Abstract: While switching costs in production have been explained in terms of top-down cognitive control, researchers do not agree whether switching costs in comprehension should be interpreted in... Show moreAbstract: While switching costs in production have been explained in terms of top-down cognitive control, researchers do not agree whether switching costs in comprehension should be interpreted in the same way. Within the BIA + model, it has been claimed that the comprehension of code-switches can be explained sufficiently in terms of bottom-up activation of lexical representations. In the current electrophysiological study, L1 speakers of Dutch with high proficiency in L2 English (n = 63) completed a Flanker task in which they intermittently read sentences with or without an alternational code-switch. With this ‘conflict-adaptation’ paradigm we examined whether reading a code-switch engages cognitive control that influences performance on a subsequent Flanker trial. Half of the participants were presented with Dutch sentences and Dutch to English code-switches, while the other half were presented with English sentences and English to Dutch code-switches. On the P300 component, we found a traditional Flanker effect, with larger amplitudes for congruent than for incongruent trials. The effect was modulated by a preceding code-switch and the direction of this modulation depended on the switching direction: the Flanker effect was smaller after a code-switch from L1 to L2 than after a monolingual L1 sentence, but larger after a code-switch from L2 to L1 than after a monolingual L2 sentence. This suggests that the L1 needs to be inhibited when reading a code-switch to the L2, while inhibition needs to be released upon encountering a code-switch from L2 to L1. These results thus show that reading code-switched sentences engages a domain-general cognitive control mechanism external to the lexicon. Show less
Rover, M. de; Brown, S.B.R.E.; Band, G.P.; Giltay, E.J.; Noorden, M.S. van; Wee, N.J.A. van der; Nieuwenhuis, S. 2015
Huntington's disease (HD) is a genetic neurodegenerative disease. Carriers of the HD gene without clinical symptoms of the disease can be identified and studied. The study of these premanifest... Show moreHuntington's disease (HD) is a genetic neurodegenerative disease. Carriers of the HD gene without clinical symptoms of the disease can be identified and studied. The study of these premanifest subjects is of importance for the understanding of preclinical disease progression and for the design of future clinical trials. HD is characterized by progressive decline in motor functioning, cognition and behaviour. The unwanted motor disturbances that patients experience are likely to be of influence on cognitive functioning, as cognitive tests almost always require a motoric response. In this thesis we investigated cognitive functioning in both premanifest HD gene carriers and HD patients by taking into account the motor disturbances that have been reported in both pre- and manifest phases of the disease. We also reports on the influence of time on cognition in HD by means of several longitudinal reports with follow-up periods as long as ten years. We found both carriers and patients deteriorate most on memory and executive functioning domains, with the latter being most sensitive in the premanifest phase. We have also found evidence for the presence of premanifest (cognitive) compensatory mechanisms. As expected, there is a substantial (negative) effect of motor functioning on cognition in HD. Show less
Hart, E.P.; Dumas, E.M.; Reijntjes, R.H.A.M.; Hiele, K. van der; Bogaard, S.J.A. van den; Middelkoop, H.A.M.; ... ; Dijk, J.G. van 2012
