INTRODUCTION

This study aimed to characterize cognitive and neural mechanisms responsive to cognitive rehabilitation in patients with traumatic brain injury (TBI). We hypothesized that prefrontal cortex (PFC) would be modulated by training in the goal-based process of strategic learning. Thirteen patients are currently planned to undergo three functional magnetic resonance imaging (fMRI) scans with a seven-week cognitive training between the second and third scans. Patients showed no significant difference on brain activation between the first two scans but preliminary results showed significant increases in activations of the superior and middle frontal gyri, putamen, and cerebellum after the cognitive rehabilitation training. These results showed increased modulatory control over working memory, providing candidate neural mechanisms that may underlie cognitive improvements with cognitive training.

GOALS

1. To characterize cognitive and neural mechanisms responsive to cognitive rehabilitation in patients with traumatic brain injury (TBI).
2. To elucidate candidate mechanisms by which strategic learning training may improve neural-cognitive functioning.

METHODS

Data Collection

• Currently 13 subacute to chronic TBI participants are enrolled in the study with a mean age of 34 years old with 9 of them being male having been recruited from National Taiwan University Hospital and Tzu Chi General Hospital outpatient clinics.
• We examined the change in cognitive activation by using T1-wighted magnetization-prepared rapid gradient-echo (MP-RAGE), and task-fMRI. The participants undergo a selective attention task involving participants seeing a sequence of pictures of either scenery or a human face developed by UCSF during the task-fMRI. The participants’ task consists of pressing buttons to indicate whether the current picture is of the correct category and matches the last one of the category that appeared earlier in the sequence.
• Three functional magnetic resonance imaging (fMRI) scans are done with the first two used as a control baseline followed by a seven-week cognitive training between the second and third scans.

Cognitive Rehabilitation Training

• Cognitive rehabilitation training consists of a seven week course which last one and half hour to two hours each.
• The course covers mindfulness breathing, strategy in attention modulation, and a game based training tool (Novakovic-Agopian, Chen et al. 2011).
• The game contains five chapters which correspond to the skills and the strategy taught during the cognitive rehabilitation training course. The game is goal-based and challenged by disruption of target cognitive processes. It requires the integration of cognitive processes, emphasizing working memory and multitasking.

Data processing and analysis

• Data analysis was performed with SPM 5 (www.fil.ion.ucl.ac.uk/spm/).
• As of now 3 subjects have completed the study.
• Comparisons of the 1^st and 2^nd scans were conducted with all data while the pre-, post-training comparison was done with the participants with complete data.

RESULTS

Pre-session Whole brain Contrasts (Control)

• Two-sample t-test analysis showed no significant difference in brain activation levels between the first two scans.

Post-session Whole brain Contrasts

• Two-sample t-test analysis revealed that post-training participants showed changes in activation when compared to pre-training.
• For the Irrelevant>Relevant contrast, participants showed increased activation in the superior and middle frontal gyri, putamen, and cerebellum.