLUSIONS: The joint assessment of mania symptoms and typical evolving course symptoms in BD increased the probability of BD detection in this clinical sample.

Comorbidity between bipolar disorder and cluster B personality disorders as indicator of affective dysregulation and clinical severity.

INTRODUCTION: Several lines of evidence have well established a relationship between Bipolar Disorder and Cluster B Personality Disorders. The study compares mood spectrum and temperamental symptoms, personality traits and clinical characteristics among outpatients (n = 63) diagnosed with major depression (MD), bipolar disorder (BD), cluster B personality disorders (PD-B) and comorbidity of BD + PD-B. METHOD: The diagnosis was determined with structured interviews (MINI and SCID II) and symptom assessments with evaluation and diagnostic instruments (MOODS-SR, BI, TEMPS-A and IPDE). Differences between groups were explored with post hoc analysis and analysis of variance. RESULTS: Patients with BD+PD-B comorbidity presented an earlier onset and more severity in suicide attempts, hospitalizations and self-harm behaviors. They showed more characteristics of cyclothymic and irritable temperament and more cluster A and B personality traits, than patients with BD only. PD-B patients obtained intermediate scores in manic like symptoms: higher than patients with depression and lower than patients with bipolar disorder. However, the Bipolarity Index clearly distinguished patients with BD or with comorbidity (BD+PD-B) from the other diagnostic groups (PD-B and MD). CONCLUSIONS: BD+PD-B comorbidity presents a more severe type of emotional dysregulation compared to the other diagnostic groups, including BD and PD-B alone. Assessing temperament, personality traits, emotional dysregulation in mania and depression, self-harm and hospitalizations severity and age onset could facilitate differential diagnosis and enhance effectiveness of treatments for BD, PD-B and their comorbidity.

La comorbilidad del trastorno bipolar con trastornos de la personalidad tipo B como indicador de severidad clínica y desregulación afectiva / Comorbidity between bipolar disorder and cluster B personality disorders as indicator of affective dysregulation and clinical severity

Introducción: Varias líneas de evidencia han establecido una relación entre el Trastorno Bipolar y los Trastornos de la Personalidad del grupo B. El estudio compara los síntomas del espectro del ánimo, temperamentales, de personalidad y características clínicas entre pacientes ambulatorios (n=63) diagnosticados con Depresión Mayor (DM), Trastorno Bipolar (TB), Trastornos de la Personalidad del grupo B (TP-B) o comorbilidad de TB+TP-B. Metodología: El diagnóstico se realizó con entrevistas estructuradas (MINI y SCID II), las evaluaciones con instrumentos de evaluación y diagnóstico (MOODS-SR, BI, TEMPSA y IPDE). Se analizaron diferencias entre grupos con análisis de varianza y análisis post hoc. Resultados: Los pacientes con comorbilidad TB+TP-B presentaron una aparición más temprana y mayor severidad en síntomas, intentos de suicidio, internaciones y autolesiones. Mostraron más características de temperamento ciclotímico e irritable y más rasgos de la personalidad del grupo Ay B que los pacientes con TB únicamente. Los pacientes TP-B obtuvieron puntajes intermedios en síntomas maníacos: mayor que pacientes con depresión y menor que pacientes con trastorno bipolar. Sin embargo, el Índice de Bipolaridad claramente distinguió a pacientes con TB solamente o comorbilidad (TB+TP-B) de los otros grupos de diagnóstico (TP-B y DM).Conclusiones: La comorbilidad TB+TP-B presenta un tipo de desregulación emocional más severa que los demás grupos, incluyendo al TB y el TP-B por sí solos. Evaluar el temperamento afectivo, rasgos de personalidad, desregulación emocional en la manía y depresión, gravedad de autolesiones, internaciones y edad de inicio, facilitaría el diagnóstico diferencial y la eficacia de tratamientos para TB,TP-B y comorbilidad (AU)

Introduction: Several lines of evidence have well established a relationship between Bipolar Disorder and Cluster B Personality Disorders. The study compares mood spectrum and temperamental symptoms, personality traits and clinical characteristics among outpatients (n = 63) diagnosed with major depression (MD), bipolar disorder (BD), cluster B personality disorders (PD-B) and comorbidity of BD+ PD-B. Method: The diagnosis was determined with structured interviews (MINI and SCID II) and symptom assessments with evaluation and diagnostic instruments (MOODS-SR, BI, TEMPS-A and IPDE). Differences between groups were explored with post hoc analysis and analysis of variance. Results: Patients with BD+PD-B comorbidity presented an earlier onset and more severity in suicide attempts, hospitalizations and self-harm behaviors. They showed more characteristics of cyclothymic and irritable temperament and more cluster A and B personality traits, than patients with BD only. PD-B patients obtained intermediate scores in manic like symptoms: higher than patients with depression and lower than patients with bipolar disorder. However, the Bipolarity Index clearly distinguished patients with BD or with comorbidity (BD+PD-B) from the other diagnostic groups (PD-B and MD).Conclusions: BD+PD-B comorbidity presents a more severe type of emotional dysregulation compared to the other diagnostic groups, including BD and PD-B alone. Assessing temperament, personality traits, emotional dysregulation in mania and depression, self-harm and hospitalizations severity and age onset could facilitate differential diagnosis and enhance effectiveness of treatments for BD, PD-B and their comorbidity (AU)

Memantine reduces mania-like symptoms in animal models.

Memantine, a selective antagonist of the N-methyl-D-aspartate receptor, is approved for the treatment of moderate to severe Alzheimer's disease. Ion dysregulation is thought to be involved in the pathophysiology of bipolar illness, suggesting that memantine may be effective in treating bipolar manic and/or depressive episodes. We utilized two preclinical models of mania that mimic pathophysiologic changes seen in bipolar illness to examine the potential efficacy of memantine in the treatment of this disorder. Locomotor hyperactivity of male Sprague-Dawley rats in an open field was induced with intracerebroventricular (ICV) administration of 10(-3) M ouabain. Memantine (2.5, 5 or 7.5mg/kg), lithium (6.75 mEq/kg), or vehicle were administered acutely via intraperitoneal injection immediately prior to ouabain, then chronically for 7 days (oral memantine 20, 30, and 40 mg/kg/day in water; lithium 2.4 g/kg food). In a second model of bipolar disorder, cycling between population spikes and epileptiform bursts was investigated in rat hippocampal slices treated with ouabain (3.3 µM) alone or in combination with memantine (0.5, 1.0, and 5.0 µM). Ouabain-induced hyperlocomotion was normalized with acute and chronic lithium and chronic use of memantine. Memantine delayed the onset of ouabain-induced-cycling in hippocampal slices. Memantine may have antimanic properties.

Positron emission tomography with fluorodeoxyglucose-F18 in an animal model of mania.

Intracerebroventricular (ICV) administration of ouabain to young adult rats has been suggested to model human bipolar mania. In the human condition, mania and bipolar depression are both associated with reductions in frontal cerebral metabolism. We utilized [(18)F]-fluorodeoxyglucose [(18)FDG] positron emission tomography (PET) to visualize glucose uptake in animals receiving ICV ouabain. Animals received 5 microl of 10(-)(3) M ouabain ICV, were anesthetized with isoflurane inhalation, and administered intraperitoneally with 0.5 mCi of (18)FDG. PET data were collected over 20 min 1 hour later. Additionally, the effect of lithium was examined in animals receiving lithium in their diet for 1 week before the ICV ouabain injection. Data were analyzed with IDL Virtual Machine software. Brain glucose utilization as measured by (18)FDG uptake was significantly reduced in animals receiving ICV ouabain compared with those receiving equal volumes of artificial cerebrospinal fluid. Pretreatment with lithium normalized (18)FDG uptake. These results mirror human studies.

Mimicking human bipolar ion dysregulation models mania in rats.

Psychiatric diseases in general, and bipolar illness in particular, are difficult to model in animals since the subjective nature of the core symptoms appears to preclude objective observation of behavioral changes. An adequate animal model of a psychiatric condition must fulfill three core criteria: share pathophysiological characteristics of the human condition (face validity), have similar behavioral manifestations as the human disease (construct validity), and improve with medications that improve the symptoms seen in afflicted humans (predictive validity). The ouabain model for bipolar illness mimics a widely reproduced biologic abnormality in mania: reduced sodium pump activity. An intracerebroventricular (ICV) administration of 5microL 10(-3)M ouabain induces motoric hyperactivity preventable by lithium, carbamazepine, and haloperidol. ICV ouabain may also produce environmentally dependent hypoactivity. The model, however, has not yet been examined for other potential manic behavior in rats such as reduced need for sleep, increased sexual activity, or increased irritability. While additional characterization of the model is required, the ouabain model for bipolar illness is the only available animal model that fulfills the three criteria for an adequate animal model for bipolar illness.