An examination of the effects of eye-tracking on behavior in psychology experiments.

Eye-tracking is emerging as a tool for researchers to better understand cognition and behavior. However, it is possible that experiment participants adjust their behavior when they know their eyes are being tracked. This potential change would be considered a type of Hawthorne effect, in which participants alter their behavior in response to being watched and could potentially compromise the outcomes and conclusions of experimental studies that use eye tracking.

Effects of categorical and numerical feedback on category learning.

Real-world learning signals often come in the form of a continuous range of rewards or punishments, such as receiving more or less money or other reward. However, in laboratory studies, feedback used to examine how humans learn new categories has almost invariably been categorical in nature (i.e.

Neural regions associated with gain-loss frequency and average reward in older and younger adults.

Research on the biological basis of reinforcement-learning has focused on how brain regions track expected value based on average reward. However, recent work suggests that humans are more attuned to reward frequency. Furthermore, older adults are less likely to use expected values to guide choice than younger adults.

Frequency effects in action versus value learning.

Recent work in reinforcement learning has demonstrated a choice preference for an option that has a lower probability of reward (A) when paired with an alternative option that has a higher probability of reward (C), if A has been experienced more frequently than C (the frequency effect). This finding is critical as it is inconsistent with widespread assumptions that expected value is based on average reward, and instead suggests that value is based on cumulative instances of reward. However, option frequency may also affect instrumental reinforcement of choosing A during training, which may then transfer to choice on AC trials.

Hearing hooves, thinking zebras: A review of the inverse base-rate effect.

People often fail to use base-rate information appropriately in decision-making. This is evident in the inverse base-rate effect, a phenomenon in which people tend to predict a rare outcome for a new and ambiguous combination of cues. While the effect was first reported in 1988, it has recently seen a renewed interest from researchers concerned with learning, attention and decision-making.

Preliminary effects of prefrontal tDCS on dopamine-mediated behavior and psychophysiology.

The ability to manipulate dopamine in vivo through non-invasive, reversible mechanisms has the potential to impact clinical, translational, and basic research. Recent PET studies have demonstrated increased dopamine release in the striatum after bifrontal transcranial direct current stimulation (tDCS). We sought to extend this work by examining whether bifrontal tDCS could demonstrate an effect on behavioral and physiological correlates of subcortical dopamine activity.

Rest-activity rhythms and white matter microstructure across the lifespan.

Study Objectives: The purpose of this study was to examine how rest-activity (RA) rhythm stability may be associated with white matter microstructure across the lifespan in healthy adults free of significant cardiovascular risk.

Methods: We analyzed multi-shell diffusion tensor images from 103 healthy young and older adults using tract-based spatial statistics (TBSS) to examine relationships between white matter microstructure and RA rhythm stability. RA measures were computed using both cosinor and non-parametric methods derived from 7 days of actigraphy data.

Acute stress enhances tolerance of uncertainty during decision-making.

Acute stress has been shown to influence reward sensitivity, feedback learning, and risk-taking during decision-making, primarily through activation of the hypothalamic pituitary axis (HPA). However, it is unclear how acute stress affects decision-making among choices that vary in their degree of uncertainty. To address this question, we conducted two experiments in which participants repeatedly chose between two options-a high-uncertainty option that offered highly variable rewards but was advantageous in the long-term, and a low-uncertainty option that offered smaller yet more consistent rewards.

Blunted Reward Sensitivity and Trait Disinhibition Interact to Predict Substance Use Problems.

Reward deficit models of addiction posit weaknesses in reward sensitivity to be promotive of substance dependence, while the externalizing spectrum model views substance problems as arising in large part from a general disinhibitory liability. The current study sought to integrate these perspectives by testing for separate and interactive associations of disinhibition and reward dysfunction with interview-assessed substance use disorders (SUDs). Community and college adults ( = 199) completed a scale measure of trait disinhibition and performed a gambling-feedback task yielding a neural index of reward sensitivity, the 'Reward Positivity' (RewP).

Learning reward frequency over reward probability: A tale of two learning rules.

Learning about the expected value of choice alternatives associated with reward is critical for adaptive behavior. Although human choice preferences are affected by the presentation frequency of reward-related alternatives, this may not be captured by some dominant models of value learning, such as the delta rule. In this study, we examined whether reward learning is driven more by learning the probability of reward provided by each option, or how frequently each option has been rewarded, and assess how well models based on average reward (e.

Acute stress improves long-term reward maximization in decision-making under uncertainty.

Acute stress influences reward-seeking tendencies and risky decision-making. However, it is unclear how acute stress influences decision-making in situations in which individuals must learn to either maximize long-term or immediate rewards from experience. Consequently, this study sought to investigate whether acute stress enhances salience of small, immediate or large, delayed rewards on decision-making under uncertainty.

Examining the link between reward and response inhibition in individuals with substance abuse tendencies.

Background: Substance use problems are often characterized by dysregulation in reward sensitivity and inhibitory control. In line with this representation, the goal of this investigation was to determine how substance abuse tendencies among university students affect incentivized response inhibition. Additionally, this study examined whether striatal dopamine moderates the impact of substance use on response inhibition performance.

Gender differences in preference for reward frequency versus reward magnitude in decision-making under uncertainty.

Extensive research has focused on gender differences in intertemporal choices made from in which participants must choose from multiple options that are specified without ambiguity. However, there has been limited work examining gender differences in intertemporal choices made from in which the possible payoffs among choice alternatives are not initially known and can only be gained from experience. Other work suggests that females attend more to reward , whereas males attend more to reward .

Substance use is associated with reduced devaluation sensitivity.

Substance use has been linked to impairments in reward processing and decision-making, yet empirical research on the relationship between substance use and devaluation of reward in humans is limited. We report findings from two studies that tested whether individual differences in substance use behavior predicted reward learning strategies and devaluation sensitivity in a nonclinical sample. Participants in Experiment 1 (N = 66) and Experiment 2 (N = 91) completed subscales of the Externalizing Spectrum Inventory and then performed a two-stage reinforcement learning task that included a devaluation procedure.

Better late than never (or early): Music training in late childhood is associated with enhanced decision-making.

Decision-making is critical to everyday life. Here we ask: to what extent does music training benefit decision-making? Supported by strong associations between music training and enhanced cross-domain skills, we hypothesize that musicians may show decision-making advantages relative to non-musicians. Prior work has also argued for a "critical period" for cross-domain plasticity such that beginning music training early enhances sensorimotor brain regions that mature early in life.

Model-based fMRI reveals dissimilarity processes underlying base rate neglect.

Extensive evidence suggests that people use base rate information inconsistently in decision making. A classic example is the inverse base rate effect (IBRE), whereby participants classify ambiguous stimuli sharing features of both common and rare categories as members of the rare category. Computational models of the IBRE have posited that it arises either from associative similarity-based mechanisms or from dissimilarity-based processes that may depend on higher-level inference.

A Case of Divergent Predictions Made by Delta and Decay Rule Learning Models.

The Delta and Decay rules are two learning rules used to update expected values in reinforcement learning (RL) models. The delta rule learns rewards, whereas the decay rule learns rewards for each option. Participants learned to select between pairs of options that had reward probabilities of .

Ostracism Reduces Reliance on Poor Advice from Others during Decision Making.

Decision-making is rarely context-free, and often both social information and non-social information are weighed into one's decisions. Incorporating information into a decision can be influenced by previous experiences. Ostracism has extensive effects, including taxing cognitive resources and increasing social monitoring.

Striatal Dopamine, Externalizing Proneness, and Substance Abuse: Effects on Wanting and Learning during Reward-Based Decision Making.

We examined whether striatal dopamine moderates the impact of externalizing proneness (disinhibition) on reward-based decision-making. Participants completed disinhibition and substance abuse subscales of the brief form Externalizing Spectrum Inventory, and then performed a delay discounting task to assess preference for immediate rewards along with a dynamic decision-making task that assessed long-term reward learning (i.e.

To not settle for small losses: evidence for an ecological aspiration level of zero in dynamic decision-making.

This work aimed to investigate how one's aspiration level is set in decision-making involving losses and how people respond when all alternatives appear to be below the aspiration level. We hypothesized that the zero point would serve as an ecological aspiration level where losses cause participants to focus on improvements in payoffs. In two experiments, we investigated these issues by combining behavioral studies and computational modeling.

Dopaminergic Genetic Polymorphisms Predict Rule-based Category Learning.

Dopaminergic genes play an important role in cognitive function. DRD2 and DARPP-32 dopamine receptor gene polymorphisms affect striatal dopamine binding potential, and the Val158Met single-nucleotide polymorphism of the COMT gene moderates dopamine availability in the pFC. Our study assesses the role of these gene polymorphisms on performance in two rule-based category learning tasks.

Neural correlates of state-based decision-making in younger and older adults.

Older and younger adults performed a state-based decision-making task while undergoing functional MRI (fMRI). We proposed that younger adults would be more prone to base their decisions on expected value comparisons, but that older adults would be more reactive decision-makers who would act in response to recent changes in rewards or states, rather than on a comparison of expected values. To test this we regressed BOLD activation on two measures from a sophisticated reinforcement learning (RL) model.

Chronic motivational state interacts with task reward structure in dynamic decision-making.

Research distinguishes between a habitual, model-free system motivated toward immediately rewarding actions, and a goal-directed, model-based system motivated toward actions that improve future state. We examined the balance of processing in these two systems during state-based decision-making. We tested a regulatory fit hypothesis (Maddox & Markman, 2010) that predicts that global trait motivation affects the balance of habitual- vs.

Dopamine, depressive symptoms, and decision-making: the relationship between spontaneous eye blink rate and depressive symptoms predicts Iowa Gambling Task performance.

Depressive symptomatology has been associated with alterations in decision-making, although conclusions have been mixed, with depressed individuals showing impairments in some contexts but advantages in others. The dopaminergic system may link depressive symptoms with decision-making performance. We assessed the role of striatal dopamine D2 receptor density, using spontaneous eye blink rates, in moderating the relationship between depressive symptoms and decision-making performance in a large undergraduate sample that had not been screened for mental illness (N = 104).

Information about foregone rewards impedes dynamic decision-making in older adults.

"Making an informed decision" implies that more information leads to better decisions, yet it may be the case that additional information biases decisions in a systematic and sometimes detrimental manner. In the present study, we examined the effect of additional information on older adults' decision-making using a task for which available rewards were dependent on the participant's recent pattern of choices. The optimal strategy was to forego the immediately rewarding option in favor of the option that yielded larger delayed reward.