The interference method transcranial magnetic stimulation has to be seen as a complimentary tool to the other noninvasive correlational techniques such as positron emission tomography, functional magnetic resonance imaging or electroencephalography in cognitive neuroscience. However, the combination of two methods e.g. transcranial magnetic stimulation and positron emission tomography seems to be the strongest approach to validate or postulate new hypotheses. In this review several studies using transcranial magnetic stimulation to disentangle working memory functions are presented. The conclusion is drawn that there exists a superordinated amodal central executive within the dorsolateral prefrontal cortex strongly connected with modality specific areas mainly within the prefrontal cortex.