235 research outputs found
Caffeine, morning-evening type and coffee odour:Attention, memory search and visual event related potentials
No full textCaffeine is said to have arousing effects (e.g., Zwyghuizen-Doorenbos et al., 1990), although its effects on perceptual and cognitive functions are not always consistent. For example, the influence of caffeine on short-term memory search processes is occasionally positive (Anderson and Revelle, 1983), sometimes negative (Anderson et al., 1989; Erikson et al., 1985), but mostly no effect has been obtained at all (Clubley et al., 1979; Mitchell et al., 1974; Erikson et al., 1985; Loke et al., 1985, 1988). One reason for this lack of consistent results is the influence of person bound factors such as boredom, fatigue, motivation and morningness-eveningness and factors in the environment like noise and odours. In general, effects of caffeine appear to be most pronounced in subjects who are in suboptimal conditions as for example when tired (Dews, 1984; Weiss and Laties, 1962; Lorist et al., 1994a). Since many experimental designs in drug research usually do not take account of these factors, it is impossible to disentangle their influences from the desired experimental effects (Gaillard, 1988).</p
Caffeine, morning-evening type and coffee odour:Attention, memory search and visual event related potentials
No full textCaffeine is said to have arousing effects (e.g., Zwyghuizen-Doorenbos et al., 1990), although its effects on perceptual and cognitive functions are not always consistent. For example, the influence of caffeine on short-term memory search processes is occasionally positive (Anderson and Revelle, 1983), sometimes negative (Anderson et al., 1989; Erikson et al., 1985), but mostly no effect has been obtained at all (Clubley et al., 1979; Mitchell et al., 1974; Erikson et al., 1985; Loke et al., 1985, 1988). One reason for this lack of consistent results is the influence of person bound factors such as boredom, fatigue, motivation and morningness-eveningness and factors in the environment like noise and odours. In general, effects of caffeine appear to be most pronounced in subjects who are in suboptimal conditions as for example when tired (Dews, 1984; Weiss and Laties, 1962; Lorist et al., 1994a). Since many experimental designs in drug research usually do not take account of these factors, it is impossible to disentangle their influences from the desired experimental effects (Gaillard, 1988).</p
Caffeine and Information Processing in Man
No full textThe increasing emphasis on cognitive work and mental efficiency in daily life, justifies research trying to answer the question what the effects of caffeine are on human information processing activities. Does caffeine have an influence on task performance, and more important, if so, which specific cognitive processes ar~ affected? Caffeine is generally accepted to be a mild stimulant acting on the central nervous system, producing diverse and complex effects, even when consumed in small quantities (for reviews, see Dews, 1984a; Garattini, 1993). Measures of cortical brain activity might serve as an indication of these stimulating effects. With increasing energy, the electroencephalogram (EEG) shows more activation and changes towards faster frequency and lower-amplitude activity. After caffeine a reduction in alpha and delta power has indeed been found (Kenemans and Lorist, 1995; Bruce et ai., 1986; Etevenon et ai., 1989; Newman et ai., 1992; Pollock et ai., 1981; Saletu et ai., 1987). Moreover, these studies have revealed some task-specific patterning in EEG activity (Gale and Edwards, 1983), although these measures seem less suitable to uncover more detailed effects of caffeine on cognitive processing.</p
Caffeine and information processing in man
No full textThe increasing emphasis on cognitive work and mental efficiency in daily life, justifies research trying to answer the question what the effects of caffeine are on human information processing activities. Does caffeine have an influence on task performance, and more important, if so, which specific cognitive processes ar~ affected? Caffeine is generally accepted to be a mild stimulant acting on the central nervous system, producing diverse and complex effects, even when consumed in small quantities (for reviews, see Dews, 1984a; Garattini, 1993). Measures of cortical brain activity might serve as an indication of these stimulating effects. With increasing energy, the electroencephalogram (EEG) shows more activation and changes towards faster frequency and lower-amplitude activity. After caffeine a reduction in alpha and delta power has indeed been found (Kenemans and Lorist, 1995; Bruce et ai., 1986; Etevenon et ai., 1989; Newman et ai., 1992; Pollock et ai., 1981; Saletu et ai., 1987). Moreover, these studies have revealed some task-specific patterning in EEG activity (Gale and Edwards, 1983), although these measures seem less suitable to uncover more detailed effects of caffeine on cognitive processing.</p
Stressing reward: Does sex matter?
Get PDFAcute stress beïnvloedt de manier waarop wij informatie over ons eigen functioneren verwerken, blijkt uit promotieonderzoek van Stella Banis. Zij vond in experimenten, waarin naast gedrag ook hersenactiviteit werd gemeten, dat proefpersonen in stresssituaties hun aandacht minder goed richtten op relevante informatie, en minder gevoelig waren voor feedback op hun prestaties. Dit is in overeenstemming met de theorie dat een verstoorde werking van juist deze functies een centrale rol speelt in de ontwikkeling van bepaalde stressgerelateerde stoornissen. Stressgerelateerde stoornissen, zoals depressie en verslaving, vormen een groot maatschappelijk probleem. Opmerkelijk is dat sommige van deze stoornissen vaker voorkomen bij vrouwen, terwijl andere vaker mannen treffen. Banis vond echter dat de effecten van stress op de verwerking van feedback grotendeels gelijk waren voor de vrouwen en mannen die deelnamen aan haar onderzoek. Eén van de aannames in het verklaren van sekseverschillen in stressgerelateerde stoornissen is dat bij vrouwen hormoonschommelingen een belangrijke rol spelen in het ontstaan van bepaalde stoornissen. Van vrouwen wordt vaak gedacht dat zij met name in de dagen voor hun menstruatie stressgevoeliger zijn dan anders. Dit idee werd echter niet bevestigd door een experiment van Banis, waaraan gezonde vrouwen tijdens twee fasen deelnamen. Een verhoogde stressgevoeligheid tijdens de premenstruele fase speelt mogelijk alleen een rol bij vrouwen met een premenstruele stemmingsstoornis. Wel vond Banis in haar onderzoek bewijs dat de menstruele fase van invloed is op de manier waarop vrouwen informatie over hun functioneren verwerken. In de dagen voor de eisprong waren vrouwen gevoeliger voor informatie over hun prestaties (doe ik het goed of niet?), ongeacht of er een beloning op het spel stond. In de dagen voor de menstruatie reageerden vrouwen sterker op beloningsprikkels
Caffeine and information processing in man
No full textThe increasing emphasis on cognitive work and mental efficiency in daily life, justifies research trying to answer the question what the effects of caffeine are on human information processing activities. Does caffeine have an influence on task performance, and more important, if so, which specific cognitive processes ar~ affected? Caffeine is generally accepted to be a mild stimulant acting on the central nervous system, producing diverse and complex effects, even when consumed in small quantities (for reviews, see Dews, 1984a; Garattini, 1993). Measures of cortical brain activity might serve as an indication of these stimulating effects. With increasing energy, the electroencephalogram (EEG) shows more activation and changes towards faster frequency and lower-amplitude activity. After caffeine a reduction in alpha and delta power has indeed been found (Kenemans and Lorist, 1995; Bruce et ai., 1986; Etevenon et ai., 1989; Newman et ai., 1992; Pollock et ai., 1981; Saletu et ai., 1987). Moreover, these studies have revealed some task-specific patterning in EEG activity (Gale and Edwards, 1983), although these measures seem less suitable to uncover more detailed effects of caffeine on cognitive processing
Nicotine, caffeine and social drinking:Behaviour and brain function
No full textOften, people use nicotine, caffeine, and some level of alcohol in varying combinations at different times of the day in order to optimize their functioning and feelings of well-being, whether at work, in leisure time, or in a social context. However, until now, studies on the effects of this everyday practice have been diverse, widespread, and insufficiently summarized. Recently developed methods to study the effects in more detail have received little attention, especially among a nonscientific readership. Nicotine, Caffeine and Social Drinking focuses readers' attention on the effects of normal, socially accepted psychoactive substances on cognitive performance and on the brain. Divided into three sections, this book studies each substance individually before examining the effects of their combined usage.</p
Nicotine, caffeine and social drinking:Behaviour and brain function
No full textOften, people use nicotine, caffeine, and some level of alcohol in varying combinations at different times of the day in order to optimize their functioning and feelings of well-being, whether at work, in leisure time, or in a social context. However, until now, studies on the effects of this everyday practice have been diverse, widespread, and insufficiently summarized. Recently developed methods to study the effects in more detail have received little attention, especially among a nonscientific readership. Nicotine, Caffeine and Social Drinking focuses readers' attention on the effects of normal, socially accepted psychoactive substances on cognitive performance and on the brain. Divided into three sections, this book studies each substance individually before examining the effects of their combined usage.</p
Nicotine, caffeine and social drinking:Behaviour and brain function
No full textOften, people use nicotine, caffeine, and some level of alcohol in varying combinations at different times of the day in order to optimize their functioning and feelings of well-being, whether at work, in leisure time, or in a social context. However, until now, studies on the effects of this everyday practice have been diverse, widespread, and insufficiently summarized. Recently developed methods to study the effects in more detail have received little attention, especially among a nonscientific readership. Nicotine, Caffeine and Social Drinking focuses readers' attention on the effects of normal, socially accepted psychoactive substances on cognitive performance and on the brain. Divided into three sections, this book studies each substance individually before examining the effects of their combined usage.</p
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