Search Strategies in Practice: Testing the Effect of Inherent Variability on Search Patterns

Abstract

To execute a motor solution to a given task, individuals search through the space of movement possibilities guided by information that arises from the interaction with task and environment. Through this search, individuals seek to avoid inappropriate solutions through local minima in the task space. The processes that lead to some but not all individuals avoiding local minima and finding solutions is not yet understood. Based on the tenets of ecological psychology for perception and action, we examined in two experiments the hypothesis that the incapacity to differentiate errors (performance of an inappropriate solution) from inherent variability would interfere with the perception of properties of the task space and result in a longer time performing an inappropriate solution for the task before exploration of other solutions. Inherent variability was shown to be a direct predictor of the changes in the search strategies. Also, we found that the specifics of the search patterns could predict the performance in the task. Thus, the pattern of motion through the task space affords perception of specific properties of this space guiding individuals in the evolving dynamics of exploration or exploitation.

Declaration of interest statement

The authors declare having no conflict of interest.

Notes

1 The concern on either minima or maxima depends on the way performance is measured. Problems with local-minima occur when we are concerned about errors (or some property that should be minimized). In the same vein, problems with local-maxima occur when we are considering performance (or something that should be maximized). In the tennis example, it was described in terms of success, which must be maximized. In the present study, the task goal was to minimize the error score and, hence, we will refer to local and global minima.

2 We refer to the naturally arising variability from the motor system as inherent variability rather than noise. The human as a complex system has variability emerging from interactions that occur within and between many levels of analysis. Such variability reflects the status of the system and is distinct from a traditional additive noise interpretation. Also, we used the term “variability” here to refer to variance around the mean (see Riley & Turvey, 2002).

3 It is not clear whether Withagen and colleagues consider the possibility of different magnitude of perceptual noise between individuals and its influence on the capacity to distinguish pick-up of inappropriate information from perceptual-noise errors. From the studies cited in the text, the authors consider that the source of individual differences comes from different learning capacities and did not consider differences in inherent variability as a cause.

4 Our experiment assumes that one can relate the inherent variability demonstrated in situations where the task is available with the search task which there was no visible task. It is an empirical matter to demonstrate that this is or is not the case.

5 The Wilson-Agresti-Coull (WAC) adjustment refers to adjustments to the confidence interval when the percentages are above 80% or below 20% given that the “traditional” (Wald) confidence interval assumes a normal approximation to the binomial distribution and this does not hold in these situations.

6 We performed the tests with a range of different block durations (number of trials per block) and with the possibility of overlapping blocks. The results were the same.

Additional information

Funding

MMP is funded by Coordination for the Improvement of Higher Education Personnel (CAPES – PNPD 2019).