Small differences can inform us about different things,
according to Dr Monika McAtarsney-Kovacs. Two quick finger-movement tests commonly used in hospital rooms are pointing researchers exploring early markers of cognitive decline to brain networks involved in planning, attention, and motor coordination.
When individuals perform delicate, novel tasks with their fingers, the brain must engage in complex coordination between multiple brain regions that are involved in thinking, attention, planning and information processing,
according to Dr Monika McAtarsney-Kovacs, a researcher in cognitive ageing and memory at Anglia Ruskin University who develops tests to spot cognitive decline early. These underlying networks—including the primary motor cortex, the prefrontal cortex, and the cerebellum—can deteriorate as neurodegenerative conditions advance, physically manifesting as difficulties with precise manual control.
Spotting Decline with the Finger Tapping Test
Data cited in reports detailing the assessments indicate that individuals with mild cognitive impairment average 54 taps with their dominant hand and 51 taps with their non-dominant hand, compared to 64 and 59 taps, respectively, among healthy control participants. The finger tapping test requires a patient to tap their index finger against their thumb as rapidly as possible for a duration of 15 seconds while maintaining a three-centimeter gap between digits. Clinicians observe both the total tap count and the consistency of the rhythm.
“They would measure the number of taps and also watch the rhythm of the taps, to see if it is consistent. Small differences can inform us about different things.”
Dr Monika McAtarsney-Kovacs, a researcher in cognitive ageing and memory at Anglia Ruskin University
An erratic rhythm or a general slowing of movement is frequently observed in patients experiencing dementia. Separate studies connecting computer-based tap reductions to physical brain structures have associated lower counts with a smaller hippocampus, a region critical for memory formation.
Evaluating Sequence Execution with the Fist-Edge-Palm Test
Longitudinal kinematic studies tracking right-handed older adults and patients with mild cognitive impairment over an average interval of 4.5 years continue to investigate how manual dexterity and hand dominance shift across the aging continuum.
Screening Protocols at Memory Clinics
Clinicians emphasize that these manual evaluations are never deployed as standalone diagnostic tools. Instead, they serve as a rapid precursor within a suite of memory clinic assessments that test memory, language, processing speed, and other cognitive domains alongside pen-and-paper examinations like the Mini-Mental State Examination or the Montreal Cognitive Assessment.
Experts caution that struggling with a physical dexterity task does not automatically indicate neurodegeneration. Fatigue, distraction, or hand mobility challenges such as arthritis can similarly affect performance, and healthy individuals occasionally struggle with the movements while some impaired individuals perform well.
Researchers Track Physical Movements of Patients over Time
In a detailed kinematic analysis examining unimanual movements of both dominant and non-dominant hands, researchers evaluated sixteen patients diagnosed with mild cognitive impairment alongside twenty healthy control participants. Recent longitudinal investigations have expanded upon traditional cross-sectional observations by tracking physical movements over extended periods. The investigations recorded an average time interval of 4.5 years between evaluations, incorporating follow-up assessments that tracked changes across the aging continuum.
The healthy control participants recorded a mean Mini-Mental State Examination score of 29.35 with a standard deviation of 1.04, whereas patients with mild cognitive impairment registered a mean score of 26.50 with a standard deviation of 2.71. Initial evaluations revealed distinct baseline cognitive scores between the cohorts. Kinematic evaluations across reaching, grasping, and transport tasks further demonstrated interactions between time and participant groups regarding linear velocity variability, overall path length, and movement angles.
Participants within the mild cognitive impairment cohort showed significant reductions in angular velocity restricted specifically to the right hand over the evaluation timeline. Specific motor parameters shifted distinctly depending on cohort grouping. Healthy individuals exhibited decreasing linear velocity variability, path length, and angular velocity variability across both hands over time, alongside a general reduction in angular velocity.
They showed significant reductions in angular velocity restricted specifically to the right hand over the evaluation timeline,
researchers noted.
