Revealing nonlinear neural decoding by analyzing choices

Sensory data about most natural task-relevant variables are entangled with task-irrelevant nuisance variables. The neurons that encode these relevant signals typically constitute a nonlinear population code. Here we present a theoretical framework for quantifying how the brain uses or decodes its nonlinear information. Our theory obeys fundamental mathematical limitations on information content inherited from the sensory periphery, describing redundant codes when there are many more cortical neurons than primary sensory neurons. The theory predicts that if the brain uses its nonlinear population codes optimally, then more informative patterns should be more correlated with choices. More specifically, the theory predicts a simple, easily computed quantitative relationship between fluctuating neural activity and behavioral choices that reveals the decoding efficiency. This relationship holds for optimal feedforward networks of modest complexity, when experiments are performed under natural nuisance variation. We analyze recordings from primary visual cortex of monkeys discriminating the distribution from which oriented stimuli were drawn, and find these data are consistent with the hypothesis of near-optimal nonlinear decoding.

Conditional Learning Deficits in Children with ADHD can be Reduced Through Reward Optimization and Response-Specific Reinforcement

When children with ADHD are presented with behavioral choices, they struggle more than Typically Developing [TD] children to take into account contextual information necessary for making adaptive choices. The challenge presented by this type of behavioral decision making can be operationalized as a Conditional Discrimination Learning [CDL] task. We previously showed that CDL is impaired in children with ADHD. The present study explores whether this impairment can be remediated by increasing reward for correct responding or by reinforcing correct conditional choice behavior with situationally specific outcomes (Differential Outcomes). An arbitrary Delayed Matching-To-Sample [aDMTS] procedure was used, in which children had to learn to select the correct response given the sample stimulus presented (CDL). We compared children with ADHD (N = 45) and TD children (N = 49) on a baseline aDMTS task and sequentially adapted the aDMTS task so that correct choice behavior was rewarded with a more potent reinforcer (reward manipulation) or with sample-specific (and hence response-specific) reinforcers (Differential Outcomes manipulation). At baseline, children with ADHD performed significantly worse than TD children. Both manipulations (reward optimization and Differential Outcomes) improved performance in the ADHD group, resulting in a similar level of performance to the TD group. Increasing the reward value or the response-specificity of reinforcement enhances Conditional Discrimination Learning in children with ADHD. These behavioral techniques may be effective in promoting the learning of adaptive behavioral choices in children with ADHD.

Single trial neuronal activity dynamics of attentional intensity in monkey visual area V4

Understanding how activity of visual neurons represents distinct components of attention and their dynamics that account for improved visual performance remains elusive because single-unit experiments have not isolated the intensive aspect of attention from attentional selectivity. We isolated attentional intensity and its single trial dynamics as determined by spatially non-selective attentional performance in an orientation discrimination task while recording from neurons in monkey visual area V4. We found that attentional intensity is a distinct cognitive signal that can be distinguished from spatial selectivity, reward expectations and motor actions. V4 spiking on single trials encodes a combination of sensory and cognitive signals on different time scales. Attentional intensity and the detection of behaviorally relevant sensory signals are well represented, but immediate reward expectation and behavioral choices are poorly represented in V4 spiking. These results provide a detailed representation of perceptual and cognitive signals in V4 that are crucial for attentional performance.

Protocol for VERITAS, (Vaping Effects: Real-World International Surveillance) Study: A multi-country, six-year prospective cohort study of daily vapers with very limited smoking history

It is clear that vaping (e-cigarette use) poses little if any health risk, and in particular is far less harmful than smoking. However, it is not clear whether there is some small health risk from vaping. Most research on health outcomes has involved people who formerly smoked, and thus who have residual health risks that are far greater than any plausible level of risk from vaping, making a sufficiently precise estimate impossible. Without studies of people who vape but who have smoked very little, it is unlikely there will ever be useful epidemiologic estimates. In addition, almost all published information about the characteristics and behaviors of people who vape focuses on people who used to smoke. The VERITAS (Vaping Effects: Real-World International Surveillance) Study, whose protocol is reported here, will begin to help address this missing information. This observational study will assemble an international cohort of 2000 or more people who vape regularly and have very little history of smoking. They will be followed over time and surveyed frequently to assess their health status, health events, behavioral choices, and motivations. Multimedia survey tools will capture more precise behavioral information than is normally measured. The assembled cohort will be available for, and is expected to be used for, embedded observational clinical research of subgroups of the study population.

Adaptation to Other Agent’s Behavior Using Meta-Strategy Learning by Collision Avoidance Simulation

In human’s cooperative behavior, there are two strategies: a passive behavioral strategy based on others’ behaviors and an active behavioral strategy based on the objective-first. However, it is not clear how to acquire a meta-strategy to switch those strategies. The purpose of the proposed study is to create agents with the meta-strategy and to enable complex behavioral choices with a high degree of coordination. In this study, we have experimented by using multi-agent collision avoidance simulations as an example of cooperative tasks. In the experiments, we have used reinforcement learning to obtain an active strategy and a passive strategy by rewarding the interaction with agents facing each other. Furthermore, we have examined and verified the meta-strategy in situations with opponent’s strategy switched.

Peptic Ulcer Disease

This chapter will discuss a peptic ulcer disease (PUD) case. PUD is a common gastrointestinal tract disease (GIT) that affects the stomach and duodenum. It is characterized by deep lesions into the mucosal thickness. Various dietary and behavioral choices could aggravate the epigastric pain associated with PUD and interfere with the healing process leading to complications. Management of PUD includes medical treatment with medications along with behavioral and nutritional changes. This case presents a complication of PUD, and choices exacerbating the condition. It will also discuss the role of medical nutrition therapy in minimizing the symptoms and promoting ulcer healing. Additionally, it will allow the dietetic professional to methodically assess the elements in the case that are relevant for planning the nutrition intervention; in addition to, educating the patient about dietary modifications to improve the patient's quality of life.

The Function of Casual Sex Action and Inaction Regret: A Longitudinal Investigation

In several recent papers the sex difference in regret predicted by sexual strategies theory has been supported: men more than women report regret passing up short-term sexual opportunities (inaction regret), while women regret having had sexual encounters (action regret). However, the adaptive function of regret, to improve future behavioral choices, has not been tested. In this first longitudinal test of behavioral change following regret, we consider whether regret actually results in adaptive shifts of behavior: will men who regret passing up sex engage in more short-term sex following regret? Will women who regret short-term encounters either choose better quality partners, reduce number of one-night stands or shift their strategy to long-term relationships? Across two waves (NT1 = 399, 65.4% women and NT2 = 222, 66.2% women) students responded to questions about casual sex action regret and inaction regret, along with possible outcomes, intrapersonal traits, and concurrent contextual predictors. There was no clear evidence for the proposed functional shifts in sexual behavior. Casual sex regret was associated with respondent sex and stable individual differences, such as sociosexual attitudes, regret processing and metacognitions, but the effect of these predictors were not consistent across the two waves. Among the tested concurrent contextual predictors, sexual disgust was the most consistent across waves. Regret is considered a gauge of the value and quality of the short-term sexual encounter. However, tentatively we conclude that after this first test of function using longitudinal data, we find no evidence of a mating strategy shifting effect following sexual regret.

Two pre-registered priming studies to unpackage value and behavior correlations

We tested whether various established priming methods affected personal values and behavioral choices in two experiments. We also aimed to test whether an activation of values through priming might shed some light on value-behavior linkages. Using a large online sample (pre-registration: https://osf.io/nz8ak/?view_only=b9110537370444d98d2b22dcf5f0774e) and a general population sample (pre-registration: https://osf.io/4juxx/?view_only=a4f0b53183824c56a90310497195d2d7), we did not find strong and consistent priming effects on either values or behavior/behavioral intentions. Nevertheless, in line with previous research, we found that values correlated with behavioral choices. Therefore, our study casts further doubt on the effectiveness of priming for activating social psychological constructs (e.g., values). Our correlational results show that values and behavior are correlated, but in the absence of experimental evidence, the causal direction of any value-behavior correlations need to be interpreted cautiously because causality (values predicting behavior) cannot be assumed.