Rhythmic encoding improves recognition memory
Alexander Jones1, Emma Ward1; 1Middlesex University London
There has recently been an increased interest in the way temporal expectancies shape perception and drive behaviour. Research has observed that intrinsic neural oscillations can entrain to external rhythms by aligning the firing pattern of neurons. This entrainment has shown to enhance perception and facilitate behaviour for stimuli that appear in phase with the rhythm, yet little is known about how temporal expectation during encoding influences subsequent memory. Participants in the present study were presented with a rapid succession of everyday objects in an encoding phase and asked in a subsequent recognition test phase to judge whether individually presented objects were presented before (old) or not (new). Importantly, the presentation of objects in the encoding phase followed a either rhythmic or arrhythmic temporal pattern, of which participants were not made aware. Recognition was significantly greater for items that were presented rhythmically compared to those presented arrhythmically. There was evidence entrainment with increased phase locking for rhythmic over arrhythmic stimuli during encoding. Moreover, memory specific ERP components at test phase were influenced by rhythmic encoding. Specifically, the FN400 old/new effect was present in both conditions, but a late positive component (LPC) old/new effect was only observed for rhythmically encoded items. This parietal old/new effect (LPC) has been proposed as an index of recollection, specifically linked to memory for the contextual details associated with the encounter with the item. The study provides new evidence through EEG and behavioural measures that presenting stimuli in a rhythmic manner provides a benefit to recognition memory.
Topic Area: LONG-TERM MEMORY: Episodic