Faculty Bibliography

BACKGROUND:Eye-hand coordination (EHC) is a sophisticated act that requires interconnected processes governing synchronization of ocular and manual motor systems. Precise, timely and skillful movements such as reaching for and grasping small objects depend on the acquisition of high-quality visual information about the environment and simultaneous eye and hand control. Multiple areas in the brainstem and cerebellum, as well as some frontal and parietal structures, have critical roles in the control of eye movements and their coordination with the head. Although both cortex and cerebellum contribute critical elements to normal eye-hand function, differences in these contributions suggest that there may be separable deficits following injury. METHOD/METHODS:As a preliminary assessment for this perspective, we compared eye and hand-movement control in a patient with cortical stroke relative to a patient with cerebellar stroke. RESULT/RESULTS:We found the onset of eye and hand movements to be temporally decoupled, with significant decoupling variance in the patient with cerebellar stroke. In contrast, the patient with cortical stroke displayed increased hand spatial errors and less significant temporal decoupling variance. Increased decoupling variance in the patient with cerebellar stroke was primarily due to unstable timing of rapid eye movements, saccades. CONCLUSION/CONCLUSIONS:These findings highlight a perspective in which facets of eye-hand dyscoordination are dependent on lesion location and may or may not cooperate to varying degrees. Broadly speaking, the results corroborate the general notion that the cerebellum is instrumental to the process of temporal prediction for eye and hand movements, while the cortex is instrumental to the process of spatial prediction, both of which are critical aspects of functional movement control.

An ability to move freely, when wanted, is an essential activity for healthy living. Visually impaired and completely blinded persons encounter many disadvantages in their day-to-day activities, including performing work-related tasks. They are at risk of mobility losses, illness, debility, social isolation, and premature mortality. A novel wearable device and computing platform called VIS⁴ION is reducing the disadvantage gaps and raising living standards for the visually challenged. It provides personal mobility navigational services that serves as a customizable, human-in-the-loop, sensing-to-feedback platform to deliver functional assistance. The platform is configured as a wearable that provides on-board microcomputers, human-machine interfaces, and sensory augmentation. Mobile edge computing enhances functionality as more services are unleashed with the computational gains. The meta-level goal is to support spatial cognition, personal freedom, and activities, and to promoting health and wellbeing. VIS⁴ION can be conceptualized as the dovetailing of two thrusts: an on-person navigational and computing device and a multimodal functional aid providing microservices through the cloud. The device has on-board wireless capabilities connected through Wi-Fi or 4/5G. The cloud-based microservices reduce hardware and power requirements while allowing existing and new services to be enhanced and added such as loading new map and real-time communication via haptic or audio signals. This technology can be made available and affordable in the economies of transition countries.

OBJECTIVE:Tests of rapid automatized naming (RAN) have been used for decades to evaluate neurological conditions. RAN tests require extensive brain pathways involving visual perception, memory, eye movements and language. To the extent that different naming tasks capture varied visual pathways and related networks, we developed the Staggered Uneven Number (SUN) test of rapid number naming to complement existing RAN tests, such as the Mobile Universal Lexicon Evaluation System (MULES). The purpose of this investigation was to determine values for time scores for SUN, and to compare test characteristics between SUN and MULES. METHODS:We administered the SUN and MULES tests to healthy adult volunteers in a research office setting. MULES consists of 54 color photographs; the SUN includes 145 single- and multi-digit numbers. Participants are asked to name each number or picture aloud. RESULTS: = 0.43, P = .001). Learning effects between first and second trials were greater for the MULES; participants improved (reduced) their time scores between trials by 5% on SUN and 16% for MULES (P < .0001, Wilcoxon signed-rank test). CONCLUSION/CONCLUSIONS:The SUN is a new vision-based test that complements presently available picture- and number-based RAN tests. These assessments may require different brain pathways and networks for visual processing, visual memory, language and eye movements.

OBJECTIVE:The Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming that captures extensive brain networks, including cognitive, language and afferent/efferent visual pathways. MULES performance is slower in concussion and multiple sclerosis, conditions in which vision dysfunction is common. Visual aspects captured by the MULES may be impaired in Parkinson's disease (PD) including color discrimination, object recognition, visual processing speed, and convergence. The purpose of this study was to compare MULES time scores for a cohort of PD patients with those for a control group of participants of similar age. We also sought to examine learning effects for the MULES by comparing scores for two consecutive trials within the patient and control groups. METHODS:MULES consists of 54 colored pictures (fruits, animals, random objects). The test was administered in a cohort of PD patients and in a group of similar aged controls. Wilcoxon rank-sum tests were used to determine statistical significance for differences in MULES time scores between PD patients and controls. Spearman rank-correlation coefficients were calculated to examine the relation between MULES time scores and PD motor symptom severity (UPDRS). Learning effects were assessed using Wilcoxon rank-sum tests. RESULTS: = 0.37, P = .02). Learning effects were greater among patients with PD (median improvement of 14.8 s between two MULES trials) compared to controls (median 7.4 s, P = .004). CONCLUSION/CONCLUSIONS:The MULES is a complex test of rapid picture naming that captures numerous brain pathways including an extensive visual network. MULES performance is slower in patients with PD and our study suggests an association with the degree of motor impairment. Future studies will determine the relation of MULES time scores to other modalities that test visual function and structure in PD.