How are decisions made between different goods? One theory spanning several fields of neuroscience proposes that their values are distilled to a single common neural currency, the calculation of which allows for rational decisions. The orbitofrontal cortex (OFC) is thought to play a critical role in this process, based on the presence of neural correlates of economic value in lateral OFC in monkeys and medial OFC in humans. We previously inactivated lateral OFC in rats without affecting economic choice behavior. Here we inactivated medial OFC in the same task, again without effect. Behavior in the same rats was disrupted by inactivation during progressive ratio responding previously shown to depend on medial OFC, demonstrating the efficacy of the inactivation. These results indicate that medial OFC is not necessary for economic choice, bolstering the proposal that classic economic choice is likely mediated by multiple, overlapping neural circuits.

Prediction errors are critical for associative learning. In the brain, these errors are thought to be signaled, in part, by midbrain dopamine neurons. However, although there is substantial direct evidence that brief increases in the firing of these neurons can mimic positive prediction errors, there is less evidence that brief pauses mimic negative errors. Whereas pauses in the firing of midbrain dopamine neurons can substitute for missing negative prediction errors to drive extinction, it has been suggested that this effect might be attributable to changes in salience rather than the operation of this signal as a negative prediction error. Here we address this concern by showing that the same pattern of inhibition will create a cue able to meet the classic definition of a conditioned inhibitor by showing suppression of responding in a summation test and slower learning in a retardation test. Importantly, these classic criteria were designed to rule out explanations founded on attention or salience; thus the results cannot be explained in this manner. We also show that this pattern of behavior is not produced by a single, prolonged, ramped period of inhibition, suggesting that it is precisely timed, sudden change and not duration that conveys the teaching signal. Here we show that brief pauses in the firing of midbrain dopamine neurons are sufficient to produce a cue that meets the classic criteria defining a conditioned inhibitor, or a cue that predicts the omission of a reward. These criteria were developed to distinguish actual learning from salience or attentional effects; thus these results formally show that brief pauses in the firing of dopamine neurons can serve as key teaching signals in the brain. Interestingly, this was not true for gradual prolonged pauses, suggesting it is the dynamic change in firing that serves as the teaching signal.

Highlights d Rats show immediate changes in choice behavior following reinforcer revaluation d Direction of satiety-specific revaluation depends on the baseline food preference d Orbitofrontal inactivation disrupts behavior following reinforcer revaluation

No abstract

Background: Despite the popularity of the undergraduate psychology major, little is known about career support and preparation available to psychology students. Objective: This study examined the prevalence, types, and methods of career assistance available to undergraduate psychology students both through their psychology programs and through their institutional career services. Method: A total of 240 programs from a stratified random sample of institutions offering undergraduate psychology programs responded to an online survey, yielding a response rate of 42.5%. Results: Undergraduate psychology programs most often provided assistance in applying to graduate school, while career services provided a wider range of resources. Baccalaureate institutions offer career assistance, via the psychology program or the institutional career center, more frequently than associate institutions. Most common forms of assistance consisted of instruction on how to apply for a job, how to find information about career possibilities in psychology subfields, resumé or curriculum vitae preparation, and individual advising. Conclusion: Although career assistance was widely available, there are several ways in which the type and scope of assistance can be improved upon to better support students and increase access. Teaching implications: Undergraduate psychology students could benefit from more career assistance content throughout psychology curricula.