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Wieser, M. J.

Publications and source records attributed to Wieser, M. J..

2 recordsLinked to original sources
bioRxiv2018

Affectively-biased Competition Favoring Rewarding Expressions is Not Modulated by Common Variation in Norepinephrine Receptor Function

It is well established that emotionally salient stimuli evoke greater visual cortex activation than neutral ones, and can distract attention from competing tasks. Yet less is known about underlying neurobiological processes. As a proxy of population level biased competition, EEG steady-state visual evoked potentials are sensitive to competition effects from salient stimuli. Here we wished to examine whether individual differences in norepinephrine activity play a role in emotionally-biased competition.\n\nOur previous research has found robust effects of a common variation in the ADRA2B gene, coding for alpha2B norepinephrine (NE) receptors, on emotional modulation of attention and memory. In the present study, EEG was collected while 87 carriers of the ADRA2B deletion variant and 95 non-carriers (final sample) performed a change detection task in which target gratings (gabor patches) were superimposed directly over angry, happy, and neutral faces. Participants indicated the number of phase changes (0-3) in the target. Overlapping targets and distractors were flickered at a distinct driving frequencies. Relative EEG power for faces vs. targets at the driving frequency served as an index of cortical resources allocated to each of the competing stimuli. Deletion carriers and non-carriers were randomly assigned to Discovery and Replication samples and reliability of results across samples was assessed before the groups were combined for greater power.\n\nOverall happy faces evoked higher competition than angry or neutral faces; however, we observed no hypothesized effects of ADRA2B. Increased competition from happy faces was not due to the effect of low-level visual features or individuals low in social anxiety. Our results indicate that emotionally biased competition during sustained attention, while reliably observed in young adults, is not influenced by commonly observed individual differences linked to NE receptor function. They further indicate an overall pattern of affectively-biased competition for happy faces, which we interpret in relation to previously observed boundary conditions.

neuroscience↗
bioRxiv2018

Model-based Pavlovian control of attention to threat.

Signals for reward or punishment attract attention preferentially, a principle termed value-modulated attention capture (VMAC). The mechanisms that govern the allocation of attention resources can be productively described with a terminology that is more often applied to the control of overt behaviours, namely, the distinction between instrumental and Pavlovian control, and between model-free and model-based control. While instrumental control of VMAC can be either model-free or model-based, it is not known whether Pavlovian control of VMAC can be model-based. To decide whether this is possible we measured Steady-State Visual Evoked Potentials (SSVEPs) while 20 healthy adults took part in a novel task. During the learning stage participants underwent aversive threat conditioning with two CSs, one that predicted pain (CS+) and one that predicted safety (CS-). Instructions given prior to the test stage in the task allowed participants to infer whether novel, ambiguous CSs (new CS+/ new CS-) were threatening or safe. Correct inference required combining stored internal representations and new propositional information, the hallmark of model-based control. SSVEP amplitudes quantified the amount of attention allocated to novel CSs on their very first presentation, before they were ever reinforced. We found that SSVEPs were higher for new CS+ than new CS-. Because task design precluded model-free or instrumental control this result demonstrates a model-based Pavlovian control of VMAC. It confirms, in the domain of internal resource allocation, the model-based Pavlovian control of incentive behaviour and underlines the potential transformative role of information as an emotion regulation technique.

neuroscience↗