Long-term memory representations play a central role helping humans to orientate in a constantly changing environment. These processes provide standards for the comparison of novel information, but also allow for adapting these standards (e.g., Bower, Thompson, Schill, & Tulving, 1994). Human faces are typically assumed to elicit such stable long-term memory representations. Carbon & Leder (2005a, 2006) have shown that the presentation of extremely distorted familiar faces of celebrities affects the ability to distinguish between an original and a shifted version of a face. These adaptation effects were not only short termed but last for minutes and even for 24 hours (Carbon, Strobach, Lanton, HarsÃ nyi, Leder, & KovÃ cs, 2007).
Studies have shown that memory representations for musical tempo and musical pitch can be remarkably stable across time - even for very long time spans (e.g., Levitin, 1996; Levitin & Cook, 1996; Schellenberg & Trehub, 2003). Within this dissertation project adaptation effects in the musical domain were investigated. This project deals, with respect to the design of the initial study by Carbon and Leder (2005a), with memory representations for musical tempo and musical pitch. The project aims to test if the findings from the visual domain can be found in the auditory domain. The overall research question was: Does the perception of extremely distorted versions of familiar pieces of music (TV themes) affect judgements about the original tempo or, respectively the original pitch level of these pieces? This overall question was tested with eight empirical studies with various designs and specific additional research questions. As stimuli I used six TV themes of US American TV series from the 1960s, 1970s, 1980s, and 1990s which were pre-tested for familiarity. The results of the eight empirical studies (N =288, mean age = 26, SD = 8.6, 78 % female participants) show that musical adaptation effects (MAEs) can be found for both domains of interest, musical tempo and musical pitch. The adaptation towards the treatment versions was found, and was not only short termed. Musical adaptation effects were also found after a delay of 30 s. The effect was absent after a delay of 3 min under the given experimental conditions, but is assumed to last somewhat between 30 s and 3 min. MAEs were found to be directional with respect to the treatment presentation. The musical adaptation effects for musical tempo were found to be clear-cut and distinct; those for musical pitch were found to be weaker. The results of the eight empirical studies gave further insights into the field of memory representations of musical tempo and musical pitch.
MAEs are in line with Dudai's (2004) neurophysiological theory of adaptive memory formation, which points to flexible updating processes of long-term memory standards. The MAEs reported in this dissertation project show strong correspondence to other modalities (e.g., the face-processing domain). Evidence points to musical adaptation effects being a facet of a domain-general long-term memory mechanism for context-dependent template updating.