This special issue of Copenhagen Studies in Language series is devoted to human and machine translation and human-computer interaction in translation, which were the two main foci of the 8th International Workshop on Natural Language Processing and Cognitive Science (NLPCS 2011), held at Copenhagen Business School, Denmark, in August 2011. The volume includes the 19 papers which were selected for presentation at the workshop and the text of invite keynote lectures. The workshop provided an attractive interdisciplinary forum for fostering interactions among researchers and practitioners in Natural Language Processing (NLP) working within the paradigm of Cognitive Science (CS). The overall emphasis of the annual NLPCS research workshop series is on the contribution of cognitive science to language processing, including human and machine translation, human-machine interface design, conceptualisation, representation, meaning construction, ontology building, and text mining.