Abstract The authors examined the hypothesis that rhesus monkeys with extreme fight frontal electroencephalographic activity would have higher cortisol levels and would be more fearful compared with monkeys with extreme left frontal activity. The authors first showed that individual differences in asymmetric frontal electrical activity are a stable characteristic. Next, the authors demonstrated that relative […]
Category Archives: Research & Projects
Metabolic rate in the right amygdala predicts negative affect in depressed patients.
Abstract THE role of the amygdala in major depression was investigated. Resting regional cerebral metabolic rate (rCMRglu) was measured with [18F] fluorodeoxyglucose positron emission tomography (PET) in two samples of subjects using two different PET cameras. The samples consisted of 10 and 17 medication-free depressives and 11 and 13 controls, respectively. Using coregistration of PET […]
Thalamic metabolic rate predicts EEG alpha power in healthy control subjects but not in depressed patients
Abstract Background: EEG alpha power has been demonstrated to be inversely related to mental activity and has subsequently been used as an indirect measure of brain activation. The hypothesis that the thalamus serves as a neuronal oscillator of alpha rhythms has been supported by studies in animals, but only minimally by studies in humans. Methods: […]
Six-month test-retest reliability of MRI-defined PET measures of regional cerebral glucose metabolic rate in selected subcortical structures
Abstract Test–retest reliability of resting regional cerebral metabolic rate of glucose (rCMR) was examined in selected subcortical structures: the amygdala, hippocampus, thalamus, and anterior caudate nucleus. Findings from previous studies examining reliability of rCMR suggest that rCMR in small subcortical structures may be more variable than in larger cortical regions. We chose to study these […]
Temporal stability of the emotion-modulated startle response.
Abstract In the present study, we examined the stability of one measure of emotion, the emotion-modulated acoustic startle response, in an undergraduate sample. Using the acoustic startle paradigm on two different occasions, we measured stability of affective modulation of the startle response during and following the presentation of pictures selected to be of positive, negative, […]
Brain electrical tomography in depression: The importance of symptom severity, anxiety, and melancholic features.
Abstract Background: The frontal lobe has been crucially involved in the neurobiology of major depression, but inconsistencies among studies exist, in part due to a failure of considering modulatory variables such as symptom severity, comorbidity with anxiety, and distinct subtypes, as codeterminants for patterns of brain activation in depression. Methods: Resting electroencephalogram was recorded in […]
Startle potentiation in aversive anticipation: Evidence for state but not trait effects.
Abstract The present study was undertaken to determine whether aversiveness contributes to startle potentiation in anticipation of affective pictures above and beyond the effects of emotional arousal. Further, participants high in trait anxious apprehension, which is characterized by worry about the future, were expected to show especially pronounced anticipatory startle responses. Startle blink reflex was […]
Functional but not structural subgenual prefrotntal cortex abnromalities in melancholia.
Abstract Major depression is a heterogeneous condition, and the search for neural correlates specific to clinically defined subtypes has been inconclusive. Theoretical considerations implicate frontostriatal, particularly subgenual prefrontal cortex (PFC), dysfunction in the pathophysiology of melancholia—a subtype of depression characterized by anhedonia but no empirical evidence has been found yet for such a link. To […]
Stability of emotion-modulated startle during short and long picture presentation.
Abstract Following reports on improved test–retest reliability of emotion-modulated startle during a 6-s picture presentation when different pictures are presented at each assessment (Larson et al., 2000) and data suggesting that brief picture presentations also elicit affective blink modulation (Codispoti, Bradley, & Lang, 2001), we assessed test–retest reliability of blink modulation during brief picture presentations. […]
Simple geometric shapes are implicitly associated with affective value
Abstract Growing evidence suggests that the underlying geometry of a visual image is an effective mechanism for conveying the affective meaning of a scene or object. Indeed, even very simple context-free geometric shapes have been shown to signal emotion. Specifically, downward-pointing V’s are perceived as threatening and curvilinear forms are perceived as pleasant. As these […]