Dopaminergic modulation of reward-based learning inParkinson's disease

N.C. van Wouwea,b, S.A. Wyliec, G.P.H. Bandb,W.P.M. van den Wildenbergd, K.R. Ridderinkhofda Department of Human Performance, TNO Defence, Security and Safety,The Netherlandsb Psychology Department, Leiden University, Leiden, The Netherlandsc Neurology Department, University of Virginia Health Systems,Charlottesville (VA), USAd Amsterdam center for the study of adaptive control in brain andbehaviour (Acacia), Psychology Department, University of Amsterdam,Amsterdam, The Netherlands

Learning to select optimal behavior in newand uncertain situationsis a crucial aspect of living and requires the ability to quickly associatestimuli and actions that lead to rewarding outcomes. According to theQ-learning model, learning to select rewarding actions requires theformation of stimulus-action-dependent reward predictions (SADRP)at the time of stimulus presentation, and a comparison betweenexpected and actual rewardwhenpresented with the reward outcome(expressed by the reward-prediction error, or RPE). Several studiesconverge on the notion that the striatum and dopamine (DA) arecritically involved in this learning process. A recent model-based fMRIstudy in healthy subjects associated SADRP and RPE parameters tostriatal activity, respectively in the putamen and caudate nucleus(Haruno and Kawato, 2006a). However, the modulatory role of DA insubstructures of the striatum during reward-based learning is not wellestablished yet. The current study aimed to differentiate the influenceof DA medication on stimulus–action–reward association learning inpatients diagnosed with Parkinson's disease (PD). Patients with PDperformed a probabilistic reward-based learning task while on DAmedication and while off DA medication. The results indicate that DAmedication for treatment of PD symptoms influences both rewardexpectation (SADRP) and reward expectation errors (RPE). Thesefindings suggest that DA activitymodulates distinct aspects of reward-based learning that are associated with putamen and caudateactivities. Importantly, learning parameters improved for patients onrelatively lowdaily dosage, but not for those patients on relatively highdosage.

doi:10.1016/j.ijpsycho.2010.06.097

Bodily reactions to music: Emotions and preference

T. Makkonen, M. TervaniemiUniversity of Helsinki, Institute of Behavioural Sciences and FinnishCenter of Excellence in Interdisciplinary Music Research, Finland

We wanted to explore whether physiological markers of emo-tional charge and music preference can be distinguished. Manystudies have shown contradictory results about the indices of theautonomic nervous system that reflect these musical features. Thisstudy shows that the incongruity depends on the method used indata analysis.

Activity of the autonomic nervous system (ANS) was studied inthree conditions in which subjects were listening to three kinds ofself-selected music: disliked, liked, and neutral. During the listeningto two-minute excerpts, hand temperature, heart rate, and facialelectromyography (EMG) in the zygomaticus region was recorded.The data were analyzed in multiple ways to reveal the optimal way toanalyse the data.

The effect of the analysis method was most clearly seen in EMGsignals, which are noisy and intrinsically irregular in time. When

comparing the different ANS measures, heart rate and EMG were thebest measures to distinguish the preference. Heart rate was decreasedduring neutral music and increased during liked music. Dislikedmusic elicited the highest activity in EMG, whereas neutral music wasthe most relaxed.

In conclusion, ANS activity reflects music preferences. Neutralmusic may decrease ANS activity because it is likely less significantthan liked and disliked music. The development work of new analysistools for ANS activity is urgently needed, due to the emergence of thenewly established field of affective neuroscience of music.

doi:10.1016/j.ijpsycho.2010.06.098

Face vs. common objects and word recognition: Neurophysiologyof intra- and cross-domain visual processing

E. Olivares, A. Santi, J. IglesiasUniversidad Autonoma de Madrid, Spain

Face recognition requires the activation and retrieval of severalkinds of information from long-term memory. Neurophysiologicalcorrelates of these processes have been used to analyze theprocessing of both non-verbal and verbal semantic information(name, occupation) associated with each known face. In the presentstudy, we compared N400-like responses concerning the visualprocessing of “pure” faces and semantic codes related to faces withthose responses related to the visual processing of common objectsand words. Voluntary students were familiarized during threeconsecutive days with faces with and without associated verbal-semantic information. Event-related potentials were recorded inseveral N400 tasks, which were different in the involved informa-tion domain: “pure” visual facial, semantic–visual facial, cross-domain facial-occupation, occupation-name, objects and words.ERPs elicited in these tasks differed in the brain activation patternevoked; especially relevant was right central–posterior activation inthe case of “pure” faces and a more anterior activity withoutlateralization in the tasks involving common objects and words. Onthe other hand, brain responses elicited in the occupation-nametask were to some extent similar to those elicited by the facialstimuli. Thus, the neural activation that supports the processing ofmultiple codes associated with familiar faces could reveal top-downmechanisms that are activated with relative independence from thenature of the stimulus.

doi:10.1016/j.ijpsycho.2010.06.099

Event-related potentials reveal the differential role of internal vs.external facial features for face recognition

E. Olivares, J. IglesiasUniversidad Autonoma de Madrid, Spain

Several behavioral studies on face processing have proposedthat the perception of internal facial features (eyes, eyebrows,nose, and mouth) compared to external ones (hairstyle and facialcontour) favors the recognition of familiar faces. Neurocognitivemechanisms supporting the “internal features advantage” are theaim of this study. In particular, we analyzed the ERP correlates ofthe differential relevance of internal vs. external features for facerecognition. A face-feature matching task was presented touniversity students with external or internal features and completefamous faces were displayed consecutively in each trial. Experi-ment 1 revealed a larger and longer-lasting N400-like effect with

265Abstracts / International Journal of Psychophysiology 77 (2010) 239–287