Current Opinion in Behavioral Sciences

Life threatening situations as urgent as defending against a predator precludes the use of slow trial and error strategies. Natural selection has led to the evolution of a behavioral system that has 3 critical elements. 1) When it is activated it limits the behaviors available to the organism to a set of prewired responses that have proven over phylogeny to be effective at defense. 2) A rapid learning system, called Pavlovian fear conditioning, that has the ability to immediately identify threats and promote prewired defensive behaviors...

Fear is considered an integral part of the brain's defensive mechanism that evolved to protect animals and humans from predation and other ecological threats. Hence, it is logical to study fear from the perspective of antipredator-survival behaviors and circuits by sampling a range of threatening situations that organisms are likely to encounter in the wild. In the past several decades, however, mainstream fear research has focused on the importance of associative learning; that is, how animals become frightened of innocuous cues as consequences of their contingent pairing with aversive events...

No abstract text is available yet for this article.

The striatal brain regions, including the caudate-putamen, nucleus accumbens core, and nucleus accumbens shell, mediate critical behavioral functions. These functions include but are not limited to motivated behavior, reward, learning, and sensorimotor function in both pathological and normal contexts. The phenotype and/or incidence of all of these behaviors either differ by sex or are sensitive to the presence of gonadal hormones such as 17β-estradiol and testosterone. All three striatal brain regions express membrane-associated estrogen receptors...

A key component of interacting with the world is how to direct ones' sensors so as to extract task-relevant information - a process referred to as active sensing. In this review, we present a framework for active sensing that forms a closed loop between an ideal observer, that extracts task-relevant information from a sequence of observations, and an ideal planner which specifies the actions that lead to the most informative observations. We discuss active sensing as an approximation to exploration in the wider framework of reinforcement learning, and conversely, discuss several sensory, perceptual, and motor processes as approximations to active sensing...

Recent work on sex differences in learning and memory has demonstrated that females and males differ in cognitive and behavioral strategies, as well as neural mechanisms required to learn, retrieve and express memory. Although our understanding of the mechanisms of memory is highly sophisticated, this work is based on male animals. As such, the study of female memory is narrowed to a comparison with behavior and mechanisms defined in males, resulting in findings of male-specific mechanisms but little understanding of how females learn and store information...

Sub-anesthetic ketamine produces rapid antidepressant effects in patients with bipolar and unipolar major depression where conventional monoaminergic-based antidepressant drugs have been ineffective or ridden with side effects. A single ketamine infusion can produce antidepressant effects lasting up to two weeks, and multiple ketamine infusions prolong this effect. Pre-clinical studies are underway to uncover ketamine's mechanisms of action, but there are still many questions unanswered regarding the safety of its long-term use...

While sex differences in the peripheral immune response have been studied extensively, sex differences in the neuroimmune response, including glial activation and associated cytokine production in the brain, is a recently emerging field. Advances in our understanding of sex differences in the neuroimmune response have important implications for understanding how neural circuits are shaped during early brain development, how activation of the immune system may impact cognitive function and behavior, and how inflammation may be associated with the risk of mental health disorders that have strong sex-biases...

Adolescence is a period associated with the initiation and escalation of substance use and is also a time during which substantial changes take place in neural development, personality and behavior. Although rates of substance use between adolescent girls and boys do not differ substantially, there is evidence for sex differences in underlying vulnerability pathways associated with the development of substance use disorder. Here we review sex differences in adolescent brain development and how these differences may contribute to different risk pathways between females and males that emerge during this developmental period...

Different kinds of decision making can be categorized by their differential effect on the agent's current and future states as well as the computational challenges they pose. Here, we draw a distinction between within-state and state-change decision-making, and propose that a dedicated decision mechanism exists in dorsomedial prefrontal cortex (dmPFC) that is specialized for state-change decisions. We set out a formal framework in which state change decisions may be made on the basis of the integrated momentary reward rate, over the intended time to be spent in a state...

Loss of interest in rewarding activities is a hallmark of many psychiatric disorders and may be relevant for neurodegenerative disorders and patients suffering from brain injury. There is increasing evidence that deficits in reward-related behaviour are more complex than previously described. The traditional view of anhedonia as 'the inability to experience pleasure' may be too limited to fully encompass the types of reward deficit observed in these patients. Developments in methods to measure different aspects of reward processing in humans and animals are starting to provide insights into the complexity of this behaviour...

Apathy is the most common neuropsychiatric symptom in patients with Alzheimer's disease (AD). The presence of apathy has been related to greater caregiver distress, decreased quality of life, and increased morbidity. Here we review the most recent studies on this neuropsychiatric syndrome, focusing on prevalence, impact on quality of life, behavioural and neuroimaging studies, and treatment options. The results of some investigations on the behavioural and neuroanatomical profile of apathy in AD point to a role of frontostriatal circuits, specifically involving the anterior cingulate cortex...

Inflammation can profoundly impact motivated behavior, as is the case with inflammation-induced depression. By evaluating objectively measurable basic neurobehavioral processes involved in motivation, recent research indicates that inflammation generally reduces approach motivation and enhances avoidance motivation. Increased effort valuation largely mediates the effects of inflammation on approach motivation. Changes in reward valuation are not uniformly observed in approach motivation. However, inflammation increases the averseness of negative stimuli...

Cognitive control - the ability to override a salient or prepotent action to execute a more deliberate one - is required for flexible, goal-directed behavior, and yet it is subjectively costly: decision-makers avoid allocating control resources, even when doing so affords more valuable outcomes. Dopamine likely offsets effort costs just as it does for physical effort. And yet, dopamine can also promote impulsive action, undermining control. We propose a novel hypothesis that reconciles opposing effects of dopamine on cognitive control: during action selection, striatal dopamine biases benefits relative to costs, but does so preferentially for "proximal" motor and cognitive actions...

Motivational impairment has long been associated with schizophrenia but the underlying mechanisms are not clearly understood. Recently, a small but growing literature has suggested that aberrant effort-based decision-making may be a potential contributory mechanism for motivational impairments in psychosis. Specifically, multiple reports have consistently demonstrated that individuals with schizophrenia are less willing than healthy controls to expend effort to obtain rewards. Further, this effort-based decision-making deficit has been shown to correlate with severity of negative symptoms and level of functioning, in many but not all studies...

Anhedonia is a severe condition that describes a near-complete absence of enjoyment, motivation, and interest. A core feature of depression, clinical manifestations of anhedonia can include deficits in experiencing pleasure, approach-related motivated behavior, and learning how to match expectations to the environment. To date, the precise neurobiological mechanisms of anhedonia in major depression are still poorly understood. We have previously argued that contradictory findings and the inability to identify specific neurobiological substrates for anhedonic symptoms may result from sample heterogeneity, suboptimal methods of assessment, and the challenge of dissociating between different components of anhedonia...

Affective neuroscience research has revealed that reward contains separable components of 'liking', 'wanting', and learning. Here we focus on current 'liking' and 'wanting' findings and applications to clinical disorders. 'Liking' is the hedonic impact derived from a pleasant experience, and is amplified by opioid and related signals in discrete sites located in limbic-related brain areas. 'Wanting' refers to incentive salience, a motivation process for reward, and is mediated by larger systems involving mesocorticolimbic dopamine...

No abstract text is available yet for this article.

Predicting the occurrence of future events from prior ones is vital for animal perception and cognition. Although how such sequence learning (a form of relational knowledge) relates to particular operations in language remains controversial, recent evidence shows that sequence learning is disrupted in frontal lobe damage associated with aphasia. Also, neural sequencing predictions at different temporal scales resemble those involved in language operations occurring at similar scales. Furthermore, comparative work in humans and monkeys highlights evolutionarily conserved frontal substrates and predictive oscillatory signatures in the temporal lobe processing learned sequences of speech signals...

While a long history of neuropsychological research places language function within a primarily left-lateralized frontotemporal system, recent neuroimaging work has extended this language network to include a number of regions traditionally thought of as 'domain-general'. These include dorsal frontal, parietal, and medial temporal lobe regions known to underpin cognitive functions such as attention and memory. In this paper, we argue that these domain-general systems are not required for language processing and are instead an artefact of the tasks typically used to study language...