The goal of this interventional study is to compare if the use of a brain-machine interface (BCI) therapy can improve the symptoms of attentional deficit by producing brain changes in the networks that modulate attention. The investigators intend to work with epileptic participants who do not respond to pharmacological treatment, who will undergo neurosurgery. The questions the study sets out to answer are: 1. is there an improvement of symptoms in an experimental group receiving the treatment versus a sham group receiving a simulation of the treatment? 2. does the application of the therapy before surgery reduce the recovery times of post-surgery cognitive deficits described in the literature? Making use of the information recorded from brain electrodes implanted before a participant's epilepsy surgery, the investigators will create a BCI decoder that works with the available activity sources to establish the level of attention of each participant when performing tasks. Participants: * will perform an offline phase first, which will consist of one day of evaluation, in which they will be familiarized with an attentional task. * will perform a training phase later, which will consist of several days of evaluation, where they will learn to modulate their level of attention. This modulation will be facilitated by the BCI decoder, which will classify the level of attention directly from the brain and provide visual feedback that the participant will use as a guide. If the participant is part of the experimental group (or BCI group), the feedback will work as described and should be easy to follow, but if the participant is part of the Sham group, the feedback will not work according to the brain activity of the actual participant, but according to that of another person. Because of this, a mismatch will be created between the moments a brain experiences inattention, and participants believe they are experiencing inattention. This is a randomized, double-blind study, in which the experimenters will evaluate how the effect of the attentional therapy with BCI affects an BCI group and a Sham group.