Biology subjects

Inzlicht, M.

Publications and source records attributed to Inzlicht, M..

4 recordsLinked to original sources

bioRxiv2017

Electrophysiological indices of anterior cingulate cortex function reveal changing levels of cognitive effort and reward valuation that sustain task performance

Successful execution of goal-directed behaviors often requires the deployment of cognitive control, which is thought to require cognitive effort. Recent theories have proposed that anterior cingulate cortex (ACC) regulates control levels by weighing the reward-related benefits of control against its effort-related costs. However, given that the sensations of cognitive effort and reward valuation are available only to introspection, this hypothesis is difficult to investigate empirically. We have proposed that two electrophysiological indices of ACC function, frontal midline theta and the reward positivity (RewP), provide objective measures of these functions. To investigate this issue, we recorded the electroencephalogram (EEG) from participants engaged in an extended, cognitively-demanding task. Participants performed a time estimation task for 2 hours in which they received reward and error feedback according to their task performance. We observed that the amplitude of the RewP, a feedback-locked component of the event related brain potential associated with reward processing, decreased with time-on-task. Conversely, frontal midline theta power, which consists of 4-8 Hz EEG oscillations associated with cognitive effort, increased with time-on-task. We also examined how these phenomena changed over time by conducting within-participant multi-level modeling analyses. Our results suggest that extended execution of a cognitively-demanding task is characterized by an early phase in which high control levels combine with strong reward valuation to foster rapid improvements in task performance, and a later phase in which high control levels counteract waning reward valuation to maintain stable task performance.

neuroscience↗

bioRxiv2017

Reward sensitivity following boredom and cognitive effort: A high-powered neurophysiological investigation

What do people feel like doing after they have exerted cognitive effort or are bored? Here, we empirically test whether people are drawn to rewards (at the neural level) following cognitive effort and when bored. This elucidates the experiences and consequences of engaging in cognitive effort, and compares it to the consequences of experiencing boredom, an affective state with predicted similar motivational consequences. Event-related potentials were recorded after participants (N=243) were randomized into one of three conditions - boredom (observing strings of numbers), cognitive effort (adding 3 to each digit of a four-digit number), or control. In the subsequent task, we focused on the feedback negativity (FN) to assess the brains immediate response to the presence or absence of reward. Phenomenologically, participants in the boredom condition reported more fatigue than those in the cognitive effort condition. Results suggest participants in the boredom condition exhibited larger FN amplitude than participants in the control condition, while the cognitive effort condition was neither different from boredom nor control. The neural and methodological implications for ego depletion research, including issues of replicability, are discussed.

neuroscience↗

bioRxiv2017

The conflict negativity: Neural correlate of value conflict and indecision during financial decision making

Individuals struggle when making financial decisions, sometimes preferring to avoid difficult decisions and receive lower future rewards over actively deliberating between options of similar value. Here, we examine how conflict deriving from objective and subjective value characteristics of stocks, as well as the behavioural and phenomenological correlates of decision conflict, are accompanied by variation in a thus far understudied ERP component, the conflict negativity (CN). In a novel EEG paradigm (N = 53), we simulated a financial decision situation in which participants made incentivized choices between different, sometimes conflicting, stock options. Our results indicate that participants become slower, more undecided, and less pleased, when choosing between similar options compared to choices in which one option clearly outweighs the other. This effect even held when participants chose between two objectively good alternatives. We further provide preliminary evidence that the CN, a negative-going ERP recorded over the medial prefrontal cortex, is not only sensitive to decision conflict, but also predicts behavioural indecision. What is more, subjective value characteristics of stocks, impressions based on brand perception of the stock options, modestly influenced affective and behavioural reactions over and above objective stock characteristics. While our results are at odds with assumptions made by classic economic theory, they may serve as one out of several indicators as to why private investors seem to avoid financial decisions.

neuroscience↗

bioRxiv2017

Midfrontal theta and pupil dilation parametrically track subjective conflict (but also surprise) during intertemporal choice

Many everyday choices are based on personal, subjective preferences. When choosing between two options, we often feel conflicted, especially when trading off costs and benefits occurring at different times (e.g., saving for later versus spending now). Although previous work has investigated the neurophysiological basis of conflict during inhibitory control tasks, less is known about subjective conflict resulting from competing subjective preferences. In this pre-registered study, we investigated subjective conflict during intertemporal choice, whereby participants chose between smaller immediate versus larger delayed rewards (e.g., $15 today vs. $22 in 30 days). We used economic modeling to parametrically vary eleven different levels of conflict, and recorded EEG data and pupil dilation. Midfrontal theta power, derived from EEG, correlated with pupil responses, and our results suggest that these signals track different gradations of subjective conflict. Unexpectedly, both signals were also maximally enhanced when decisions were surprisingly easy. Therefore, these signals may track events requiring increased attention and adaptive shifts in behavioral responses, with subjective conflict being only one type of such event. Our results suggest that the neural systems underlying midfrontal theta and pupil responses interact when weighing costs and benefits during intertemporal choice. Thus, understanding these interactions might elucidate how individuals resolve self-control conflicts.\n\nHighlightsO_LIModeled conflict during intertemporal choice and measured EEG and pupil responses.\nC_LIO_LIMidfrontal theta and pupil responses parametrically tracked subjective conflict.\nC_LIO_LIBut theta and pupil responses were also large when decisions were surprisingly easy.\nC_LIO_LIThese signals may implement adaptive control during value-guided choice.\nC_LI

neuroscience↗