Brain - Machine Interfaces

Question 0

Visual prosthetics

Brindley & Lewin (68)

Answer 0

Implanted 80 electrodes into VC of blind human volunteer.

Evoked bright points of light. Phosphine locations corresponded with topographic space in V1

Question 1

Visual prosthetics

Metabet et al (05)

Answer 1

Focal stimulation of intact visual system invokes sensation of discrete points of light. Delivering stimulation could invoke geometrical pattern perception.

1. Retinal stimulation
2. Optical nerve stimulation
3. Cortical stimulation

Question 2

Visual prosthetics

Dobelle (00)

Answer 2

62yrs, blind at 38
VC electrodes & glasses & portable pc
Could detect outline of a person, certain letters also
PC decoded images

Question 3

Visual prosthetics

Schiller & Tehounik (08)

Answer 3

Stimulate point at V1
Stat like percept, dots on RVF
Middle dots larger than peripheral
Mapping is complex: magnifications, distortions, mirror reversals

Question 4

Brain machine interfaces
Movement control
Chaplin et al (99)

Answer 4

Trained rats to position robotic arm by pressing lever to obtain water.
Multi unit activity recorded in PMC and V.thalamus - calculated/predicted lever trajectory
4 of 6 animals used brain derived signals
Animal level movement stopped/dropped whilst neurally controlling the device

Question 5

Brain machine interfaces
Movement control
Serruya et al (02)

Answer 5

7-30 M1 neurons decoded
Monkey immediately able to move computer cursor in workspace
(Suitable for humans)
Cursor control nearly as good as direct hand positional control.
Had to reach target within 20sec of appearance.
Math and biology.

Question 6

Brain machine interfaces
Movement control
Hochberg et al (06)

Answer 6

25yrs tetrapelagic SS
10x10 electrode array implanted in arm
Neurons still fire 3yrs after injury
Motor intent (imagined movement modulated neural firing on multiple electrodes consistent with in monkey research)
Motor cortex used to check emails and change TV channel

Question 7

Brain machine interfaces
Movement control
Wessberg et al (00)

Answer 7

Recorded monkey PMC, posterior parietal cortex and PM
Performed 2 distinct motor tasks
Accurate real time predictions of 1&3d arm movement traj,
Linear and non linear algorithms
Successful real time control of robotic devices: locally and through the Internet
Cortical area signals

Question 8

Brain machine interfaces
Movement control
Meel Veliste et al (08)

Answer 8

First use of correct signals to control multi-jointed prosthetic device for direct interaction real time.
2 monkeys, electrodes in PMC to control arm and grip.
Natural experiment- corrective movements made to avoid collisions
Finger licking, opened gripper in anticipation of rewards

Question 9

Brain machine interfaces
Movement control
Moritz et al (08)

Answer 9

Own limbs are best actuators
Interrupted route from MC to muscles
Monkeys controlled muscle stimulation through MC activity
Restored goal directed movements to transiently paralysed arm
Neurons controlled functional stimulation regardless of previous association to movement
Used artificial connections to generate bidirectional wrist torques

Question 10

Brain machine interfaces
Movement control
O’Doherty et al (11)

Answer 10

Need tactile feedback
Monkey performed active exploration task with actuator/cursor with derived motor commands from the PMC
Intracranial microstimulation used to return feedback to PSC
Temporal patterns of ICMS restored artificial tactile properties

Question 11

Brain machine interfaces

Answer 11

Facilitate direct collaborations between brain and outside world