In 29 bilateral RAM FR1 SEEG patients, the subsequent memory effect was not significantly larger in the left hemisphere

We tested if the word-encoding subsequent memory effect (SME) is larger in the left hemisphere than in the right hemisphere. We used archived band power of 54 RAM FR1 patients (d3aeb47e) and MNI electrode coordinates from OpenNeuro ds004789. In 29 patients with at least 5 bipolar pairs in each hemisphere, the left-minus-right SME difference was not significant. Tilt (HFA minus theta) D = +0.019, 95% CI -0.009 to +0.049, p = 0.23. HFA p = 0.22 and theta p = 0.49 (Holm p = 0.67 for all). The left SME was significant (tilt +0.039, n = 41, p = 0.003) and the right SME was not (+0.012, n = 39, p = 0.28). But the direct test does not support lateralization. The result did not change with a 0 mm midline threshold, with evoked pairs only, with the electrodes.tsv hemisphere column, or in lateral temporal cortex only (n = 23, p = 0.27). Power is low (80% power only for |dz| >= 0.52), and region coverage is not matched across hemispheres.

subsequent memory effect · SEEG · verbal memory · hemispheric lateralization · RAM FR1 · intracranial EEG