Biomedical subjects

Jorge L Armony

Publications and source records attributed to Jorge L Armony.

12 recordsLinked to original sources

PubMed2006

The influence of trait anxiety on autonomic response and cognitive performance during an anticipatory anxiety task.

The interaction between emotion and cognition is thought to be intimately involved in the development and maintenance of anxiety disorders. In a set of studies, we investigated whether trait anxiety modulates cognitive performance and autonomic activity during an anticipatory anxiety task. Participants completed a letter-size decision-making task with two alternating 28-32 s background screen color-blocks. One of the colors was associated with the presentation of an aversive noise [unconditioned stimulus (UCS)]. Participants were aware of the background color that would (CTX+) and would not (CTX-) be paired with the UCS but did not know when or how often the UCS would be presented. Two experiments were conducted. In Experiment 1, the UCS was presented during the decision-making task in the CTX+ color-blocks using a partial reinforcement schedule. Different noises were presented each time to increase unpredictability and prevent habituation. In Experiment 2, the UCS was never presented during the decision-making task. Results suggested that only the paradigm used in Experiment 1 was successful in eliciting anticipatory anxiety. In Experiment 1, continuously measured skin conductance response (SCR) data suggested that anxiety was significantly greater during CTX+ compared to CTX- trials; no SCR differences were found between high and low trait-anxious participants. Results further indicated that high trait-anxious participants responded significantly faster on the decision-making task during CTX+ compared to CTX- trials, whereas low trait-anxious participants displayed the opposite pattern. Our results reveal an interesting dissociation between the effects of individual differences in trait anxiety on autonomic activity and cognitive performance during an anticipatory anxiety task.

Adult↗

PubMed2006

A process-specific functional dissociation of the amygdala in emotional memory.

Converging evidence highlights the important role of the amygdala in the enhanced memory for emotional material. However, it is unknown whether any regional and/or hemispheric specificity exists regarding its involvement in the different memory stages, such as encoding and retrieval. We directly addressed this issue by conducting an event-related functional magnetic resonance imaging study of memory for faces with different emotional expressions, in which both encoding and recognition were scanned. We found significant amygdala activation associated with both successful encoding and retrieval of fearful faces. Critically, a direct comparison between both stages revealed that whereas the right amygdala was involved in emotional memory formation, the retrieval of those memories relied on the left amygdala. Thus, this study demonstrates a hemispheric dissociation of amygdala involvement in different stages of emotional memory in humans.

Adult↗

PubMed2005

Size versus shape differences: contrasting voxel-based and volumetric analyses of the anterior cingulate cortex in individuals with acute posttraumatic stress disorder.

BACKGROUND: Two studies found morphological differences in the anterior cingulate cortex (ACC) of individuals with chronic posttraumatic stress disorder (PTSD). We sought to replicate and extend these findings in a sample of individuals with acute PTSD. METHODS: The ACCs of individuals with acute PTSD (n = 14) and matched healthy control subjects (n = 14) were compared using voxel-based morphometry (VBM), semi-automated volumetric analyses, and probabilistic maps. Posttraumatic stress disorder diagnosis was ascertained by a psychologist using a structured interview. RESULTS: Voxel-based morphometry analyses revealed significantly less gray-matter density in the right pregenual ACC and in the left insula of the PTSD group. However, volumetric analyses of the ACC revealed no significant differences between groups. Probabilistic maps of the labels of the pregenual ACC indicated that the difference between groups in gray matter density was due to shape differences. CONCLUSIONS: Although there are no volumetric differences in the ACC of acute PTSD individuals compared with normal control subjects, significant shape differences exist, which might indicate volumetric differences in the surrounding structures.

Accidents, Traffic↗

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

A face to remember: emotional expression modulates prefrontal activity during memory formation.

Emotion can exert a modulatory role on episodic memory. Several studies have shown that negative stimuli (e.g., words, pictures) are better remembered than neutral ones. Although facial expressions are powerful emotional stimuli and have been shown to influence perception and attention processes, little is known about their effect on memory. We used functional magnetic resonance imaging (fMRI) in humans to investigate the effects of expression (happy, neutral, and fearful) on prefrontal cortex (PFC) activity during the encoding of faces, using a subsequent memory effect paradigm. Our results show that activity in right PFC predicted memory for faces, regardless of expression, while a homotopic region in the left hemisphere was associated with successful encoding only for faces with an emotional expression. These findings are consistent with the proposed role of right dorsolateral PFC in successful encoding of nonverbal material, but also suggest that left DLPFC may be a site where integration of memory and emotional processes occurs. This study sheds new light on the current controversy regarding the hemispheric lateralization of PFC in memory encoding.

Adult↗

PubMed2005

Amygdala response in patients with acute PTSD to masked and unmasked emotional facial expressions.

OBJECTIVE: This study used functional magnetic resonance imaging to investigate amygdala response in patients with acute posttraumatic stress disorder (PTSD) to emotional expressions. METHOD: Thirteen medication-free individuals with acute PTSD and no axis I psychiatric comorbidity were scanned while viewing pictures of fearful or happy faces, presented above or below consciousness, with backward masking. RESULTS: There was a significant positive correlation between the severity of PTSD and the difference in amygdala responses between masked fearful and happy faces and a corresponding negative correlation for the difference between unmasked fearful and happy faces. CONCLUSIONS: These findings suggest that functional abnormalities in brain responses to emotional stimuli observed in chronic PTSD are already apparent in its acute phase.

Acute Disease↗

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

Distant influences of amygdala lesion on visual cortical activation during emotional face processing.

Emotional visual stimuli evoke enhanced responses in the visual cortex. To test whether this reflects modulatory influences from the amygdala on sensory processing, we used event-related functional magnetic resonance imaging (fMRI) in human patients with medial temporal lobe sclerosis. Twenty-six patients with lesions in the amygdala, the hippocampus or both, plus 13 matched healthy controls, were shown pictures of fearful or neutral faces in task-releant or task-irrelevant positions on the display. All subjects showed increased fusiform cortex activation when the faces were in task-relevant positions. Both healthy individuals and those with hippocampal damage showed increased activation in the fusiform and occipital cortex when they were shown fearful faces, but this was not the case for individuals with damage to the amygdala, even though visual areas were structurally intact. The distant influence of the amygdala was also evidenced by the parametric relationship between amygdala damage and the level of emotional activation in the fusiform cortex. Our data show that combining the fMRI and lesion approaches can help reveal the source of functional modulatory influences between distant but interconnected brain regions.

Adult↗

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

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

Distinct spatial frequency sensitivities for processing faces and emotional expressions.

High and low spatial frequency information in visual images is processed by distinct neural channels. Using event-related functional magnetic resonance imaging (fMRI) in humans, we show dissociable roles of such visual channels for processing faces and emotional fearful expressions. Neural responses in fusiform cortex, and effects of repeating the same face identity upon fusiform activity, were greater with intact or high-spatial-frequency face stimuli than with low-frequency faces, regardless of emotional expression. In contrast, amygdala responses to fearful expressions were greater for intact or low-frequency faces than for high-frequency faces. An activation of pulvinar and superior colliculus by fearful expressions occurred specifically with low-frequency faces, suggesting that these subcortical pathways may provide coarse fear-related inputs to the amygdala.

Adolescent↗

PubMed2002

Modulation of spatial attention by fear-conditioned stimuli: an event-related fMRI study.

Stimuli that signal threat can capture subjects' attention, leading to more efficient detection of, and faster responses to, events occurring in that part of the environment. In the present study we explored the behavioural and anatomical correlates of the modulation of spatial attention by emotion using a fear conditioning paradigm, combined with a covert spatial orienting task. Reaction times for the detection of a peripheral target, which was preceded by brief (50ms) presentations of the visual conditioned stimulus (CS+) in either the same or opposite visual field, showed an interaction between stimulus emotionality and attention shifts. We used event-related functional magnetic resonance imaging (fMRI) to characterise the associated neural responses. Consistent with previous studies, conditioning-induced enhanced responses were observed in the amygdala and extrastriate visual cortex. The modulation of spatial attention by a conditioned stimulus was associated with enhanced activity in regions of frontal and parietal cortices previously implicated in spatial attention, as well as in the lateral orbitofrontal cortex (lOFC).

Amygdala↗