Quantifying Cognitive-Motor

Interference in Virtual Reality

Training after Stroke: the Role of

interfaces

Athanasios Vourvopoulos

PhD Student

University of Madeira/M-ITI

athanasios.vourvopoulos@m-iti.org

Athanasios Vourvopoulos

ICDVRAT ’14 September 5, 2014 2

Impact of Stroke

Worldwide

• Approximately 15 million people have a

stroke each year. 2

• 1 in 6 people around the world will have

a stroke in their lifetime. 2

• 2/3 of stroke deaths occur in less

developed countries. 1

In Europe

• Stroke is the second most common

cause of death, with 1.1 million deaths

each year. 1

• 10% of all deaths in men

• 15% of all deaths in women. 1

1 European Cardiovascular Disease Statistics (2012)2 WHO atlas(2014)

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ICDVRAT ’14 September 5, 2014 3

Accessibility Compliance Effectiveness

Rehabilitation Approach

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VR Training in Stroke

4

Virtual Reality (VR) for rehabilitation can contribute

towards:

• Low-cost and long-term

rehabilitation

• Controlled environments

• Motivation mechanisms

• Personalized tasks and

feedback

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Cognitive & Motor Training

• A dual task requires the performance of

complex tasks simultaneously.

• Involves cognitive tasks combined with

motor control.

• Concurrent performance of motor and

cognitive tasks affects the performance

of one or both tasks (Bherer et al., 2005).

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Cognitive & Motor Interference

• Cognitive-motor interference occurs

when 1 or 2 tasks that interfere with

each other are being performed.

• Interference between cognitive tasks

and motor control activities (such as

grasping) is important for functional

improvement.

• We must address both cognitive and

motor training in planning

rehabilitation therapy.

Virtual World

Real World

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ICDVRAT ’14 September 5, 2014

The Role of Interfaces

7

1. The role and effect of the type of

interface in VR is unclear

2. Also, the relationship between

cognitive profile and type of

interface.

Virtual World

Real World

? Identify and understand the effect

of different types of low-cost interfaces

in a dual cognitive and motor VR task

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Cancelation Task - Paper & Pencil

Toulouse – Piéron task (Toulouse et al.,

2004)

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Cancelation Task – Dual motor-

Cognitive VR

• VR Cancelation task (Toulouse-Piéron*)

• Virtual paretic arm for navigation

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Interface Assessment

2D 3D

TI TINUI NUI

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Interface Assessment

2D 3D

TI NUI TI NUI

Dimension

Type

Domain Mot Cog. CogMot Mot Cog. CogMot

Mot

Cog.

Velocity – Acceleration – Smoothness - RoM

Score – Time – Mistakes

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User Study

UID 1 2 3 4 5 6 7 8 9

Age 47 72 46 27 24 32 27 40 30

Gender Male Female Female Male Male Male Male Female Female

Time After

Stroke

10

months

6

months

5

months

- - - - - -

Hemisphere Left Left Left - - - - - -

ACE-R (total) 78 93 57 - - - - - -

Fugl-Meyer

(UL)

50 24 48 - - - - - -

ADL (Barthel) 80 85 80 - - - - - -

• Average of 12 training sessions • 5 training sessions

A total sample of 66 training sessions

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TI vs. NUI & 2D vs. 3D

2D 3DKeyboard Mouse AnTS (NUI) Airmouse Kinect (NUI)

Velocity (m/s) 1 2 4 3

MotorAcceleration

(m/s^2) 1 2 4 3Smoothness

(zero crossings) 1 3 2 4

R.O.M (cm^2) 2 1 4 3Total 5 8 14 13

Score (%) 3 2 5 1 4Cognitive Time (s) 5 3 2 1 4

Mistakes 1 2 5 4 4Total 9 7 12 6 12

Healthy:

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ICDVRAT ’14 September 5, 2014

2D 3DKeyboard Mouse AnTS (NUI) Airmouse Kinect (NUI)

Velocity (m/s) 3 4 1 2

MotorAcceleration

(m/s^2) 3 2 1 4Smoothness

(zero crossings) 1 2 3 4

R.O.M (cm^2) 1 2 4 3Total 8 10 9 13

Score (%) 3 5 4 2 1Cognitive Time (s) 1 2 3 4 5

Mistakes 5 3 1 2 4Total 9 10 9 9 10

14

TI vs. NUI & 2D vs. 3D

Patients:

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TI vs. NUI & 2D vs. 3D

Multi-linear regression model

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Conclusions

2D Faster

Better Scores

Limited RoM

3D Smoother

Large RoM

Tiring

TI Grasping

NUI Intuitive

Better Motor Performance

Patients:

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Conclusions

In this pilot study:

• Gather insights on how the interface affects the

outcome in the motor and cognitive domains

• Identify the particular benefits of interfaces and their

characteristics on cognitive and motor performance.

• Provide useful pointers towards the design and

deployment of future VR rehabilitation systems

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The ultimate goal is to widen the

spectrum of patients that can benefit

from virtual rehabilitation, for in-home

or clinical environments.

Extend this study by including more

stroke survivors and also extend the

analysis to include motor and cognitive

clinical evaluations.

Future Work

THANKS for your attention!!

Any QUESTIONS?

neurorehabilitation.m-iti.org