Easy quantitative methodology to assess visual-motor skills

Matteo Chiappedi,¹ Alessio Toraldo,² Silvia Mandrini,³ Federica Scarpina,² Melissa Aquino,² Francesca Giulia Magnani,² Maurizio Bejor<sup>3

1</sup>Don Carlo Gnocchi ONLUS Foundation, Milan, Italy; ²University of Pavia, Department of Psychology, Pavia, Italy; ³University of Pavia, Department of Surgical, Resuscitative, Rehabilitative and Transplant Sciences, Pavia, Italy

Introduction: Visual-motor skills are the basis for a great number of daily activities. To define a correct rehabilitation program for neurological patients who have impairment in these skills, there is a need for simple and cost-effective tools to determine which of the visual-motor system levels of organization are compromised by neurological lesions. In their 1995 book, The Visual Brain in Action (Oxford: Oxford University Press), AD Milner and MA Goodale proposed the existence of two pathways for the processing of visual information, the “ventral stream” and “dorsal stream,” that interact in movement planning and programming. Beginning with this model, our study aimed to validate a method to quantify the role of the ventral and dorsal streams in perceptual and visual-motor skills.
Subjects and methods: Nineteen right-handed healthy subjects (mean age 22.8 years ± 3.18) with normal or corrected-to-normal vision were recruited. We proposed that a delayed pointing task, a distance reproduction task, and a delayed anti-pointing task could be used to assess the ventral stream, while the dorsal stream could be evaluated with a grasping task and an immediate pointing task. Performance was recorded and processed with the video-analysis software Dartfish ProSuite.
Results: Results showed the expected pattern of predominance of attention for the superior left visual field, predominance of the flexor tone in proximal peri-personal space arm movements, tendency toward overestimation of short distances, and underestimation of long distances.
Conclusion: We believe that our method is advantageous as it is simple and easily transported, but needs further testing in neurologically compromised patients.

Keywords: dorsal stream, ventral stream, visual-motor skills, rehabilitation, neurological disorders