Shared structuring resources across domains: double task effects from linguistic processing on the structural integration of pitch sequences.

Many studies have reported evidence suggesting that resources involved in linguistic structural processing might be domain-general by demonstrating interference from simultaneously presented non-linguistic stimuli on the processing of sentences (Slevc, Rosenberg, & Patel, 2009 ). However, the complexity of the analysed linguistic processes often precludes the interpretation of such interference as being based on structural-rather than more general-processing resources (Perruchet & Poulin-Charronnat, 2013 ). We therefore used linguistic structure as a source of interference for another structural processing task, by asking participants to read sentences while processing experimentally manipulated pitch sequences. Half of the sentences contained a segment with either an "out-of-context" sentential violation or a "garden path" unexpectancy. Furthermore, the pitch sequences contained a cluster shift, which did or did not align with the sentential unexpectancies. A two-tone recognition task followed each pitch sequence, providing an index of the strength with which this structural boundary was processed. When a "garden path" unexpectancy (requiring structural reintegration) accompanied the cluster shift, the structural boundary induced by this shift was processed more shallowly. No such effect occurred with non-reintegratable "out-of-context" sentential violations. Furthermore, the discussed interference effect can be isolated from general pitch recognition performance, supporting the interpretation of such interference as being based on overlapping structural processing resources (Kljajevic, 2010 ; Patel, 2003 ).