Stimulus uncertainty and relative reward rates determine adaptive responding in perceptual decision-making.

In dynamic environments, animals must select actions based on sensory input as well as expected positive and negative consequences. This type of behavior is typically studied using perceptual decision making (PDM) tasks. The arguably most influential framework for describing the cognitive processes underlying PDM is signal detection theory (SDT).

A neuroimmune circuit mediates cancer cachexia-associated apathy.

Cachexia, a severe wasting syndrome associated with inflammatory conditions, often leads to multiorgan failure and death. Patients with cachexia experience extreme fatigue, apathy, and clinical depression, yet the biological mechanisms underlying these behavioral symptoms and their relationship to the disease remain unclear. In a mouse cancer model, cachexia specifically induced increased effort-sensitivity, apathy-like symptoms through a cytokine-sensing brainstem-to-basal ganglia circuit.

Castration-Resistant Prostate Cancer: Sequencing Oral and Infusion Agents.

Purpose Of Review: To update treatment options and considerations for castration-resistant prostate cancer with specific attention to sequencing of agents based on available evidence and treatment rationale.

Recent Findings: The newest research developments over the last several years include multicenter studies that address the sequencing of therapies to improve the treatment of metastatic castration-resistant prostate cancer. Chemotherapy agents, as well as androgen receptor antagonists, are evolving, and there are new tests available to define which patients are more likely to benefit.

Integration of contextual cues into memory depends on "prefrontal" N-methyl-D-aspartate receptors.

Every learning event is embedded in a context, but not always does the context become an integral part of the memory; however, for extinction learning it usually does, resulting in context-specific conditioned responding. The neuronal mechanisms underlying contextual control have been mainly investigated for Pavlovian fear extinction with a focus on hippocampal structures. However, the initial acquisition of novel responses can be subject to contextual control as well, although the neuronal mechanisms are mostly unknown.

Context specificity of both acquisition and extinction of a Pavlovian conditioned response.

It is widely held that the extinction of a conditioned response is more context specific than its initial acquisition. One proposed explanation is that context serves to disambiguate the meaning of a stimulus. Using a procedure that equated the learning histories of the contexts, we show that the memory of an appetitive Pavlovian association can be highly context specific despite being unambiguous.

Neurons in the pigeon caudolateral nidopallium differentiate Pavlovian conditioned stimuli but not their associated reward value in a sign-tracking paradigm.

Animals exploit visual information to identify objects, form stimulus-reward associations, and prepare appropriate behavioral responses. The nidopallium caudolaterale (NCL), an associative region of the avian endbrain, contains neurons exhibiting prominent response modulation during presentation of reward-predicting visual stimuli, but it is unclear whether neural activity represents valuation signals, stimulus properties, or sensorimotor contingencies. To test the hypothesis that NCL neurons represent stimulus value, we subjected pigeons to a Pavlovian sign-tracking paradigm in which visual cues predicted rewards differing in magnitude (large vs.

Recording single neurons' action potentials from freely moving pigeons across three stages of learning.

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e.

Suboptimal criterion setting in a perceptual choice task with asymmetric reinforcement.

Performance on psychophysical tasks is influenced by a variety of non-sensory factors, most notably the magnitude or probability of reinforcement following correct responses. When reinforcement probability is unequal for hits and correct rejections, signal detection theory specifies an optimal decision criterion which maximizes the number of reinforcers. We subjected pigeons to a task in which six different stimuli (shades of gray) had to be assigned to one of two categories.

Stimulus-response-outcome coding in the pigeon nidopallium caudolaterale.

A prerequisite for adaptive goal-directed behavior is that animals constantly evaluate action outcomes and relate them to both their antecedent behavior and to stimuli predictive of reward or non-reward. Here, we investigate whether single neurons in the avian nidopallium caudolaterale (NCL), a multimodal associative forebrain structure and a presumed analogue of mammalian prefrontal cortex, represent information useful for goal-directed behavior. We subjected pigeons to a go-nogo task, in which responding to one visual stimulus (S+) was partially reinforced, responding to another stimulus (S-) was punished, and responding to test stimuli from the same physical dimension (spatial frequency) was inconsequential.