Biomedical subjects

Yves Joanette

Publications and source records attributed to Yves Joanette.

13 recordsLinked to original sources

PubMed2006

Simulating the pattern of right-hemisphere-damaged patients for the processing of the alternative metaphorical meanings of words: evidence in favor of a cognitive resources hypothesis.

Lately, many studies have suggested that communication impairments in brain-damaged individuals might be explained--at least in part--in terms of cognitive resource allocation. Reproducing a clinical pattern in normal subjects by using a dual-task treatment might be a way of evaluating the role of cognitive resources in the right hemisphere's contribution to verbal communication. This study suggests that the RH's presumed specific contribution to the processing of the alternative metaphorical meanings of words is, at least to some extent, the expression of the RH's complementary, and necessary, contribution to the pool of attentional resources needed for the most effortful processing.

Aged↗

PubMed2006

[Normal aging and cognition].

It is now well documented that normal aging modifies the cognitive functioning and most observations suggest that cognition evolves in the direction of deterioration. The more frequently impaired functions are memory, attention and visual-spatial abilities. On the other hand, some abilities seem to increase, such as vocabulary. Considering the aging effect on cognition, questions remain regarding directionality, universality and reversibility. A great variability in aged related impacts is observed among subjects and among cognitive domains. Some individuals evolved more rapidly than others. Some cognitive functions are more affected by aging than others. General and specific factors are hypothesized to explain the aged related cognitive decline. Among them, educational level, health, cognitive style, life style, personality, are likely to modulate the aged related cognitive evolution by influencing attentional resources and cerebral plasticity. Cognitive resources are essential to develop adaptative strategies. During the life span, resources are activated and increased by learning and training. Considering the role of cognitive resources, successful aging is dependent on several conditions : absence of disease leading to a loss of autonomy, maintenance of cognitive and physical activities, and active and social engaged lifestyle.

Aged↗

PubMed2005

Sensitivity to voice in human prefrontal cortex.

We report two functional MRI (fMRI) experiments showing sensitivity to human voice in a region of human left inferior prefrontal cortex, pars orbitalis. The voice-enhanced response was observed for speech as well as non-linguistic vocalizations and was stronger for emotional than neutral vocalizations. This region could constitute a human prefrontal auditory domain similar to the one recently identified in the macaque brain.

Acoustic Stimulation↗

PubMed2005

Real-life spatial skills, handedness, and family history of handedness.

According to , pronounced left hemisphere lateralization for language abilities in women, as in female absolute right-handers, limits their right hemisphere capacity and spatial abilities. This study examines the degree of handedness and the family history of non-right-handedness with respect to real-life spatial abilities in women. Twenty-four women had, first, to learn a new route and, second, to orient themselves within a labyrinth. In the former task, the number of errors and completion time were evaluated; in the latter task, degree of error for orienting was recorded. The results show that, contrary to Annett's prediction, right-handers with and without a family history of non-right-handedness did not differ on these measures. In addition, and unexpectedly, absolute right-handers were found to surpass non-absolute ones in the spatial orientation task. These findings do not support Annett's hypothesis and are discussed in relation to functional cerebral organization.

Adult↗

PubMed2005

Judgment of emotional nonlinguistic vocalizations: age-related differences.

Humans make extensive use of vocal information to attribute emotional states to other individuals. To date, most studies exploring perception of vocal emotions have done so in the context of speech prosody, although nonlinguistic emotional vocalizations represent an important, perhaps more universal, means to express emotions. Here, we explored the perception of emotional nonlinguistic vocalizations in healthy individuals, with an emphasis on potential age- and sex-related differences. Sixty participants rated 563 positive (e.g., laughs, sexual vocalizations), negative (e.g., cries, screams of fear), and neutral vocalizations (e.g., coughs), according to the valence, intensity, and authenticity of the emotion expressed. Ratings were consistent among individuals, suggesting that valence is an adequate measure of emotional categorization. An important effect of age emerged: (a) age by vocalization category interactions were observed for both valence and intensity ratings, and (b) younger participants rated stimuli as more emotional than older individuals (i.e., higher valence for positive, lower for negative, and more intense for both positive and negative). We also found a sex effect in the authenticity ratings: older women rated the vocalizations as less authentic than younger women whereas authenticity judgments did not differ between the two age groups in men. Taken together, these findings suggest that, as previously observed for facial expressions and prosody, the judgments of emotional vocalizations may vary with age.

Adult↗

PubMed2004

Quantification judgement in high functioning autism: superior or different?

This study examined the hypothesis of superior quantification abilities of persons with high functioning autism (HFA). Fourteen HFA individuals (mean age: 15 years) individually matched with 14 typically developing (TD) participants (gender, chronological age, full-scale IQ) were asked to quantify as accurately and quickly as possible numerosities, represented by the number of squares (2-9) presented in random configurations. In addition, the visual angles of stimuli presentation were manipulated in order to induce a local (large visual angle) and a global (small visual angle) bias on participants' quantification performance (accuracy and naming time). Findings revealed no effect of local and global bias of stimuli presentation in the two groups' performance, and no superior quantification abilities in HFA participants. However, analyses of the naming time slopes for identification by HFA participants of small consecutive numerosities (2-5), suggested their use of counting processes instead of subitizing (or immediate apprehension of numerosities) as in TD participants. Possible explanations for these results are discussed with reference to models of locally-oriented information processing in autism.

Adolescent↗

PubMed2004

Priming of non-speech vocalizations in male adults: the influence of the speaker's gender.

Previous research reported a priming effect for voices. However, the type of information primed is still largely unknown. In this study, we examined the influence of speaker's gender and emotional category of the stimulus on priming of non-speech vocalizations in 10 male participants, who performed a gender identification task. We found a significant priming effect, which was greater for female than male vocalizations. In contrast, the emotional category of the stimuli did not appear to modulate the magnitude of priming. These data suggest that different aspects of the information conveyed in non-speech vocalizations may contribute differently to behavioral priming, possibly influenced by task relevance.

Adult↗

PubMed2004

Phonological processing of words in right- and left-handers.

It is commonly accepted that phonology is the exclusive domain of the left hemisphere. However, this pattern of lateralization, which posits a right visual field advantage, has been questioned by several studies. In fact, certain factors such as characteristics of the stimuli and subjects' handedness can modulate the right visual field advantage. Thus, the goal of this study was to compare the hemispheric dynamics of right-handers and left-handers during a divided visual field presentation of words that varied in terms of their phonological transparency. For non-transparent words, the left hemisphere seems more competent in both handedness groups. With regard to transparent words, the right hemisphere of both groups also appears competent. Surprisingly, left-handers achieved optimal processing with a functionally isolated left hemisphere, whereas right-handers needed the participation of both hemispheres. The pattern of performance cannot be fully explained by either the callosal or the direct access model.

Adult↗

PubMed2004

Is voice processing species-specific in human auditory cortex? An fMRI study.

Recent studies suggested a sensitivity of regions of the human superior temporal sulcus (STS) to the sound of the human voice. However, the question of the species specificity of this response is still open. Healthy adult volunteers were scanned in an event-related fMRI design to compare responses in the STS to human and animal vocalizations, as well as to control nonvocal sounds (e.g., musical instruments). Bilateral activation of anterior STS was observed for human vocalizations, when contrasted with both nonvocal sounds and animal vocalizations. Animal vocalizations, compared to nonvocal sounds, elicited a more restricted left STS activation, although this region responded even more strongly to human vocalizations. This study provides the first evidence suggesting a species specificity in STS responses to vocalizations in humans.

Acoustic Stimulation↗

PubMed2003

Neural circuitry underlying voluntary suppression of sadness.

BACKGROUND: The ability to voluntarily self-regulate negative emotion is essential to a healthy psyche. Indeed, a chronic incapacity to suppress negative emotion might be a key factor in the genesis of depression and anxiety. Regarding the neural underpinnings of emotional self-regulation, a recent functional neuroimaging study carried out by our group has revealed that the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex are involved in voluntary suppression of sexual arousal. As few things are known, still, with respect to the neural substrate underlying volitional self-regulation of basic emotions, here we used functional magnetic resonance imaging to identify the neural circuitry associated with the voluntary suppression of sadness. METHODS: Twenty healthy female subjects were scanned during a Sad condition and a Suppression condition. In the Sad condition, subjects were instructed to react normally to sad film excerpts whereas, in the Suppression condition, they were asked to voluntarily suppress any emotional reaction in response to comparable stimuli. RESULTS: Transient sadness was associated with significant loci of activation in the anterior temporal pole and the midbrain, bilaterally, as well as in the left amygdala, left insula, and right ventrolateral prefrontal cortex (VLPFC) (Brodmann area [BA] 47). Correlational analyses carried out between self-report ratings of sadness and regional blood oxygen level dependent (BOLD) signal changes revealed the existence of positive correlations in the right VLPFC (BA 47), bilaterally, as well as in the left insula and the affective division of the left anterior cingulate gyrus (BA 24/32). In the Suppression condition, significant loci of activation were noted in the right DLPFC (BA 9) and the right orbitofrontal cortex (OFC) (BA 11), and positive correlations were found between the self-report ratings of sadness and BOLD signal changes in the right OFC (BA 11) and right DLPFC (BA 9). CONCLUSIONS: These results confirm the key role played by the DLPFC in emotional self-regulation. They also indicate that the right DLPFC and right OFC are components of a neural circuit implicated in voluntary suppression of sadness.

Adult↗

PubMed2003

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.

Adult↗

PubMed2003

Impact of right hemispheric damage on a hierarchy of complexity evidenced in young normal subjects.

The occurrence of a right-hemisphere lesion can interfere with pragmatic abilities and particularly with the processing of non-literal speech acts in which the listener has to identify the speaker's intention. The aim of this study was to test RHD subjects' ability to process non-literal speech acts. A chronometric approach to RHD and matched control performance showed that RHD subjects are impaired in the processing of non-literal speech, though they are also sensitive to the hierarchy of complexity among types. Only the processing of indirect speech acts was not shown to differ from that of normals, probably because the stimuli were of the conventional type. These results show the relevancy of a chronometric approach. They also emphasize the importance of further studying RHD subjects' ability to attribute intentions to protagonists in a short story.

Adult↗

PubMed2003

Semantic processing of words, cognitive resources and N400: an event-related potentials study.

The specificity of the right hemisphere (RH) contribution to the semantic processing of words is still debated. Indeed, the semantic impairments of right hemisphere damaged (RHD) subjects may be the expression of limited general cognitive resources rather than a specific impairment of semantic processing ([Monetta et al., 2001]; [Murray, 2000]). The purpose of this study was to evaluate the possibility that the N400 reflect the availability of cognitive resources through an analysis of its different amplitudes according to different semantic complexity level. Ten young adults without any history of neurological damage participated in a semantic categorization task with two different levels of difficulty based on prototypicality. Event related potential (ERP) signals from 64 electrodes were recorded. An N400 was observed during the processing of difficult words and distractors. The results show that the greatest N400 activation was observed during the processing of difficult words, thus reflecting a possible increase in the amount of required cognitive resources.

Adult↗