Verbal Fluency,Semantics, Context and Symptom Complexes in Schizophrenia

Lexical-semantic access and retrieval was examined in 15 adults diagnosed with schizophrenia and matched controls. This study extends the literature through the inclusion of multiple examinations of lexical-semantic production within the same patient group and through correlating performance on these tasks with various positive and negative clinical symptoms. On tasks of verbal fluency, meaning generation, sentence production using contextual information and confrontation naming, participants with schizophrenia made significantly more semantic errors on naming tasks; produced fewer meanings for homophones; produced fewer items on semantic, phonological, cued and switching fluency tasks; and produced more errors on sentence production tasks when compared to healthy controls. Significant correlations were also observed between ratings of psychomotor poverty and measures of semantic production and mental inflexibility. This study has provided additional evidence for deficits in lexical-semantic retrieval which are not due to underlying semantic store degradation, do not involve phonological based retrieval, and at the level of sentence generation appear to vary as a function of the contextual constraints provided.     

Discrimination of acoustic communication signals by grasshoppers (Chorthippus biguttulus): temporal resolution, temporal integration, and the impact of intrinsic noise

A characteristic feature of hearing systems is their ability to resolve both fast and subtle amplitude modulations of acoustic signals. This applies also to grasshoppers, which for mate identification rely mainly on the characteristic temporal patterns of their communication signals. Usually the signals arriving at a receiver are contaminated by various kinds of noise. In addition to extrinsic noise, intrinsic noise caused by stochastic processes within the nervous system contributes to making signal recognition a difficult task. The authors asked to what degree intrinsic noise affects temporal resolution and, particularly, the discrimination of similar acoustic signals. This study aims at exploring the neuronal basis for sexual selection, which depends on exploiting subtle differences between basically similar signals. Applying a metric, by which the similarities of spike trains can be assessed, the authors investigated how well the communication signals of different individuals of the same species could be discriminated and correctly classified based on the responses of auditory neurons. This spike train metric yields clues to the optimal temporal resolution with which spike trains should be evaluated.     

How to Exploit Diversity for Scientific Gain: Using Individual Differences to Constrain Cognitive Theory

ABSTRACT— People often show considerable systematic variability in their ability to perform many different cognitive tasks. In this article, we argue that by combining an individual-differences approach with an experimental-cognitive-neuroscience approach one can often further constrain potential theories of the underlying cognitive mechanisms. In support of this proposal, we outline three basic benefits of using an individual-differences approach: validating neurophysiological measures, demonstrating associations among constructs, and demonstrating dissociations among apparently similar constructs. To illustrate these points, we describe recent work by us and other researchers that utilizes each of these techniques to address specific questions within the domain of visual working memory. It is our hope that some of these techniques for utilizing individual variability may be applied to other domains within cognitive neuroscience.     

Why do the effects of delaying reinforcement in animals and delaying feedback in humans differ? A working-memory analysis

Animal research has shown that reinforcement is substantially less effective when it is delayed, but in studies of human motor learning delays in providing feedback typically have much less effect. One possible explanation is that in human research participants know the response to be learned and can thus focus on it during the delay; that is not the case in experiments on animals. We tested this hypothesis using a task in which participants had minimal information on what movement was correct and found that, as in animal experiments, participants learned only when feedback was immediate. A second experiment confirmed that the effects of the delay depended on how many responses had to be held in working memory: the greater the memory load, the poorer the learning. The results point to the importance of activity during a delay on learning; implications for the teaching of motor skills are discussed.     

Using Gender Role Conflict Theory in Counseling Male‐to‐Female Transgender Individuals

Ignoring gender socialization while counseling transgender clients neglects a significant aspect of the transgender experience. To address this, the authors review the literature on gender role conflict (GRC) theory as it pertains to the transgender experience of biological males whose authentic self is female. They explore the main types of distress experienced by transgender individuals, detail the therapeutic process using a GRC theory perspective, specify how GRC applies to transgender individuals, and suggest ways to work with this population.     

Development of the Brain’s Functional Network Architecture

A full understanding of the development of the brain’s functional network architecture requires not only an understanding of developmental changes in neural processing in individual brain regions but also an understanding of changes in inter-regional interactions. Resting state functional connectivity MRI (rs-fcMRI) is increasingly being used to study functional interactions between brain regions in both adults and children. We briefly review methods used to study functional interactions and networks with rs-fcMRI and how these methods have been used to define developmental changes in network functional connectivity. The developmental rs-fcMRI studies to date have found two general properties. First, regional interactions change from being predominately anatomically local in children to interactions spanning longer cortical distances in young adults. Second, this developmental change in functional connectivity occurs, in general, via mechanisms of segregation of local regions and integration of distant regions into disparate subnetworks.     

Bemerkingen zur Ausfagentheorie des radikalen Phyfikalismus

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