High-frequency oscillations (HFOs) reflect rapid, synchronized bursts of neuronal assembly in frequencies extending beyond the traditional gamma bands and provide a testable mechanism for encoding and recalling specific memory items by neuronal assemblies in a given brain region. We explored the role of ripple frequency HFOs (80-200Hz) during verbal word-screening (WS) and free-recall (FR) memory tasks in 20 patients. We statistically determined HFO active channels and responses to a set of 180 words in the WS to compare HFO responses to the same words in the FR. Channels with active and inactive word responses within and across the tasks and subsequent sessions were identified in specific brain regions. The highest proportion of active words was observed in the visual areas of the occipital region, whereas the smallest proportions were present in the higher order frontal regions. Brain structures persistently showing significant differences between active and inactive words across the WS and FR were localized in the orbitofrontal cortex, middle and inferior frontal gyrus, hippocampus, cuneus, fusiform gyrus, lateral temporal gyri and inferior parietal gyrus. We found significant differences preceding recall of the items in middle frontal and inferior parietal gyri, suggesting a role of these regions in memory-related reactivation of the item representations. Our results show evidence that HFO bursts reflect processing of specific word concepts stable across time and different verbal tasks. The prefrontal and parietal HFO bursts during item presentation and before free recall suggest the same neural assembly process underlying the formation and retrieval of memory traces.