Neural dynamics during acquisition of motivational significance

Keil, A., Moratti, S., Stolarova, M., and Ihssen, N.
Department of Psychology, University of Konstanz, Germany

Perception and evaluation of emotionally arousing scenes is essential for the organization and regulation of an organism?s behavior. Recent work in the field of the cognitive neuroscience of emotions has provided a dimensional framework for emotional perception being based on the two dimensions of valence (appetitive versus defensive/aversive system) and arousal (amount of activation in either system or degree of co-activation of both systems). This work is based on network approaches to the organization of emotional perception and memory. Affective modulation of visual processing, for instance, may be effected by afferent projections to visual cortices, resulting in a facilitation of the neural tissue in cases where perceptual content is emotionally arousing. While interactions and overlaps between emotional arousal systems and attentional systems have recently been studied extensively, the dynamics of acquisition of affective dispositions remain largely unclear. The present talk presents a series of experiments using large-scale high-frequency and low-frequency oscillations as measured using Electro- and Magnetoencephalography, examining the time course of learning aversive reactions to conditioned stimuli. Using measures of within-site and between-site phase-locking, the functional organization of various subsystems was examined that act to bind together the activity of the distributed areas and finally establish emotional perception. Both induced and evoked (driven) oscillations showed time-dependent sensitivity to classical conditioning, with phase-locking and amplitude being increased as a function of (i) duration and (ii) motivational significance of a given stimulus.