Rapid and Highly Resolving: Affective Evaluation of Olfactorily Conditioned Faces

Abstract

Evidence from hemodynamic and electrophysiological measures suggests that the processing of emotionally relevant information occurs in a spatially and temporally distributed affective network. ERP studies of emotional stimulus processing frequently report differential responses to emotional stimuli starting around 120 msec. However, the involvement of structures that seem to become activated at earlier latencies (i.e., amygdala and OFC) would allow for more rapid modulations, even in distant cortical areas. Consistent with this notion, recent ERP studies investigating associative learning have provided evidence for rapid modulations in sensory areas earlier than 120 msec, but these studies either used simple and/or very few stimuli. The present study used high-density whole-head magneto-encephalography to measure brain responses to a multitude of neutral facial stimuli, which were associated with an aversive or neutral odor. Significant emotional modulations were observed at intervals of 50-80 and 130-190 msec in frontal and occipito-temporal regions, respectively. In the absence of contingency awareness and with only two learning instances, a remarkable capacity for emotional learning is observed.

Emotion-Associated Tones Attract Enhanced Attention at Early Auditory Processing: Magnetoencephalographic Correlates

“…Recording magnetoencephalographic responses to a multitude of ultrashort tones that were assigned affective meaning through MultiCS conditioning (cf. Steinberg et al, 2011), this study was the first to provide insights into the spatio-temporal dynamics of auditory emotion processing in humans. Consistent with our hypotheses, motivated attention (1) led to differential processing of emotion-associated compared with neutral auditory stimuli; (2) modulated early AEF components, suggesting common neural mechanisms underlying both motivated and directed attention effects; and (3) recruited neural circuitry overlapping with a domainindependent fronto-parieto-temporal attention network.…”

“…In the present study, the preconditioning session was additionally taken into account (cf. Steinberg et al, 2011). This more conservative presession/postsession design controls for potential preconditioning variance in CS processing and thus improves signal-to-noise ratio.…”

“…We used this novel MultiCS-conditioning paradigm (cf. Steinberg et al, 2011) for several reasons: (1) to show that the neural system underlying emotion processing is rapid and highly resolving in terms of its capacity to differentiate a multitude of emotional stimuli; (2) to investigate motivated attention effects on early cortical processing stages in the absence of participants' explicit knowledge about CS-UCS contingencies; since we revealed in a pilot study with a different set of subjects (N ϭ 8) that they were already unable to recall three CS-UCS pairs per emotion condition (data not shown), it was expected that the participants of the present study would be completely unaware of the stimulus associations for even larger numbers of pairs; (3) to allow for a sufficiently high number of trials within each condition assuring good signalto-noise ratio for MEG data analysis, whereas at the same time, every single stimulus has to be repeated only a few times reducing extinction of the acquired emotional meaning because of repeated non-reinforced CS presentations (Rogan et al, 1997).…”

Abnormal, affect-specific modulatory effects on early auditory processing in schizophrenia: Magnetoencephalographic evidence

“…To investigate electrophysiological correlates of early emotion processing, affective MultiCS conditioning was introduced by our group (Bröckelmann et al, 2011;Steinberg et al, 2012;Steinberg et al, 2013). While classical affective conditioning typically uses one neutral stimulus (conditioned stimulus, CS) that becomes associated with an unconditioned stimulus (US) within several contingent CS-US pairings and acquires the power to elicit a conditioned response (CR) that was previously evoked by US presentation, MultiCS conditioning involves multiple complex stimuli (e.g., faces or tones) per affective category that acquire emotional meaning within a few associative learning trials.…”

Emotional Correlates of Unirhinal Odor Identification

“…In line with this interpretation, those areas of brain (i.e. amygdala and prefrontal cortex) implicated in the identification of both smell and facial emotion respond at very short (<120ms) post-stimulus latencies (Steinberg et al, 2012).…”