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Biomedical subjects

F Lolas

Publications and source records attributed to F Lolas.

At least 55 records · Page 3Linked to original sources
PubMed1978

[Understanding implicit behavior].

The point of departure of the present paper is the comprobation that the visible behaviour of an individual conveys information about his internal state to others, yet the description of this information transfer is limited by an insufficient conceptual framework. The most important historical approaches to the field of expressive behaviour are discussed. The peculiarity of language in information transfer as an "explicit" system of rules is constrasted with all the other kinds of behaviour which also play "informative" and "communicative" roles. For these the concept of "implicit" system is proposed and discussed. It is further shown that a strict distinction between "implicit" and "explicit" is not possible for behavioural manifestations, but rather they constitute poles of a continuum in which all communicative modes could be incorporated. Dichotomies most commonly used in human and animal communication and interaction researach are compared with the presented implicit - explicit dichotomy. The advantages of the latter are seen in the semantic clarification it could provide, thus leading to a somewhat clearer approach to different forms of behaviour research.

Communication↗
PubMed1978

[Voice and vibration sensations in the speech forming organs: clinical and theoretical aspects of rare symptoms specific for schizophrenia].

When studying 750 psychiatric in-patients with psychoses of various diagnostic groups, the symptoms of voice sensations and vibration feelings could only be found among patients with paranoid schizophrenia. In addition, these symptoms were located exclusively in body areas that are involved in the peripheral motor production of voice and speech (areas of head, throat, thorax). In 11 of 15 such cases that could be identified, the sensations of voices and vibrations occurred simultaneously and in identical body parts; in the remaining 4 cases only voices without vibration sensations were reported. Therefore these symptoms can be considered as highly specific for schizophrenia. According to the terminology of Bleuler these two symptoms are because of their rareness to be taken as accessoric symptoms; according to the terminology of Kurt Schneider they have the value of first rank symptoms because of their highly diagnostic specifity for schizophrenia. The pathogenesis of these symptoms is on the one hand discussed under the perspective of language development and the changing function of language for behaviour control; on the other hand, the pathogenesis of these symptoms is discussed from the viewpoint of cybernetic, or neurophysiological-neuroanatomical foundation of speech production and speech control. Both models of explanation have in common that the ideational component of speech is noticed as acustic halluzinations and the motor proprioceptive part of speech is noticed as sensation of vibrations, both in a typically schiphrenic manner, i.e. dissociated and ego-alienated.

Adult↗
PubMed1977

Neuroticism, extraversion and slow brain potentials.

Peak amplitude and area under the curve of average vertex slow potentials recorded during the foreperiod of a reaction time task were found to discriminate between high- and low-neuroticism subjects, defined according to the Eysenck Personality Inventory. High-neuroticism subjects developed smaller peak amplitude, greater area and longer reaction times, presenting a high extinction rate when the imperative stimulus was omitted. Differences between extraverts and introverts were found within the low-neuroticism group and for area values, extraverts exhibiting larger area. A significant interaction effect of extraversion and neuroticism on slow-potential parameters was evidenced. Results are interpreted in terms of heightened arousal and disrupted focused attention in high-neuroticism subjects. Although evolutionary indexes of slow potentials could differentiate between extraverts and introverts, further work using inhibition indicators is needed to further clarify the differences between them. The data reported also suggest that different aspects of overt behavior would be associated diversely with slow-potential parameters.

Arousal↗
PubMed1977

Low-level electrical currents and brain indicators of behavioral activation.

Distinguishing between slow brain potential correlates of arousal and activation on the basis of their functional role and temporal involvement during a reaction-time task, data are presented which suggest that weak electrical polarizing currents applied to the head in human subjects modify predominantly activation indicators rather than arousal ones.

Behavior↗
PubMed1977

Brain polarization: behavioral and therapeutic effects.

Polarization is the passage of small constant direct currents through the brain. During the last 12 years some authors have investigated its therapeutic effectiveness in psychiatric patients with different and sometimes contradictory results. Although there seems to be a "fairly consistent body of evidence concerned with the effects of direct currents applied to the head in psychiatric patients" (Nias, 1976), only the procedure involving pulsating low-level currents (electrosleep) has received increasingly more attention in recent years, while polarization (constant d-c currents) is not even mentioned in most standard textbooks. This review concentrates on work dealing with behavioral and therapeutic effects of polarization. The procedure involves the continuous flow of low-level current (up to 1 ma) between cephalic and noncephalic electrodes during prolonged periods of time (usually hours), without inducing convulsions (as in electroconvulsive therapy) or sleep, the subject being almost unaware of the treatment. Because of its implications for research, attention is also devoted to some representative work on physiological effects of polarizing currents.

Animals↗
PubMed1977

[Cerebral potentials related to visual stimulation. Pattern inversion and flash].

Distinguishing between electroencephalogram (EEG) and event-related potentials (ERP) as indicators of brain electrical activity, methodological considerations pertaining to the recording of ERP to visual stimulation (evoked potentials, EP) are presented. Visual EP may be either steady-state or transient, depending upon stimulation used (repetitive versus transient) and method of analysis (frequency domain versus time domain). While both have diagnostic applications, this paper concentrates on transient visual EP. Based on the contention that intra and interindividual EP variability is the single most important issue in clinical practice, it presents data comparing two widely employed techniques (checkerboard reversal and flash stimulation) with respect to their stability in normal populations and their diagnostic sensitivity in demyelinating disease.

Adult↗
PubMed1977

Brainstem auditory evoked response (BAER): Clinical perspectives and normative data.

Research pertaining to the physiological mechanisms involved in the generation of brainstem auditory evoked responses is reviewed emphasizing the current status of its clinical applications, pointing out present gaps in knowledge and delineating avenues for further inquiry. Some work conducted in our laboratory aimed at statistical description of BAER parameters relevant to clinical practice is presented, along with assessment procedures that are deemed promising for routine work. Relevant implementation procedures are described.

Acoustic Stimulation↗
PubMedDate not supplied

[The influence of personality on suicidal behavior].

With the purpose of studying the influence of personality on suicidal behavior, 63 female suicide attempters were assessed by means of standardized interviews, Eysenck's personality questionnaire (EPQ-R) and other psychometric scales. Personality disorders (DMS III-R) were found in almost 70 per 100 and associated with previous attempts, higher hopelessness, suicide ideation, and to a more severe attempt. The most relevant dimensions were psychoticism and extraversion. The first one correlated to repetition, hopelessness, and suicide ideation; the second exerted a moderating effect, showing association with feelings of conformity towards survival. Neuroticism showed a rather unspecific effect on studied factors. Results confirm a relationship between personality disorders and suicidal behavior, and suggest possible mediating variables.

Adolescent↗