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AbstractThe functional equivalence model suggests a common internal representation initiates both imagery and execution. This suggestion is supported by the mental chronometry effect, where there is a positive relation between task difficulty (as defined by the Index of Difficulty; ID) and imagined movement time. The present study extends this logic by examining whether imagery captures the spatial trajectory. Participants were initially tasked with the imagery and execution of a rapid aiming movement under different IDs. These initial attempts were adapted to configure auditory tones at early (25%) and late (75%) intervals for a separate set of imagery trials. If a tone had sounded, participants had to estimate post-trial where their imagined limb would have been located. The findings revealed increases in ID that coincided with increases in imagined and executed movement times. However, participant mean and standard deviation of estimated locations revealed limited differences between the early and late tones. Further inspection revealed some evidence for these estimated locations shifting further along in space following more rapid imagined movements. While equivalence is clearly evident within the temporal domain, there is comparatively little to suggest that this logic extends to the resolution required for simulating the spatial characteristics of movement. [ABSTRACT FROM AUTHOR]

Background: DICER1 mutations, though infrequent, are encountered on preoperative molecular testing of indeterminate adult and pediatric thyroid fine‐needle aspiration (FNA) specimens. Yet, published cytomorphologic features of DICER1‐altered thyroid lesions are limited. Cytomorphological features of DICER1‐altered thyroid lesions were examined in a multipractice FNA cohort with clinical, radiological, and histologic data. Methods: The cohort comprised 18 DICER1‐altered thyroid FNAs, with 14 having slides available and eight having corresponding surgical resections. Smears, ThinPrep, and formalin‐fixed cell block slides were reviewed and correlated with histology, when available. Clinical and radiologic data were obtained from the medical record. Results: Most DICER1‐altered FNAs were classified as atypia of undetermined significance (94.4%). DICER1 mutations occurred in codons 1709 (50%), 1810 (27.8%), and 1813 (22.2%). One patient had an additional DICER1 p.D1822N variant in both of their FNAs. Lesions were often hypoechoic (35.3%) and solid (47.1%) on ultrasound. Notable cytomorphologic features include mixed but prominent microfollicular or crowded component, variable colloid, and insignificant nuclear atypia. On resection (n = 10), histologic diagnoses ranged from benign follicular adenoma and low‐risk follicular thyroid carcinoma to high‐grade follicular–derived nonanaplastic thyroid carcinoma. Subcapsular infarct‐type change was the most common histologic change. There was no evidence of recurrence or metastasis in eight patients on limited follow‐up. Conclusion: DICER1‐altered thyroid lesions occurred frequently in young females and FNAs show RAS‐like cytomorphology including crowded, mixed macro‐/microfollicular pattern, and bland nuclear features. On resection, DICER1‐altered thyroid lesions include benign (50%), low‐risk lesions (30%), or high‐risk malignancies (20%). A comprehensive multipractice cytologic‐histologic‐molecular correlation of a DICER1‐altered thyroid lesion cohort, comprising one of the largest to date. [ABSTRACT FROM AUTHOR]