Luciano Mecacci

Morning and evening types: stress-related personality aspects☆

Abstract A group of 232 adult subjects was administered the Morningness-Eveningness Questionnaire to assess their individual circadian typology and a battery of questionnaires of personality and psychological and psychosomatic disorders (Beck Depression Inventory; Bortner Type A Scale; Eysenck Personality Questionnaire; Jenkins Activity Survey; Middlesex Hospital Questionnaire; Strelau Temperament Inventory). Significant correlations between circadian typology scores and data relative to personality, psychosomatic disorders, and stress-prone behaviour were found. Evening types reported psychological and psychosomatic disturbances more frequently and intensively than morning types, and showed more problems in coping with environmental and social demands. The relevance of the morningness-eveningness dimension for research on stress and cardiovascular diseases is discussed.

The relationships between morningness-eveningness, ageing and personality

In an attempt to study the relationship between ageing and personality and the morningness-eveningness dimension two experiments were carried out. In experiment I, an Italian version of the Morningness-Eveningness Questionnaire (MEQ) was administered to 435 Ss ranging in age from 20 to 79 yr, and divided in to six age groups. In comparison with younger people older S tended to display greater Morningness-Eveningness scores. These results suggest that ageing relates to a shifting toward morningness. In Experiment II the Eysenck Personality Questionnaire (EPQ) and the MEQ were administered to 233 Ss (20–29 yr). Morning-types had significantly higher N scores and tended to be insignificantly more introverted. Evening-types had significantly higher N scores and tended to be insignificantly more extraverted. The present findings are consistent with reports of a tendency for morning-types to be introverted and for evening-types extraverted. However, they do provide some evidence of individual differences on the neuroticism and psychoticism dimensions of personality between the two diurnal types.

Anxiety, cognitive self-evaluation and performance: ERP correlates

The relation between anxiety, cognitive self-evaluation, performance, and electrical brain activity (event-related potentials, ERPs) in a sustained attention task (Go/NoGo; SART) was investigated in 18 participants. No significant correlation was found between reaction times and anxiety (assessed by State and Trait Anxiety Inventory or STAI), and cognitive self-evaluation (assessed by Cognitive Failures Questionnaire or CFQ). N2 (ERP time-window 250-350ms) and P3 (350-650ms) amplitudes were found to be related to anxiety and cognitive self-evaluation. N2 amplitude increased in trait and state high anxious participants, whereas P3 decreased in participants who reported a higher frequency of cognitive failures. Electrophysiological responses revealed that cognitive strategies were probably activated by more anxious and less self-confident individuals in order to be efficient in their performance. As shown by current research, frontal areas and anterior cingulated cortex appear to be particularly involved in this affective-cognitive interaction.

The effects of spatial frequency adaptation on human evoked potentials

Abstract The spatial frequency selectivity of the adaptation to gratings in man has been verified with the technique of evoked potentials. The amplitude of the potentials evoked by a low contrast grating is reduced after the adaptation to a high contrast grating of the same spatial frequency and orientation. The effect is maximum for the adapting frequency and extends to other frequencies enclosed within about two octaves. Differences have been found between evoked potentials and contrast threshold for what regards the width of the channel affected and the recovery after the adaptation.

Scanning eye movements made when viewing film: Preliminary observations

Eye movements were recorded in 10 adult subjects during the viewing of fiction and nonfiction films. Individual differences in scan paths for fiction films were found to be relatively small. Generally, eyes concentrated on the screen center when looking at characters and objects in rapid motion. Scan paths through the screen were observed in special cases, for example, in the case of a dialogue between two characters. No differences emerged in scan paths for the same clip presented in black-and-white and color versions. Results are relevant for both filmmaking and research on perceptual and cognitive strategies involved in processing motion pictures.

Influence of spatial frequency and handedness on hemispheric asymmetry in visually steady-state evoked potentials.

Recent suggestions on the involvement of the spatial frequency of visual stimuli in the hemispheric lateralization were investigated by recording steady-state evoked potentials in two groups of subjects: five right-handers and five left-handers. Sinusoidal gratings at spatial frequency of 0.5, 1, 3, 4, 6, 8, 10, 12 or 16 cpd were phase reversed at 4 Hz or 12 Hz. Evoked potentials recorded from temporal leads over each hemisphere were submitted to a FFT analysis. Results concern the amplitude of the fundamental component. In right-handers, the temporal frequency was the deciding factor of the lateralization: the evoked activities were greatest in the RH at 4 Hz and in the LH at 12 Hz. This effect was obvious for the range of spatial frequencies from 3-12 cpd. Results, discussed in terms of global/local information, suggested the existence of two transient and sustained systems. In left-handers, both the spatial and temporal parameters were relevant to the lateralization. A spatio-temporal interaction was observed which was reversed at 6 cpd.

Abnormalities of visual evoked potentials by checkerboards in children with specific reading disability

Visual evoked potentials by checkerboards of varying check sizes were recorded in the two hemispheres of 16 specific reading disabled and 8 normal children. In most of the disabled subjects a gross hemisphere asymmetry was assessed, while in the control group the usual evoked potential symmetry was observed. In some disabled subjects the evoked potentials had a larger amplitude in the right hemisphere, while in others the amplitude was larger in the left hemisphere. In a small subgroup the evoked potentials were symmetrical, but they had a smaller amplitude than in the control subjects. The results, giving evidence of a dysfunction in basic visual processing, are discussed in the context of current literature on clinical subgroups and the interhemispheric relationship in the dyslexic syndrome.

Pattern reversal visual evoked potentials in fencers

Visual evoked potentials were recorded from occipital and temporal leads in the two cerebral hemispheres of eight fencers and eight control subjects. The stimulus was a checkerboard subtending a small (1 degree) or large (30 degrees) visual field. Significant differences in P60, N75 and P100 latency and amplitude were found between the two subject groups, especially during the processing of the large visual field. In fencers and left-handers shorter latencies were found for the large visual field condition, whereas right-handers showed an opposite trend. The results give further evidence of special patterns of visual processing in athletes, like fencers, in agreement with the literature.

Hemispheric asymmetry of pattern reversal visual evoked potentials in healthy subjects

Pattern reversal visual evoked potentials were recorded from temporal leads of both hemispheres in 3 right-handed and 3 left-handed subjects. The stimuli subtended 6 degrees of visual field (full field condition), or 1 degree of visual field (foveal condition), or were restricted to the peripheral portion of the visual field (annular condition). Check sizes varied from 16 to 2.8 min of arc. The stimuli were phase-reversed at 1 or 8 Hz. Remarkable hemispheric asymmetries were found, depending on the portion of the visual field and temporal frequency. In right-handed subjects the amplitude of visual evoked potentials recorded over the left hemisphere was larger for stimuli phase-reversed at 8 Hz in full-field and annular conditions, whereas the amplitude of visual evoked potentials recorded over the right hemisphere was larger for stimuli phase-reversed at 1 Hz in the foveal condition. Different patterns of hemispheric asymmetries were observed in left-handed subjects.

Handedness and hemispheric asymmetry of pattern reversal visual-evoked potentials☆

Pattern reversal visual-evoked potentials (EP) from temporal leads in the two hemispheres of 26 right-handed (14 right-eye-dominant and 12 left-eye-dominant) and 10 left-handed (left-eye-dominant) adults were recorded. Checkerboard patterns (check sizes: 5.7 and 17 min of arc) at 1 and 8 Hz were reversed. Stimuli (a) subtended 6 degrees of visual field, (b) subtended 1 degree of visual field (foveal condition), and (c) were restricted to the annular portion of the visual field around the fovea (peripheral condition). Larger EP amplitudes in right or left hemisphere in relation to handedness, temporal frequency, and visual field condition were recorded. Eye dominance of dextrals appeared to play a role in determining the hemispheric asymmetry. Previous literature data and present results in relation to the hypothesis of different hemispheric specialization for basic visual information are discussed.