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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]

Contemporary models of sensorimotor control contend that visually regulated movement adjustments may unfold early during a target-directed limb movement through an impulse control process that makes use of anticipatory forward models. To date, evidence surrounding impulse control has involved adjustments to a purported misperception in limb velocity following the unexpected onset of a moving background. That is, the limb is perceived to move faster and undershoots more when there is an incongruent moving background and vice versa. However, this particular behavior may manifest from an independent oculo-manual-following response. The present study aimed to deconstruct these proposals and, with them, the processes that underlie impulse control. Participants had to rapidly reach upward to land their index finger accurately on a target. On 33% of trials, the background, over which the movement was made, moved either up, down, right, or left. Displacements in the primary and perpendicular directions of movement showed spatial trajectories that were consistent with the directions of the moving backgrounds. This behavior was most prevalent in measurements taken at the movements' peak negative acceleration and endpoints. Moreover, analysis of standardized displacements in the moving background conditions indicated no significant differences in the extent of the movements toward each of the moving backgrounds. These findings indicate that movement adjustments can manifest from an oculo-manual-following response rather than a misperception of limb velocity. We suggest that the anticipatory forward model that comprises impulse control may incorporate features of the environment that surround the vicinity of the limb. KEYWORDS: aiming, impulse control, retinal motion, oculo-manual, visuomotor, One role of the visuomotor system is to facilitate control of timely and accurate upper limb movements. Given that the need to move our hands quickly and accurately to specific [...]

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]

The failure of perceptual illusions to elicit corresponding biases within movement supports the view of two visual pathways separately contributing to perception and action. However, several alternative findings may contest this overarching framework. The present study aimed to examine the influence of perceptual illusions within the planning and control of aiming. To achieve this, we manipulated and measured the planning/control phases by respectively perturbing the target illusion (relative size-contrast illusion; Ebbinghaus/Titchener circles) following movement onset and detecting the spatiotemporal characteristics of the movement trajectory. The perceptual bias that was indicated by the perceived target size estimates failed to correspondingly manifest within the effective target size. While movement time (specifically, time after peak velocity) was affected by the target configuration, this outcome was not consistent with the direction of the perceptual illusions. These findings advocate an influence of the surrounding contextual information (e.g., annuli) on movement control that is independent of the direction predicted by the illusion. [ABSTRACT FROM AUTHOR]