Efficient foraging requires an ability to coordinate discrete reward-seeking and reward-retrieval... more Efficient foraging requires an ability to coordinate discrete reward-seeking and reward-retrieval behaviors. We used pathway-specific chemogenetic inhibition to investigate how rats’ mesolimbic and mesocortical dopamine circuits contribute to the expression and modulation of reward seeking and retrieval. Inhibiting ventral tegmental area dopamine neurons disrupted the tendency for reward-paired cues to motivate reward seeking, but spared their ability to increase attempts to retrieve reward. Similar effects were produced by inhibiting dopamine inputs to nucleus accumbens, but not medial prefrontal cortex. Inhibiting dopamine neurons spared the suppressive effect of reward devaluation on reward seeking, an assay of goal-directed behavior. Attempts to retrieve reward persisted after devaluation, indicating they were habitually performed as part of a fixed action sequence. Our findings show that complete bouts of reward seeking and retrieval are behaviorally and neurally dissociable fr...
As scientists, we are keenly aware that if putative causes perfectly co-vary, the independent inf... more As scientists, we are keenly aware that if putative causes perfectly co-vary, the independent influence of neither can be discerned, a no confounding constraint on inference, fundamental to philosophical and statistical perspectives on causation. Intriguingly, a substantial behavioral literature suggests that naive human reasoners, adults and children, are tacitly sensitive to causal confounding. Here, a combination of fMRI and cognitive modeling was used to investigate neural substrates mediating such sensitivity. While being scanned, participants observed and judged the influences of various putative causes with confounded or non-confounded, deterministic or stochastic, influences. Formal comparisons of a Bayesian causal model, sensitive to both confounding and stochasticity, and a purely error-driven algorithm, sensitive only to stochasticity, revealed selective neural representations of uncertainty across several regions, including the DMPFC and insula. Implications for the dete...
Consensus seeking -abandoning one's own judgment to align with a group majority -is a fundamental... more Consensus seeking -abandoning one's own judgment to align with a group majority -is a fundamental feature of human social interaction. Notably, such striving for majority affiliation often occurs in the absence of any apparent economic or social gain, suggesting that achieving consensus might have intrinsic value. Here, using a simple gambling task, in which the decisions of ostensible previous gamblers were indicated below available options on each trial, we examined the affective properties of agreeing with a group majority by assessing the trade-off between social and non-social currencies, and the transfer of social valence to concomitant stimuli. In spite of demonstrating near-perfect knowledge of objective reward probabilities, participant's choices and evaluative judgments reflected a reliable preference for conformity, consistent with the hypothesized value of social alignment.
Reward-paired cues stimulate reward-seeking behavior through a combination of motivational and co... more Reward-paired cues stimulate reward-seeking behavior through a combination of motivational and cognitive processes. We used pathway-specific chemogenetic inhibition of dopamine neurons to determine their role in the cue-elicited reward seeking, and applied a novel analytic approach to assay cue-induced changes in reward expectancy. Inhibiting ventral tegmental area dopamine neurons abolished cue-induced reward seeking but not reward retrieval, indicating that this pathway modulates response vigor but not reward expectancy. Locally inhibiting dopamine inputs to nucleus accumbens also disrupted cue-elicited reward seeking but not retrieval. Interestingly, the suppression produced by this treatment was greater in rats that responded to cues with exploratory reward seeking, without attempting to retrieve reward, than in rats exhibiting complete bouts of seeking with retrieval, indicating that individuals differ in their reliance on a dopamine-mediated motivational process. These finding...
A critical aspect of flexible choice is that alternative actions yield distinct consequences: Onl... more A critical aspect of flexible choice is that alternative actions yield distinct consequences: Only when available action alternatives produce distinct outcome states does discrimination and selection between actions allow an agent to flexibly obtain the currently most desired outcome. Here, we use instrumental divergence -the degree to which alternative actions differ with respect to their outcome probability distributions -as an index of flexible instrumental control, and assess the influence of this novel decision variable on choice preference. In Experiment 1, when other decision variables, such as expected value and outcome entropy, were held constant, we found a significant preference for high instrumental divergence. In Experiment 2, we used an "auto-vs. self-play" manipulation to eliminate outcome diversity as a source of behavioral preferences, and to contrast flexible instrumental control with the complete absence of voluntary choice. Our results suggest that flexible instrumental control over decision outcomes may have intrinsic value.
Recent research in instrumental conditioning has focused on the striatum, particularly the role o... more Recent research in instrumental conditioning has focused on the striatum, particularly the role of the dorsal striatum in the learning processes that contribute to instrumental performance in rats. This research has found evidence of what appear to be parallel, functionally and anatomically distinct circuits involving dorsomedial striatum (DMS) and dorsolateral striatum (DLS) that contribute to two independent instrumental learning processes. Evidence suggests that the formation of the critical action-outcome associations mediating goal-directed action are localized to the dorsomedial striatum, whereas the sensorimotor connections that control the performance of habitual actions are localized to the dorsolateral striatum. In addition to the dorsal striatum, these learning processes appear to engage distinct corticostriatal networks and to be embedded in a complex of converging and partially segregated loops that constitute the cortico-striatal thalamo-cortical feedback circuit. As the entry point for the basal ganglia, cortical circuits involving the dorsal striatum are clearly in a position to control a variety of motor functions but, as recent studies of various neurodegenerative disorders have made clear, they are also involved in a number of cognitive and executive functions including action selection, planning, and decision-making.
Two competing psychological models of causal strength estimation make different predictions regar... more Two competing psychological models of causal strength estimation make different predictions regarding when simple causal hypotheses will be rejected in favor of more complex ones. Two experiments tested these predictions, employing a novel method for indirectly assessing perceived causal strength. In both experiments, the task required a judgment regarding the existence of an interaction between a candidate cause and unobserved background causes. Results indicate that reasoners revise simple causal hypotheses based on the mental construct of causal power .
We present a Bayesian model of causal learning that incorporates generic priors on distributions ... more We present a Bayesian model of causal learning that incorporates generic priors on distributions of weights representing potential powers to either produce or prevent an effect. These generic priors favor necessary and sufficient causes. Across three experiments, the model explains the systematic pattern of human judgments observed for questions regarding support for a causal link, for both generative and preventive causes.
According to the causal power view, two core constraints-that causes occur independently (i.e., n... more According to the causal power view, two core constraints-that causes occur independently (i.e., no confounding) and influence their effects independently-serve as boundary conditions for causal induction. This study investigated how violations of these constraints modulate uncertainty about the existence and strength of a causal relationship. Participants were presented with pairs of candidate causes that were either confounded or not, and that either interacted or exerted their influences independently. Consistent with the causal power view, uncertainty about the existence and strength of causal relationships was greater when causes were confounded or interacted than when unconfounded and acting independently. An elemental Bayesian causal model captured differences in uncertainty due to confounding but not those due to an interaction. Implications of distinct sources of uncertainty for the selection of contingency information and causal generalization are discussed.
Two competing psychological models of causal strength estimation make different predictions regar... more Two competing psychological models of causal strength estimation make different predictions regarding when simple causal hypotheses will be rejected in favor of more complex ones. Two experiments tested these predictions, employing a novel method for indirectly assessing perceived causal strength. In both experiments, the task required a judgment regarding the existence of an interaction between a candidate cause and unobserved background causes. Results indicate that reasoners revise simple causal hypotheses based on the mental construct of causal power .
Logical consistency and objectivity are cornerstones of science that distinguish it from cult and... more Logical consistency and objectivity are cornerstones of science that distinguish it from cult and dogma. Scientists' concern with objectivity has led to the dominance of associative statistics, which define the basic concept of independence on observations. The same concern with avoiding subjective beliefs has led many scientific journals to favor frequentist over Bayesian statistics. Our analysis here reveals that to infer causes of a binary outcome, (1) the associative definition of independence results in a logical inconsistency --even for data from an ideal experiment --for both frequentist and Bayesian statistics, and (2) removing the logical error requires defining independence on counterfactual causal events. The logically coherent causal definition is the one intuitively adopted by humans. Our findings have direct implications for more consistent and generalizable causal discoveries in medicine and other sciences.
Efficient foraging requires an ability to coordinate discrete reward-seeking and reward-retrieval... more Efficient foraging requires an ability to coordinate discrete reward-seeking and reward-retrieval behaviors. We used pathway-specific chemogenetic inhibition to investigate how rats’ mesolimbic and mesocortical dopamine circuits contribute to the expression and modulation of reward seeking and retrieval. Inhibiting ventral tegmental area dopamine neurons disrupted the tendency for reward-paired cues to motivate reward seeking, but spared their ability to increase attempts to retrieve reward. Similar effects were produced by inhibiting dopamine inputs to nucleus accumbens, but not medial prefrontal cortex. Inhibiting dopamine neurons spared the suppressive effect of reward devaluation on reward seeking, an assay of goal-directed behavior. Attempts to retrieve reward persisted after devaluation, indicating they were habitually performed as part of a fixed action sequence. Our findings show that complete bouts of reward seeking and retrieval are behaviorally and neurally dissociable fr...
As scientists, we are keenly aware that if putative causes perfectly co-vary, the independent inf... more As scientists, we are keenly aware that if putative causes perfectly co-vary, the independent influence of neither can be discerned, a no confounding constraint on inference, fundamental to philosophical and statistical perspectives on causation. Intriguingly, a substantial behavioral literature suggests that naive human reasoners, adults and children, are tacitly sensitive to causal confounding. Here, a combination of fMRI and cognitive modeling was used to investigate neural substrates mediating such sensitivity. While being scanned, participants observed and judged the influences of various putative causes with confounded or non-confounded, deterministic or stochastic, influences. Formal comparisons of a Bayesian causal model, sensitive to both confounding and stochasticity, and a purely error-driven algorithm, sensitive only to stochasticity, revealed selective neural representations of uncertainty across several regions, including the DMPFC and insula. Implications for the dete...
Consensus seeking -abandoning one's own judgment to align with a group majority -is a fundamental... more Consensus seeking -abandoning one's own judgment to align with a group majority -is a fundamental feature of human social interaction. Notably, such striving for majority affiliation often occurs in the absence of any apparent economic or social gain, suggesting that achieving consensus might have intrinsic value. Here, using a simple gambling task, in which the decisions of ostensible previous gamblers were indicated below available options on each trial, we examined the affective properties of agreeing with a group majority by assessing the trade-off between social and non-social currencies, and the transfer of social valence to concomitant stimuli. In spite of demonstrating near-perfect knowledge of objective reward probabilities, participant's choices and evaluative judgments reflected a reliable preference for conformity, consistent with the hypothesized value of social alignment.
Reward-paired cues stimulate reward-seeking behavior through a combination of motivational and co... more Reward-paired cues stimulate reward-seeking behavior through a combination of motivational and cognitive processes. We used pathway-specific chemogenetic inhibition of dopamine neurons to determine their role in the cue-elicited reward seeking, and applied a novel analytic approach to assay cue-induced changes in reward expectancy. Inhibiting ventral tegmental area dopamine neurons abolished cue-induced reward seeking but not reward retrieval, indicating that this pathway modulates response vigor but not reward expectancy. Locally inhibiting dopamine inputs to nucleus accumbens also disrupted cue-elicited reward seeking but not retrieval. Interestingly, the suppression produced by this treatment was greater in rats that responded to cues with exploratory reward seeking, without attempting to retrieve reward, than in rats exhibiting complete bouts of seeking with retrieval, indicating that individuals differ in their reliance on a dopamine-mediated motivational process. These finding...
A critical aspect of flexible choice is that alternative actions yield distinct consequences: Onl... more A critical aspect of flexible choice is that alternative actions yield distinct consequences: Only when available action alternatives produce distinct outcome states does discrimination and selection between actions allow an agent to flexibly obtain the currently most desired outcome. Here, we use instrumental divergence -the degree to which alternative actions differ with respect to their outcome probability distributions -as an index of flexible instrumental control, and assess the influence of this novel decision variable on choice preference. In Experiment 1, when other decision variables, such as expected value and outcome entropy, were held constant, we found a significant preference for high instrumental divergence. In Experiment 2, we used an "auto-vs. self-play" manipulation to eliminate outcome diversity as a source of behavioral preferences, and to contrast flexible instrumental control with the complete absence of voluntary choice. Our results suggest that flexible instrumental control over decision outcomes may have intrinsic value.
Recent research in instrumental conditioning has focused on the striatum, particularly the role o... more Recent research in instrumental conditioning has focused on the striatum, particularly the role of the dorsal striatum in the learning processes that contribute to instrumental performance in rats. This research has found evidence of what appear to be parallel, functionally and anatomically distinct circuits involving dorsomedial striatum (DMS) and dorsolateral striatum (DLS) that contribute to two independent instrumental learning processes. Evidence suggests that the formation of the critical action-outcome associations mediating goal-directed action are localized to the dorsomedial striatum, whereas the sensorimotor connections that control the performance of habitual actions are localized to the dorsolateral striatum. In addition to the dorsal striatum, these learning processes appear to engage distinct corticostriatal networks and to be embedded in a complex of converging and partially segregated loops that constitute the cortico-striatal thalamo-cortical feedback circuit. As the entry point for the basal ganglia, cortical circuits involving the dorsal striatum are clearly in a position to control a variety of motor functions but, as recent studies of various neurodegenerative disorders have made clear, they are also involved in a number of cognitive and executive functions including action selection, planning, and decision-making.
Two competing psychological models of causal strength estimation make different predictions regar... more Two competing psychological models of causal strength estimation make different predictions regarding when simple causal hypotheses will be rejected in favor of more complex ones. Two experiments tested these predictions, employing a novel method for indirectly assessing perceived causal strength. In both experiments, the task required a judgment regarding the existence of an interaction between a candidate cause and unobserved background causes. Results indicate that reasoners revise simple causal hypotheses based on the mental construct of causal power .
We present a Bayesian model of causal learning that incorporates generic priors on distributions ... more We present a Bayesian model of causal learning that incorporates generic priors on distributions of weights representing potential powers to either produce or prevent an effect. These generic priors favor necessary and sufficient causes. Across three experiments, the model explains the systematic pattern of human judgments observed for questions regarding support for a causal link, for both generative and preventive causes.
According to the causal power view, two core constraints-that causes occur independently (i.e., n... more According to the causal power view, two core constraints-that causes occur independently (i.e., no confounding) and influence their effects independently-serve as boundary conditions for causal induction. This study investigated how violations of these constraints modulate uncertainty about the existence and strength of a causal relationship. Participants were presented with pairs of candidate causes that were either confounded or not, and that either interacted or exerted their influences independently. Consistent with the causal power view, uncertainty about the existence and strength of causal relationships was greater when causes were confounded or interacted than when unconfounded and acting independently. An elemental Bayesian causal model captured differences in uncertainty due to confounding but not those due to an interaction. Implications of distinct sources of uncertainty for the selection of contingency information and causal generalization are discussed.
Two competing psychological models of causal strength estimation make different predictions regar... more Two competing psychological models of causal strength estimation make different predictions regarding when simple causal hypotheses will be rejected in favor of more complex ones. Two experiments tested these predictions, employing a novel method for indirectly assessing perceived causal strength. In both experiments, the task required a judgment regarding the existence of an interaction between a candidate cause and unobserved background causes. Results indicate that reasoners revise simple causal hypotheses based on the mental construct of causal power .
Logical consistency and objectivity are cornerstones of science that distinguish it from cult and... more Logical consistency and objectivity are cornerstones of science that distinguish it from cult and dogma. Scientists' concern with objectivity has led to the dominance of associative statistics, which define the basic concept of independence on observations. The same concern with avoiding subjective beliefs has led many scientific journals to favor frequentist over Bayesian statistics. Our analysis here reveals that to infer causes of a binary outcome, (1) the associative definition of independence results in a logical inconsistency --even for data from an ideal experiment --for both frequentist and Bayesian statistics, and (2) removing the logical error requires defining independence on counterfactual causal events. The logically coherent causal definition is the one intuitively adopted by humans. Our findings have direct implications for more consistent and generalizable causal discoveries in medicine and other sciences.
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Papers by Mimi Liljeholm