Reaction time correlations as a measure of eye-hand coordination

Heather DeanPesaran Lab

Center for Neural ScienceNew York University

Interconnected brain areas may interact to plan and initiate

coordinated movements

• How are arm movements coordinated with eye movements?

Getting at interacting circuits through behavior

Correlated Reaction Times

100 200 300 400100

200

300

400

500

SaccadeRT (ms)

Reac

hRT (

ms)

100 200 300 400100

200

300

400

500

SaccadeRT (ms)

Reac

hRT (

ms)

AvgSaccRT = 219

AvgReachRT = 294

Std SRT: 37 msStd RRT: 41 ms

R = 0.55

There are several stages in movement preparation

SensoryInput

MovementPlanning

MovementExecution

Variability in RT is due to variability in the duration of these stages

Shared sensory processing attention/arousal

SensoryInput

SaccadePlanning

ReachPlanning

ReachExecution

SaccadeExecution

Shared sensory processingattention / arousal

ArousalAttention

Stimulus Onset Asynchrony Task

• Delay reach with respect to saccade up to 600 ms.

• This will disrupt coordination but not arousal.

Baseline

Hand GoSound

Stimulus Onset Asynchrony Task

Eye Go

Reward

SOA

Baseline

Hand GoSound

Eye Go

Reward

SOA

Baseline

Hand GoSound

Stimulus Onset Asynchrony Task

Eye Go

Reward

SOA

Baseline

Hand GoSound

Eye Go

Reward

SOA

Baseline

Hand GoSound

Stimulus Onset Asynchrony Task

Eye Go

Reward

SOA

Baseline

Hand GoSound

Eye Go

Reward

SOA

Baseline

Hand GoSound

Stimulus Onset Asynchrony Task

Eye Go

Reward

SOA

Baseline

Hand GoSound

Eye Go

Reward

SOA

Baseline

Hand GoSound

Stimulus Onset Asynchrony Task

Eye Go

Reward

SOA

Baseline

Hand GoSound

Eye Go

Reward

SOA

SOA is the time between movement go cues

0 600 No reachSOA durations

Propo

rtion

of tr

ials

Saccade

Reach

Go Sacc Start

Go

SOA

Reach StartReach RT

Saccade RT

Time

RT Correlations are not due to arousal

Correlations between SRT and RRT decrease with increasing time between movements.

0 200 400 6000

0.2

0.4

SOA (ms)

0 200 400 600300

350

400

Reac

hRT (

ms)

0 200 400 600

150

200

Sacc

adeR

T (ms

)Co

rrelat

ion

SOA (ms)

SOA (ms)

0 200 400 6000

0.2

0.4

SOA (ms)

0 200 400 600300

350

400

Reac

hRT (

ms)

0 200 400 600

150

200

Sacc

adeR

T (ms

)Co

rrelat

ion

SOA (ms)

SOA (ms)

0 200 400 6000

0.2

0.4

SOA (ms)

Corre

lation

AverageSaccadeR

Shared sensory processing attention/arousal

SensoryInput

SaccadePlanning

ReachPlanning

ReachExecution

SaccadeExecution

Shared sensory processingattention / arousal

ArousalAttention

Overlap in plans

Overlap is defined as the time between the start of the saccade and the cue to begin planning the reach.

Saccade

Reach

Go Sacc Start

Go

SOA

Reach StartReach RT

Saccade RT

Overlap

Time

-175 -75 25 125

00.20.40.6

-200-100 0 100300

350

400

-200-100 0 100150

200

Overlap (ms)

Reac

hRT (

ms)

Sacc

adeR

T (ms

)Co

rrelat

ion

175

Overlap (ms)

Overlap (ms)

RT correlations are nonzero when movement plans overlap

Correlations between SRT and RRT increase with increasing time of plan overlap.

Interacting Movement Planning

SensoryInput

SaccadePlanning

ReachPlanning

ReachExecution

SaccadeExecution

SensoryInput

ReachExecution

SaccadeExecution

MovementPlanning

SensoryInput

SaccadePlanning

ReachPlanning

ReachExecution

SaccadeExecution

InitialPlanning

Shared

SensoryInput

SaccadePlanning

ReachPlanning

ReachExecution

SaccadeExecution

RTCo

rrelat

ionRT

Corre

lation

RTCo

rrelat

ionRT

Corre

lation

SOA

End of shared initial planning

0

0

0

0End of saccade planning

SOA

SOA

SOA

SharedMovementPlanning

Shared Initial MovementPlanning

SeparateMovementPlanning

InteractingMovementPlanning

Accumulating Process Model

Saccade

Reach

Go Sacc Start

Go Reach StartReach RT

Saccade RT

movementthreshold

movementthreshold

initialactivity

initialactivity

Summary• For movement of two effectors, correlations

of RTs can show us how coordinated movements are.

• When hand and eye movements are made separately, RT correlations disappear.

• The degree of correlation seems to depend on the overlap between movement plans.

• Simultaneous multiple area recordings will let us identify neural mechanisms for coupling movement plans

Acknowledgements

Pesaran Lab

Eva TsuiBridget DiPrisco

FundingPatterson TrustSwartz Foundation Burroughs-Wellcome Fund

Bijan Pesaran

Alfred P Sloan Foundation