Target Bar Research Articles

Visual feedback and motor memory contributions to sustained motor control deficits in autism spectrum disorder across childhood and into adulthood.

Background Autistic individuals show deficits in sustained fine motor control which are associated with an over-reliance on visual feedback. Motor memory deficits also have been reported during sustained fine motor control in autism spectrum disorders (ASD). The development of motor memory and visuomotor feedback processes contributing to sustained motor control issues in ASD are not known. The present study aimed to characterize age-related changes in visual feedback and motor memory processes contributing to sustained fine motor control issues in ASD. Methods Fifty-four autistic participants and 31 neurotypical (NT) controls ages 10-25 years completed visually guided and memory guided sustained precision gripping tests by pressing on force sensors with their dominant hand index finger and thumb. For visually guided trials, participants viewed a stationary target bar and a force bar that moved upwards with increased force for 15s. During memory guided trials, the force bar was visible for 3s, after which participants attempted to maintain their force output without visual feedback for another 12s. To assess visual feedback processing, force accuracy, variability (standard deviation), and regularity (sample entropy) were examined. To assess motor memory, force decay latency, slope, and magnitude were examined during epochs without visual feedback. Results Relative to NT controls, autistic individuals showed a greater magnitude and steeper slope of force decay during memory guided trials. Across conditions, the ASD group showed reduced force accuracy (β = .41, R 2 = 0.043, t 79.3 =2.36, p = 0.021) and greater force variability (β=-2.16, R 2 = .143, t 77.1 =-4.04, p = 0.0001) and regularity (β=-.52, R 2 = .021, t 77.4 =-2.21, p = 0.030) relative to controls at younger ages, but these differences normalized by adolescence (age x group interactions). Lower force accuracy and greater force variability during visually guided trials and steeper decay slope during memory guided trials were associated with overall autism severity. Conclusions Our findings that autistic individuals show a greater rate and magnitude of force decay than NT individuals following the removal of visual feedback indicate that motor memory deficits contribute to fine motor control issues in ASD. Findings that sensorimotor differences in ASD were specific to younger ages suggest delayed development across multiple motor control processes.

Feature variability determines specificity and transfer in multiorientation feature detection learning.

Historically, in many perceptual learning experiments, only a single stimulus is practiced, and learning is often specific to the trained feature. Our prior work has demonstrated that multi-stimulus learning (e.g., training-plus-exposure procedure) has the potential to achieve generalization. Here, we investigated two important characteristics of multi-stimulus learning, namely, roving and feature variability, and their impacts on multi-stimulus learning and generalization. We adopted a feature detection task in which an oddly oriented target bar differed by 16° from the background bars. The stimulus onset asynchrony threshold between the target and the mask was measured with a staircase procedure. Observers were trained with four target orientation search stimuli, either with a 5° deviation (30°-35°-40°-45°) or with a 45° deviation (30°-75°-120°-165°), and the four reference stimuli were presented in a roving manner. The transfer of learning to the swapped target-background orientations was evaluated after training. We found that multi-stimulus training with a 5° deviation resulted in significant learning improvement, but learning failed to transfer to the swapped target-background orientations. In contrast, training with a 45° deviation slowed learning but produced a significant generalization to swapped orientations. Furthermore, a modified training-plus-exposure procedure, in which observers were trained with four orientation search stimuli with a 5° deviation and simultaneously passively exposed to orientations with high feature variability (45° deviation), led to significant orientation learning generalization. Learning transfer also occurred when the four orientation search stimuli with a 5° deviation were presented in separate blocks. These results help us to specify the condition under which multistimuli learning produces generalization, which holds potential for real-world applications of perceptual learning, such as vision rehabilitation and expert training.

Attentional guidance from unique faster/slower discrete and smooth feature changes in visual search

ABSTRACT Two studies examine the circumstances in which singletons, defined by unique feature-change rate, guide attention in visual search. Participants searched for a static vertical/horizontal white target bar amidst tilted distractors. Bars were contained inside surround shapes with periodically oscillating features. In Experiment 1, displays consisted of surrounds with abrupt (discrete) or continuous (smooth) changes between two values (red–blue, square–diamond). For discrete displays, target surrounds did not guide attention when uniquely faster-oscillating than distractor surrounds, but did in smooth displays. For unique-slow oscillating target surrounds, the opposite guidance pattern was found across discrete and smooth displays. In Experiment 2, displays had a mixture of discrete and smooth surrounds. Here, only unique slow-oscillating discrete surrounds guided attention. No guidance was found for smooth surrounds. Findings suggest that faster oscillations are masked by higher-frequency harmonic signals from slower changing discrete items, and there is attentional prioritization of discrete over smooth changes.

Normative Value of Accommodative Convergence to Accommodation in Indian Population Measured by Heterophoria Method

Abstract Introduction: Near response is a complex synkinesis required for a good binocular vision. accommodative convergence per diopter of accommodation (AC/A ratio) is a value of significance in this synkinetic movement. In addition, the value is used to classify and treat ocular movement abnormalities. The two commonly used methods for determining the AC/A ratio are Gradient Method and Heterophoria method. The normative data for Indian population by gradient method was described in two studies. However, the normative data for heterophoria method is lacking in Indian population. Objective: The purpose of this cross-sectional study is to generate the normative value for AC/A ratio for the Indian population by heterophoria method. One hundred healthy ophthalmologically normal adults with no presbyopia or refractive error were chosen consecutively among the attendants of patients visiting the center. Materials and Methods: After thorough ophthalmic evaluation, the participants were subjected to AC/A ratio calculation by heterophoria method using 6/9 fixation target and PMMA Prism bar. Results: One hundred healthy adults with no refractive error or ocular abnormality were selected with a mean age of 25.70 years (standard deviation [SD] = 4.92) and equal gender distribution. The mean Inter Pupillary Distance (IPD) was found to be 62.88 mm with a SD of 3.91 mm. The average phoria at distance was 1.82 prism diopters (SD = 2.03pd) of exophoria and for near at 33 cm was 4.20pd (SD = 1.92pd). The mean AC/A ratio by heterophoria method was found to be 5.49PD/D with an SD of 0.54PD/D. The highest being 6.90PD/D and the lowest being 4.27PD/D with no statistically significant difference between genders. Conclusion and Relevance: According to the previous studies, the normative data arrived is lesser than the value reached in the current study for similar population groups when considering both methodologies of testing. This variation between the gradient method and heterophoria method accounted for by the involvement of proximal convergence during the heterophoria method.

Development of methods for regeneration and genetic transformation of the commercial plum variety Startovaya from somatic tissues

An effi cient technique for regeneration of plants from somatic tissues of domestic plum (Prunus domestica L.) varieties, as well as selecting schemes using various reporter (uidA, gfp) and selective marker genes (nptII, hpt) have been developed. During the transformation of somatic tissues of the commercial plum variety, transgenic plants containing both reporter genes and genes of economically valuable traits were obtained. For the fi rst time, the eff ect of calcium pantothenate on the adventive regeneration of plum shoots was investigated. It was shown that the selective antibiotic hygromycin is more eff ective for the selection of plum transformants than kanamycin or geneticin, which was expressed in a higher frequency of transformation — 1.2-2.2 % versus 0.2-0.5 % in selection on kanamycin. When using geneticin, transgenic plants were not obtained. Optimization of conditions made it possible to increase the percentage of regeneration of shoots to 79.4 % for the variety Startovaya and up to 39.6 % for the variety Etude. Analysis of GFP expression in transgenic lines showed that the leader sequences of herbaceous plant species encoding signal peptides can be used to eff ectively cellular compartmentalization of heterologous gene expression products in the plum. Preliminary results also show a higher level of expression of the reticular form of GFP in comparison with the vacuolar and cytosolic forms. Nine transgenic lines containing the insertion of the target bar gene, which gives resistance to phosphinothricin-containing herbicides of the “Basta” type, were obtained, which was confi rmed by the presence in the genome of the sequence of the transferred gene and the resistance of the obtained transgenic plants to 3 times the fi eld concentration of the herbicide “Basta”.

On the relation between crowding and ensemble perception: Examining the role of attention.

Ensemble perception of a crowd of stimuli is very accurate, even when individual stimuli are invisible due to crowding. The ability of high-precision ensemble perception can be an evolved compensatory mechanism for the limited attentional resolution caused by crowding. Thus the relationship of crowding and ensemble coding is like two sides of the same coin wherein attention may play a critical factor for their coexistence. The present study investigated whether crowding and ensemble coding were similarly modulated by attention, which can promote our understanding of their relation. Experiment 1 showed that diverting attention away from the target harmed the performance in both crowding and ensemble perception tasks regardless of stimulus density, but crowding was more severely harmed. Experiment 2 showed that directing attention toward the target bar enhanced the performance of crowding regardless of stimulus density. Ensemble perception of high-density bars was also enhanced but to a lesser extent, while ensemble perception of low-density bars was harmed. Together, our results indicate that crowding is strongly modulated by attention, whereas ensemble perception is only moderately modulated by attention, which conforms to the adaptive view.

Swing control for a three-link brachiation robot based on sliding-mode control on irregularly distributed bars

Abstract. The bionic-gibbon robot is a popular bionic robot. The bionic-gibbon robot can imitate a gibbon in completing brachiation motion between branches. With nonlinear and underactuated properties, the robot has important research value. This paper designs a type of bionic-gibbon robot with three links and two grippers. To simplify the controller, a plane control model is proposed, and its dynamic model is established. The control strategy in this paper divides the brachiation motion into several processes: adjust posture, open the gripper, the swing process and close the gripper. Based on sliding-mode control (SMC), the control method for the swing process is designed. The target position of the brachiation motion is set as the origin of the sliding-mode surface. In a finite time, the robot will reach the target position along the approach rate we adopt. In this way, the robot can complete the desired brachiation motion only by setting the position parameters of the target bar. We perform some simulations in ROS-Gazebo. The simulation results show that the bionic-gibbon robot can complete continuous brachiation motion on irregularly distributed bars. The sliding-mode control and the three-link structure significantly improve the robustness and swing efficiency of the bionic-gibbon robot.

Visual and somatosensory feedback mechanisms of precision manual motor control in autism spectrum disorder

BackgroundIndividuals with autism spectrum disorder (ASD) show deficits processing sensory feedback to reactively adjust ongoing motor behaviors. Atypical reliance on visual and somatosensory feedback each have been reported during motor behaviors in ASD suggesting that impairments are not specific to one sensory domain but may instead reflect a deficit in multisensory processing, resulting in reliance on unimodal feedback. The present study tested this hypothesis by examining motor behavior across different visual and somatosensory feedback conditions during a visually guided precision grip force test.MethodsParticipants with ASD (N = 43) and age-matched typically developing (TD) controls (N = 23), ages 10–20 years, completed a test of precision gripping. They pressed on force transducers with their index finger and thumb while receiving visual feedback on a computer screen in the form of a horizontal bar that moved upwards with increased force. They were instructed to press so that the bar reached the level of a static target bar and then to hold their grip force as steadily as possible. Visual feedback was manipulated by changing the gain of the force bar. Somatosensory feedback was manipulated by applying 80 Hz tendon vibration at the wrist to disrupt the somatosensory percept. Force variability (standard deviation) and irregularity (sample entropy) were examined using multilevel linear models.ResultsWhile TD controls showed increased force variability with the tendon vibration on compared to off, individuals with ASD showed similar levels of force variability across tendon vibration conditions. Individuals with ASD showed stronger age-associated reductions in force variability relative to controls across conditions. The ASD group also showed greater age-associated increases in force irregularity relative to controls, especially at higher gain levels and when the tendon vibrator was turned on.ConclusionsOur findings that disrupting somatosensory feedback did not contribute to changes in force variability or regularity among individuals with ASD suggests a reduced ability to integrate somatosensory feedback information to guide ongoing precision manual motor behavior. We also document stronger age-associated gains in force control in ASD relative to TD suggesting delayed development of multisensory feedback control of motor behavior.

35156 Sensory mechanisms of atypical motor variability and regularity in autism spectrum disorder

ABSTRACT IMPACT: This project aims to better understand mechanisms of sensory and motor deficits in individuals with ASD with the goal of informing diagnosis and treatment development. OBJECTIVES/GOALS: Over-reliance on both visual and proprioceptive feedback have both been observed during motor behavior in persons with Autism Spectrum Disorders (ASD), suggesting that separate sensory feedback processes may be selectively altered during different behaviors. The objective of this study is to clarify sensory mechanisms of fine motor control in ASD. METHODS/STUDY POPULATION: Participants with ASD (N=43) and controls (N=23) matched on age (10-20 yrs) and non-verbal IQ completed tests of precision gripping. Participants were instructed to press on force sensors with their index finger and thumb so that a moving bar corresponding to their force output reached and stayed as stable as possible at the level of a stationary target bar. Visual feedback was manipulated by changing the visual gain of the force bar (low, medium and high). The force bar moved more per change in force output at higher gains. Proprioceptive feedback was manipulated by applying 80 Hz tendon vibration at the wrist to induce an illusion of muscle contraction. This was compared to a condition with the tendon vibrator turned off. Force variability (standard deviation) and regularity (sample entropy) were examined. RESULTS/ANTICIPATED RESULTS: Controls showed increased force variability with the tendon vibration on compared to off (t = -3.372, p < 0.001); however, the ASD group showed no difference in force variability between the tendon vibration conditions (t = -0.960, p = 0.338). Individuals with ASD had stronger age-associated reductions in force variability relative to controls across tendon vibrator and gain conditions (Group x Age: t = -4.05, p < .001). The ASD group also had greater age-associated increases in force regularity relative to controls, especially at higher gain levels (Group x Gain Level x Age: t = -3.22, p = 0.001). Unlike the ASD group for whom regularity increased with age in both tendon vibration conditions, controls only showed these age-related gains when the tendon vibrator was off (Group x Vibration Frequency x Age: t = 2.46, p = .014). DISCUSSION/SIGNIFICANCE OF FINDINGS: Our findings indicate that while controls integrate proprioceptive and visual feedback online to accurately adjust fine motor behavior, persons with ASD rely mostly on visual feedback. Our results suggest delayed development of sensory integration and reduced reliance on multisensory feedback during online fine motor control in persons with ASD.

The influence of the Sander parallelogram illusion and early, middle and late vision on goal-directed reaching and grasping

Vision is one of the most robust sensory inputs used for the execution of goal-directed actions. Despite a history of extensive visuomotor research, how individuals process visual context for the execution of movements continues to be debated. This experiment examines how early, middle and late visuomotor control is impacted by illusory characteristics in a reaching and grasping task. Participants either manually estimated or reached out and picked up a three-dimensional target bar resting on a two-dimensional picture of the Sander parallelogram illusion. Participants performed their grasps within a predefined time movement window based on their own average grasp time, allowing for the manipulation of visual feedback. On some trials, vision was only available before the response cue (an auditory tone), while on others vision was occluded until the response cue, becoming available for either the full, early, middle or late portions of the movement. While results showed that the effect of the illusion was stronger on manual estimations than on grasping, maximum grip apertures in the occluded vision and early vision grasping conditions were also consistent to a lesser extent with the illusion. The late vision condition showed longer movement time, wrist deceleration period, time to maximum grip aperture and lower maximum velocity. These findings indicate that visual context affects visuomotor control distinctly depending on when vision is available, and supports the notion that human vision is comprised of two functionally and anatomically distinct systems.

Trans-saccadic adaptation of perceived size independent of saccadic adaptation.

Systematic shortening or lengthening of target objects during saccades modifies saccade amplitudes and perceived size of the objects. These two events are concomitant when size change during the saccade occurs asymmetrically, thereby shifting the center of mass of the object. In the present study, we asked whether or not the two are necessarily linked. We tested human participants in symmetrical systematic shortening and lengthening of a vertical bar during a horizontal saccade, aiming to not modify the saccade amplitude. Before and after a phase of trans-saccadic changes of the target bar, participants manually indicated the sizes of various vertically oriented bars by open-loop grip aperture. We evaluated the effect of trans-saccadic changes of bar length on manual perceptual reports and whether this change depended on saccade amplitude. As expected, we did not induce any change in horizontal or vertical components of saccade amplitude, but we found a significant difference in perceived size after the lengthening experiment compared to after the shortening experiment. Moreover, after the lengthening experiment, perceived size differed significantly from pre-lengthening baseline. These findings suggest that a change of size perception can be induced trans-saccadically, and its mechanism does not depend on saccadic amplitude change.

Objective method with deep learning to calibrate the spatial color resolution of a color charge-coupled device

An objective method to calibrate the spatial color resolution (SCR) of a color charge-coupled device (CCD) is provided. The experimental prototype contains a target generation system, a test platform, and an analytical processing system. The target generation system creates colors with an adjustable light source and two complementary resolution panels (each one has target bars). The test platform aims at creating images through adjusting parameters of a light source of the target generation system. And the analytical processing system is used to process images to evaluate the SCR of a color CCD. We focus on the third module and utilize the minimum detectable color difference (MDCD) and the minimum resolvable color difference (MRCD) to evaluate the SCR. In the process of data collecting, we first set the two channels (one is foreground channel and the other is background channel) of a generation system the same color and then gradually change wavelength of the foreground channel until the foreground image is slightly visible. As it is difficult to let the ratio of detectable pixels of target bars just meet the requirements of the MDCD and the MRCD by only adjusting the wavelength, we adopt the general regression neural network to estimate the two indicators and the maximum estimation error of which are within 6%. In order to deal with more complex scenarios with brightness and saturation change, an image augmentation network (a modified generative adversarial network) is applied to generate synthetic images, which cannot be easily captured by our prototype due to limits of the light source. The experimental results show that the estimation error of MDCD and MRCD is decreased to almost 1%. The method is a human-eye independent way and performs well in selecting the right kind of a color CCD, which guarantees the reliability and security of the visual detection and recognition system.

Motion control for an underactuated brachiation robot based on Lyapunov direct method

This paper studies a control strategy to drive a brachiation robot to realize the movement from an arbitrary initial posture to the desired target position imitating a gibbon to move from branch to branch. The main control aim is to drive an underactuated 2-DOF brachiation robot to reach the target in two action modes of swing motion and locomotion motion. Then, a brachiation motion controller is designed to consist of two control processes in which one is used to drive the brachiation robot to move from the suspend posture to the target position via a Lyapunov method, and the other is to ensure that the end of the link of the robot can reach the target bar through direction feedback control. Finally, some experimental results show that the control method can succeed to control a brachiation robot to achieve successfully the movement from one bar to another adjacent bar in two different cases.

Visual working memory capacity in Korsakoff’s amnesia

ABSTRACTIntroduction: Despite the interest in memory functioning in Korsakoff’s syndrome (KS), visual working memory capacity in KS is still poorly understood. Results from the last decades on working memory limitations in KS appear to be mixed, clearly calling for further investigations.Method: We investigated visual working memory storage capacity of patients diagnosed with KS using a change detection paradigm. Nine patients diagnosed with KS and thirty age- and education- matched healthy controls were presented twice with 2, 3, 4, or 6 bars with different orientations and had to detect whether the orientation of the target bar had changed.Results: As a group, KS patients performed significantly worse than controls on all set sizes, with an average capacity of 1.13 items, compared to 1.75 items in the control participants. In case study analysis, 4 out of 9 patients performed significantly worse than control participants, while 5 had relatively intact visual working memory capacity. In patients, deficits in visual working memory could not be explained by other cognitive deficits.Conclusion: Based on these results, we conclude that visual working memory deficits are a prominent characteristic in some, but not all KS patients. Training visual working memory capacity could possibly optimize other cognitive difficulties in this population.

Cerebellar-cortical function and connectivity during sensorimotor behavior in aging FMR1 gene premutation carriers

IntroductionPremutation carriers of the FMR1 gene are at risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disease characterized by motor, cognitive, and psychiatric decline as well as cerebellar and cerebral white matter pathology. Several studies have documented preclinical sensorimotor issues in aging premutation carriers, but the extent to which sensorimotor brain systems are affected and may represent early indicators of atypical neurodegeneration has not been determined. Materials and methodsEighteen healthy controls and 16 FMR1 premutation carriers (including five with possible, probable, or definite FXTAS) group-matched on age, sex, and handedness completed a visually guided precision gripping task with their right hand during fMRI. During the test, they used a modified pinch grip to press at 60% of their maximum force against a custom fiber-optic transducer. Participants viewed a horizontal white force bar that moved upward with increased force and downward with decreased force and a static target bar that was red during rest and turned green to cue the participant to begin pressing at the beginning of each trial. Participants were instructed to press so that the white force bar stayed as steady as possible at the level of the green target bar. Trials were 2-sec in duration and alternated with 2-sec rest periods. Five 24-sec blocks consisting of six trials were presented. Participants’ reaction time, the accuracy of their force relative to the target force, and the variability of their force accuracy across trials were examined. BOLD signal change and task-based functional connectivity (FC) were examined during force vs. rest. ResultsRelative to healthy controls, premutation carriers showed increased trial-to-trial variability of force output, though this was specific to younger premutation carriers in our sample. Relative to healthy controls, premutation carriers also showed reduced extrastriate activation during force relative to rest. FC between ipsilateral cerebellar Crus I and extrastriate cortex was reduced in premutation carriers compared to controls. Reduced Crus I-extrastriate FC was related to increased force accuracy variability in premutation carriers. Increased reaction time was associated with more severe clinically rated neurological abnormalities. ConclusionsFindings of reduced activation in extrastriate cortex and reduced Crus I-extrastriate FC implicate deficient visual feedback processing and reduced cerebellar modulation of corrective motor commands. Our results are consistent with documented cerebellar pathology and visual-spatial processing in FXTAS and pre-symptomatic premutation carriers, and suggest FC alterations of cerebellar-cortical networks during sensorimotor behavior may represent a “prodromal” feature associated with FXTAS degeneration.

Research on Digital Image Correlation Method used for Strain Detection

Strain measurement is an important means to study structural strength. Strain gauge measurement method is widely used in different industry area. The strain gauge should be stuck on the surface of the measured object to detect displacement or strain. As the measurement mode is contact measurement, strain gauge can have a certain impact on the measured object itself. So research of strain detection is increasingly moving from contact method to non-contact method. In this paper, we design a digital image correlation non-contact method used for strain detection. The basic principle of image correlation method is introduced. And the image process algorithm is detailed described. A set of laser lighting hardware is especially used for object illumination to get a random distribution light spot instead of sticking target bar on object. The measurement results show that this method can detect strain with good effect and can be applied to non-contact strain detection test.

Upturn of the contour-interaction function at small flanking bar-to-target separations

Nearby flanking bars degrade letter identification and resolution, a phenomenon known as contour interaction. However, many previous studies found that the relationship between foveal letter identification and flanker separation is non-monotonic, with an upturn in performance at very small target-to-flanker separations. Here, we replicate this observation and show that a similar upturn occurs also for targets presented at 5 deg in the inferior field, if the target-to-flanker separation is sufficiently small. The presence and magnitude of the observed performance upturn depends on the flanking-bar width, being more evident for narrower compared to wider flanking bars. We interpret our results to indicate that neural interactions between nearby contours reduce performance when the target and flanking bars form discrete neural images. At sufficiently small separations, the images of the target and flanking bars can not be distinguished and performance is governed by the contrast of the target in the blended neural image.

Calibration method of light-field camera for photogrammetry application

As a novel imaging method, the light-field camera can extract different ray traces in the space due to the micro-lens array fixed ahead of the imaging sensor. However, when it is used in photogrammetry such as light pen orientation, attitude estimation and indoor navigation, the classical collinear constraint cannot be applied directly since the refraction effect from the main lens. Therefore, this paper has proposed a mathematical model to calibrate the positions of sub-apertures on the main lens by using bundle adjustment algorithm. Firstly, the reference position for the sub-apertures will be calibrated by using center sub-aperture images. Secondly, the virtual imaging points of the target bar through different sub-apertures can be obtained by the focal length of the main lens. Then the sub-apertures on the main lens can be calculated by using bundle adjustment algorithm. Finally, the experiments results verified the accuracy and effectiveness of the proposed method.

3322 Functional brain mechanisms of sensorimotor deficits in individuals with autism spectrum disorder

OBJECTIVES/SPECIFIC AIMS: Abnormalities in sensorimotor behavior are present in the majority of individuals with ASD and associated with core symptoms. Cortico-cerebellar networks that control sensorimotor behavior have been implicated in ASD, but little is known about their function during sensorimotor actions. The purpose of this functional magnetic resonance imaging (fMRI) study was to examine cortical-cerebellar function during feedback-guided motor behavior in ASD. METHODS/STUDY POPULATION: Individuals with ASD (11-30 years; N = 18) and age-matched controls (N = 15) completed a visuomotor task of feedback-guided precision gripping during fMRI. Participants pressed with their right thumb and forefinger on a force transducer while viewing a green FORCE bar on a screen that moved upwards with increased force toward a fixed white TARGET bar. Individuals were instructed to maintain the FORCE bar at the level of the TARGET bar for 24 seconds. Target force levels were set at 20% and 60% of each participant’s maximum voluntary contraction (MVC). Force variability was characterized as the coefficient of variation (i.e., standard deviation of the force time series / mean force output; CoV). RESULTS/ANTICIPATED RESULTS: Mean force did not differ between groups indicating participants were able to follow task demands. Participants with ASD showed increased force variability (F(1,30) = 5.214, p = 0.03) at both 20% (d = .45) and 60% (d = .77) MVC compared to controls. Compared to controls, individuals with ASD showed decreased activation in left angular gyrus during the visuomotor task compared to rest (AG; maximum t = 4.31). Individuals with ASD also showed greater visuomotor activation compared to controls in ipsilateral ventral M1, extending anteriorly into posterior ventral pre-motor cortex (PMv; maximum t = −4.06, cluster size = 38 voxels). This difference reflected the finding that control participants showed a selective deactivation of ipsilateral M1/PMv during visuomotor behavior, whereas individuals with ASD did not show this pattern. A significant group x force interaction was observed for contralateral Crus I activation (maximum t = −2.42) that was driven by an increase in activity during 60% compared to 20% MVC in control participants, while individuals with ASD showed no change in Crus I activation between force levels. DISCUSSION/SIGNIFICANCE OF IMPACT: Increased force variability in individuals with ASD suggests impaired processing of sensory feedback to guide precision motor behaviors. Individuals with ASD did not show deactivation of right motor cortex during visuomotor behavior relative to rest, suggesting reduced ability to selectively modulate motor cortical output. Reduced activation in left AG may reflect an inability to integrate visual, haptic, and proprioceptive inputs to reactively adjust ongoing motor output. Failure to show force-dependent scaling of Crus I in ASD suggests lateral cerebellar circuits do not adapt sensory prediction and error processes to maintain precision motor output during more demanding conditions. Together, our results demonstrate multiple cortical-cerebellar mechanisms associated with sensorimotor imprecision in ASD.

Study of transgene expression in Triticum aestivum L. after Agrobacterium-mediated in planta transformation

Aim. Detection of sequences of target transgenes nptII and bar in the genome of probable transformants of bread winter wheat Triticum aestivum L. cultivars Zymoiarka and Podolianka obtained as a result of Agrobacterium-mediated transformation in planta and determination of their expression level. Methods. Polymerase chain reaction (PCR) method was used independently and in combination with reverse transcription (RT-PCR), electrophoresis of DNA in agarose gel. Tolerance to the herbicide was evaluated in the physiological test. Results Through PCR analysis, the sequence of nptII transgene was detected in 30 samples of 145 analyzed, the frequency of transformation was 20.7 %. The sequence of the gene bar was observed in 85 experimental plants, and the frequency of transformation was 15.6 %. mRNAs of both transgenes were detected, indicating their transcriptional activity and stable expression. Conclusions PCR analysis allowed to detect nptII transgenic signal in 20.7 % of plants, while the presence of the bar gene was detected in 15.6 % of cases, indicating a higher efficiency of this genetic construct. The transcription is shown in all the specimens studied for both transgene. According to the results of the physiological test, 25 % of plants containing the gene bar showed resistance to the Basta® herbicide.Keywords: genetically modified organisms, transgenic plants, biotechnological cultures, bread winter wheat, genetic engineering.