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Circadian Rhythms and Attentional Dysfunction in type1 NarcolepsyFilardi, Marco <1984> January 1900 (has links)
The aim of this investigation was to explore the nature and the severity of circadian abnormalities and attentional deficit in type 1 narcolepsy. In three studies, narcolepsy patients were compared with patients suffering from other central disorders of hypersomnolence and healthy controls on attentional functions and circadian rhythms. Study 1 evaluated the sensibility of actigraphic monitoring in distinguishing the features of daytime and nighttime sleep between adult patients with type 1 Narcolepsy, Idiopathic Hypersomnia and healthy controls. Actigraphy provides a reliable assessment of sleep quality and daytime napping behavior able to distinguish central disorders of hypersomnolence and identify Narcolepsy Type 1 patients.
Study 2 describes the features of circadian activity rhythm of narcolepsy type 1 children with recent disease onset. Type 1 narcolepsy children and healthy children were monitored for seven days during the school week, circadian activity rhythms were analyzed through functional linear modeling. Children with type 1 narcolepsy present an altered rest-activity rhythm characterized by enhanced motor activity throughout the night and blunted activity in the first afternoon. The observation of a discrete circadian profile provides new insight on the nature of diurnal variations and suggested that the quantitative assessment of motor activity is a promising behavioral biomarker of Type 1 narcolepsy.
The aim of Study 3 was to explore the nature and the severity of attentional Deficits of Narcoleptic patients. This study examined whether narcoleptic patients would exhibit impairments in alerting, orienting, and executive control of attention relative to healthy controls. Narcoleptic patients present a deficit in alerting network, while orienting and executive control networks resulted preserved. Moreover the alerting network efficiency significantly correlate with levels of subjective sleepiness. Results indicates that in narcolepsy the unstable tonic component of alerting process make necessary monitoring and compensation strategies.
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L'influenza del sonno sull'andamento temporale della consolidazione delle abilità proceduraliCampi, Claudio <1973> 28 April 2008 (has links)
Background: It is well known, since the pioneristic observation by Jenkins and Dallenbach (Am J
Psychol 1924;35:605-12), that a period of sleep provides a specific advantage for the consolidation
of newly acquired informations. Recent research about the possible enhancing effect of sleep on
memory consolidation has focused on procedural memory (part of non-declarative memory system,
according to Squire’s taxonomy), as it appears the memory sub-system for which the available data
are more consistent.
The acquisition of a procedural skill follows a typical time course, consisting in a substantial
practice-dependent learning followed by a slow, off-line improvement. Sleep seems to play a
critical role in promoting the process of slow learning, by consolidating memory traces and making
them more stable and resistant to interferences.
If sleep is critical for the consolidation of a procedural skill, then an alteration of the
organization of sleep should result in a less effective consolidation, and therefore in a reduced
memory performance. Such alteration can be experimentally induced, as in a deprivation protocol,
or it can be naturally observed in some sleep disorders as, for example, in narcolepsy.
In this research, a group of narcoleptic patients, and a group of matched healthy controls,
were tested in two different procedural abilities, in order to better define the size and time course of
sleep contribution to memory consolidation.
Experimental Procedure: A Texture Discrimination Task (Karni & Sagi, Nature 1993;365:250-2)
and a Finger Tapping Task (Walker et al., Neuron 2002;35:205-11) were administered to two
indipendent samples of drug-naive patients with first-diagnosed narcolepsy with cataplexy
(International Classification of Sleep Disorder 2nd ed., 2005), and two samples of matched healthy
controls. In the Texture Discrimination task, subjects (n=22) had to learn to recognize a complex
visual array on the screen of a personal computer, while in the Finger Tapping task (n=14) they had
to press a numeric sequence on a standard keyboard, as quickly and accurately as possible. Three
subsequent experimental sessions were scheduled for each partecipant, namely a training session, a
first retrieval session the next day, and a second retrieval session one week later. To test for possible
circadian effects on learning, half of the subjects performed the training session at 11 a.m. and half
at 17 p.m. Performance at training session was taken as a measure of the practice-dependent
learning, while performance of subsequent sessions were taken as a measure of the consolidation
level achieved respectively after one and seven nights of sleep. Between training and first retrieval
session, all participants spent a night in a sleep laboratory and underwent a polygraphic recording.
Results and Discussion: In both experimental tasks, while healthy controls improved their
performance after one night of undisturbed sleep, narcoleptic patients showed a non statistically
significant learning. Despite this, at the second retrieval session either healthy controls and
narcoleptics improved their skills. Narcoleptics improved relatively more than controls between
first and second retrieval session in the texture discrimination ability, while their performance
remained largely lower in the motor (FTT) ability.
Sleep parameters showed a grater fragmentation in the sleep of the pathological group, and a
different distribution of Stage 1 and 2 NREM sleep in the two groups, being thus consistent with the
hypothesis of a lower consolidation power of sleep in narcoleptic patients. Moreover, REM density
of the first part of the night of healthy subjects showed a significant correlation with the amount of
improvement achieved at the first retrieval session in TDT task, supporting the hypothesis that
REM sleep plays an important role in the consolidation of visuo-perceptual skills.
Taken together, these results speak in favor of a slower, rather than lower consolidation of
procedural skills in narcoleptic patients.
Finally, an explanation of the results, based on the possible role of sleep in contrasting the
interference provided by task repetition is proposed.
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Presa di decisione in situazioni rischiose: effetto della rabbiaGambetti, Elisa <1979> 28 April 2008 (has links)
The current studies assessed the role of trait anger and anger expression styles on
risk decision-making in adulthood, adolescence and childhood. In the first experiment
158 adults completed the STAXI-2 and an inventory consisting of a battery of
hypothetical everyday decision-making scenarios. Participants were also asked to
evaluate the perception of risk for each chosen option and some contextual
characteristics, that are familiarity and salience for each scenario. The study provides
evidence for a relationship between individual differences in the tendency to feel and
express anger and risky decisions and for mediation effects of familiarity and salience
appraisals. Moreover, results indicated that trait anger was predictive of risk
perception and they provide evidence for a positive relationship between risk
decision-making and risk perception.
In the second study, we examined the relationship between specific components of
anger (i.e., cognitive, affective and behavioural) and risk decision-making in
adolescents. 101 subjects completed specific tasks, measuring risk decision-making,
assessed using hypothetical choice scenarios, and anger, evaluated through the
STAXI-CA and the MSAI-R. Results showed that adolescents higher on hostility,
anger experience and destructive expression, make more risky decisions in everyday
life situations. Moreover, regression analyses indicated that destructive expression of
anger and hostility were predictive of adolescents’ risky decisions.
In the third experiment, 104 children completed three tasks: the STAXI-CA, the
MSAI-R and a task measuring risk decision-making in everyday situations. Subjects
were also asked to evaluate the degree of danger, benefit, fun and fear perceived for
each risky choice. Analyses indicated that: (a) risk decision-making was predicted by
both trait anger and outward expression of anger; (b) destructive expression o anger
was predictive of children’s risky decisions; (c) appraisal of danger fully mediated
the relation between trait anger and risk; (d) perceptions of benefit, scare and fun
partially mediated the relationship between trait anger and risk; and (e) appraisal of
danger partially mediated the relationship between outward expression of anger and
risk decision-making. The results provide evidence for a relationship between
dispositional anger and risk decision-making during childhood, suggesting a possible
explanation of the mechanisms below. In particular, risk decision-making can be
viewed as the output of cognitive and emotive processes, linked to dispositional anger
that leads children to be amused, optimistic and fearless in potentially risky
situations.
These findings substantiate the importance of incorporating cognitive and emotive
factors in theories that seek to explain the relationship between personality traits and
risk decision making across a broad range of age.
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Effetto crowding e dislessia evolutiva: un confronto inter e intra-linguisticoBellocchi, Stéphanie <1980> 28 April 2008 (has links)
Crowding is defined as the negative effect obtained by adding visual distractors
around a central target which has to be identified. Some studies have suggested the
presence of a marked crowding effect in developmental dyslexia (e.g. Atkinson, 1991;
Spinelli et al., 2002).
Inspired by Spinelli’s (2002) experimental design, we explored the hypothesis
that the crowding effect may affect dyslexics’ response times (RTs) and accuracy in
identification tasks dealing with words, pseudowords, illegal non-words and symbolstrings.
Moreover, our study aimed to clarify the relationship between the crowding
phenomenon and the word-reading process, in an inter-language comparison
perspective. For this purpose we studied twenty-two French dyslexics and twenty-two
Italian dyslexics (total forty-four dyslexics), compared to forty-four subjects matched
for reading level (22 French and 22 Italians) and forty-four chronological age-matched
subjects (22 French and 22 Italians).
Children were all tested on reading and cognitive abilities. Results showed no
differences between French and Italian participants suggesting that performances were
homogenous. Dyslexic children were all significantly impaired in words and
pseudowords reading compared to their normal reading controls.
Regarding the identification task with which we assessed crowding effect, both
accuracy and RTs showed a lexicality effect which meant that the recognition of words
was more accurate and faster in words than pseudowords, non-words and symbolstrings.
Moreover, compared to normal readers, dyslexics’ RTs and accuracy were
impaired only for verbal materials but not for non-verbal material; these results are in
line with the phonological hypothesis (Griffiths & Snowling, 2002; Snowling, 2000;
2006) . RTs revealed a general crowding effect (RTs in the crowding condition were
slower than those recorded in the isolated condition) affecting all the subjects’
performances. This effect, however, emerged to be not specific for dyslexics. Data
didn’t reveal a significant effect of language, allowing the generalization of the
obtained results.
We also analyzed the performance of two subgroups of dyslexics, categorized
according to their reading abilities. The two subgroups produced different results
regarding the crowding effect and type of material, suggesting that it is meaningful to
take into account also the heterogeneity of the dyslexia disorder.
Finally, we also analyzed the relationship of the identification task with both
reading and cognitive abilities.
In conclusion, this study points out the importance of comparing visual tasks
performances of dyslexic participants with those of their reading level-matched
controls. This approach may improve our comprehension of the potential causal link
between crowding and reading (Goswami, 2003).
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Scene di violenza, esperienze emotive e condotte aggressiveTosini, Giorgio <1953> 28 April 2008 (has links)
The aim of this research is to estimate the impact of violent film excerpts on university
students (30 f, 30 m) in two different sequences, a “justified” violent scene followed by an
“unjustified” one, or vice versa, as follows:
1) before-after sequences, using Aggressive behaviour I-R Questionnaire, Self Depression
Scale and ASQ-IPAT Anxiety SCALE;
2) after every excerpt, using a self-report to evaluate the intensity and hedonic tone of
emotions and the violence justification level.
Emotion regulation processes (suppression, reappraisal, self-efficacy) were considered.
In contrast with the “unjustified” violent scene, during the “justified” one, the justification
level was higher; intensity and unpleasantness of negative emotions were lower.
Anxiety (total and latent) and rumination diminished after both types of sequences.
Rumination decreases less after the JV-UV sequence than after the UV-JV sequence.
Self-efficacy in controlling negative emotions reduced rumination, whereas suppression
reduced irritability.
Reappraisal, self-efficacy in positive emotion expression and perceived emphatic selfefficacy
did not have any effects.
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Componenti spaziali della rappresentazione cognitiva della grandezza del numeroFabbri, Marco <1979> 28 April 2008 (has links)
The humans process the numbers in a similar way to animals. There are countless
studies in which similar performance between animals and humans (adults and/or children)
are reported. Three models have been developed to explain the cognitive mechanisms
underlying the number processing. The triple-code model (Dehaene, 1992) posits an mental
number line as preferred way to represent magnitude. The mental number line has three
particular effects: the distance, the magnitude and the SNARC effects. The SNARC effect
shows a spatial association between number and space representations. In other words, the
small numbers are related to left space while large numbers are related to right space.
Recently a vertical SNARC effect has been found (Ito & Hatta, 2004; Schwarz & Keus,
2004), reflecting a space-related bottom-to-up representation of numbers. The magnitude
representations horizontally and vertically could influence the subject performance in explicit
and implicit digit tasks. The goal of this research project aimed to investigate the spatial
components of number representation using different experimental designs and tasks. The
experiment 1 focused on horizontal and vertical number representations in a within- and
between-subjects designs in a parity and magnitude comparative tasks, presenting positive or
negative Arabic digits (1-9 without 5). The experiment 1A replied the SNARC and distance
effects in both spatial arrangements. The experiment 1B showed an horizontal reversed
SNARC effect in both tasks while a vertical reversed SNARC effect was found only in
comparative task. In the experiment 1C two groups of subjects performed both tasks in two
different instruction-responding hand assignments with positive numbers. The results did not
show any significant differences between two assignments, even if the vertical number line
seemed to be more flexible respect to horizontal one. On the whole the experiment 1 seemed
to demonstrate a contextual (i.e. task set) influences of the nature of the SNARC effect. The
experiment 2 focused on the effect of horizontal and vertical number representations on
spatial biases in a paper-and-pencil bisecting tasks. In the experiment 2A the participants were
requested to bisect physical and number (2 or 9) lines horizontally and vertically. The findings
demonstrated that digit 9 strings tended to generate a more rightward bias comparing with
digit 2 strings horizontally. However in vertical condition the digit 2 strings generated a more
upperward bias respect to digit 9 strings, suggesting a top-to-bottom number line. In the
experiment 2B the participants were asked to bisect lines flanked by numbers (i.e. 1 or 7) in
four spatial arrangements: horizontal, vertical, right-diagonal and left-diagonal lines. Four
number conditions were created according to congruent or incongruent number line
representation: 1-1, 1-7, 7-1 and 7-7. The main results showed a more reliable rightward bias
in horizontal congruent condition (1-7) respect to incongruent condition (7-1). Vertically the
incongruent condition (1-7) determined a significant bias towards bottom side of line respect
to congruent condition (7-1). The experiment 2 suggested a more rigid horizontal number line
while in vertical condition the number representation could be more flexible. In the
experiment 3 we adopted the materials of experiment 2B in order to find a number line effect
on temporal (motor) performance. The participants were presented horizontal, vertical, rightdiagonal
and left-diagonal lines flanked by the same digits (i.e. 1-1 or 7-7) or by different
digits (i.e. 1-7 or 7-1). The digits were spatially congruent or incongruent with their respective
hypothesized mental representations. Participants were instructed to touch the lines either
close to the large digit, or close to the small digit, or to bisected the lines. Number processing
influenced movement execution more than movement planning. Number congruency
influenced spatial biases mostly along the horizontal but also along the vertical dimension.
These results support a two-dimensional magnitude representation. Finally, the experiment 4
addressed the visuo-spatial manipulation of number representations for accessing and retrieval
arithmetic facts. The participants were requested to perform a number-matching and an
addition verification tasks. The findings showed an interference effect between sum-nodes
and neutral-nodes only with an horizontal presentation of digit-cues, in number-matching
tasks. In the addition verification task, the performance was similar for horizontal and vertical
presentations of arithmetic problems. In conclusion the data seemed to show an automatic
activation of horizontal number line also used to retrieval arithmetic facts. The horizontal
number line seemed to be more rigid and the preferred way to order number from left-to-right.
A possible explanation could be the left-to-right direction for reading and writing. The vertical
number line seemed to be more flexible and more dependent from the tasks, reflecting
perhaps several example in the environment representing numbers either from bottom-to-top
or from top-to-bottom. However the bottom-to-top number line seemed to be activated by
explicit task demands.
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Emotional engagement and orienting: the effects of picture size on affective responseDe Cesarei, Andrea <1978> 27 April 2009 (has links)
For their survival, humans and animals can rely on motivational systems which are specialized in assessing the valence and imminence of dangers and appetitive cues. The Orienting Response (OR) is a fundamental response pattern that an organism executes whenever a novel or significant stimulus is detected, and has been shown to be consistently modulated by the affective value of a stimulus. However, detecting threatening stimuli and appetitive affordances while they are far away compared to when they are within reach constitutes an obvious evolutionary advantage. Building on the linear relationship between stimulus distance and retinal size, the present research was aimed at investigating the extent to which emotional modulation of distinct processes (action preparation, attentional capture, and subjective emotional state) is affected when reducing the retinal size of a picture. Studies 1-3 examined the effects of picture size on emotional response. Subjective feeling of engagement, as well as sympathetic activation, were modulated by picture size, suggesting that action preparation and subjective experience reflect the combined effects of detecting an arousing stimulus and assessing its imminence. On the other hand, physiological responses which are thought to reflect the amount of attentional resources invested in stimulus processing did not vary with picture size. Studies 4-6 were conducted to substantiate and extend the results of studies 1-3. In particular, it was noted that a decrease in picture size is associated with a loss in the low spatial frequencies of a picture, which might confound the interpretation of the results of studies 1-3. Therefore, emotional and neutral images which were either low-pass filtered or reduced in size were presented, and affective responses were measured. Most effects which were observed when manipulating image size were replicated by blurring pictures. However, pictures depicting highly arousing unpleasant contents were associated with a more pronounced decrease in affective modulation when pictures were reduced in size compared to when they were blurred. The present results provide important information for the study of processes involved in picture perception and in the genesis and expression of an emotional response. In particular, the availability of high spatial frequencies might affect the degree of activation of an internal representation of an affectively charged scene, and might modulate subjective emotional state and preparation for action. Moreover, the manipulation of stimulus imminence revealed important effects of stimulus engagement on specific components of the emotional response, and the implications of the present data for some models of emotions have been discussed. In particular, within the framework of a staged model of emotional response, the tactic and strategic role of response preparation and attention allocation to stimuli varying in engaging power has been discussed, considering the adaptive advantages that each might represent in an evolutionary view. Finally, the identification of perceptual parameters that allow affective processing to be carried out has important methodological applications in future studies examining emotional response in basic research or clinical contexts.
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Il rapporto tra percezione e previsione in compiti di compatibilità spazialeBazzarin, Valentina <1980> 27 April 2009 (has links)
The aim of this work is to investigate whether the actual position of a stimulus is more relevant than intuitive knowledge about the direction of an object's movement and the participants’ intention (Michaels 1988; Hommel, 1993; Proctor, Van Zandt, Lu and Weeks, 1993; Ansorge, 2000). To investigate this we used a spatial compatibility task in 4 experiments replicating what had be done by Hommel (1993) and Micheals (1988), but changing a single aspect of the procedure: neither the movement nor the effects of the action were visible to the participant. The experimental task asked them to simply imagine an action in movement.
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Language and Embodiment: sensory-motor and linguistic-social experience. Evidence on sentence comprehensionScorolli, Claudia <1977> 19 June 2009 (has links)
In this work I address the study of language comprehension in an “embodied” framework. Firstly I show behavioral evidence supporting the idea that language modulates the motor system in a specific way, both at a proximal level (sensibility to the effectors) and at the distal level (sensibility to the goal of the action in which the
single motor acts are inserted). I will present two studies in which the method is basically the same: we manipulated the linguistic stimuli (the kind of sentence: hand
action vs. foot action vs. mouth action) and the effector by which participants had to respond (hand vs. foot vs. mouth; dominant hand vs. non-dominant hand). Response
times analyses showed a specific modulation depending on the kind of sentence: participants were facilitated in the task execution (sentence sensibility judgment)
when the effector they had to use to respond was the same to which the sentences referred. Namely, during language comprehension a pre-activation of the motor system
seems to take place. This activation is analogous (even if less intense) to the one detectable when we practically execute the action described by the sentence. Beyond this effector specific modulation, we also found an effect of the goal suggested by the sentence. That is, the hand effector was pre-activated not only by hand-action-related
sentences, but also by sentences describing mouth actions, consistently with the fact that to execute an action on an object with the mouth we firstly have to bring it to the
mouth with the hand.
After reviewing the evidence on simulation specificity directly referring to the body (for instance, the kind of the effector activated by the language), I focus on the
specific properties of the object to which the words refer, particularly on the weight. In this case the hypothesis to test was if both lifting movement perception and lifting
movement execution are modulated by language comprehension. We used behavioral and kinematics methods, and we manipulated the linguistic stimuli (the kind of sentence: the lifting of heavy objects vs. the lifting of light objects). To study the movement perception we measured the correlations between the weight of the objects lifted by an actor (heavy objects vs. light objects) and the esteems provided by the participants. To study the movement execution we measured kinematics parameters variance (velocity, acceleration, time to the first peak of velocity) during the actual lifting of objects (heavy objects vs. light objects). Both kinds of measures revealed that language had a specific effect on the motor system, both at a perceptive and at a motoric level.
Finally, I address the issue of the abstract words. Different studies in the “embodied” framework tried to explain the meaning of abstract words The limit of
these works is that they account only for subsets of phenomena, so results are difficult to generalize. We tried to circumvent this problem by contrasting transitive verbs
(abstract and concrete) and nouns (abstract and concrete) in different combinations.
The behavioral study was conducted both with German and Italian participants, as the two languages are syntactically different. We found that response times were faster for both the compatible pairs (concrete verb + concrete noun; abstract verb + abstract noun) than for the mixed ones. Interestingly, for the mixed combinations analyses showed a modulation due to the specific language (German vs. Italian): when the concrete word precedes the abstract one responses were faster, regardless of the word grammatical class. Results are discussed in the framework of current views on abstract words. They highlight the important role of developmental and social aspects of
language use, and confirm theories assigning a crucial role to both sensorimotor and linguistic experience for abstract words.
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La caratterizzazione endofenotipica del rimuginioOttaviani, Cristina <1974> 27 April 2009 (has links)
Rumination, defined as the tendency to think about the negative affect evoked by stressful events, has been identified as potentially playing a role in the development of cardiovascular diseases. Specifically, recent studies suggest that ruminative thoughts might be mediators of the prolonged physiological effects of stress. The main goal of this research was to study the effect of rumination, evoked in the laboratory, during the subsequent 24 hours. As rumination has been associated with the activity of several physiological systems, including the cardiovascular, endocrine, and immune system, we also aimed at studying the process from a psychoneuroendocrine point of view. Levels
of anxiety, depression, anger, hostility, and trait rumination were assessed by the use of validated questionnaires. Impedance cardiography-derived measures, skin conductance, respiration, and beat-to-beat blood pressure (BP) were monitored continuously in 60 subjects during baseline, the Anger Recall Inteview, a reading task and two recovery periods. Half of the sample was randomly
assigned to a distracter condition after the Anger Recall Inteview. Cortisol, plasma concentrations of epinephrine, norepinephrine, and inflammatory biomarkers (CRP, sICAM-1) were also obtained at baseline and at the end of the session. Then, all subjects were asked to wear an ambulatory BP monitor for 24 hours. Results show that the distracter was effective in stopping rumination in the
laboratory but did not have a long-lasting effect in the subsequent 24 hours. Rumination was associated with prolonged sympathetic activity, vagal withdrawal, cortisol secrection, pro-inflammatory reaction and mood impairment compared to the reading task. After controlling for age
and body mass index, rumination also proved to be a strong predictor of daily moods, and ambulatory HR and BP. Personality traits did not have an effect in determining the frequency or duration of daily rumination. Findings suggest that perseverative cognition can prolong stress-
related affective and physiological activation and might act directly on somatic disease via the cardiovascular, immune, endocrine, and neurovisceral systems.
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