Potential Impact of a Pass or Fail United States Medical Licensing Exam Step 1 Scoring System on Radiology Residency Applications.

RATIONALE AND OBJECTIVES: To assess the anticipated impact of the change in United States Medical Licensing Examination Step 1 scoring from numerical to pass or fail on the future selection of radiology residents. MATERIALS AND METHODS: An anonymous electronic 14-item survey was distributed to 308 members of the Association of Program Directors in Radiology and included questions regarding the anticipated importance of various application metrics when Step 1 becomes pass or fail. Secondary analyses compared responses based on the current use of a Step 1 scoring screen. RESULTS: Eighty eight respondents (28.6% [88/308]) completed the survey. Most (64% [56/88]) noted that the United States Medical Licensing Examination Step 2 Clinical Knowledge (CK) score will likely be one of the top three most important factors in assessing applicants, followed by class ranking or quartile (51% [45/88]) and the Medical Student Performance Evaluation/Dean's Letter (42% [37/88]). Over 90% (82/88) of respondents anticipate potentially or definitively requiring Step 2 CK scores before application review, and 50% (44/88) of respondents anticipate extending interview invites at a later date to receive Step 2 CK scores. These results did not significantly differ between programs who currently use a Step 1 scoring screen and those who do not. CONCLUSION: As Step 1 transitions from a numerical score to pass or fail, radiology residency program directors will likely rely on Step 2 CK scores as an objective and standardized metric to screen applicants. Further investigation is needed to identify other objective metrics to evaluate applicants before Step 1 becomes pass or fail.

Sickle Cell Trait and Risk of Ischemic Stroke in Young Adults.

BACKGROUND AND PURPOSE: Approximately 8% of Blacks have sickle cell trait (SCT), and there are conflicting reports from recent cohort studies on the association of SCT with ischemic stroke (IS). Most prior studies focused on older populations, with few data available in young adults. METHODS: A population-based case-control study of early-onset IS was conducted in the Baltimore-Washington region between 1992 and 2007. From this study, 342 Black IS cases, ages 15 to 49, and 333 controls without IS were used to examine the association between SCT and IS. Each participant's SCT status was established by genotyping and imputation. For analysis, χ2 tests and logistic regression models were performed with adjustment for potential confounding variables. RESULTS: Participants with SCT (n=55) did not differ from those without SCT (n=620) in prevalence of hypertension, previous myocardial infarction, diabetes mellitus, and current smoking status. Stroke cases had increased prevalence in these risk factors compared with controls. We did not find an association between SCT and early-onset IS in our overall population (odds ratio=0.9 [95% CI, 0.5-1.7]) or stratified by sex in males (odds ratio=1.26 [95% CI, 0.56-2.80]) and females (odds ratio=0.67 [95% CI, 0.28-1.69]). CONCLUSIONS: Our data did not find evidence of increased risk of early-onset stroke with SCT.

High-beta/low-gamma frequency activity reflects top-down predictive coding during a spatial working memory test.

Numerous mental health disorders are characterized by cognitive impairments that result in poor vocational and social outcomes. Among the cognitive domains commonly affected, working memory deficits have been noted in patients with attention-deficit/hyperactivity disorder (Martinussen et al. in J Am Acad Child Adolesc Psychiatry 44:377-384, 2005), post-traumatic stress disorder (Honzel et al. in Cogn Affect Behav Neurosci 14:792-804, 2014), and consistently with schizophrenia patients (Callicott et al. in Cereb Cortex 10:1078-1092, 2000; Lewis et al. in Front Hum Neurosci 10:85, 2005; Amann et al. in Brain Res Bull 83:147-161, 2010; Limongi et al. in Schizophr Res 197:386-391, 2018). Oscillations in neural activity from electroencephalogram (EEG) recordings are decomposed by frequency, and band-specific decreases in gamma power (> 30 Hz) have been correlated with working memory ability. This study examined within-subject changes in power of frequency-specific bands during sample versus choice trials during a spatial working memory paradigm (T-maze). EEG was recorded using a relatively novel wireless EEG telemetry system fully implanted within the mouse, enabling uninhibited movement during behavioral tasks. No significant differences were found between sample and correct choice phases in the alpha, theta or gamma frequency ranges. Evoked power was significantly higher during the choice phase than the sample phase in the high-beta/low-gamma frequency range. This frequency range has been implicated in the propagation of cortical predictions to lower levels of stimuli encoding in a top-down hierarchical manner. Results suggest there is an increase in brain activity during correct trials when the mouse enters the opposite arm during the choice phase compared to the sample phase, likely due to prediction error resulting from a discrepancy between present and prior experience. Future studies should identify specific cortical networks involved and investigate neural activity at the neuronal level.

Pyramidal cell-selective GluN1 knockout causes impairments in salience attribution and related EEG activity.

Schizophrenia is a disabling psychiatric disease characterized by symptoms including hallucinations, delusions, social withdrawal, loss of pleasure, and inappropriate affect. Although schizophrenia is marked by dysfunction in dopaminergic and glutamatergic signaling, it is not presently clear how these dysfunctions give rise to symptoms. The aberrant salience hypothesis of schizophrenia argues that abnormal attribution of motivational salience to stimuli is one of the main contributors to both positive and negative symptoms of schizophrenia. The proposed mechanisms for this hypothesis are overactive striatal dopaminergic and hypoactive glutamatergic signaling. The current study assessed salience attribution in mice (n = 72) using an oddball paradigm in which an infrequent stimulus either co-occurred with shock (conditioned group) or was presented alone (non-conditioned group). Behavioral response (freezing) and electroencephalogram (whole brain and amygdala) were used to assess salience attribution. Mice with pyramidal cell-selective knockout of ionotropic glutamate receptors (GluN1) were used to reproduce a prominent physiological change involved in schizophrenia. Non-conditioned knockout mice froze significantly more in response to the unpaired stimulus than non-conditioned wild-type mice, suggesting that this irrelevant cue acquired motivational salience for the knockouts. In accordance with this finding, low-frequency event-related spectral perturbation was significantly increased in non-conditioned knockout mice relative to both conditioned knockout and non-conditioned wild-type mice. These results suggest that pyramidal cell-selective GluN1 knockout leads to inappropriate attribution of salience for irrelevant stimuli as characterized by abnormalities in both behavior and brain circuitry functions.