Neural correlates of a default response in a delayed go/no-go task

Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with increasing delay duration, indicating that working memory fades across a delay. However, no such performance decrease has been found when the sample cues exist of present vs. absent stimuli, suggesting that pigeons do not rely on working memory, but seem to respond by default in those trials. We trained 3 pigeons in a DGNG task and found a similar default response pattern: The diverging slopes of the retention functions on correct Go and No-Go trials suggested that pigeons by default omitted their response following No-Go stimuli, but actively retained task-relevant information across the delay for successful responses on Go trials. We conducted single-cell recordings in the avian nidopallium caudolaterale, a structure comparable to the mammalian prefrontal cortex. On Go trials, many neurons displayed sustained elevated activity during the delay preceding the response, replicating previous findings and suggesting that task-relevant information was neurally represented and maintained across the delay. However, the same units did not show enhanced delay activity preceding correct response suppressions in No-Go trials. This activation-inactivation pattern presumably constitutes a neural correlate of the default response strategy observed in the DGNG task.     

Differential acquisition of lever pressing in inbred and outbred mice: comparison of one-lever and two-lever procedures and correlation with differences in locomotor activity

Recent progress in mouse genetics has led to an increased interest in developing procedures for assessing mouse behavior, but relatively few of the behavioral procedures developed involve positively reinforced operant behavior. When operant methods are used, nose poking, not lever pressing, is the target response. In the current study differential acquisition of milk-reinforced lever pressing was observed in five inbred strains (C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and BALB/cJ) and one outbred stock (CD-1) of mice. Regardless of whether one or two levers (an "operative" and "inoperative" lever) were in the operant chamber, a concomitant variable-time fixed-ratio schedule of milk reinforcement established lever pressing in the majority of mice within two 120-min sessions. Substantial differences in lever pressing were observed across mice and between procedures. Adding an inoperative lever retarded acquisition in C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ mice, but not in CD-1 and BALB/cJ mice. Locomotor activity was positively correlated with number of lever presses in both procedures. Analyses of durations of the subcomponents (e.g., time to move from hopper to lever) of operant behavior revealed further differences among the six types of mice. Together, the data suggest that appetitively reinforced lever pressing can be acquired rapidly in mice and that a combination of procedural, behavioral, and genetic variables contributes to this acquisition.     

Variation, repetition, and choice

Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence.     

Prefrontal brain activity predicts temporally extended decision-making behavior

Although functional neuroimaging studies of human decision-making processes are increasingly common, most of the research in this area has relied on passive tasks that generate little individual variability. Relatively little attention has been paid to the ability of brain activity to predict overt behavior. Using functional magnetic resonance imaging (fMRI), we investigated the neural mechanisms underlying behavior during a dynamic decision task that required subjects to select smaller, short-term monetary payoffs in order to receive larger, long-term gains. The number of trials over which the longterm gains accrued was manipulated experimentally (2 versus 12). Event-related neural activity in right lateral prefrontal cortex, a region associated with high-level cognitive processing, selectively predicted choice behavior in both conditions, whereas insular cortex responded to fluctuations in amount of reward but did not predict choice behavior. These results demonstrate the utility of a functional neuroimaging approach in behavioral psychology, showing that (a) highly circumscribed brain regions are capable of predicting complex choice behavior, and (b) fMRI has the ability to dissociate the contributions of different neural mechanisms to particular behavioral tasks.     

Behavioral perspectives on the neuroscience of drug addiction

Neuroscientific approaches to drug addiction traditionally have been based on the premise that addiction is a process that results from brain changes that in turn result from chronic administration of drugs of abuse. An alternative approach views drug addiction as a behavioral disorder in which drugs function as preeminent reinforcers. Although there is a fundamental discrepancy between these two approaches, the emerging neuroscience of reinforcement and choice behavior eventually may shed light on the brain mechanisms involved in excessive drug use. Behavioral scientists could assist in this understanding by devoting more attention to the assessment of differences in the reinforcing strength of drugs and by attempting to develop and validate behavioral models of addiction.     

Bilateral Art: Integrating Art Therapy,Family Therapy,and Neuroscience

This paper describes the systemic use of a neurologically-based art therapy modality—bilateral art—that engages both dominant and non-dominant hands in the process of creating images in response to opposing cognitions or feelings. It describes both neuroscience and family therapy perspectives that argue for the use of bilateral art. A specific protocol for bilateral art therapy is provided along with a case study demonstrating integration of the protocol into the systemic treatment of a young family. Carole M. McNamee, PhD, is Research Professor and Clinical Associate, Director of the Arts in Healthcare Project, The Family Therapy Center, Department of Human Development, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (cmcnamee@vt.edu).     

执行功能中认知灵活性发展的研究进展

近十多年以来,执行功能已成为研究的热点和前沿。认知灵活性是执行功能的主要成分,它对个体能力发展和对环境适应的方面起着重要作用。该文从认知灵活性的本质、发展、研究方法及其与教育的关系进行探讨。     

Psychometric Properties of the Grief Cognitions Questionnaire (GCQ)

Cognitive behavioral conceptualizations of complicated grief propose that negative cognitions play a core role in the development and persistence of emotional problems after bereavement, because they generate negative emotions and cause mourners to engage in counterproductive attempts to avoid the implications and the pain of the loss. To facilitate the assessment of potentially problematic cognitions after bereavement, the Grief Cognitions Questionnaire (GCQ) has been developed—a 38-item questionnaire representing 9 categories of cognitions. Building on a previous study that supported the reliability and validity of the GCQ, the current study further examined its psychometric properties, with data of 531 bereaved individuals who completed research questionnaires online through the Internet. Confirmatory factor analyses supported the nine-factor structure with 9 interrelated factors. The reliability and convergent and discriminative validity were found to be adequate. Altogether the GCQ seems to be a useful tool for the assessment of negative thinking after bereavement in research and clinical practice.     

A Meta-Analysis of Cognitive Deficits in Adults with a Diagnosis of Schizophrenia

This review identified 1275 studies examining cognitive deficits in people with schizophrenia, published between 1990 and 2003. Data from 113 studies (4365 patients and 3429 controls) were combined in a meta-analysis carried out on the five cognitive domains of IQ, memory, language, executive function, and attention. Studies were excluded where they lacked a suitable control group or failed to present complete information. In all five cognitive domains, analysis indicated a consistent trend for patients to perform more poorly than healthy controls, with significant heterogeneity across studies. Sources of heterogeneity were analyzed and a need to ensure more appropriate composition of patient and control groups and to adopt a more refined and methodologically correct, hypothesis-driven approach was identified.     

A matter of facts

We discuss the justification of Bickle's “ruthless” reductionism. Bickle intends to show that we know enough about neurons to draw conclusions about the “whole” brain and about the mind. However, his reductionism does not take into account the complexity of the nervous system and the fact that new properties emerge at each significant level of integration from the coupled functioning of elementary components. From a methodological point of view, we argue that neuronal and cognitive models have to exert a mutual constraint(MC) on each other. This approach would refuse to award any priority of cognitive approaches over neuroscience, and reciprocally, to refuse any priority of neuroscience over cognitive approaches. MC thus argues against radicalreductionism at the methodological level.