ACQUISITION AND FUNCTIONAL ANALYSIS OF MANDING WITH AUTISTIC STUDENTS

Three autistic students were trained to request a specific object from an adult “supplier” with the sentence, “Give me —” and to deliver that object to another adult, the “director.” Subsequently, the degree to which the object offered by the supplier controlled the “Give me —” verbal response was assessed by delivering to the student an object other than the one requested. Despite knowing the names of all objects used in the experiment, students accepted and delivered to the director any object offered by the supplier regardless of its match with the requested object. After training to say “That's not it. Give me —” when nonrequested objects were offered, students responded differentially to requested and nonrequested objects, suggesting control of the “Give me —” response by the requested object, a characteristic of a mand. These results generalized across settings and objects. Results are discussed in terms of the training technique to establish manding and the functional analysis of the resulting verbal behavior.     

A simple method to dissociate sensory-attentional and motor-intentional biases in unilateral visual neglect

A variant of a line bisection test was devised. Patients with unilateral visual neglect and control subjects were asked to perform the test, which consisted of two subtasks: a verbal and a manual task. The verbal task was newly designed and did not require manual responses from the subjects. The manual task was similar to conventional line bisection tasks. This paper reports and discusses the results obtained from each task and their correlations. This technique is compatible with bedside examinations, does not require a complex apparatus, and provides useful data for the assessment of unilateral visual neglect.     

RNA interference: a new mechanism by which FMRP acts in the normal brain? What can Drosophila teach us?

Fragile X syndrome is the most common heritable form of mental retardation caused by loss-of-function mutations in the FMR1 gene. The FMR1 gene encodes an RNA-binding protein that associates with translating ribosomes and acts as a negative translational regulator. Recent work in Drosophila melanogaster has shown that the fly homolog of FMR1 (dFMR1) plays an important role in regulating neuronal morphology, which may underlie the observed deficits in behaviors of dFMR1 mutant flies. Biochemical analysis has revealed that dFMR1 forms a complex that includes ribosomal proteins and, surprisingly, Argonaute2 (AGO2), an essential component of the RNA-induced silencing complex (RISC) that mediates RNA interference (RNAi) in Drosophila. dFMR1 also associates with Dicer, another essential processing enzyme of the RNAi pathway. Moreover, both a micro-RNA (miRNA) and short interfering RNAs (siRNAs) can coimmunoprecipitate with dFMR1. Together these findings suggest that dFMR1 functions in an RNAi-related apparatus to regulate the expression of its target genes at the level of translation. These findings raise the possibility that Fragile X syndrome may be the result of a protein synthesis abnormality caused by a defect in an RNAi-related apparatus. Because the core mechanisms of complex behaviors such as learning and memory and circadian rhythms appear to be conserved, studies of Fragile X syndrome using Drosophila as a model provide an economy-of-scale for identifying biological processes that likely underlie the abnormal morphology of dendritic spines and behavioral disturbances observed in Fragile X patients.     

Involvement of BDNF receptor TrkB in spatial memory formation

The N-methyl-D-aspartate (NMDA) receptors are involved in long-term potentiation (LTP), and are phosphorylated by several tyrosine kinases including a Src-family tyrosine kinase Fyn. Brain-derived neurotrophic factor (BDNF) is a neurotrophin, which also enhances hippocampal synaptic transmission and efficacy by increasing NMDA receptor activity. Here, we show that Fyn is a key molecule linking the BDNF receptor TrkB with NMDA receptors, which play an important role in spatial memory formation in a radial arm maze. Spatial learning induced phosphorylation of TrkB, Fyn, and NR2B, but not NR2A, in the hippocampus. Fyn was coimmunoprecipitated with TrkB and NR2B, and this association was increased in well-trained rats compared with control animals. Continuous intracerebroventricular infusion of PP2, a tyrosine kinase inhibitor, in rats delayed memory acquisition in the radial arm maze, but PP2-treated animals reached the same level of learning as the controls. The phosphorylation of Fyn and NR2B, but not TrkB, was diminished by PP2 treatment. Our findings suggest the importance of interaction between BDNF/TrkB signaling and NMDA receptors for spatial memory in the hippocampus.     

A Capuchin monkey (<Emphasis Type="Italic">Cebus apella</Emphasis>) recognizes when people do and do not know the location of food

In a previous study, Kuroshima and colleagues demonstrated that capuchin monkeys (Cebus apella) learned to discriminate between a "knower" who inspected a box for food, and a "guesser" who did not. The aim of the present study was to specify whether the subjects learned a simple conditional discrimination or a causal relationship that seeing leads to knowing. In experiment 1, we introduced five types of novel containers to two subjects. Each container was of different shape and color. The subjects gradually learned to reach toward the container the knower suggested. In experiment 2, we diversified the behavior of the knower and the guesser. In experiment 3, in order to eliminate the possibility of discrimination based on differences in the magnitude and the complexity of two trainers, we equated their behaviors. One subject adapted to the novel behaviors of the knower and the guesser, successfully discriminating the two trainers. Thus this monkey clearly learned to use the inspecting action of the knower and the non-inspecting action of the guesser as a discriminative cue to recognize the baited container. This result suggests that one capuchin monkey learned to recognize the relationship between seeing and knowing.     

Spontaneous blinks as a criterion of visual fatigue during prolonged work on visual display terminals

Visual fatigue caused by prolonged work viewing a Visual Display Terminals (VDT) and of work reading a hard-copy were assessed by electromyogram (EMG) waveform and electrooculogram (EOG) waveform in spontaneous blinks as objective criteria, and by questionnaire of subjective feeling, and by task performance. The duration and the amplitude of the EMG of the orbicularis ocular muscle on the right side and the EOG of the vertical direction to the eyelid were measured for 10 subjects who participated in a figure task consisting of the addition of single-digit numbers on a VDT work or a work with a hard-copy. The mean values of the duration and the amplitude of the EMG and the EOG were evaluated by the averaging of 10 waveforms of the spontaneous blinks for all subjects. The time lag from the EMG to the EOG in the process of the generation of spontaneous blinks was also analyzed. These five parameters were evaluated during the work time. The mean values for the duration of the EMG increased gradually during the work time, but the amplitude did not show significant difference between the prework and a work time. There was no significant change of the duration of the EOG, but the mean amplitude of the EOG decreased as the work time progressed, and the time lag significantly extended. The blinks frequency increased relatively when using a VDT. The rate of fluctuation for these parameters was higher during use of a VDT than use of a hard-copy. The time lag at five hours of VDT work was extended by 90% based on the value at the pre-work. The symptoms of general fatigue and fatigue of the eyes increased linearly during the VDT work for six hours. The results indicated a significant correlation between the objective parameters for the activity of the spontaneous blinks, i.e., duration and amplitude of EMG and EOG, and the time lag between EMG and EOG, and the subjective feeling was recognized in the time course of the task. These experimental results suggested that the parameters regarding the EMG and the EOG for the spontaneous blinks were effective indices for assessing visual fatigue during prolonged VDT work.     

The Relationship Among Major Depression, Depressive Symptoms, and Self-Preoccupation

The present study investigates whether highly self-preoccupied people (exhibiting a tendency to focus primarily on the self and to maintain self-focused attention) were more likely to experience major depressive episodes (MDEs) than those without such tendencies. One hundred nineteen young community residents, aged 18 to 21, took part in semistructured interviews, during which we investigated their past and present history of mental illness, including MDEs, as delineated by the Diagnostic and Statistical Manual of Mental Disorders (3rd ed. rev.; DSM-III-R). Self-preoccupation was measured by the Self-Preoccupation Scale (SPS). Of the 119 participants interviewed, the lowest and highest quarters in the SPS scores formed the low- and high-self-preoccupation (SP) groups. The lifetime prevalence of the DSM-III-R MDE was significantly greater among those high in SP than in the low SP group. Moreover, the high-SP group had significantly more depressive symptoms than the low-SP group. The contributory role of self-preoccupation to suicide ideation and the interpersonal aspects of self-preoccupation were discussed.     

The left superior longitudinal fasciculus within the primary sensory area of inferior parietal lobe plays a role in dysgraphia of kana omission within sentences

Functional neurological changes after surgery combined with diffusion tensor imaging (DTI) tractography can directly provide evidence of anatomical localization of brain function. Using these techniques, a patient with dysgraphia before surgery was analyzed at our hospital in 2011. The patient showed omission of kana within sentences before surgery, which improved after surgery. The brain tumor was relatively small and was located within the primary sensory area (S1) of the inferior parietal lobe (IPL). DTI tractography before surgery revealed compression of the branch of the superior longitudinal fasciculus (SLF) by the brain tumor. These results suggest that the left SLF within the S1 of IPL plays a role in the development of dysgraphia of kana omission within sentences.     

The Nature and Organization of Individual Differences in Executive Functions: Four General Conclusions

Executive functions (EFs)-a set of general-purpose control processes that regulate one's thoughts and behaviors-have become a popular research topic lately and have been studied in many subdisciplines of psychological science. This article summarizes the EF research that our group has conducted to understand the nature of individual differences in EFs and their cognitive and biological underpinnings. In the context of a new theoretical framework that we have been developing (the unity/diversity framework), we describe four general conclusions that have emerged from our research. Specifically, we argue that individual differences in EFs, as measured with simple laboratory tasks, (1) show both unity and diversity (different EFs are correlated yet separable); (2) reflect substantial genetic contributions; (3) are related to various clinically and societally important phenomena; and (4) show some developmental stability.