Memories of painful events constitute the basis for assessing patients' pain. This study explores temporal and spatial aspects of brain activity during short-term memorization of a nociceptive stimulus. Highdensity EEG activity (128-electrodes) was recorded in 13 healthy subjects during a match-to-sample sensory discrimination task, whereby participants compared the intensity of a thumb-located electric shock (S2) with a prior-stimulus to the same location (S1) delivered 8-10sec earlier. Stimuli were above or below the individual nociceptive-threshold. EEG activity with intracortical-source-localization via LORETA source reconstruction was analyzed during the inter-stimuli period, and contrasted with a non-memory-related control task. The inter-stimulus memorization phase was characterized by a focal alpha-activity enhancement, significant during the nociceptive condition only, which progressed from bilateral occipital regions (cuneus and mid-occipital gyri) during the first encoding-memorization phase toward the right-superior and right midtemporal gyri during the 2-4 sec immediately preceding S2. Initial alpha enhancement in occipital areas/cuneus is consistent with rapid non-specific inhibition of task-irrelevant visual processing during initial stimulus encoding. Its transfer to the right-temporal regions was concomitant to the temporary upholding of the stimulus perceptual representation, previous to receiving S2, and suggests an active and local blockade of external interferences while these regions actively maintain internal information. These results add to a growing field indicating that alpha oscillations, while indicating local inhibitory processes, can also indirectly reveal active stimulus-handling, including maintenance in short-term memory buffers, by objectivizing the filtering out of irrelevant and potentially disrupting inputs in brain regions engaged in internally-driven operations.