1 Introduction

1.1 Neurofeedback, stress and brain-computer interfaces

Neurofeedback training (or neurofeedback therapy) is based on giving real time feedback on brain activity. This feedback enables the brain to navigate towards some desired brain state. Certain brain states have been shown to be positively correlated with cognitive performance, de-stressing etc. Such brain states form the goal for the neurofeedback.

Stress - a big and growing problem to both society and individuals - is one of the conditions neurofeedback therapy is targeting within a clinical context. For example, it is used within the US army as treatment for veteran soldiers suffering from post-traumatic stress disorder (PTSD) [69]. However, neurofeedback systems targeting consumers remain rare and expensive due to the required specialized hardware - in order to sense brain states, a neurofeedback system includes a Brain-Computer Interface (BCI). Though most BCIs are expensive and aimed at professionals, within recent years a number of BCIs targeting consumers with prices starting from $ 50,- have emerged. Interaxon's Muse ¹ BCI exemplifies the new generation of discrete consumer BCIs (Figure 1.1).

Figure 1.1: Muse consumer BCI (Image courtesy of Interaxon).

The combination of the emerging consumer interfaces and the prospects of neurofeedback motivates our hypothesis.

1.2 Hypothesis

We hypothesize that it is feasible to build a neurofeedback system comprising of a consumer BCI and a mobile device which will enable neurofeedback training in an everyday setting.

To test our hypothesis, we have set the following goals:

G1

Evaluate relevant consumer BCI's feasibility for neurofeedback training.

G2

Design, implement and evaluate AlphaTrainer - a system enabling neurofeedback training in an everyday setting.

If such a system shows feasible, it would enable wide adoption of neurofeedback training in eliminating the obstacle of expensive hardware. This could move the neurofeedback practice out of a clinical setting and into the homes and workplaces of people motivated to reduce their stress.

1.3 Method

The vision and goal of AlphaTrainer - to enable neurofeedback training in an everyday context - is rooted in the ideas of the early pioneers of ubiquitous computing (ubicomp) who envisioned invisible computing, prototypes and the move away from desktop computers into devices that "weave themselves into the fabric of everyday life" [66] [65] [67].

In short, our method is to design, implement, deploy and evaluate AlphaTrainer. This approach is inspired by later adapters of ubicomp stressing the importance of deploying working systems for real usage. For example, Bardram and Friday argue that "... the most valuable lessons to take from looking at successful ubicomp systems is the need to mature the system through actual use" [8]. By deploying AlphaTrainer for actual use in an everyday context, we are able to learn about the system and the usage "in situ" which can not be investigated in a lab or by means of lo-fi prototypes.

The process of building AlphaTrainer involves several activities. Which can be mapped and understood through a framework proposed by Mackay and Fayard [41]. The framework explains how HCI research can benefit from triangulating across science and design disciplines while continuously producing artifacts. Figure 1.2 outlines the major activities of this thesis. The arrows between activities show when output of one activity has been fed into another thus mapping how activities have benefited from each other across disciplines.

Figure 1.2: Mapping of the thesis activities and process - applying the triangulation framework proposed by Mackay and Fayard [41].

1.4 Thesis overview

We outline the structure of this thesis below based on the thesis activities mapped in Figure 1.2.

In Chapter 2 we establish a broad overview of BCIs and neurofeedback training. The chapter describes related consumer products and related works within the area of consumer BCIs and neurofeedback. This is the foundation of our hypothesis and it frames Neurofeedback theory and Investigate current neurofeedback systems.

Chapter 3 describes the design of the Experimental prototype and the Evaluation of consumer BCIs within the designed experiment. This evaluation addresses our first goal - G1 (Section 1.2). The gained knowledge of the BCIs capabilities leads us to a Revised Hypothesis which enables us to develop the system design in the next chapter.

The Design and implementation of AlphaTrainer is split in two chapters. Chapter 4 outlines the design activities, decisions and process that lead us to our final design, while Chapter 5 covers the implementation of the AlphaTrainer system.

In Chapter 6 we evaluate the system through a User Evaluation of AlphaTrainer. The chapter addresses directly our second goal - G2 (Section 1.2) and leads us to a Verified Hypothesis and a Revised AlphaTrainer design.

Finally we make out the conclusion and outline future works - Chapter 7.

1.5 Limitations

This thesis does not attempt to make any clinical claims about AlphaTrainer's efficacy regarding stress treatment. Nor does it address the security aspects of data management which would be required for a system for clinical use.

Rather, it explores whether a neurofeedback system can actually be build using a mobile device and a low-cost consumer BCI. Furthermore, it explores through real world deployment of a prototype whether it makes sense for users to perform neurofeedback training in an everyday context.

Footnotes

[1]	http://www.interaxon.ca