Eligibility Criteria:
Inclusion Criteria for Healthy Group:
* Able and willing to provide informed consent
* Normal function of both upper extremities
* Generally in good health
Exclusion Criteria for Healthy Group:
* Any self-reported disease or disorder that might affect this study, including neurologic, psychiatric, muscular, orthopedic, cardiac, vascular, pulmonary, hematologic, infectious, immune, gastrointestinal, urogenital, integumentary, oncologic, or endocrine conditions
* Any self-reported or demonstrated loss of sensation, passive range of motion, or motor function affecting any part of the upper limb on either side
Inclusion Criteria for Stroke Group:
* Able and willing to provide informed consent
* Subcortical ischemic stroke OR incomplete spinal cord injury, diagnosed by a neurologist at least 3 months before enrollment
* Upper limb sensorimotor impairment on one or both sides, as indicated by a score of 10 to 56 out of 66 points on the Fugl-Meyer Assessment of the Upper Extremity
* Cognitive ability that is normal or only mildly impaired, as indicated by a score of 9 or less on the Short Blessed Test
* Normal receptive and expressive language abilities, as indicated by a score of 0 on the Best Language item of the National Institutes of Health Stroke Scale
Exclusion Criteria for Stroke Group:
* Any self-reported or medically documented disease or disorder that might affect this study, including other neurologic conditions besides stroke or spinal cord injury, psychiatric, muscular, orthopedic, cardiac, vascular, pulmonary, hematologic, infectious, immune, gastrointestinal, urogenital, integumentary, oncologic, or endocrine conditions
* Diagnosis of hemorrhagic stroke or hemorrhagic conversion
* Diagnosis of an infarct affecting the motor cortex