Improvements in the treatment of stroke lead to an increase in the number of patients living with the consequences of stroke. Although stroke induces cognitive impairment, a lack in mobility or difficulties in walking are common problems for stroke survivors and restoring the walking pattern is one of the main targets in the rehabilitation procedures. Perturbation application is helpful in creating a suitable environment in gait training and it drives problem solving. In our study we aimed to investigate the instantaneous and direct effectiveness of perturbation in stroke patients on the brain during walking by using Near Infrared Spectroscopy (NIRS) and also evaluated the cognitive functions of these patients by Mini Mental Test and Montreal Cognitive Assessment. Study groups were composed of 6 healthy and 6 stroke survivors. Perturbation was applied to subjects by using Re-Step Rehabilitation System and NIRS was used to analyse the instant effect of perturbation on oxygen consumption dynamics of the brain. Although HHb did not change in both groups, HbO2 value showed significant changes in healthy group during walking protocol of the study. Healthy Group Mini Mental Test score was found to be increased significantly when compared to Patient Group. We may suggest that the perturbation implantation increases the prefrontal circulation which is activated during motor planning and central input processing, especially in healthy group compared to stroke patients. This determination may consequently be thought as increase in activity in neural centers related to the task and parallel effect of plasticity.