Temporal dysfunction in traumatic brain injury Temporal dysfunction in traumatic brain injury patientspatients

Mioni G.*, Stablum F.* and Cantagallo A.°*Dipartimento di Psicologia Generale Università di Padova

°Modulo di Neuropsicologia Riabilitativa, UMR – Dipartimento di Neuroscienze/Riabilitazione Azienda Ospedaliero-Universitaria di Ferrara

Different cognitive processes are involved in time estimation, in particular the role of attention and working memory have been documented. Given thevulnerability of the frontal lobes to damage as a result of a Traumatic Brain Injury (TBI) and the common occurrence of executive dysfunction following TBI itseems reasonable to expect that time perception would be affected in TBI patients. To our knowledge only three studies have investigate time estimationabilities in TBI patients (Meyers & Levin, 1992; Perbal et al., 2003; Schmitter-Edgecombe & Rueda, 2008). All studies employed time reproduction tasks withduration ranged between 5 and 60 second. In the present study we investigate time perception in TBI patients employing a time discrimination task.Furthermore, since we used a discrimination task where stimuli are presented in temporal succession, we further investigate the presence of a Time-Order Error(TOE) Time discrimination performance are also correlate with executive functions task to study the involvement of attention and working memory in time

INTRODUCTION

METHODS: PARTICIPANTS

(TOE). Time discrimination performance are also correlate with executive functions task to study the involvement of attention and working memory in timeperception.

METHOD: TIME DISCRIMINATION TASK

Trial: 12 trials Visual stimuli

Standard: 500 ms and 1300 ms

Comparison: 25% respect to the standard

Training phase: 2 trials for duration

TBI patients (n=27) Controls (n=27) t p

Gender F = 6 M = 21 F = 9 M = 18M DS M DS

Age (year) 34.77 11.60 31.59 7.40 1.18 nsEducation (year) 11.10 4.31 11.67 3.47 -.50 ns

Level of Cognitive 6 67 0 73

Filled intervals

No feedback

Functioning 6.67 0.73

Post-Traumatic12 9.46

Amnesia (day)Glasgow Coma Scale 6.85 4.20

METHOD: ATTENTION and WORKING MEMORY TASKS

Congruent Incongruent

STROOP TASK N-BACK TASK

Standard Comparison

Time discrimination accuracy for TBI and controlsRESULTS:

BLU BLU GREEN BLU GREEN GREEN

FLOWER

+

MOON

+

FLOWER

Group p<.001

Duration p<.01

Minus/plus p=.22

RESULTS:

Correlation between time discrimination, attention and working memory tasks

Discrimination500 ms

Discrimination1300 ms Attention Working

memory

Discrimination500 ms .387* -.237 -.492**

Di i i ti

Number of “lung” responces in TBI patients and controls

Group p=.20

i 001

DISCUSSION:• Our data support the hypothesis that TBI patients present a temporal dysfunction. Patients were less accurate than control in particular when tested withbrief durations (below 1 sec)

Discrimination1300 ms -.109 -.546** -.617**

Attention -.322 -.358* .661**

Working memory .188 -.518** .518**

* p< .05 **.p< .01

Duration p<.001

brief durations (below 1 sec).• The TOE results confirmed the group differences, furthermore showed a bias of response higher than controls.• Previous studies fail to show temporal dysfunction in TBI patients instead the time discrimination task seems to be me sensible to highlight temporaldysfunctions.• Correlations analysis showed different involvement of attention and working memory in TBI and controls. In particular TBI patients involved workingmemory abilities with stimulus both refer and longer than 1 sec; whereas controls engaged working memory ability with duration longer than 1 sec.

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