Activating response codes by stimuli in the neglected visual field.

The ability of 2 patients with a clinical deficit of extinction to process stimuli presented contralaterally to their lesions was tested with 2 variants of the flanker task. The patients saw 2 colored stimuli, 1 of which appeared in the center of the visual field and the other either on the ipsior contralateral side. In the peripheral report task, the patients had to report the color of the peripheral stimulus. In the center report task, the patients had to report the color of the central stimulus. The patients were much slower in the peripheral report task when the target was presented contralaterally to their lesion. By contrast, the responses in the center report task were equally influenced by ipsi- and contralateral flankers. The findings indicate that the patients were not impaired in the perceptual processing or the activation of response codes for contralateral stimuli. Their impairment is related to processes needed for generation of overt responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context, cortex, and dopamine: A connectionist approach to behavior and biology in schizophrenia.

Connectionist models are used to explore the relationship between cognitive deficits and biological abnormalities in schizophrenia. Schizophrenic deficits in tasks that tap attention and language processing are reviewed, as are biological disturbances involving prefrontal cortex and the mesocortical dopamine system. Three computer models are then presented that simulate normal and schizophrenic performance in the Stroop task, the continuous performance test, and a lexical disambiguation task. They demonstrate that a disturbance in the internal representation of contextual information can provide a common explanation for schizophrenic deficits in several attention- and language-related tasks. The models also show that these behavioral deficits may arise from a disturbance in a model parameter (gain) corresponding to the neuromodulatory effects of dopamine, in a model component corresponding to the function of prefrontal cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anatomical study of the cervical sympathetic trunk and ganglia in the albino rat (Mus norvegicus albinus)

Nine adult albino rats of both sexes were studied. 16 sympathetic trunks and ganglia were dissected in detail in eight rats. The right and left superior cervical ganglion and the sympathetic trunk below the ganglion were removed from an additional rat. The cell bodies of these ganglia and the axons of the trunks were counted with the aid of light and electron microscopy. Considering the number and location of ganglia and patterns of branching, the rat's cervical sympathetic nervous system compares closely with man's. There appears to be a relationship between body size and myelination of preganglionic neurons in the cervical sympathetic trunks, with smaller animals having the least number of myelinated fibers.     

Impaired fatty acid oxidation in children on valproic acid and the effect of L-carnitine

Fatty acid oxidation was studied in 12 patients (aged 3 to 19 years) receiving valproic acid (VPA), predominantly as monotherapy, before and after 1 month of L-carnitine supplementation (50 mg/kg/day po) in order to determine whether L-carnitine plays a role in preventing the hepatotoxic effects of this drug. Five of these patients were also studied prior to VPA treatment. Only one patient taking VPA had an abnormally low plasma free carnitine. Acyl-/free carnitine ratios were elevated in five patients on VPA and normalized after L-carnitine supplementation. Mean plasma concentrations of free fatty acids, beta-OH-butyrate, and cumulative excretion of 13CO2 after administration of 1-13C-octanoic acid were not changed by VPA or L-carnitine treatment. Urinary dicarboxylic acids, acylglycines, and octanoylcarnitine were elevated during VPA therapy and unaltered by L-carnitine. These results suggest that, in patients at low risk for VPA-induced hepatotoxicity (patients aged > 2 years and taking VPA as monotherapy), VPA causes metabolic abnormalities resembling those found in inborn errors of mitochondrial beta-oxidation which are not corrected by L-carnitine.     

The quantity and quality of aftercare services: Relationship with recidivism in mental hospital patients.

Studied 79 16–88 yr old mental patients who were released to a 3-county area and received aftercare services. Patient information on prehospital, inhospital, and posthospital variables was collected from existing records to determine the relationship between the community support system available to the patient and 3 criteria of subsequent recidivism. Current situational factors were found to be the most important single predictors of recidivism, while the magnitude of aftercare services received was not related to recidivism. However, when variables associated with self-selection into the aftercare program were partialled out, the patient's living situation was the best predictor of recidivism, and greater aftercare costs indicating a greater amount of contact were found to be associated with a higher recidivism rate. Results suggest that aftercare services need to be directed at prevention and skill building and that aftercare should not be relied on as an intervention strategy. (French summary) (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An empirical study of some election systems.

Uses presidential election data of the American Psychological Association for 5 yrs to compare a number of election systems in frequency of selecting Condorcet winners, consistency over subslates, and the effect of relevant and irrelevant candidates. The results from each system could be scaled in 1 dimension for each of the 5 elections, using the Kemeny metric. These scales were closely related to the weighting given to the variance of the candidates' rankings. An interpretation is given in terms of the polarizing effect of a candidate on an electorate. Election systems are discussed as strategies for the accumulation of subelectorates to reach a decisive set of voters. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morse-code-controlled computer aid for the nonvocal quadriplegic

A computer-based communications system was established for a quadriplegic patient who suffered a brainstem infarction that left him with normal intelligence, but without speech and without functional motor control except for the thumb of his right hand. An arm brace was developed to support the hand and thumb so it could control two switches that generated Morse code signals. An interface was also devised to translate Morse code into ASCII characters to access a personal computer. Additional codes were added to represent keyboard control functions. This device allows the patient to communicate with others and control, to some extent, his environment.     

Microsystems Macro-Assemblers and Macro-Based Languages in Microprocessor Software Development

Using a conventional macro-assembler as a multi-target cross-assembler and cross-compiler, the authors developed portable algorithmic code for microprocessor controllers.