Biomedical subjects

Lisa M Shin

Publications and source records attributed to Lisa M Shin.

24 records · Page 2Linked to original sources

PubMed2003

Novelty responses and differential effects of order in the amygdala, substantia innominata, and inferior temporal cortex.

Recent studies of amygdala function have focused on examining responses to emotionally valenced versus neutral stimuli. However, electrophysiologic and neuroimaging studies also suggest that novel neutral faces activate the amygdala, though few investigations have examined the effects of novelty and its relation to changes in stimulus condition. To further investigate how the human amygdala and related structures react to novel neutral faces and to stimulus condition changes, we evaluated human brain responses to blocks containing multiple novel and single repeated face stimuli, presented in two different orders, using functional magnetic resonance imaging (fMRI). Significantly increased signal was present in the amygdala, substantia innominata (SI), and inferior temporal cortex (ITC) to the contrast of multiple novel versus single faces. However, these regions differed in their responses based on whether a stimulus condition was presented 1st or 2nd, with the amygdala and SI having significantly different response profiles than the ITC. Specifically, greater responses to stimuli presented 2nd (i.e., after a condition change) were found in the amygdala and SI, but not in the ITC. Furthermore, the response difference to the Multiple versus Single contrast was greatest in the amygdala and SI, when single faces were presented 1st, and multiple faces presented 2nd, but this pattern was the reverse in the ITC. We speculate that the signal changes to neutral faces in the amygdala and SI with respect to condition (multiple or single faces) and stimulus order may relate to the involvement of these structures in novelty detection and the orienting response.

Adult↗

PubMed2003

Neuroimaging studies of amygdala function in anxiety disorders.

Neuroimaging research has helped to advance neurobiological models of anxiety disorders. The amygdala is known to play an important role in normal fear conditioning and is implicated in the pathophysiology of anxiety disorders. The amygdala may also be a target for the beneficial effects of cognitive-behavioral and medication treatments for anxiety disorders. In the current paper, we review neuroimaging research pertaining to the role of the amygdala in anxiety disorders and their treatment. Moreover, we discuss the development of new neuroimaging paradigms for measuring aspects of amygdala function, as well as the function of related brain regions. We conclude that such tools hold great promise for facilitating progress in relevant basic neuroscience as well as clinical research domains.

Amygdala↗

PubMed2002

Enhanced amygdala responses to emotional versus neutral schematic facial expressions.

Human facial emotional expressions are complex. This may confound studies examining brain responses to these stimuli in control and clinical populations. However, several lines of evidence suggest that a few elementary facial features convey the gist of emotional expressions. Using fMRI, we assessed brain responses to line drawings of emotionally valenced (i.e. angry and happy) and neutral faces in healthy human subjects. Significantly increased fMRI signal was found in the amygdala, hippocampus and prefrontal cortex in response to emotional vs neutral schematic faces. Although direct comparisons of schematic and human faces will be needed, these initial results suggest that schematic faces may be useful for studying brain responses to emotional stimuli because of their simplicity relative to human faces.

Adult↗

PubMed2002

Predictors of fluvoxamine response in contamination-related obsessive compulsive disorder: a PET symptom provocation study.

The purpose of this study was to identify neuroimaging predictors of medication response in contamination-related obsessive compulsive disorder (OCD). Prior studies of OCD had indicated that glucose metabolic rates within orbitofrontal cortex (OFC) were inversely correlated with subsequent response to serotonergic reuptake inhibitors (SRIs) and that glucose metabolic rates within posterior cingulate cortex (PCC) were positively correlated with subsequent response to cingulotomy. Nine subjects with contamination-related OCD underwent a 12-week open trial of treatment with the SRI fluvoxamine. Percent change in Yale-Brown Obsessive Compulsive Scale score, from pre- to post-treatment, served as the index of treatment response. Positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) were obtained prior to treatment, in the context of a symptom provocation paradigm. Statistical parametric mapping was used to identify brain loci where pre-treatment rCBF was significantly correlated with subsequent treatment response. Consistent with a priori hypotheses, lower rCBF values in OFC and higher rCBF values in PCC predicted better treatment response. This same pattern of associations was present regardless of whether the imaging data were acquired during a provoked or neutral state. These findings are consistent with prior studies of OCD, indicating that PET indices of brain activity within OFC are inversely correlated with subsequent response to SRIs. In addition, similar to findings regarding cingulotomy for OCD, indices of activity within PCC appear to be positively correlated with response to fluvoxamine as well. Finally, this pattern is sufficiently robust as to be relatively independent of symptomatic state at the time of tracer uptake.

Adolescent↗

PubMed2002

Functional neuroimaging studies of the amygdala in depression.

Here we review human functional neuroimaging studies suggesting that the amygdala may play a key role in depression. We begin by reviewing animal and human data concerning the function of the amygdala. We then compare these results with those of neuroimaging studies of normal human amygdala function. Finally, we discuss functional neuroimaging studies of the amygdala in depression in light of the animal and human data. We conclude that the initial studies of this disorder provide evidence of amygdala involvement. Furthermore, we suggest that the scope of the amygdala's involvement may go beyond its well-known role in fear to its more subtle and generalized role in modulating moment-to-moment vigilance levels.

Amygdala↗

PubMedDate not supplied

Psychiatric and emotional sequelae of surgical amputation.

The prevalence of posttraumatic stress symptoms after the experience of amputation is not well established. The current study gathered data on the prevalence of posttraumatic stress disorder (PTSD) and other psychiatric disorders after amputation. Participants were recruited from a large Northeastern rehabilitation hospital and were assessed with structured clinical interviews. The data suggest that planned surgical amputations resulting from chronic illness do not frequently lead to PTSD symptoms. In contrast, data suggest that amputation resulting from accidental injury may lead to a higher prevalence of PTSD, in part because of the emotional stress surrounding the accident.

Adult↗