Neurofunctional correlates of personality traits in relapsing-remitting multiple sclerosis: An fMRI study

Extraversion and Neuroticism are two fundamental dimensions of human personality that influence cognitive functioning in healthy subjects. Little is known about personality changes that may occur in patients with multiple sclerosis (MS) nor about, in particular, their neurofunctional basis. The aim of this study is to determine the impact of personality characteristics on brain activity in patients with MS. Eighteen patients with clinically definite relapsing-remitting MS without any evidence of psychiatric or cognitive disorders and thirteen healthy controls matched for age, gender and education were investigated using functional magnetic resonance imaging (fMRI) during the execution of an “n-back” task. No differences were detected on the behavioral tests between the two groups, although the MS patients had lower total IQ and showed a trend towards higher Extraversion and Neuroticism scores than did the controls. fMRI analyses demonstrated that Extraversion scores were positively associated with brain activity in the fronto-parietal network including the superior parietal lobule and dorsolateral prefrontal cortex in both groups during the high load condition of the n-back task. Given the overlapping neural systems found in the two groups, we suggest that the neural activity associated with specific personality dimension is a neurophysiological characteristic preserved in patients with MS at an early stage in the course of their disease.     

Neurofunctional correlates of personality traits in relapsing-remitting multiple sclerosis: An fMRI study

Extraversion and Neuroticism are two fundamental dimensions of human personality that influence cognitive functioning in healthy subjects. Little is known about personality changes that may occur in patients with multiple sclerosis (MS) nor about, in particular, their neurofunctional basis. The aim of this study is to determine the impact of personality characteristics on brain activity in patients with MS. Eighteen patients with clinically definite relapsing-remitting MS without any evidence of psychiatric or cognitive disorders and thirteen healthy controls matched for age, gender and education were investigated using functional magnetic resonance imaging (fMRI) during the execution of an “n-back” task. No differences were detected on the behavioral tests between the two groups, although the MS patients had lower total IQ and showed a trend towards higher Extraversion and Neuroticism scores than did the controls. fMRI analyses demonstrated that Extraversion scores were positively associated with brain activity in the fronto-parietal network including the superior parietal lobule and dorsolateral prefrontal cortex in both groups during the high load condition of the n-back task. Given the overlapping neural systems found in the two groups, we suggest that the neural activity associated with specific personality dimension is a neurophysiological characteristic preserved in patients with MS at an early stage in the course of their disease.     

Orbitofrontal dysfunction in multiple sclerosis: Iowa Gambling Task

Cognitive dysfunction has been widely studied in multiple sclerosis (MS), however decision-making has been less investigated. The current study examined the decision-making processes of patients with multiple sclerosis (MS) using a computerized version of the Iowa Gambling Task (IGT). This task was applied to 18 patients with clinically diagnosed MS and 18 healthy control subjects matched for age, sex, and years of education. The results showed that IGT scores differ significantly between patients with MS and the healthy control subjects: the patients with MS made significantly less advantageous decisions than the controls in the IGT. Possible causes of impaired decision-making in multiple sclerosis are discussed.     

Effects of cognitive impairment on prosodic parameters of speech production planning in multiple sclerosis

Cognitive impairment (CI) affects 40–65% of patients with multiple sclerosis (MS). CI can have a negative impact on a patient's everyday activities, such as engaging in conversations. Speech production planning ability is crucial for successful verbal interactions and thus for preserving social and occupational skills. This study investigates the effect of cognitive-linguistic demand and CI on speech production planning in MS, as reflected in speech prosody. A secondary aim is to explore the clinical potential of prosodic features for the prediction of an individual's cognitive status in MS. A total of 45 subjects, that is 22 healthy controls (HC) and 23 patients in early stages of relapsing-remitting MS, underwent neuropsychological tests probing specific cognitive processes involved in speech production planning. All subjects also performed a read speech task, in which they had to read isolated sentences manipulated as for phonological length. Results show that the speech of MS patients with CI is mainly affected at the temporal level (articulation and speech rate, pause duration). Regression analyses further indicate that rate measures are correlated with working memory scores. In addition, linear discriminant analysis shows the ROC AUC of identifying MS patients with CI is 0.70 (95% confidence interval: 0.68–0.73). Our findings indicate that prosodic planning is deficient in patients with MS-CI and that the scope of planning depends on patients’ cognitive abilities. We discuss how speech-based approaches could be used as an ecological method for the assessment and monitoring of CI in MS.     

Self and body esteem perception in multiple sclerosis

Self esteem and body esteem were examined in a group of 35 relapsing-remitting multiple sclerosis (MS) patients using the Body Esteem Scale (BES) and the Eysenck Self Esteem Scale (ESES) and compared to age and sex matched normal controls. There were 23 females and 12 males in the MS patient's group; average age 38.9 years (range: 22-52). All participants completed the self-rated BES evaluating the following subscales: females - sexual attractiveness, physical condition and weight concern; males - physical attractiveness, physical condition and upper body strength. In addition all participants were scored, following a semi-structured interview, on the ESES. Psychiatric co-morbidity was excluded using a semi-structured interview by the consulting psychiatrist. All evaluations were carried out during the remitting phase. Statistical analysis, comparing patients to healthy controls, demonstrated lowered self-rating of the physical condition (males < 0.05, females < 0.001). On the other hand, no significant differences were found in the physical (male) or sexual (female)--attractiveness subscales. The mean ESES score in the patients group was 23.2 +/- 4.0, slightly above the reported average. The controls mean ESES was 28.4 +/- 3.6, (P < 0.05). No correlation was found between self and body esteem amongst M.S. patients. This study emphasizes impaired perception of body esteem in multiple sclerosis patients even in remission. The preservation of physical and sexual attractiveness may be related to the non-disfiguring nature of the disease. Preservation of self-esteem in MS patients suggests that body-esteem should be the focus of supportive treatment.     

Self and body esteem perception in multiple sclerosis

Self esteem and body esteem were examined in a group of 35 relapsing-remitting multiple sclerosis (MS) patients using the Body Esteem Scale (BES) and the Eysenck Self Esteem Scale (ESES) and compared to age and sex matched normal controls. There were 23 females and 12 males in the MS patient's group; average age 38.9 years (range: 22-52). All participants completed the self-rated BES evaluating the following subscales: females - sexual attractiveness, physical condition and weight concern; males - physical attractiveness, physical condition and upper body strength. In addition all participants were scored, following a semi-structured interview, on the ESES. Psychiatric co-morbidity was excluded using a semi-structured interview by the consulting psychiatrist. All evaluations were carried out during the remitting phase. Statistical analysis, comparing patients to healthy controls, demonstrated lowered self-rating of the physical condition (males < 0.05, females < 0.001). On the other hand, no significant differences were found in the physical (male) or sexual (female)?attractiveness subscales. The mean ESES score in the patients group was 23.2 ± 4.0, slightly above the reported average. The controls mean ESES was 28.4 ± 3.6, (P < 0.05). No correlation was found between self and body esteem amongst M.S. patients. This study emphasizes impaired perception of body esteem in multiple sclerosis patients even in remission. The preservation of physical and sexual attractiveness may be related to the non-disfiguring nature of the disease. Preservation of self-esteem in MS patients suggests that body-esteem should be the focus of supportive treatment.     

Lifespan changes in attention: The visual search task

There are two popular frameworks for the study of visual attention. Treisman's Feature Integration Theory focuses on the effortful process of binding together the multiple attributes of an object. Posner's Visual Orienting Theory emphasizes the movement of an attentional spotlight across space. Although both aspects are undoubtedly important in any visual search task, it is not clear how each of these aspects changes with age. We tested observers aged 6, 8, 10, 22, and 72 years on visual search tasks designed to isolate these factors. No age-related differences were found in single- or double-feature discrimination, attention movement to a single item, or search for a single-feature target among distractors. Two age-related changes were found: (1) young children were less able than either young adults or seniors to search for targets defined by a conjunction of features, and (2) both children and seniors were less able than young adults to move attention voluntarily from item to item. This implies that feature integration and voluntary movement of attention have different trajectories over the lifespan.     

The neurological substrates for prosodic aspects of speech

The ability to comprehend and produce the stress contrast between noun compounds and noun phrases (e.g., greenhouse vs. green house) was examined for 8 nonfluent aphasics, 7 fluent aphasics, 7 right hemisphere damaged (RHD) patients, and 22 normal controls. The aphasics performed worse than normal controls on the comprehension task, and the RHD group performed as well as normals. The ability to produce stress contrasts was tested with a sentence-reading task; acoustic measurements revealed that no nonfluent aphasic used pitch to distinguish noun compounds from phrases, but two used duration. All but one of the RHD patients and all but one of the normals produced pitch and/or duration cues. These results suggest that linguistic prosody is processed by the left hemisphere and that with brain damage the ability to produce pitch and duration cues may be dissociated at the lexical level.     

Phagocytic reactivity of granulocytes in the peripheral blood of patients with multiple sclerosis and normal probands

For estimation of phagocytic activity the uptake by granulocytes of heat-inactivated, opsonised yeast particles (Saccharomyces cerevisiae) was measured. Peripheral granulocytes of multiple sclerosis patients revealed an enhanced ability for phagocytosis in comparison to normal healthy controls, if tested with normal serum as opsonic source. An activated state of cells in multiple sclerosis is supposed. The selective influence on granulocyte phagocytosis of treatment by ultraviolet-irradiated blood in multiple sclerosis patients supports the view of altered reactivity of these cells in comparison to normal controls.     

Delay of gratification and delay maintenance by rhesus macaques (Macaca mulatta)

The authors tested the self-control of rhesus macaques by assessing if they could refrain from reaching into a food container to maximize the accumulation of sequentially delivered food items (a delay-maintenance task). Three different versions of the task varied the quantity and quality of available food items. In the first 2 versions, food items accumulated across the length of the trial until a monkey consumed the items. In the 3rd task, a single less-preferred food item preceded a single more-preferred food item. Some monkeys delayed gratification even with relatively long delays between deliveries of items. However, the data suggested that self-control, in the majority of tested individuals, was not significantly different across different task versions and that self-control by macaques was not as prevalent in these tasks as it is in chimpanzees and human children.     

Neuropsychology of mildly disabled patients with relapsing-remitting multiple sclerosis

Previous papers have mainly demonstrated the presence of cognitive impairment in patients with multiple sclerosis (MS), these changes have been traditionally associated with the later stages of the disease. In the current study, a comprehensive neuropsychological battery was administered to 216 relapsing-remitting MS patients with mild clinical disability (EDSS相似文献   

Fluency versus conscious recollection in the word completion performance of amnesic patients

To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind.     

The revelation effect for item and associative recognition: Familiarity versus recollection

The revelation effect occurs when items on a recognition test are more likely to be judged as being old if they are preceded by a cognitive task that involves the processing of similar types of stimuli. This effect was examined for item (single-word) and associative (word-pair) recognition. We found, in Experiments 1 and 2, a revelation effect for item, but not for associative recognition under normal study conditions. A revelation effect for both item and associative recognition was observed in Experiments 3 and 4 when study time was extremely brief, thus limiting the encoding of information that would support recall or recollection. In Experiment 5, we demonstrated that the revelation effect for item recognition is eliminated when item recognition decisions are made in the context of a study item. The results show that the revelation task influenced recognition decisions based on familiarity, but not decisions that involved recall or recollection.     

Recollection-based recognition eliminates the revelation effect in memory

The revelation effect refers to the tendency to call an item on a recognition test old if it is preceded by a cognitive task that involves the processing of a similar stimulus (Watkins &; Peynircioglu, 1990). It has been proposed that the revelation effect occurs because of an increase in the familiarity of the test items in the revelation condition (Luo, 1993; Westerman &; Greene, 1998). In the present experiments, the revelation effect was investigated in recognition tasks that were not based solely on the familiarity of the test items but,also, on a recall-like retrieval process. A revelation effect was not found on an associative-recognition task or on a plurality recognition task. The results of this study show that the revelation effect does not occur when the contribution of familiarity to recognition decisions is reduced by factors that encourage the recollection of the study episode.     

A test of two different revelation effects using forced-choice recognition

The revelation effect refers to the finding of an increased propensity to classify recognition test probes as old when they are preceded by a problem solving task. Recent research indicates that revelation effects are dissociable based on whether the revelation task involves an item that is the same as or different than the subsequently presented recognition probe. Using a two-alternative forced-choice design, we found a revelation effect for both words (Experiment 1) and nonwords (Experiment 2) in the condition where the revealed item was the same as the target item (same revelation condition), but no effect when the revealed item was different than either test alternative (different revelation condition). These results were replicated using a mixed list design containing both words and nonwords (Experiment 3). Results support Verde and Rotello’s (2004) two-factor account of the revelation effect, which proposes that changes in memory sensitivity underlie revelation effects in the same revelation condition, and that changes in the decision criterion are responsible in the different revelation condition.     

Encoding processes and sex-role preferences

Seven- and 10-year-old children were tested on memory and sex-role preference tasks. The memory task was the Wickens release from proactive inhibition paradigm in which short-term recall of words is tested on successive trials. On Trials 1–4, words were selected from one of two categories, either words with masculine or feminine connotations. On Trial 5, words were drawn from the second category. Sex-role preference was assessed by asking the child to select his favorite pictures from an array that included masculine and feminine items. Recall by boys at both ages increased following a shift between words with masculine or feminine connotations, suggesting that this dimension of a word's meaning was encoded in memory. Recall by girls who selected a feminine item as their favorite on the sex-role preference task increased following a category shift; recall by girls who chose a masculine item did not increase. These results are discussed in relation to previous research on the attributes of encoding in children's memory.     

Gains and losses in action memory.

Enacting action phrases (SPT for subject-performed task) produces better free recall than only learning the phrases verbally (VT for verbal task). A widespread explanation of the enactment effect is based on the distinction between item-specific and relational information. There is widespread agreement that the main reason is the excellent item-specific encoding by enactment. However, there is little direct evidence in the case of free recall. The role of relational information is less clear. We suggest that content-based relational encoding is better in VTs than in SPTs. In three experiments, in which multiple free recall testing used item gains and losses as indices of item-specific and content-based relational encoding, respectively, these assumptions were confirmed. Consistently more gains (indexing better item-specific encoding) and more losses (indexing poorer relational encoding) were observed in SPTs than in VTs (Experiments 1 and 2). Furthermore, it was demonstrated that the content-based relational information underlying losses is not identical with order-relational information (Experiment 2). In Experiment 3, it was shown that an item-specific orienting task for VTs produced an equivalent number of item gains and losses as did the SPT condition.     

Spatial probability cuing and right hemisphere damage

In this experiment we studied statistical learning, inter-trial priming, and visual attention. We assessed healthy controls and right brain damaged (RBD) patients with and without neglect, on a simple visual discrimination task designed to measure priming effects and probability learning. All participants showed a preserved priming effect for item color. Contrary to healthy controls and RBD participants without neglect, RBD participants with neglect did not show positional priming and both RBD groups learned the underlying spatial probability distribution of target locations to a lesser degree. To see if the latter deficiency could be improved, we tested a patient with long standing chronic spatial neglect on three separate days and observed improved identification times for left sided, high probability, targets. In summary, we found preservation of priming per se in people with spatial neglect. However, this was only clearly demonstrable for color priming and not for positional priming. Associated with this impairment was a difficulty in learning the overall statistical structure of target locations. In a patient with severe persistent neglect we were able to demonstrate that the deficit in statistical learning was not absolute, as this subject improved his identification times for targets appearing in high probability regions of the test display.     

The phonological neighbourhood effect on short-term memory for order

There is a growing body of literature that suggests that long-term memory (LTM) and short-term memory (STM) structures that were once thought to be distinct are actually co-dependent, and that LTM can aid retrieval from STM. The mechanism behind this effect is commonly argued to act on item memory but not on order memory. The aim of the current study was to examine whether LTM could exert an influence on STM for order by examining an effect attributed to LTM, the phonological neighbourhood effect, in a task that reduced the requirement to retain item information. In Experiment 1, 18 participants completed a serial reconstruction task where neighbourhood density alternated within the lists. In Experiment 2, 22 participants completed a serial reconstruction task using pure lists of dense and sparse neighbourhood words. In Experiment 3, 22 participants completed a reconstruction task with both mixed and pure lists. There was a significant effect of neighbourhood density with better recall for dense than sparse neighbourhood words in pure lists but not in mixed lists. Results suggest that LTM exerts an influence prior to that proposed by many models of memory for order.     

Spatial probability cuing and right hemisphere damage

In this experiment we studied statistical learning, inter-trial priming, and visual attention. We assessed healthy controls and right brain damaged (RBD) patients with and without neglect, on a simple visual discrimination task designed to measure priming effects and probability learning. All participants showed a preserved priming effect for item color. Contrary to healthy controls and RBD participants without neglect, RBD participants with neglect did not show positional priming and both RBD groups learned the underlying spatial probability distribution of target locations to a lesser degree. To see if the latter deficiency could be improved, we tested a patient with long standing chronic spatial neglect on three separate days and observed improved identification times for left sided, high probability, targets. In summary, we found preservation of priming per se in people with spatial neglect. However, this was only clearly demonstrable for color priming and not for positional priming. Associated with this impairment was a difficulty in learning the overall statistical structure of target locations. In a patient with severe persistent neglect we were able to demonstrate that the deficit in statistical learning was not absolute, as this subject improved his identification times for targets appearing in high probability regions of the test display.