The use of transcranial Electrical Stimulation in the modulation of cognitive brain functions to improve neuropsychiatric conditions has extensively increased over the decades. tES techniques have also raised new challenges associated with study design, stimulation protocol, functional specificity, and dose-response relationship. In this paper, we addressed challenges through the emerging methodology to investigate the dose-response relationship of High Definition-transcranial Direct Current Stimulation, identifying the role of negative valence in tinnitus perception. In light of the neurofunctional testable framework and tES application, (...) hypotheses were formulated to measure clinical and surrogate endpoints. We posited that conscious pairing adequately pleasant stimuli with tinnitus perception results in correction of the loudness misperception and would be reinforced by concurrent active HD-tDCS on the left Dorsolateral Prefrontal Cortex. The dose-response relationship between HD-tDCS specificity and the loudness perception is also modeled. We conducted a double-blind, randomized crossover pilot study with six recruited tinnitus patients. Accrued data was utilized to design a well-controlled adaptive seamless Bayesian dose-response study. The sample size and optimum interims were anticipated for adaptive decision-making about efficacy, safety, and single session dose parameters. Furthermore, preliminary pilot study results were sufficient to show a significant difference within the longitudinally detected self-report tinnitus loudness between before and under positive emotion induction. This study demonstrated a research methodology used to improve emotion regulation in tinnitus patients. In the projected method, positive emotion induction is essential for promoting functional targeting under HD-tDCS anatomical specificity to indicate the efficacy and facilitate the dose-finding process. The continuous updating of prior knowledge about efficacy and dose during the exploratory stage adapts the anticipated dose-response model. Consequently, the effective dose range to make superiority neuromodulation in correcting loudness misperception of tinnitus will be redefined. Highly effective dose adapts the study to a standard randomized trial and transforms it into the confirmatory stage in which active HD-tDCS protocol is compared with a sham trial. Establishing the HD-tDCS intervention protocols relying on this novel method provides reliable evidence for regulatory agencies to approve or reject the efficacy and safety. Furthermore, this paper supports a technical report for designing multimodality data-driven complementary investigations in emotion regulation, including EEG-driven neuro markers, Stroop-driven attention biases, and neuroimaging-driven brain network dynamics. (shrink)

Emotions can have both enhancing and impairing effects on various cognitive processes, from lower to higher level processes. The present article discusses emerging brain imaging evidence linking these opposing effects of emotion, which points to overlapping and dissociable neural systems involving both bottom-up and top-down mechanisms. The link between the enhancing and impairing effects is also discussed in a clinical context, with a focus on posttraumatic stress disorder, where these opposing effects tend to co-occur, are exacerbated, and are detrimental. Overall, (...) the present review highlights the need to consider together enhancing and impairing effects of emotion on cognition in studies investigating emotion–cognition interactions. (shrink)

The effect of emotion on memory often leads to the trade-off: enhanced memory for emotional items comes at the cost of memory for background information. Although this effect is usually attributed...