Neural correlates of effective learning in experienced medical decision-makers.
ABSTRACT: Accurate associative learning is often hindered by confirmation bias and success-chasing, which together can conspire to produce or solidify false beliefs in the decision-maker. We performed functional magnetic resonance imaging in 35 experienced physicians, while they learned to choose between two treatments in a series of virtual patient encounters. We estimated a learning model for each subject based on their observed behavior and this model divided clearly into high performers and low performers. The high performers showed small, but equal learning rates for both successes (positive outcomes) and failures (no response to the drug). In contrast, low performers showed very large and asymmetric learning rates, learning significantly more from successes than failures; a tendency that led to sub-optimal treatment choices. Consistently with these behavioral findings, high performers showed larger, more sustained BOLD responses to failed vs. successful outcomes in the dorsolateral prefrontal cortex and inferior parietal lobule while low performers displayed the opposite response profile. Furthermore, participants' learning asymmetry correlated with anticipatory activation in the nucleus accumbens at trial onset, well before outcome presentation. Subjects with anticipatory activation in the nucleus accumbens showed more success-chasing during learning. These results suggest that high performers' brains achieve better outcomes by attending to informative failures during training, rather than chasing the reward value of successes. The differential brain activations between high and low performers could potentially be developed into biomarkers to identify efficient learners on novel decision tasks, in medical or other contexts.
Project description:OBJECTIVES:The present study examined the day-to-day fluctuation of state-like anticipatory coping (coping employed prior to stressors) and how these coping processes relate to important outcomes for older adults (i.e., physical health, affect, memory failures). METHOD:Forty-three older adults aged 60-96 (M = 74.65, SD = 8.19) participated in an 8-day daily diary study of anticipatory coping, stressors, health, affect, and memory failures. Participants reported anticipatory coping behaviors on one day with respect to 6 distinct stressor domains that could occur the following day. RESULTS:Multilevel models indicated that anticipatory coping changes from day to day and within stressor domains. Lagged associations suggested that yesterday's anticipatory coping for potential upcoming arguments is related to today's physical health and affect. Increased stagnant deliberation is associated with reduced cognitive reactivity (i.e., fewer memory failures) to arguments the next day. DISCUSSION:Taken together, these findings suggest that anticipatory coping is dynamic and associated with important daily outcomes.
Project description:Probabilistic reward learning reflects the ability to adapt choices based on probabilistic feedback. The dopaminergically innervated corticostriatal circuit in the brain plays an important role in supporting successful probabilistic reward learning. Several components of the corticostriatal circuit deteriorate with age, as it does probabilistic reward learning. We showed previously that D1 receptor availability in NAcc predicts the strength of anticipatory value signaling in vmPFC, a neural correlate of probabilistic learning that is attenuated in older participants and predicts probabilistic reward learning performance. We investigated how white matter integrity in the pathway between nucleus accumbens (NAcc) and ventromedial prefrontal cortex (vmPFC) relates to the strength of anticipatory value signaling in vmPFC in younger and older participants. We found that in a sample of 22 old and 23 young participants, fractional anisotropy in the pathway between NAcc and vmPFC predicted the strength of value signaling in vmPFC independently from D1 receptor availability in NAcc. These findings provide tentative evidence that integrity in the dopaminergic and white matter pathways of corticostriatal circuitry supports the expression of value signaling in vmPFC which supports reward learning, however, the limited sample size calls for independent replication. These and future findings could add to the improved understanding of how corticostriatal integrity contributes to reward learning ability.
Project description:Analysis used total RNA samples of individual brain superior protocerebrum of a backcrossed hygienic strain of adult bees maintained in four colonies. Individuals from the four colonies (67, 98, 73, 299) that showed high vs low performances in the behavioural procedure were analysed to determine behavioural differences. Colony and seasonal effects were minimised in this experimental set. A total of 24 biological replicates subdivided in high and low performers was analysed: 2 high and 2 low performers from colony 67, 4 high and 4 low performers from colony 73, 4 high and 4 low performers from colony 98, 2 high and 2 low performers from colony 299 (Arrays 13-36). In a second analysis, colony effects were analysed by comparing high performer bees from different colonies. Seasonal effect were minimised during this experimental set. A total of 12 biological replicates subdivided in high performers from the four colonies were analysed. Three individuals from each colony were compared to individuals from other colonies (Arrays 1-12). Each individual brain RNA sample was divided into two subsamples labelled with cy3 resp. cy5. Dye were swapped for each sample, which was analysed twice with two other samples of the other comparison group. The sample were analysed in 'loop' by terminating the analysis with the comparison of the first sample with the last one.
Project description:People find it easier to learn about topics that interest them, but little is known about the mechanisms by which intrinsic motivational states affect learning. We used functional magnetic resonance imaging to investigate how curiosity (intrinsic motivation to learn) influences memory. In both immediate and one-day-delayed memory tests, participants showed improved memory for information that they were curious about and for incidental material learned during states of high curiosity. Functional magnetic resonance imaging results revealed that activity in the midbrain and the nucleus accumbens was enhanced during states of high curiosity. Importantly, individual variability in curiosity-driven memory benefits for incidental material was supported by anticipatory activity in the midbrain and hippocampus and by functional connectivity between these regions. These findings suggest a link between the mechanisms supporting extrinsic reward motivation and intrinsic curiosity and highlight the importance of stimulating curiosity to create more effective learning experiences.
Project description:Learning from successes and failures often improves the quality of subsequent decisions. Past outcomes, however, should not influence purely perceptual decisions after task acquisition is complete since these are designed so that only sensory evidence determines the correct choice. Yet, numerous studies report that outcomes can bias perceptual decisions, causing spurious changes in choice behavior without improving accuracy. Here we show that the effects of reward on perceptual decisions are principled: past rewards bias future choices specifically when previous choice was difficult and hence decision confidence was low. We identified this phenomenon in six datasets from four laboratories, across mice, rats, and humans, and sensory modalities from olfaction and audition to vision. We show that this choice-updating strategy can be explained by reinforcement learning models incorporating statistical decision confidence into their teaching signals. Thus, reinforcement learning mechanisms are continually engaged to produce systematic adjustments of choices even in well-learned perceptual decisions in order to optimize behavior in an uncertain world.
Project description:Opioid painkillers are a promising treatment for chronic breathlessness, but are associated with potentially fatal side effects. In the treatment of breathlessness, their mechanisms of action are unclear. A better understanding might help to identify safer alternatives. Learned associations between previously neutral stimuli (e.g. stairs) and repeated breathlessness induce an anticipatory threat response that may worsen breathlessness, contributing to the downward spiral of decline seen in clinical populations. As opioids are known to influence associative learning, we hypothesized that they may interfere with the brain processes underlying a conditioned anticipatory response to breathlessness in relevant brain areas, including the amygdala and the hippocampus. Healthy volunteers viewed visual cues (neutral stimuli) immediately before induction of experimental breathlessness with inspiratory resistive loading. Thus, an association was formed between the cue and breathlessness. Subsequently, this paradigm was repeated in two identical neuroimaging sessions with intravenous infusions of either low-dose remifentanil (0.7ng/ml target-controlled infusion) or saline (randomised). During saline infusion, breathlessness anticipation activated the right anterior insula and the adjacent operculum. Breathlessness was associated with activity in a network including the insula, operculum, dorsolateral prefrontal cortex, anterior cingulate cortex and the primary sensory and motor cortices. Remifentanil reduced breathlessness unpleasantness but not breathlessness intensity. Remifentanil depressed anticipatory activity in the amygdala and the hippocampus that correlated with reductions in breathlessness unpleasantness. During breathlessness, remifentanil decreased activity in the anterior insula, anterior cingulate cortex and sensory motor cortices. Remifentanil-induced reduction in breathlessness unpleasantness was associated with increased activity in the rostral anterior cingulate cortex and nucleus accumbens, components of the endogenous opioid system known to decrease the perception of aversive stimuli. These findings suggest that in addition to effects on brainstem respiratory control, opioids palliate breathlessness through an interplay of altered associative learning mechanisms. These mechanisms provide potential targets for novel ways to develop and assess treatments for chronic breathlessness.
Project description:'Anticipatory affect' refers to emotional states that people experience while anticipating significant outcomes. Historically, technical limitations have made it difficult to determine whether anticipatory affect influences subsequent choice. Recent advances in the spatio-temporal resolution of functional magnetic resonance imaging, however, now allow researchers to visualize changes in neural activity seconds before choice occurs. We review evidence that activation in specific brain circuits changes during anticipation of monetary incentives, that this activation correlates with affective experience and that activity in these circuits may influence subsequent choice. Specifically, an activation likelihood estimate meta-analysis of cued response studies indicates that nucleus accumbens (NAcc) activation increases during gain anticipation relative to loss anticipation, while anterior insula activation increases during both loss and gain anticipation. Additionally, anticipatory NAcc activation correlates with self-reported positive arousal, whereas anterior insula activation correlates with both self-reported negative and positive arousal. Finally, NAcc activation precedes the purchase of desirable products and choice of high-risk gambles, whereas anterior insula activation precedes the rejection of overpriced products and choice of low-risk gambles. Together, these findings support a neurally plausible framework for understanding how anticipatory affect can influence choice.
Project description:Probabilistic reward learning is characterised by individual differences that become acute in aging. This may be due to age-related dopamine (DA) decline affecting neural processing in striatum, prefrontal cortex, or both. We examined this by administering a probabilistic reward learning task to younger and older adults, and combining computational modelling of behaviour, fMRI and PET measurements of DA D1 availability. We found that anticipatory value signals in ventromedial prefrontal cortex (vmPFC) were attenuated in older adults. The strength of this signal predicted performance beyond age and was modulated by D1 availability in nucleus accumbens. These results uncover that a value-anticipation mechanism in vmPFC declines in aging, and that this mechanism is associated with DA D1 receptor availability.
Project description:Humans can acquire fear through the observation of others' (learning models') threat responses. These responses can be direct responses to aversive stimuli, or anticipatory responses to threats. Most research focuses on learning from observation of direct responses only. Here, we investigated how observational fear conditioning is influenced by a learning model's typically anxious anticipatory responses. High anxiety individuals often display typically anxious anticipatory behaviour, such as worsened discrimination between safe and unsafe stimuli, characterized by increased threat responses to safe stimuli. We hypothesized that observation of an anxiously behaving model would worsen discriminatory learning. To this end, we developed an observational conditioning paradigm where a learning model was exposed to one safe and one unsafe stimuli. The learning model displayed anticipatory aversion to either to the unsafe stimulus only (Non-Anxious Model group) or to both the safe and unsafe stimuli (Anxious Model group) in addition to reacting directly to an aversive stimulus paired with the unsafe stimulus. Contrary to expectations, discriminatory learning was not worsened in the Anxious Model group compared to the Non-Anxious Model group. Rather, we saw more robust discriminatory learning in the Anxious Model group. The study provides a first step towards understanding the effect of other's anticipatory responses in general and typically anxious anticipatory responses in particular, on observational fear learning.
Project description:To estimate differences in post-treatment psychosocial functioning among treatment 'failures' (i.e. heavy drinkers, defined as 4+/5+ drinks for women/men) from two large multi-site clinical trials and to compare these levels of functioning to those of the purported treatment 'successes' (i.e. non-heavy drinkers).Separate latent profile analyses of data from two of the largest alcohol clinical trials conducted in the United States, COMBINE (Combined Pharmacotherapies and Behavioral Interventions) and Project MATCH (Matching Alcoholism Treatments to Client Heterogeneity), comparing psychosocial outcomes across derived classes of heterogeneous treatment responders.Eleven US academic sites in COMBINE, 27 US treatment sites local to nine research sites in Project MATCH.A total of 962 individuals in COMBINE (69% male, 77% white, mean age: 44 years) treated January 2001 to January 2004 and 1528 individuals in Project MATCH (75% male, 80% white, mean age: 40 years) treated April 1991 to September 1994.In COMBINE, we analyzed health, quality of life, mental health symptoms and alcohol consequences 12 months post-baseline. In Project MATCH, we examined social functioning, mental health symptoms and alcohol consequences 15 months post-baseline.Latent profile analysis of measures of functioning in both samples supported a three-profile solution for the group of treatment 'failures', characterized by high-, average- and low-functioning individuals. The high-functioning treatment 'failures' generally performed better across measures of psychosocial functioning at follow-up than participants designated treatment 'successes' by virtue of being abstainers or light drinkers.Current United States Food and Drug Administration guidance to use heavy drinking as indicative of treatment 'failure' fails to take into account substantial psychosocial improvements made by individuals who continue occasionally to drink heavily post-treatment.