Antipsychotic dose modulates behavioral and neural responses to feedback during reinforcement learning in schizophrenia

Schizophrenia is characterized by an abnormal dopamine system, and dopamine blockade is the primary mechanism of antipsychotic treatment. Consistent with the known role of dopamine in reward processing, prior research has demonstrated that patients with schizophrenia exhibit impairments in reward-based learning. However, it remains unknown how treatment with antipsychotic medication impacts the behavioral and neural signatures of reinforcement learning in schizophrenia. The goal of this study was to examine whether antipsychotic medication modulates behavioral and neural responses to prediction error coding during reinforcement learning. Patients with schizophrenia completed a reinforcement learning task while undergoing functional magnetic resonance imaging. The task consisted of two separate conditions in which participants accumulated monetary gain or avoided monetary loss. Behavioral results indicated that antipsychotic medication dose was associated with altered behavioral approaches to learning, such that patients taking higher doses of medication showed increased sensitivity to negative reinforcement. Higher doses of antipsychotic medication were also associated with higher learning rates (LRs), suggesting that medication enhanced sensitivity to trial-by-trial feedback. Neuroimaging data demonstrated that antipsychotic dose was related to differences in neural signatures of feedback prediction error during the loss condition. Specifically, patients taking higher doses of medication showed attenuated prediction error responses in the striatum and the medial prefrontal cortex. These findings indicate that antipsychotic medication treatment may influence motivational processes in patients with schizophrenia.     

Backward inhibitory learning in honeybees: a behavioral analysis of reinforcement processing

One class of theoretical accounts of associative learning suggests that reinforcers are processed according to learning rules that minimize the predictive error between the expected strength of future reinforcement and its actual strength. The omission of reinforcement in a situation where it is expected leads to inhibitory learning of stimuli indicative for such a violation of the prediction. There are, however, results indicating that inhibitory learning can also be induced by other mechanisms. Here, we present data from olfactory reward conditioning in honeybees that show that (1) one- and multiple-trial backward conditioning results in conditioned inhibition (CI); (2) the inhibition is maximal for a 15-sec interval between US and CS; (3) there is a nonmonotonic dependency on the degree of CI from the US-CS interval during backward pairing; and (4) the prior association of context stimuli with reinforcement is not necessary for the development of CI. These results cannot be explained by models that only minimize a prediction error. Rather, they are consistent with models of associative learning that, in addition, assume that learning depends on the temporal overlap of a CS with two processes, a fast excitatory and a slow inhibitory one, both evoked by a reinforcer. The fmdings from this behavioral analysis of reinforcement processing are compared with the known properties of an individual, identified neuron involved in reinforcement processing in the bee brain, to further understand the mechanisms underlying predictive reward learning.     

Zinc-induced peripheral anosmia and behavioral responses to novelty in mice: a quantitative-genetic analysis

Adult male mice were made anosmic by intranasal flushing with a 5% zinc sulfate solution. Twelve behavioral variables were measured in treated as well as saline-irrigated control animals placed in a novel environment. The genetic underpinnings and the genotype-treatment interactions with regard to these behaviors were analyzed in a classical Mendelian cross between the inbred strains C57BL/6 and DBA/2 and in a full 4 X 4 diallel cross, replicated five times, between these strains and strains C3H/St an CPB-K. Based on the hypothesis of an evolutionary history of directional selection for a well-balanced information-processing system, one might expect directional dominance for decrease in exploration after anosmization. Although decreases were found for several behavioral phenotypes, only few and relatively unimportant genotype-treatment interactions were present. This absence of any kind of genetic variation for behavioral change after anosmization points to an extremely strong directional selection which has eliminated all less favorable alleles. The findings support the hypothesis of directional selection for an efficient olfactory information-processing system.     

A statistical test of a prediction from information theory in a card-sorting situation

Previous work with cards left the joint effects of varying entropy and discriminability on choice-reaction times somewhat in doubt. A card-sorting situation is here constructed in which entropy and discriminability can be varied independently. Two experiments are described with naive subjects and two different treatments of the practice effect. The effect of varying entropy with discriminability held constant is. shown to be significantly non-linear, contrary to the prediction from information theory. Finally a statistical model is proposed which shows at least, qualitative agreement with the results of these experiments.     

A problem for rationalist responses to skepticism

Rationalism, my target, says that in order to have perceptual knowledge, such as that your hand is making a fist, you must “antecedently” (or “independently”) know that skeptical scenarios don’t obtain, such as the skeptical scenario that you are in the Matrix. I motivate the specific form of Rationalism shared by, among others, White (Philos Stud 131:525–557, 2006) and Wright (Proc Aristot Soc Suppl Vol 78:167–212, 2004), which credits us with warrant to believe (or “accept”, in Wright’s terms) that our senses are reliably veridical, where that warrant is one we enjoy by default, that is, without relying on any evidence or engaging in any positive argument. The problem with this form of Rationalism is that, even if you have default knowledge that your senses are reliable, this is not adequate to rule out every kind of skeptical scenario. The problem is created by one-off skeptical scenarios, scenarios that involve a highly reliable perceiver who, by a pure fluke, has a one-off, non-veridical experience. I claim you cannot infer that your present perceptual experience is veridical just on the basis of knowledge of your general reliability. More generally, if you infer that the present F is G, just on the basis of your knowledge that most Fs are Gs, this is what I call statistical inference, and, as I argue, statistical inference by itself does not generate knowledge. I defend this view of statistical inference against objections, including the objection that radical skepticism about our ordinary inductive knowledge will follow unless statistical inference generates knowledge.     

The effects of fixed-time reinforcement schedules on problem behavior of children with emotional and behavioral disorders in a day-treatment classroom setting

The current study assessed the effects of fixed-time reinforcement schedules on problem behavior of students with emotional-behavioral disorders in a clinical day-treatment classroom setting. Three elementary-aged students with a variety of emotional and behavioral problems participated in the study. Initial functional assessments indicated that social attention was the maintaining reinforcer for their verbally disruptive behavior. Baseline phases were alternated with phases in which attention was provided on fixed-time schedules in the context of an ABAB design. The results indicated that the provision of attention on fixed-time schedules substantially reduced the participants' rate of verbal disruptions. These decreases were maintained during initial thinning of the schedules. The results provide one of the first examples that such an intervention can be successfully implemented in a classroom setting.     

A comparison of differential reinforcement and noncontingent reinforcement for the treatment of a child's multiply controlled problem behavior

Noncontingent reinforcement (NCR) and differential reinforcement of other behavior (DRO) with escape as the reinforcer were evaluated after an initial functional analysis indicated the problem behaviors exhibited by a 7 year old child were maintained by escape. When NCR and DRO did not decrease the problem behaviors, a second functional analysis was conducted and showed that the behaviors were maintained by attention and escape. DRO with attention and escape as reinforcers was compared to NCR with attention and escape as reinforcers for the treatment of the child's multiply controlled behavior problems. Results showed that DRO and NCR were both effective at reducing the problem behavior to low levels and increasing compliance. Copyright © 2003 John Wiley & Sons, Ltd.     

Child and family correlates of toddlers' emotional and behavioral responses to a mishap

This study evaluated the unique and joint contributions of internal state language, externalizing behavior, and maternal talk about emotions to the prediction of toddlers' empathy‐related responsiveness. The empathy‐based guilt reactions of 47 toddlers (27 boys) were observed in response to distress that they thought they had caused. In addition, mothers reported on the children's internal state language, externalizing behavior, and empathy‐based guilt. In a separate observation, the mothers discussed emotional expressions with their children, and the functional significance of their emotional discourse was considered. Results revealed that toddlers' internal state language ability was positively related to their attempts to comprehend another's affective state and to maternal reports of children's sympathy reactions. There was also an unexpected inverse relation between externalizing behavior and arousal level. In terms of the parent measures, maternal explanations of emotions were positively related to children's attempts to comprehend another's affective state, whereas mothers' directives for children to label emotions were positively related to children's expressed emotional concern for others. The implications of these findings for understanding empathy and guilt development in young children are discussed. ©2003 Michigan Association for Infant Mental Health.     

Verbal and behavioral responses to familiar and unfamiliar music

Thirty adult subjects completed an Operant Music Listening Recorder (OMLR) task with two unfamiliar and two familiar music channels (one “popular” and one “classical” in each case), then rated the music on each channel on seven-point scales for liking, quality, and familiarity. The two familiar music channels received significantly higher ratings than the two unfamiliar channels on all three rating scales, and there were no significant main effects or interactions involving musical style. The predictions (a) that subjects would spend more time listening to the familiar channels on the OMLR task, and (b) that measures of listening time would display higher correlations with ratings of liking than with those of quality both received weak support from the direction of the results, but neither was confirmed by statistical significance tests. The results are discussed in terms of the fragmentation between the affective and evaluative components of attitudes toward music.     

心理与教育测验中异常反应侦查新技术：变点分析法

变点分析法(change point analysis, CPA)近些年才引入心理与教育测量学, 相较于传统方法, CPA不仅可以侦查异常作答被试, 还能自动精确地定位变点位置, 高效清洗作答数据。其原理在于：判断作答序列中是否存在可将该序列划分为具有不同统计学属性两部分的点(即变点), 并且需使用被试拟合统计量(person-fit statistic, PFS)来量化两个子序列之间的差异。未来可将单变点分析拓展至多变点, 结合反应时等信息, 构建非参数化指标以及将现有指标拓展至多级计分或多维测验, 以提高CPA的适用广度及效力。     

An experimental application of a social reinforcement approach to the problem of job-finding

The current conception of the employment process is that positions become available, are publicized, and are filled by the most qualified job seekers. An alternative conception is proposed that social factors play a major role in the process and that job finding can be analyzed as an exchange of social reinforcers in which the first behavioral step is to locate job openings. A questionnaire survey of 120 jobs found that two-thirds of the job leads came from friends or relatives who: (1) usually knew of a specific opening (63%); (2) were themselves employed by the hiring firm (71%); and (3) actively influenced the hiring process (53%). An experimental evaluation was made of an "Information-Reward" advertisement procedure for motivating community residents to report unpublicized openings. It was found that the Information-Reward procedure produced 10 times as many job leads and eight times as many placements as a noreward control advertisement. These findings represent a first step toward a much needed technology of job finding that is based on experimental evidence and support the notion that the employment process depends on factors unrelated to work skills.