Lateralisation and fitts paradigm- rapid aimed movement study

Introduction

Relationship between the speed at which a limb moves and its resulting accuracy, or the relationship between movement distance and movement time named after Paul Fitts [1], who has first described it as a formal mathematical law, are one of the fundamental principles and cornerstone in the physical sciences. The focus of this study was to examine aspect of lateralisation in spatially constrained rapid arm goal-directed movement using Fitts’ task (paradigm).

Methods

The research experiment was conducted on 24 young male and female right-handed subjects recruited from among the students of the Academy of Physical Education. They were drawn from the population randomly. All measurements were taken in the Laboratory of the Department of Motor Control in Academy of Physical Education. Fitts’ task was executed with the use of specially constructed manipulator connected to the computer. During the experiment subjects had visual feedback of its movement on the monitor screen. They were instructed to move light circle of certain radius along the monitor as quickly as possible and stop at destination field marked with two horizontal lines. The procedure was repeated three times with both arms sequentially (dominant hand first). In third attempt there was a visual noise introduced (decrease of brightness of the controlled circle) to examine if it has influence on analysed variable, which was movement time (MT).

Results

Analysis of achieved data show statistically insignificant differences in MT variable between right and left hand across the subjects. Significance level of the difference in MT between left and right hand p=0,702 in standard visual circumstances and p=0,156 for the visually constrained trials (decrease in brightness of the guided circle). Also analysis of MT in standard and visually constrained circumstances for the same hand didn’t show statistically significant differences, p=0,827 for right hand and p=0,386 for left hand.

Discussion /Conclusions

Conducted study shows that Fitts’ paradigm can be successfully adopted in studies as such concerning lateralization. Results allow assuming that there is no difference between upper limbs in rapid goal-directed movement. Existence of slight tendency can be observed which would be in accordance to the hypothesis that left hand (non dominant) is faster than right [2]. Of course more experiments would be needed to confirm these assumptions on different groups and populations what is actual intention of the experimenters.

References

[1] Fitts P. M. (1954). Journal of Experimental Psychology, 47(6),381-91
[2] Plamondon R. & Alimi A.. M.(1997). Behavioral and Brain Sciences, 20,279-349