The nervous system as a solution for implementing closed negative feedback control loops.

Behavior can be regarded as the output of a system (action), as a function linking stimulus to response (reaction), or as an abstraction of the bidirectional relationship between the environment and the organism (interaction). When considering the latter possibility, a relevant question arises concerning how an organism can materially and continuously implement such a relationship during its lifetime in order to perpetuate itself. The feedback control approach has taken up the task of answering just that question. During the last several decades, said approach has been progressing and has started to be recognized as a paradigm shift, superseding certain canonical notions in mainstream behavior analysis, cognitive psychology, and even neuroscience. In this paper, we describe the main features of feedback control theory and its associated techniques, concentrating on its critiques of behavior analysis, as well as the commonalities they share. While some of feedback control theory's major critiques of behavior analysis arise from the fact that they focus on different levels of organization, we believe that some are legitimate and meaningful. Moreover, feedback control theory seems to blend with neurobiology more smoothly as compared to canonical behavior analysis, which only subsists in a scattered handful of fields. If this paradigm shift truly takes place, behavior analysts-whether they accept or reject this new currency-should be mindful of the basics of the feedback control approach.

Chronic exposure to cyclohexane induces stereotypic circling, hyperlocomotion, and anxiety-like behavior associated with atypical c-Fos expression in motor- and anxiety-related brain regions.

Recreational abuse of solvents continues, despite cyclohexane (CHX) is used as a safe replacement in gasoline or adhesive formulations. Increasing evidence indicates that CHX inhalation affects brain functioning; however, scanty information is available about its effects on behavior and brain activity upon drug removal. In this study, we used CD1 adult mice to mimic an intoxication period of recreational drugs for 30 days. During the CHX exposure (~30,000 ppm), we analyzed exploratory and biphasic behaviors, stereotypic circling, and locomotion. After CHX removal (24 h or a month later), we assessed anxiety-like behaviors and quantified c-Fos cells in motor- and anxiety-related brain regions. Our findings indicate that the repeated inhalation of CHX produced steady hyperactivity and reduced ataxia, sedation, and seizures as the exposure to CHX progressed. Also, CHX decreased grooming and rearing behaviors. In the first week of CHX inhalation, a stereotypic circling behavior emerged, and locomotion increased gradually. One month after CHX withdrawal, mice showed low activity in the center zone of the open field and more buried marbles. Twenty-four hours after CHX removal, c-Fos expression was low in the dorsal striatum, ventral striatum, motor cortex, dorsomedial prefrontal cortex, basolateral amygdala, lateral hypothalamus, and ventral hippocampus. One month later, c-Fos expression remained low in the ventral striatum and lateral hypothalamus but increased in the dorsomedial prefrontal cortex and primary motor cortex. This study provides a comprehensive behavioral characterization and novel histological evidence of the CHX effects on the brain when is administered in a recreational-like mode.

Similar attention and performance in female and male CD1 mice in the peak procedure.

Inaccurate and distorted timing are associated with neurodegenerative disorders such as Alzheimer's disease and schizophrenia in humans, which generates interest in the discovery and understanding of the factors behind such timing difficulties. Timing research in mice has taken an important role, because the availability of genetically-altered strains allows establishing the causal role of specific genes on such neurodegenerative disorders. Nevertheless, few studies have considered mice's sex and some have found sex differences in timing, although results are not yet conclusive. We tested female and male CD1 mice, an outbred strain not yet studied in a peak procedure. By varying the percentage of peak trials and the presence of a gap and/or a distractor in the tests, we found no sex differences in accuracy, precision, or attention. Both females and males followed a stop-clock strategy after distractor and gap + distractor trials. This suggests that both male and female CD1 mice may be exposed to a peak procedure to study factors associated to neurotoxicology or neurogenesis.

Increased generalization in a peak procedure after delayed reinforcement.

Temporal control of behavior might be impaired by reinforcement devaluation and other motivational operations such as delaying reinforcement of the instrumental response. Here, we report an experiment that assessed the effect of delayed reinforcement on a timing peak procedure. Using a within-subject design with a multiple two-component schedule of reinforcement, we found evidence of flat temporal generalization gradients, along with degraded response-reinforcer contingency, lower response rates and changes in the responding patterns due to delayed reinforcement. This result is consistent with the Learning to Time (LeT) and some versions of Scalar Expectancy Theory (SET).

Poor People Are Hospitalized Three Times More for Mental Health Services than the Non-Poor in Central Valley California.

Introduction: Providing health insurance to the poor has become a standard policy response to health disparities between the poor and the non-poor. It is often assumed that if the poor people are given health insurance, they will use preventative care, which will prevent more expensive emergency visits and inpatient hospitalization, and in turn, it will save healthcare cost in the long run. This paper presents the findings from our study in California about what happens to the poor when they are given health insurance. The purpose of the study was to understand how the healthcare system in California treats the poor patients differently than the non-poor. Method: Using multivariate logistic regressions, this study analyzed a large patient discharge data (PDD) from the California Office of Statewide Planning and Development (OSHPD) for eight counties in the Central Valley California (N = 423,640). First, utilizing International Classification of Diseases (ICD 10) as diagnostic criteria, mental-health vs. non-mental health hospitalization rates were estimated. Second, health insurance status was used as a proxy measure of poverty of the patients. Using chi-Square, the probability of hospitalization for mental health services was estimated based on their insurance types. Finally, using step-wise logistic regression, the odds of mental health hospitalization was estimated conditional on individual characteristics, health insurance types, and geographic characteristics. Findings: When the poor people were given health insurance, they were three times more likely to be hospitalized for mental health services than the non-poor. The more than three-fold variation in mental health hospitalization was not driven by demographic or geographic characteristics. The findings are new and have important implications for the healthcare policies for the poor. Further studies are needed to understand the extent to which the disproportionately high rate of mental health hospitalizations of the poor are driven by the provider-induced needs.