Pulvinar and Affective Significance: Responses Track Moment-to-Moment Stimulus Visibility

Research on emotion has considered the pulvinar to be an important component of a subcortical pathway conveying visual information to the amygdala in a largely “automatic” fashion. An older literature has focused on understanding the role of the pulvinar in visual attention. To address the inconsistency between these independent literatures, in the present study, we investigated how pulvinar responses are involved in the processing of affectively significant stimuli and how they are influenced by stimulus visibility during attentionally demanding conditions. Subjects performed an attentional blink task during fMRI scanning involving affectively significant (CS+) and neutral stimuli (CS−). Pulvinar responses were not influenced by affective significance (CS+ vs. CS−) per se. Instead, evoked responses were only modulated by affective significance during hit trials, but not during miss trials. Importantly, moment-to-moment fluctuations in response magnitude closely tracked trial-by-trial detection performance, and thereby visibility. This relationship was only reliably detected during the affective condition. Our results do not support a passive role of the pulvinar in affective processing, as invoked in the context of the subcortical-pathway hypothesis. Instead, the pulvinar appears to be involved in mechanisms that are closely linked to attention and awareness. As part of thalamocortical loops with diverse cortical territories, we argue that the medial pulvinar is well positioned to influence information processing in the brain according to a stimulus's biological significance. In particular, when weak and/or brief visual stimuli have affective significance, cortico-pulvino-cortical circuits may act to coordinate and amplify signals in a manner that enhances their behavioral impact

Combined Effects of Attention and Motivation on Visual Task Performance: Transient and Sustained Motivational Effects

We investigated how the brain integrates motivational and attentional signals by using a neuroimaging paradigm that provided separate estimates for transient cue- and target-related signals, in addition to sustained block-related responses. Participants performed a Posner-type task in which an endogenous cue predicted target location on 70% of trials, while motivation was manipulated by varying magnitude and valence of a cash incentive linked to task performance. Our findings revealed increased detection performance (d′) as a function of incentive value. In parallel, brain signals revealed that increases in absolute incentive magnitude led to cue- and target-specific response modulations that were independent of sustained state effects across visual cortex, fronto-parietal regions, and subcortical regions. Interestingly, state-like effects of incentive were observed in several of these brain regions, too, suggesting that both transient and sustained fMRI signals may contribute to task performance. For both cue and block periods, the effects of administering incentives were correlated with individual trait measures of reward sensitivity. Taken together, our findings support the notion that motivation improves behavioral performance in a demanding attention task by enhancing evoked responses across a distributed set of anatomical sites, many of which have been previously implicated in attentional processing. However, the effect of motivation was not simply additive as the impact of absolute incentive was greater during invalid than valid trials in several brain regions, possibly because motivation had a larger effect on reorienting than orienting attentional mechanisms at these sites

Differential modulations of reward expectation on implicit facial emotion processing: ERP evidence

Implicit emotional processing refers to the preferential processing of emotional content even if it is task irrelevant. Given that motivation enhances executive control by biasing attentional resources toward target stimuli, here we investigated the effects of reward expectation on implicit facial emotional processing in two experiments using ERPs. A precue signaling additional monetary reward for fast and accurate response for the upcoming trial (incentive condition; relative to a cue indicating no such additional reward, i.e., nonincentive condition) was followed by the presentation of a happy, angry, or neutral face. Participants had to determine the gender of the face in Experiment 1 and decide whether a number superimposed on the face was even or odd in Experiment 2. In both experiments, incentive cues elicited larger P3 and contingent negative variation responses, and the targets following incentive cues elicited more positive-going ERPs (200-700 ms), compared with the nonincentive condition. Importantly, the N2 responses (200-280 ms) to the target exhibited differential patterns of Reward × Emotion interaction: relative to the nonincentive condition, the N2 amplitude differences between emotional (i.e., happy and/or angry) and neutral faces increased in the incentive condition in Experiment 1, but diminished in Experiment 2. These results indicate that reward expectation can differentially modulate implicit processing of facial expressions, with increased sensitivity to emotions when the processing of whole faces is required, but with reduced sensitivity when the processing of faces is distractive. This study enriches the evidence for interactions between reward-related executive control and implicit emotional processing

The variable nature of cognitive control in a university sample of young adult drinkers

The current study investigates the effect of task-irrelevant alcohol distractors on cognitive control and its interaction with heavy/light drinking in a group of young adult drinkers. It was hypothesised that alcohol distractors would result in a reduction of proactive control (reduced conflict adaptation) especially in heavy drinkers. 60 participants took part in a face-word version of the Stroop task preceded by an alcohol or neutral image. Light drinkers only showed a congruency effect which indicated a greater level of proactive control. Heavy drinkers showed a greater level of reactive control in which the conflict adaptation effect occurred with neutral images but not with alcohol images. Possible explanations are discussed

Reward elicits cognitive control over emotional distraction:Evidence from pupillometry

Attention is biased toward emotional stimuli, even when they are irrelevant to current goals. Motivation, elicited by performance-contingent reward, reduces behavioural emotional distraction. In emotionally-neutral contexts, reward is thought to encourage use of a proactive cognitive control strategy, altering anticipatory attentional settings to more effectively suppress distractors. The current preregistered study investigates whether a similar proactive shift occurs even when distractors are highly arousing emotional images. We monitored pupil area, an online measure of both cognitive and emotional processing, to examine how reward influences the timecourse of control. Participants (n = 110) identified a target letter flanking an irrelevant central image. Images were meaningless scrambles on 75% of trials; on the remaining 25%, they were intact positive (erotic), negative (mutilation), or neutral images. Half the participants received financial rewards for fast and accurate performance, while the other half received no performance-contingent reward. Emotional distraction was greater than neutral distraction, and both were attenuated by reward. Consistent with behavioural findings, pupil dilation was greater following emotional than neutral distractors, and dilation to intact distractors (regardless of valence) was decreased by reward. Although reward did not enhance tonic pupil dilation (an index of sustained proactive control), exploratory analyses showed that reward altered the timecourse of control – eliciting a sharp, rapid, increase in dilation immediately preceding stimulus-onset (reflecting dynamic use of anticipatory control), that extended until well after stimulus-offset. These findings suggest that reward alters the timecourse of control by encouraging proactive preparation to rapidly disengage from emotional distractors

Context Modulation of Facial Emotion Perception Differed by Individual Difference

Background: Certain facial configurations are believed to be associated with distinct affective meanings (i.e. basic facial expressions), and such associations are common across cultures (i.e. universality of facial expressions). However, recently, many studies suggest that various types of contextual information, rather than facial configuration itself, are important factor for facial emotion perception. Methodology/Principal Findings: To examine systematically how contextual information influences individuals ’ facial emotion perception, the present study estimated direct observers ’ perceptual thresholds for detecting negative facial expressions via a forced-choice psychophysical procedure using faces embedded in various emotional contexts. We additionally measured the individual differences in affective information-processing tendency (BIS/BAS) as a possible factor that may determine the extent to which contextual information on facial emotion perception is used. It was found that contextual information influenced observers ’ perceptual thresholds for facial emotion. Importantly, individuals ’ affectiveinformation tendencies modulated the extent to which they incorporated context information into their facial emotion perceptions. Conclusions/Significance: The findings of this study suggest that facial emotion perception not only depends on facial configuration, but the context in which the face appears as well. This contextual influence appeared differently wit

The Role of Stimulus Salience and Attentional Capture Across the Neural Hierarchy in a Stop-Signal Task

Inhibitory motor control is a core function of cognitive control. Evidence from diverse experimental approaches has linked this function to a mostly right-lateralized network of cortical and subcortical areas, wherein a signal from the frontal cortex to the basal ganglia is believed to trigger motor-response cancellation. Recently, however, it has been recognized that in the context of typical motor-control paradigms those processes related to actual response inhibition and those related to the attentional processing of the relevant stimuli are highly interrelated and thus difficult to distinguish. Here, we used fMRI and a modified Stop-signal task to specifically examine the role of perceptual and attentional processes triggered by the different stimuli in such tasks, thus seeking to further distinguish other cognitive processes that may precede or otherwise accompany the implementation of response inhibition. In order to establish which brain areas respond to sensory stimulation differences by rare Stop-stimuli, as well as to the associated attentional capture that these may trigger irrespective of their task-relevance, we compared brain activity evoked by Stop-trials to that evoked by Go-trials in task blocks where Stop-stimuli were to be ignored. In addition, region-of-interest analyses comparing the responses to these task-irrelevant Stop-trials, with those to typical relevant Stop-trials, identified separable activity profiles as a function of the task-relevance of the Stop-signal. While occipital areas were mostly blind to the task-relevance of Stop-stimuli, activity in temporo-parietal areas dissociated between task-irrelevant and task-relevant ones. Activity profiles in frontal areas, in turn, were activated mainly by task-relevant Stop-trials, presumably reflecting a combination of triggered top-down attentional influences and inhibitory motor-control processes

On the Role of the Striatum in Response Inhibition

BACKGROUND: Stopping a manual response requires suppression of the primary motor cortex (M1) and has been linked to activation of the striatum. Here, we test three hypotheses regarding the role of the striatum in stopping: striatum activation during successful stopping may reflect suppression of M1, anticipation of a stop-signal occurring, or a slower response build-up. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-four healthy volunteers underwent functional magnetic resonance imaging (fMRI) while performing a stop-signal paradigm, in which anticipation of stopping was manipulated using a visual cue indicating stop-signal probability, with their right hand. We observed activation of the striatum and deactivation of left M1 during successful versus unsuccessful stopping. In addition, striatum activation was proportional to the degree of left M1 deactivation during successful stopping, implicating the striatum in response suppression. Furthermore, striatum activation increased as a function of stop-signal probability and was to linked to activation in the supplementary motor complex (SMC) and right inferior frontal cortex (rIFC) during successful stopping, suggesting a role in anticipation of stopping. Finally, trial-to-trial variations in response time did not affect striatum activation. CONCLUSIONS/SIGNIFICANCE: The results identify the striatum as a critical node in the neural network associated with stopping motor responses. As striatum activation was related to both suppression of M1 and anticipation of a stop-signal occurring, these findings suggest that the striatum is involved in proactive inhibitory control over M1, most likely in interaction with SMC and rIFC

Transient and sustained incentive effects on electrophysiological indices of cognitive control in younger and older adults

Preparing for upcoming events, separating task-relevant from task-irrelevant information and efficiently responding to stimuli all require cognitive control. The adaptive recruitment of cognitive control depends on activity in the dopaminergic reward system as well as the frontoparietal control network. In healthy aging, dopaminergic neuromodulation is reduced, resulting in altered incentive-based recruitment of control mechanisms. In the present study, younger adults (18–28 years) and healthy older adults (66–89 years) completed an incentivized flanker task that included gain, loss, and neutral trials. Event-related potentials (ERPs) were recorded at the time of incentive cue and target presentation. We examined the contingent negative variation (CNV), implicated in stimulus anticipation and response preparation, as well as the P3, which is involved in the evaluation of visual stimuli. Both younger and older adults showed transient incentive-based modulation of CNV. Critically, cue-locked and target-locked P3s were influenced by transient and sustained effects of incentives in younger adults, while such modulation was limited to a sustained effect of gain incentives on cue-P3 in older adults. Overall, these findings are in line with an age-related reduction in the flexible recruitment of preparatory and target-related cognitive control processes in the presence of motivational incentives