Month: September 2020

David Zald
Center for Advanced Human Brain Imaging Research
Rutgers University

The emotional attentional blink (EAB) refers to a transient impairment in the ability to detect or discriminate a target when it is presented closely in time to an emotional distractor. The paradigm, which is also referred to in the literature as emotion induced blindness, has provided insight into the nature of bottom-up capture of attention by emotionally salient stimuli in both health and in psychopathology. Although the most dramatic aspect of the phenomena occurs when the target is not perceived at all, recent data indicate that the effects of the emotional distractor are more consistent with a graded impact on target processing than a purely “all or none” phenomena, with emotional distractors often slowing target detection and lowering the subjective vividness of target representations, rather than eliminating all subjective awareness of the target. Such data have implications for computational models of the competition of bottom-up and top-down attentional mechanisms.

Thorsten Kahnt
Department of Neurology
Northwestern University Feinberg School of Medicine

Research across species has shown that the orbitofrontal cortex (OFC) is important for decision making. However, it is less clear what specific computations are carried out in this region that make it so important for this function. Recent work from our lab and others has shown that OFC activity is correlated with expectations about specific outcomes. In this talk, I will present evidence from functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) experiments suggesting that outcome expectations in OFC are required for decisions that are based on inferred or simulated outcomes, as opposed to behavior that can be based on direct experience alone. Because OFC is not directly accessible to TMS, we utilize network-targeted TMS and apply continuous theta burst stimulation (cTBS) to sites in lateral PFC that are individually selected to be functionally connected to the OFC. We show that OFC network-targeted cTBS selectively disrupts choices that require subjects to infer outcomes, without affecting choices that can be based on direct experiences alone. These findings suggest that the OFC contributes to decision making by representing associative relationships that can be used to simulate outcomes when direct experience is missing.