Transcranial Doppler Ultrasonography Monitoring of Cerebral Hemodynamics During Performance of Cognitive Tasks: A Review

The examination of blood flow velocity (BFV) changes during the performance of mental tasks is one of the applications of transcranial Doppler (TCD) ultrasonography. The purpose of this review is to summarize the results of the functional TCD literature, to investigate the effects of methodological differences between studies, and to provide guidelines for future research. It is concluded that larger series of more homogeneous groups concerning age and handedness, and stricter criteria for subject selection and laboratory setting are required. The implication of quantitative and qualitative performance measures and psychological parameters (motivation, anxiety, and task anticipation) could also yield important information. We recommend future agreement upon a more standardized methodology. TCD promises to be a useful tool to provide further insight into the cerebral organization and temporal reactivity of the human brain.     

Diurnal cycle of salivary cortisol in older adult men and women with subjective complaints of memory deficits and/or depressive symptoms: relation to cognitive functioning

In populations of young and older adults, it has been shown that individuals may be categorized into one of three diurnal subgroups when salivary cortisol levels are assessed over a 2-day period and compared for their consistency across days: a typical subgroup, a flat subgroup, and an inconsistent subgroup. Interestingly, recent studies have reported that the typical subgroup represents the majority of the young and older adult population, a finding that is difficult to reconcile with previous studies showing increased cortisol levels in older adults with depression or cognitive impairments. In order to assess whether a typical diurnal cortisol profile is representative across different subgroups of older adults, we assessed diurnal cortisol cycle representation in a sample of older adults with subjective complaints of depression and/or memory problems. Furthermore, given the robust relationship between cortisol and cognitive function, the present study examined the association between the three diurnal subgroups and cognitive performance. Forty-two older individuals were recruited on the basis of reporting subjective complaints of either memory problems and/or depressive mood. Participants were asked to sample their saliva over a 2-day period and were then asked to undergo a neuropsychological evaluation that taps into short-term memory, declarative memory and language. The results showed that 69% of the sample presented a Flat cycle of salivary cortisol over a 2-day period while 19% presented an inconsistent pattern and 12% presented a typical pattern. Participants in the flat subgroup were significantly impaired on letter verbal fluency. Furthermore, a relationship was found between diurnal cortisol subgroup representation and subjective complaint profile. These findings show that older adults with complaints of memory problems and/or depressive symptoms do not present the typical profile of the diurnal cortisol cycle, and they provide a preliminary view of how diurnal cortisol profile relates to cognitive function during human aging.     

Episodic autobiographical memory in depression: Specificity, autonoetic consciousness, and self-perspective

Autobiographical memory (AM) and the self are closely linked. AM retrieval in depression is characterized by a lack of specificity, suggesting an impairment of episodic AM. Autonoetic consciousness and self-perspective, which are critical to episodic AM, have never been addressed in depression. Twenty-one depressed inpatients and 21 matched controls were given an episodic AM task designed to assess positive and negative memories regarding specificity, autonoetic consciousness (remember/know procedure), and self-perspective (field/observer procedure). For specificity, "remember", and "field" responses, ANOVAs revealed a main group effect and a group x valence interaction. Between groups, patients showed lower scores than controls for positive memories. Within groups, patients showed greater scores for negative memories, and controls showed greater scores for positive memories. There is a global episodic AM impairment of positive memories in depression regarding specificity, autonoetic consciousness, and self-perspective. Our results suggest new cognitive interventions to improve the self-relevance of positive memories in depression.     

Introducing uninteresting tasks to children: a comparison of the effects of rewards and autonomy support

Two experiments compared rewards and autonomy support as methods to promote children's self-regulation for an uninteresting vigilance task. Dependent measures were ratings of positive affect, perception of the task's value, and free-choice engagement. ANOVA results revealed some positive effects associated with autonomy support, whereas no effect for rewards was found in either study. The outcomes of most interest were correlations between free-choice behavior and self-reported measures of affect and value, reflecting the level of integration in self-regulation. As predicted by self-determination theory (Deci & Ryan, 1985, 1991, 2000), rewards were associated with behaviors incongruent from affect and value, whereas autonomy support led to integrated self-regulation. This finding was first detected in Study 1 and later replicated in Study 2. Together, these results point to autonomy support as a beneficial alternative to the common use of rewards.     

Neural correlates of lexical and sublexical processes in reading

The purpose of the present study was to compare the brain regions and systems that subserve lexical and sublexical processes in reading. In order to do so, three types of tasks were used: (i). silent reading of very high frequency regular words (lexical task); (ii). silent reading of nonwords (sublexical task); and, (iii). silent reading of very low frequency regular words (sublexical task). All three conditions were contrasted with a visual/phonological baseline condition. The lexical condition engaged primarily an area at the border of the left angular and supramarginal gyri. Activation found in this region suggests that this area may be involved in mapping orthographic-to-phonological whole word representations. Both sublexical conditions elicited significantly greater activation in the left inferior prefrontal gyrus. This region is thought to be associated with sublexical processes in reading such as grapheme-to-phoneme conversion, phoneme assembly and underlying verbal working memory processes. Activation in the left IFG was also associated with left superior and middle temporal activation. These areas are thought to be functionally correlated with the left IFG and to contribute to a phonologically based form of reading. The results as a whole demonstrate that lexical and sublexical processes in reading activate different regions within a complex network of brain structures.     

Interplay between environmental and genetic factors in temperament/personality traits in horses (Equus caballus)

The aim of the present study was to broach the question of the relative influence of different genetic and environmental factors on different temperament/personality traits of horses (Equus caballus). The researchers submitted 702 horses to standardized experimental tests and investigated 9 factors, either genetic or environmental. Genetic factors, such as sire or breed, seemed to influence more neophobic reactions, whereas environmental factors, such as the type of work, seemed to play a more dominant role in reactions to social separation or learning abilities. Additive effects were evident, showing how environmental factors may modulate behavioral traits. This study constitutes a first step toward understanding the relative weights of genetic factors and how the environment may intervene in determining individual behavioral characteristics.     

Influence of education on the benton visual retention test performance as mediated by a strategic search component

Age-related cognitive decline has been reported by several studies. However, little investigations have dealt with the effect of education on this decline. In the present study, we examined the influence of educational level on visual working memory, evaluated by the Benton Visual Retention Test (BVRT in recognition format) in 829 elderly participants of the PAQUID study. A multivariate linear model suggested that the effect of education on BVRT performance was not mediated by visual discrimination abilities suggesting that it was mainly supported by better executive abilities. Moreover, the analysis of success and error location suggested that subjects with higher educational level use a more exhaustive exploration strategy during the recognition phase than subjects with lower educational level, which permit them to better perform. The ability of high educational level subjects to use more efficient strategies may participate to the 'cognitive reserve' capacity.     

Processing of metaphoric and non-metaphoric alternative meanings of words after right- and left-hemispheric lesion

This study examines the specificity of the contribution of the right hemisphere to the processing of metaphoric meaning of words. Ten right- and 10 left-hemisphere-damaged subjects, and 20 normal control subjects were submitted to: (1) a word-triad task where they had to associate alternative metaphoric and non-metaphoric words to a target word, and to (2) a word-dyad task where they had to decide whether or not there was a semantic relationship between two words. The two tasks aimed at differentiating between the subjects' preference for a given semantic meaning versus a genuine semantic deficit for a particular meaning. Results revealed that both right- and left-hemisphere-damaged groups presented a genuine semantic deficit for the processing of metaphoric meaning. The absence of a double dissociation between the two brain-damaged groups does not support the hypothesis of a specific contribution of the right-hemisphere to the processing of metaphoric meaning of words.     

Validation française d'un inventaire de micro-stresseurs de la vie quotidienne: combinaison du “Daily Hassles Scale” et du “Uplifts Scale”

Ce travail présente les résultats d'une étude de validité de la version française d'un instrument d'auto-évaluation des micro-stresseurs de la vie quotidienne (“Daily Hassles Scale”; “Uplifts Scale”; Lazarus & Folkman, 1989). Les informations de validité reposent sur des structures factorielles ainsi que des analyses de cohérence interne et de convergence avec une mesure de stress psychologique (MSP: Lemyre, Tessier, & Fillion, 1990). Auprès d'une communauté universitaire (N = 265), six facteurs d'embětements quotidiens et cinq facteurs d'encouragements journaliers ont été isolés. Comme prévu, le score d'intensité aux différents facteurs d'embětements corrèle positivement et significativement avec l'état d'ětre stressé ce qui n'est pas le cas des encouragements quotidiens. La discussion soulève la nécessité d'utiliser différents groupes de micro-stresseurs plutôt qu'un facteur général. Elle évalue également le rôle ambigu des encouragements quotidiens comme facteur de protection dans l'expérience du stress.     

Defining clinically significant changes in the treatment of child stutterers.

This study established a clinically significant criterion to evaluate outcomes of children's stuttering therapy. 30 stutterers, ages 6 to 15 years, and 30 non-stutterers served as subjects. Speech samples were recorded and the percentage of stuttered syllables and rate of speech analyzed. According to Jacobson and Revenstorf's procedure, 3% of stuttered syllables and 160 syllables per minute should become the target behaviors in the treatment of children's stuttering.