Pathological visual field and brain tumor]

The general relationships between an operatively or autoptically localized tumor and the visual field determined by means of ikineticer perimetry are investigated, the patient stock being a total of 1756 neurosurgical brain-tumor inpatients. Examination of the visual field was possible with four fifths of the brain-tumor patients. Hemianopic, quadrantanopsic, or scotomatous defects of a topically localizable nature could be found in almost one third of the total patient stock available for examination. The clinically particularly interesting criteria of localization of homonymous-hemianopsia defects such as macular sparing and incongruence/congruence of visual field changes should be of no importance to the localization within the visual pathway of brain-tumor patients.     

O2 multistep method as a supplement to therapy of standard brain energy balance disorders]

The possibility of improving the brain's energy state by the O2 multistep method is discussed. An outline is given of several variations of the O2 multistep method, and this is followed by a discussion of the results of studies of the increase and decrease in concentration of high-energy phosphates in the brains of rats during and after the O2 multistep process. In conclusion, the author reports a twin series of tests where psychic irritations lasting for a short time only were triggered and in which such irritations were suppressed through using the O2 multistep procedure.     

Results of nuclear medical, electroencephalographic, and angiographic examinations after brain tumor operations]

The methods of nuclear medicine and electro-encephalography allow, in combination, in almost every case the answer to the question of the cerebral tumour relapse. Our evaluation confirms the discovery of the greater sensitivity of the isotopic methods with relapses of glioblastomas, while relapses of meningiomas, astrocytomas, oligodendrogliomas and spongioblastomas can be recognized more frequently only by electro-encephalographic methods. The value of angiography is limited in cases of cerebral tumour relapses without pathological vascularisation, since the swelling can spread in the resection cavity without retroaction on the surrounding areas. For this reason vascular displacement (an only be observed very late on. Clinical judgement is furthermore complicated by the fact that after the removal of the primary tumour, often no reposition of the arteries ensues. After our exainations, a negative angiographic condition can be rule out a diagnosis of a relapse which has been established by electro-encephaolographic and isotopic methods.     

Disorders of higher mentae functions as first symptoms in patients with brain tumors]

It has been established that in 29 (or 36,25%) of examined patients with neoplasms of the brain in the left dominant hemisphere, disturbances in the psychic functions seem to be the first and most early symptoms of the disease. They develop slowly, progressively, or in the form of epileptic language equivalents (in 5% of examined patients). As early symptoms, disturbances in language indicate existance of a brain disease and give cause to suspect a neoplasm, in this way stating the necessity of further examination, and from the other side - in some cases show the localization of the process.     

Anorexia nervosa and brain tumor in a 14-year-old girl

A 14-year-old girl with anorexia nervosa (AN) was found to have an intracranial neoplasm. Atypical psychological symptoms prompted further evaluation, including electroencephalogram and neuroimaging, which revealed a sellar and suprasellar mass. This patient had an eating disorder and a brain tumor, which appear to be two unrelated conditions. However, it remains unclear how each affected the other. The diagnosis of AN, like all other psychiatric disorders, requires that possible medical etiologies and coexisting medical problems be excluded. AN and other eating disorders are particularly difficult to diagnose in children and adolescents because they often do not present in the manner typical of adults. Perceptual and cognitive disturbances associated with AN are difficult to evaluate because children and adolescents normally change over time as they progress through different stages of development. Therefore, it is particularly important to evaluate for the presence of medical conditions when a diagnosis of an eating disorder is made in a child or adolescent.     

Facial myokomias in brain stem tumors]

Four cases of brain-stem tumor were described, in which myokymias were electromyographically derived from the region of several cerebral nerves. An attempt is made to interpret the effects of twitching by reference to the electromyogram. Myokymias are a positive indication of organic brain stem damage. The use subtle techniques of electromyographic examination shows that this muscular hyperkinesis is not so infrequent a symptom as is generally believed.     

Simplest tasks have greatest dual task interference with balance in brain injured adults

Attention difficulties and poor balance are both common sequel following a brain injury. This study aimed to determine whether brain injured adults had greater difficulty than controls in performing a basic balance task while concurrently completing several different cognitive tasks varying in visuo-spatial attentional load and complexity. Twenty brain injured adults and 20 age-, sex- and education level-matched controls performed a balance-only task (step stance held for 30 s), five cognitive-only tasks (simple and complex non-spatial, visuo-spatial, and a control articulation task), and both together (dual tasks). Brain injured adults showed a greater centre of pressure (COP) excursion and velocity in all conditions than controls. Brain injured adults also demonstrated greater interference with balance when concurrently performing two cognitive tasks than control subjects. These were the control articulation and the simple non-spatial task. It is likely that distractibility during these simple tasks contributed to an increase in COP motion and interference with postural stability in stance. Performing visuo-spatial tasks concurrently with the balance task did not result in any change in COP motion. Dual task interference in this group is thus unlikely to be due to structural interference. Similarly, as the more complex tasks did not uniformly result in increased interference, a reduction in attentional capacity in the brain injured population is unlikely to be the primary cause of dual task interference in this group.     

Biofeedback of slow brain potentials]

Slow cortical potentials constitute neurophysiological indicators of cortical excitability. Behaviorally they correlate with attention and motor preparation. A system for biofeedback and self-regulation of slow cortical potentials (SCP) has been developed. The portable system allows on-line visual feedback of filtered and corrected slow brain potentials in a predetermined sequence of trials. Three different algorithms for transforming the original SCP-signal into a feedback-signal have been developed and were compared in a controlled outcome study. With the optimal feedback method subjects were able to produce cortical positivity and negativity on command after three sessions. Increases and decreases of negativity of up to 20 microV were also achieved. Therefore a simple and portable PC-based device for the clinical application of SCP-biofeedback is now available.     

Aphasia syndromes in brain tumors. Clinico-pathological correlations]

A clinica-psychological and pathoanatomical analysis of 40 observations with neoplasms of the brain in the left dominant hemisphere and 4 observations with neoplasms in the right subdominant hemisphere, has been carried out. In 36 cases, a desintegration in the language in a form of aphasia, has been established, while in 4 cases this was not present. In 22 observations the established neuro-psychological syndrome completely indicated and coincided with the localization of the neoplasm in the corresponding part or parts of the brain, in 10 it only partialy coincided, while in 4 cases it did not coincide with the localization of the neoplasm in the brain. The established neuro-psychological syndrome in observations with neoplasms in the right subdominant hemisphere possesses only a tentative topico-diagnostical significance. In conclusion the authors consider that the established syndromes of aphasia in patients with neoplasms of the brain may be of a considerable significance and help in substantiating a precise topical diagnosis.     

Awareness and equilibrium

There has been a recent surge of interest among economists in developing models of doxastic states that can account for some aspects of human cognitive limitations that are ignored by standard formal models, such as awareness. Epistemologists purport to have a principled reason for ignoring the question of awareness: under the equilibrium conception of doxastic states they favour, a doxastic state comprises the doxastic commitments an agent would recognise were he fully aware, so the question of awareness plays no role. The objective of this paper is to scrutinize this argument. A thesis underlying the argument, which we call the independence of doxastic commitments with respect to awareness, is identified, and examples are given where it appears to be violated. By considering these examples, one can get an idea of the price of accepting this thesis. On the one hand, one can escape the conclusion that the thesis is violated, but only at the expense of another principle espoused by all major formal models of belief, which we call constant doxastic rest; and abandoning this principle necessitates extensive revision of current models of belief. On the other hand, there are epistemologically valid reasons for thinking that the thesis fails to hold in the examples, which have to be rebutted if the thesis, and the equilibrium justification for ignoring the issue of awareness, are to be retained.     

Lymphocyte sensitivity to brain specific glycoprotein in multiple sclerosis]

The lymphocytes of seven out of eight multiple sclerosis patients were sensitized to brain-specific glycoproteins that had been isolated from extracts of human white matter and purified by means of affinity chromatography utilizing specific antibodies as immunoadsorbents. The diagnosis of multiple sclerosis for the eighth patient, whose lymphocytes were not sensitized, was doubtful. A significant correlation between the severity of the disease and degree of lymphocyte sensitization was not obtained, although the most disabled patient showed the greatest sensitization.     

Rationality and reflective equilibrium

Cohen (1981) and others have made an interesting argument for the thesis that humans are rational: normative principles of reasoning and actual human reasoning ability cannot diverge because both are determined by the same process involving our intuitions about what constitutes good reasoning as a starting point. Perhaps the most sophisticated version of this argument sees reflective equilibrium as the process that determines both what the norms of reasoning are and what actual cognitive competence is. In this essay, I will evaluate both the general argument that humans are rational and the reflective equilibrium argument for the same thesis. While I find both accounts initially appealing, I will argue that neither successfully establishes that humans are rational.     

Attentional balance and intelligence

Recent studies of neuroimaging during cognitive tasks suggest that most tasks involve the activity of widespread areas in both cerebral hemispheres. In many cases, information must be shared between the two hemispheres. The coordination of these areas involves the brain's attentional networks. Unilateral brain damage often causes asymmetries in attention and reduced speed of processing. Based on these findings it was hypothesized that mental processing in normals will be more efficient when normal people can shift attention to either hemisphere with equal efficiency. Attentional balance was measured by the degree of asymmetry found during the covert visual-orienting task. Intelligence was measured by the Raven Standard Progressive Matrices. Data from two experiments suggest that low asymmetry in attention shifting is associated with higher intelligence.     

Effectiveness of taping and bracing in balance

Taping and bracing are thought to be effective methods in restricting the ankle's joint motion and assisting prevention of injuries. Research evidence suggests that taping and bracing enhance both the mechanical support and the proprioception of the ankle. However, there is little research concerning the influence of taping and bracing on sport performance. Research has mainly examined tasks with demands on the frontal plane. Therefore, the present study examined the effect of taping and bracing on the performance of a task with demands on the frontal plane. A sample of 30 physical education students (Mage=21.9 yr.) performed a balance task requiring estimation of balance and both right and left deviations. The subjects performed the balance task on four different conditions, with tape, with Swede-O (a lace-up, boot style stabilizer), with Aircast (an inflatable cast), and without any stabilizer. There were no significant differences among the conditions. These findings indicate that taping and bracing do not have negative effects on balance in the frontal plane. This study created concerns regarding the appropriate stabilizer for different tasks, bilateral coordination after the application of a stabilizer, and the influence of psychological factors on prevention of injury.