Lecturer & Research Fellow of Clinical Neuropsychology University of Melbourne, Australia
Rationale: “What will my life look like if I go ahead with surgery and become seizure-free?...And what will it look like if I decline?” Discussing treatment options with epilepsy patients assumes that they are able to mentally project themselves into an imagined future, envisaging the pros and cons of various outcomes. The current study evaluates this assumption in unilateral temporal lobe epilepsy (TLE) by evaluating the integrity of future thinking in this population. Methods: Participants comprised 68 adults: 37 with unilateral TLE (18 Left TLE; 19 Right TLE) and 31 healthy controls matched for age, sex, and educational attainment. Future thinking was measured using an imagined experiences task that separates future thinking per se from atemporal scene construction. Tools well-established in epilepsy were used to measure potential cognitive correlates of future thinking. Results: ANOVA revealed impoverished future thinking in both Left and Right TLE relative to controls (P=.001, ηp2=.206 i.e., large effect size), with no difference between the two patient groups (P >.05). Hierarchical multiple regression was used to assess whether the laterality of the seizure focus predicts worse future thinking, after first accounting for lower order cognitive capabilities that contribute to future thinking. The final model accounted for 70% of the variance in future thinking scores. Furthermore, the model suggests that while reduced future thinking scores in left TLE are largely explainable by lower-order cognitive difficulties (verbal function, autobiographic memory and scene construction), those in right TLE reflect an additional higher-order impairment of future thinking itself. Conclusions: Both left TLE and right TLE patients show significant impairments in their future thinking. Patient counseling must accommodate this novel cognitive deficit. Our modeling suggests that while impoverished future thinking in left TLE is secondary to dysfunction in subordinate cognitive processes, people with right TLE show a primary impairment of future thinking. These results imply that future thinking is a multi-determined, ‘higher-order’ cognitive operation in which the right temporal lobe plays a fundamental role. Funding: Please list any funding that was received in support of this abstract.: This research was supported by a National Health and Medical Research Council (NHMRC) project grant (1081151), an NHMRC program grant (1091593), an NHMRC practitioner fellowship (1060312), and by a Victorian Government Operational Infrastructure Support Grant.
