Emotionally salient aspects of the world are experienced with greater perceptual vividness than mundane ones; however, such emotionally enhanced vividness (EEV) may be experienced to different degrees for different people. We examined whether BOLD activity associated with a deletion variant of the ADRA2b gene coding for the ␣2b adrenoceptor modulates EEV in humans. Relative to noncarriers, ADRA2b deletion carriers showed higher levels of perceptual vividness, with the ventromedial prefrontal cortex (VMPFC) showing greater modulation by EEV. Deletion carriers were also more sensitive to the featural salience of the images, suggesting a more pervasive role of norepinephrine in perceptual encoding. Path analysis revealed that, whereas a simple model by which the amygdala modulated the lateral occipital complex best characterized EEV-related activity in noncarriers, contributions of an additional VMPFC pathway best characterized deletion carriers. Thus, common norepinephrine-related neurogenetic differences enhance the subjective vividness of perceptual experience and its emotional enhancement.

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Emotionally arousing events are typically better remembered than mundane ones, in part because emotionally relevant aspects of our environment are prioritized in attention. Such biased attentional tuning is itself the result of associative processes through which we learn affective and motivational relevance of cues. We propose that the locus coeruleus-noradrenaline (LC-NA) system plays an important role in the genesis of attentional biases through associative learning processes as well as their maintenance. We further propose that individual differences in and disruptions of the LC-NA system underlie the development of maladaptive biases linked to psychopathology. We provide support for the proposed role of the LC-NA system by first reviewing work on attentional biases in development and its link to psychopathology in relation to alterations and individual differences in NA availability. We focus on pharmacological manipulations to demonstrate the effect of a disrupted system as well as the ADRA2b polymorphism as a tool to investigate naturally occurring differences in NA availability. We next review associative learning processes that—modulated by the LC-NA system—result in such implicit attentional biases. Further, we demonstrate how NA may influence aversive and appetitive conditioning linked to anxiety disorders as well as addiction and depression.

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The ability to interrogate specific representations in the brain, determining how, and where, difference sources of information are instantiated can provide invaluable insight into neural functioning. Pattern component modelling (PCM) is a recent analytic technique for human neuroimaging that allows the decomposition of representational patterns in brain into contributing sub components. In the current study, we present a novel PCM variant that tracks the contribution of pre-specified representational patterns to brain representation across areas, thus allowing hypothesis-guided employment of the technique. We apply this technique to investigate the contributions of hedonic and non-hedonic information to the neural representation of tactile experience. We applied aversive pressure and appetitive brush to stimulate distinct peripheral nerve pathways for tactile information (C-/CT-fibers respectively) while patients underwent fMRI scanning. We performed representational similarity analyses with pattern component modeling to dissociate how discriminatory vs. hedonic tactile information contributes to population code representations in the human brain. Results demonstrated that information about appetitive and aversive tactile sensation is represented separately from non-hedonic tactile information across cortical structures. This also demonstrates the potential of new hypothesis-guided PCM variants to help delineate how information is instantiated in the brain.Synthesis StatementThis work provides a novel brain imaging analyses that enables the decomposition of brain states into subcomponent states each associated with distinct patterns of experience or information. This technique is applied to human neuroimaging data acquired during hedonic touch to demonstrate a dual role of somatosensation in affective and sensory experience.The analytic advancement highlights exciting new developments in human neuroscience, allowing for the decomposition of human experience into discrete representation state both within and across brain areas.