The explore/exploit tradeoff is a fundamental property of choice selection during reward-guided decision making. In perceptual decision making, higher certainty decisions are more motorically precise, even when the decision does not require motor accuracy. However, while we can parametrically control uncertainty in perceptual tasks, we do not know what variables - if any - shape motor precision and reflect subjective certainty during reward-guided decision making.
View Article and Find Full Text PDFPsychopharmacology (Berl)
December 2024
Sex has a strong influence on the prevalence and course of brain conditions, including autism spectrum disorders. The mechanistic basis for these sex differences remains poorly understood, due in part to historical bias in biomedical research favoring analysis of male subjects, and the exclusion of female subjects. For example, studies of male mice carrying autism-associated mutations in neuroligin-3 are over-represented in the literature, including our own prior work showing diminished responses to chronic morphine exposure in male neuroligin-3 knockout mice.
View Article and Find Full Text PDFSex has a strong influence on the prevalence and course of brain conditions, including autism spectrum disorders. The mechanistic basis for these sex differences remains poorly understood, due in part to historical bias in biomedical research favoring analysis of male subjects, and the exclusion of female subjects. For example, studies of male mice carrying autism-associated mutations in neuroligin-3 are over-represented in the literature, including our own prior work showing diminished responses to chronic morphine exposure in male neuroligin-3 knockout mice.
View Article and Find Full Text PDFEssentially all neuropsychiatric diagnoses show some degree of sex and/or gender differences in their etiology, diagnosis, or prognosis. As a result, the roles of sex-related variables in behavior and cognition are of strong interest to many, with several lines of research showing effects on executive functions and value-based decision making in particular. These findings are often framed within a sex binary, with behavior of females described as less optimal than male "defaults"-- a framing that pits males and females against each other and deemphasizes the enormous overlap in fundamental neural mechanisms across sexes.
View Article and Find Full Text PDFThe catecholamines dopamine (DA) and norepinephrine (NE) have been repeatedly implicated in neuropsychiatric vulnerability, in part via their roles in mediating the decision making processes. Although the two neuromodulators share a synthesis pathway and are co-activated under states of arousal, they engage in distinct circuits and roles in modulating neural activity across the brain. However, in the computational neuroscience literature, they have been assigned similar roles in modulating the latent cognitive processes of decision making, in particular the exploration-exploitation tradeoff.
View Article and Find Full Text PDFDelay discounting and probability discounting decision making tasks in rodent models have high translational potential. However, it is unclear whether the discounted value of the large reward option is the main contributor to variability in animals' choices in either task, which may limit translation to humans. Male and female mice underwent sessions of delay and probability discounting in sequence to assess how choice behavior adapts over experience with each task.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
February 2022
We propose a new conceptual framework (computational validity) for translation across species and populations based on the computational similarity between the information processing underlying parallel tasks. Translating between species depends not on the superficial similarity of the tasks presented, but rather on the computational similarity of the strategies and mechanisms that underlie those behaviours. Computational validity goes beyond construct validity by directly addressing questions of information processing.
View Article and Find Full Text PDFSex-based modulation of cognitive processes could set the stage for individual differences in vulnerability to neuropsychiatric disorders. While value-based decision making processes in particular have been proposed to be influenced by sex differences, the overall correct performance in decision making tasks often show variable or minimal differences across sexes. Computational tools allow us to uncover latent variables that define different decision making approaches, even in animals with similar correct performance.
View Article and Find Full Text PDFA frequent assumption in value-based decision-making tasks is that agents make decisions based on the feature dimension that reward probabilities vary on. However, in complex, multidimensional environments, stimuli can vary on multiple dimensions at once, meaning that the feature deserving the most credit for outcomes is not always obvious. As a result, individuals may vary in the strategies used to sample stimuli across dimensions, and these strategies may have an unrecognized influence on decision-making.
View Article and Find Full Text PDFNeuropsychopharmacology
June 2019
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View Article and Find Full Text PDFNeuropsychopharmacology
January 2019
The executive functions allow for purposeful, deliberate, and intentional interactions with the world-attention and focus, impulse control, decision making, and working memory. These measures have been correlated with academic outcomes and quality of life, and are impacted by deleterious environmental events throughout the life span, including gestational and early life insults. This review will address the topic of sex differences in executive function including a discussion of differences arising in response to developmental programming.
View Article and Find Full Text PDFNeurodevelopmental disorders, such as ASD and ADHD, affect males about three to four times more often than females. 16p11.2 hemideletion is a copy number variation that is highly associated with neurodevelopmental disorders.
View Article and Find Full Text PDFDuring gestation, fetal nutrition is entirely dependent on maternal diet. Maternal consumption of excess fat during pregnancy has been linked to an increased risk of neurologic disorders in offspring, including attention deficit/hyperactivity disorder, autism, and schizophrenia. In a mouse model, high-fat diet (HFD)-fed offspring have cognitive and executive function deficits as well as whole-genome DNA and promoter-specific hypomethylation in multiple brain regions.
View Article and Find Full Text PDFNutritional conditions in early life can have a lasting impact on health and disease risk, though the underlying mechanisms are incompletely understood. In the healthy individual, physiological and behavioral responses to stress are coordinated in such a way as to mobilize resources necessary to respond to the stressor and to terminate the stress response at the appropriate time. Induction of proinflammatory gene expression within the brain is one such example that is initiated in response to both physiological and psychological stressors, and is the focus of the current study.
View Article and Find Full Text PDFBirthweight is a marker for suboptimal fetal growth and development in utero. Offspring can be born large for gestational age (LGA), which is linked to maternal obesity or excessive gestational weight gain, as well as small for gestational age (SGA), arising from nutrient or calorie deficiency, placental dysfunction, or other maternal conditions (hypertension, infection). In humans, LGA and SGA babies are at an increased risk for certain neurodevelopmental disorders, including Attention Deficit/Hyperactivity Disorder, schizophrenia, and social and mood disorders.
View Article and Find Full Text PDFA significant contributor to the obesity epidemic is the overconsumption of highly palatable, energy dense foods. Chronic intake of palatable foods is associated with neuroadaptations within the mesocorticolimbic dopamine system adaptations which may lead to behavioral changes, such as overconsumption or bingeing. We examined behavioral and molecular outcomes in mice that were given chronic exposure to a high-fat diet (HFD; 12weeks), with the onset of the diet either in adolescence or adulthood.
View Article and Find Full Text PDFPoor-quality maternal diet during pregnancy, and subsequent gestational growth disturbances in the offspring, have been implicated in the etiology of multiple neurodevelopmental disorders, including ADHD, schizophrenia, and autism. These disorders are characterized, in part, by abnormalities in responses to reward and errors of executive function. Here, we demonstrate dissociable deficits in reward processing and executive function in male and female mice, solely due to maternal malnutrition via high-fat or low-protein diets.
View Article and Find Full Text PDFNeuropsychopharmacology
March 2014
Maternal obesity during pregnancy increases the risk for offspring obesity, in part through effects on the developing brain. Previous research has shown that perinatal consumption of highly palatable foods by the mother can influence the development of offspring taste preferences and alter gene expression within the central nervous system (CNS) reward system. Opioids stimulate consumption of both fats and carbohydrates, and overconsumption of these energy dense foods increases the risk for obesity.
View Article and Find Full Text PDFThe size of an infant at birth, a measure of gestational growth, has been recognized for many years as a biomarker of future risk of morbidity. Both being born small for gestational age (SGA) and being born large for gestational age (LGA), are associated with increased rates of obesity and metabolic disorder, as well as a number of mental disorders including attention deficit/hyperactivity disorder, autism, anxiety, and depression. The common risks raise the question of what neurobiological mechanisms are altered in SGA and LGA offspring.
View Article and Find Full Text PDFRecent advances in chromatin biology have identified a role for epigenetic mechanisms in the regulation of neuronal gene expression changes, a necessary process for proper synaptic plasticity and memory formation. Experimental evidence for dynamic chromatin remodeling influencing gene transcription in postmitotic neurons grew from initial reports describing posttranslational modifications of histones, including phosphorylation and acetylation occurring in various brain regions during memory consolidation. An accumulation of recent studies, however, has also highlighted the importance of other epigenetic modifications, such as DNA methylation and histone methylation, as playing a role in memory formation.
View Article and Find Full Text PDFHistone deacetylases (HDACs) have previously been shown to be critical for the formation of long-term memories. Recent findings now show that a specific HDAC isoform, HDAC2, negatively regulates formation of hippocampus-dependent memory. These recent findings published in Nature highlight potential new therapeutic interventions for the treatment of memory impairments associated with human neurological disorders.
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