Article Review: Sensory and Motor Input

Marken and Horth (2011) sought to investigate the relationship between sensory input and motor input. Specifically, their work had the goal of testing two competing theories of the ways in which the human mind uses emotion and cognitive processes to accomplish a causal task which requires constant monitoring of new data and adjustment. As the pair explained, open-loop theory suggests that the way the mind processes these types of tasks is by making one motor output adjustment to a given sensory stimulus, responding to changes one at a time—hence the “open” nature of the flow of data through the system, which in this case is the brain. On the other hand, the closed-loop model posits an iterative relationship between input and output, in which people automatically compensate for the motor output in the process while mentally determining the next output based on the effects of both the previous output and the new input.

Which method of processing humans ultimately use is still a question up for debate, but Marken and Horth managed to weigh in on the closed-loop side of the issue by means of a simple experiment and its associated data. In order to move the discussion out of the theoretical realm and into the arena of evidence-based management and thought, they devised a setup in which subjects were asked to keep a computer mouse cursor on a target on the screen while deviations of varying magnitude were applied. These inputs were determined randomly, but in an ever-increasing radius from the center so that the difficulty level of keeping the cursor in place varied. Their hypothesis was that if the correlation between input and output improved with overall tracking performance, this would be an indication that the open-loop model was at work, because the better the subjects were at doing the task, the more putting in the single correct output would occur. Instead, the closed-loop model was supported, because there was very little correlation between input and output regardless of performance as if subjects were constantly re-evaluating every move they made. This study contributed meaningful data to the theoretical area investigated and is thus valuable.

Reference

Marken, R. S., & Horth, B. (2011). When causality does not imply correlation: More spadework at the foundations of scientific psychology. Psychological Reports, 108(3), 943-954.