Exploring the time features of recognition memory for music in the semantic and episodic systems: An ERP study

Previous studies Olivetti Belardinelli 2005; Olivetti Belardinelli et al. 1999, 2000) have shown that musical memory relies on different memory systems according to music characteristics (tonality is recollected by means of semantic memory, salience – defined as redundancy of melodic and/or rhythmic parameters – by means of episodic memory), and that such systems recruit different cerebral districts. Nevertheless the time course of such process is still relatively unknown. The aim of this study was to explore the temporal dynamics of musical memory in the semantic and episodic systems. 20 healthy (10 males) right-handed non-musicians participated in this study. Stimuli were 72 short musical themes composed for experimental purposes and employed in our previous studies. They had variable durations (6,5-12,5 s) and were administered in random order with an ISI of 5 s. Stimuli were divided into two different version of a “study lists” (36 stimuli) and two related “test lists” (72 stimuli). Subjects were asked to attentively listen to one “study list”. After 15-20 min. they started the EEG session (electrodes in Fz, Cz, Pz, F7, F8, T3, T4, T5, T6), where they were administered the related “test list” and had to perform a recognition task, pressing a different button whether, according to Tulving’s model (1972): 1) they recognized the melody as previously heard (Remember response); 2) the melody evoked in them a sense of familiarity (Know response); 3) they could not recognize the melody at all (X response). Half of the subjects were asked to press the button as soon as they could decide among the three kinds of response, half of them were instead required to press the button as soon as the musical excerpt was expired. In both cases the analysis concerned the 1000 ms. preceding and following the button press.