© 2005 The Experimental Psychology Society http://www.tandf.co.uk/journals/pp/02724987.html DOI:10.1080/02724980443000700 THE QUARTERLY JOURNAL OF EXPERIMENTAL PSYCHOLOGY 2005, 58A (8), 1462–1478 Phonological similarity effects in verbal complex span Katy J. Lobley Department of Clinical Psychology, University of Liverpool, Liverpool, UK Alan D. Baddeley Department of Psychology, University of York, York, UK Susan E. Gathercole Department of Psychology, University of Durham, Durham, UK Phonological similarity effects were used to assess the role of acoustic coding in verbal complex span, a processing-plus-storage measure found to correlate significantly with aspects of complex cognition. Three experiments demonstrated consistent effects of phonological simi- larity on listening span. These effects appeared relatively insensitive to manipulations of task materials (Experiment 1) and differences in processing task demands (Experiments 2 and 3). The results were interpreted as reflecting a significant role for the phonological loop in sup- porting verbal complex span and a multicomponent view of working memory, as tapped by these tests. Phonological similarity did not significantly interact with aspects of the tasks varied across Experiments 1 to 3, suggesting a relative robustness of the effect. However, variation in the phonological similarity effect sizes across Experiments 1 to 3 supports the suggestion that task demands and characteristics have the potential to disrupt the phonological similarity effect and, by implication, the reliance on a phonological code. Baddeley and Hitch’s (1974) tripartite working memory framework has been applied to many accounts of cognitive processes that require the short-term retention and manipula- tion of information. The original framework comprised two slave systems—the phonologi- cal loop and visuo-spatial scratch pad—and a limited capacity processor—the central Correspondence should be addressed to Katy Lobley, Dept of Clinical Psychology, The Whelan Building, University of Liverpool, Quadrangle, Brownlow Hill, Liverpool L69 3GB, UK. Email: katy.lobley@rlc.nhs.uk We would like to thank Alastair Smith and Sara Williams for their help in preparing the stimuli. Robert Clark provided invaluable help in administering Experiment 3. All experiments were conducted whilst the authors were at the University of Bristol, which provided funds and facilities to support the work. This work formed part of the first author’s PhD thesis and was supported in part (Experiments 1 and 2) by an ESRC postgraduate studentship.