Biomedical subjects

Peter J Lang

Publications and source records attributed to Peter J Lang.

12 recordsLinked to original sources

PubMed2005

Parallel amygdala and inferotemporal activation reflect emotional intensity and fear relevance.

Much research demonstrates that emotional stimuli prompt increased amygdala and visual cortical activation. Here we measure functional activity in the visual cortex and amygdala with fMRI while selected fearful and control participants view a range of neutral, emotionally arousing, and fear-relevant pictures. BOLD signal in the amygdala and inferotemporal visual cortex closely covaried during emotional picture viewing, increasing systematically with rated picture arousal. Furthermore, fearful individuals reacting to specific fear cues show parallel, heightened activation in these two structures compared with non-fearful controls. The findings suggest an individually-sensitive, positive linear relationship between the arousing quality of visual stimuli and activation in amygdala and ventral visual cortex, supporting the hypothesized functional connectivity described in the animal model.

Adolescent↗

PubMed2004

Additive effects of emotional content and spatial selective attention on electrocortical facilitation.

Affectively arousing visual stimuli have been suggested to automatically attract attentional resources in order to optimize sensory processing. The present study crosses the factors of spatial selective attention and affective content, and examines the relationship between instructed (spatial) and automatic attention to affective stimuli. In addition to response times and error rate, electroencephalographic data from 129 electrodes were recorded during a covert spatial attention task. This task required silent counting of random-dot targets embedded in a 10 Hz flicker of colored pictures presented to both hemifields. Steady-state visual evoked potentials (ssVEPs) were obtained to determine amplitude and phase of electrocortical responses to pictures. An increase of ssVEP amplitude was observed as an additive function of spatial attention and emotional content. Statistical parametric mapping of this effect indicated occipito-temporal and parietal cortex activation contralateral to the attended visual hemifield in ssVEP amplitude modulation. This difference was most pronounced during selection of the left visual hemifield, at right temporal electrodes. In line with this finding, phase information revealed accelerated processing of aversive arousing, compared to affectively neutral pictures. The data suggest that affective stimulus properties modulate the spatiotemporal process along the ventral stream, encompassing amplitude amplification and timing changes of posterior and temporal cortex.

Adult↗

PubMed2004

Affective picture perception: gender differences in visual cortex?

Activity in extrastriate visual cortex is greater when people view emotional relative to neutral pictures. Prior brain imaging and psychophysiological work has further suggested a bias for men to react more strongly to pleasant pictures, and for women to react more strongly to unpleasant pictures. Here we investigated visual cortical activity using fMRI in 28 men and women during picture viewing. Men and women showed reliably greater visual cortical reactivity during both pleasant and unpleasant pictures, relative to neutral, consistent with the view that the motivational relevance of visual stimuli directs attention and enhances elaborative perceptual processing. However, men did show greater extrastriate activity than women specifically during erotic picture perception, possibly reflecting a gender-specific visual mechanism for sexual selection.

Adolescent↗

PubMed2004

Psychopathy and physiological response to emotionally evocative sounds.

Despite considerable evidence that psychopathic criminals are deviant in their emotional reactions, few studies have examined responses to both pleasurable and aversive stimuli or assessed the role of different facets of psychopathy in affective deviations. This study investigated physiological reactions to emotional sounds in prisoners selected according to scores on the 2 factors of Hare's Psychopathy Checklist--Revised (PCL-R; R. D. Hare, 1991). Offenders high on the PCL-R emotional-interpersonal factor, regardless of scores on the social deviance factor, showed diminished skin conductance responses to both pleasant and unpleasant sounds, suggesting a deficit in the action mobilization component of emotional response. Offenders who scored high only on the social deviance factor showed a delay in heart rate differentiation between affective and neutral sounds. These findings indicate abnormal reactivity to both positive and negative emotional stimuli in psychopathic individuals, and suggest differing roles for the 2 facets of psychopathy in affective processing deviations.

Acoustic Stimulation↗

PubMed2003

Brain activation by disgust-inducing pictures in obsessive-compulsive disorder.

BACKGROUND: There is growing interest in the role of disgust in the pathogenesis of obsessive-compulsive disorder (OCD). METHODS: Eight OCD subjects with contamination preoccupations and eight gender- and age-matched healthy volunteers viewed pictures from the International Affective Picture System during functional magnetic resonance imaging scans. RESULTS: A different distribution of brain activations was found during disgust-inducing visual stimulation in several areas, most notably the insula, compared with neutral stimulation in both OCD subjects and healthy volunteers. Furthermore, whereas activation during the threat-inducing task in OCD subjects showed a pattern similar to that in healthy volunteers, the pattern of activation during the disgust-inducing task was significantly different, including greater increases in the right insula, parahippocampal region, and inferior frontal sites. CONCLUSIONS: This pilot study supports the relevance of disgust in the neurocircuitry of OCD with contamination-preoccupation symptoms; future studies looking at non-OCD individuals with high disgust ratings, non-contamination-preoccupied OCD individuals, and individuals with other anxiety disorders are needed.

Adult↗

PubMed2003

Activation of the visual cortex in motivated attention.

Functional activation (measured with fMRI) in occipital cortex was more extensive when participants view pictures strongly related to primary motive states (i.e., victims of violent death, viewer-directed threat, and erotica). This functional activity was greater than that observed for less intense emotional (i.e., happy families or angry faces) or neutral images (i.e., household objects, neutral faces). Both the extent and strength of functional activity were related to the judged affective arousal of the different picture contents, and the same pattern of functional activation was present whether pictures were presented in color or in grayscale. It is suggested that more extensive visual system activation reflects "motivated attention," in which appetitive or defensive motivational engagement directs attention and facilitates perceptual processing of survival-relevant stimuli.

Adolescent↗

PubMed2003

[Long-term results after perforating corneo-scleroplasty in a case of acute unilateral superior pellucid marginal corneal degeneration].

PURPOSE: This case report shows the long-term results after perforating corneo-scleroplasty in a rare case of superior pellucid marginal corneal degeneration with acute hydrops due to rupture of Descemet's membrane. PATIENT: In the left cornea of a 20-year-old patient with peripheral stromal thinning from 9 to 3 o'clock a rupture in Descemet's membrane occurred followed by lamellar splitting of the mid-stromal region. Due to the decrease in visual acuity and pain from corneal edema a surgical treatment was performed consisting of a perforating/lamellar corneo-scleroplasty protecting the anterior chamber angle. RESULTS: The status has remained stable for 17 years after surgery with nearly clear graft, best corrected visual acuity of 0.8 and no signs of recurrence or progression of the disease. Central astigmatism is regular, the endothelial cell count is 1250/mm2 in the central cornea, the central corneal thickness is 540 microm and only a mild vascularised superficial pannus and slight opacities in the predescemetal layer of the graft are found. There are no anterior synechia. On the right eye visual acuity is 0.8 due to slight amblyopia. There are no corneal changes which would indicate bilaterality of the disease. CONCLUSIONS: Our findings must be interpreted as an atypically localised superior pellucid marginal corneal degeneration with rupture of Descemet's membrane followed by acute corneal hydrops. When reduction of visual acuity or pain occurs a surgical treatment by perforating/lamellar corneo-scleroplasty can be performed stopping the progression of the disease and achieving a stable optical rehabilitation and absence of pain even after decades.

Adult↗

PubMed2003

The psychophysiology of anxiety disorder: fear memory imagery.

Psychophysiological response to fear memory imagery was assessed in specific phobia, social anxiety disorder, panic disorder with agoraphobia, post-traumatic stress disorder (PTSD), and healthy controls. Heart rate, skin conductance, and corrugator muscle were recorded as participants responded to tone cues signaling previously memorized descriptor sentences. Image contents included personal fears, social fears, fears of physical danger, and neutral (low arousal) scenes. Reactions to acoustic startle probes (eyeblink) were assessed during recall imagery and nonsignal periods. Participants were significantly more reactive (in physiology and report of affect) to fear than neutral cues. Panic and PTSD patients were, however, less physiologically responsive than specific phobics and the socially anxious. Panic and PTSD patients also reported the most anxiety and mood symptoms, and were most frequently comorbidly depressed. Overall, physiological reactivity to sentence memory cues was greatest in patients with focal fear of specific objects or events, and reduced in patients characterized by generalized, high negative affect.

Acoustic Stimulation↗

PubMed2003

Startle reflex modulation, affective ratings and autonomic reactivity in incarcerated Spanish psychopaths.

Startle probe modulation during affective picture viewing was assessed in a Spanish prison population. As for North American inmates, psychopaths failed to display normal blink potentiation during unpleasant slides even though their evaluative judgments and autonomic reaction to affective stimuli paralleled those of other inmate and noninmate participants. The results suggest that diminished defense activation characterizes psychopaths despite cultural differences.

Adult↗

PubMed2003

Early modulation of visual perception by emotional arousal: evidence from steady-state visual evoked brain potentials.

Allocation of processing resources to emotional picture stimuli was examined using steady-state visual evoked brain potentials (ssVEPs). Participants viewed a set of 60 colored affective pictures from the International Affective Picture System, presented in a flickering mode at 10 Hz in order to elicit ssVEPs. Phase and amplitude of the 10-Hz ssVEP were examined for six picture categories: threat and mutilation (unpleasant), families and erotica (pleasant), and household objects and persons (neutral). Self-reported affective arousal and hedonic valence of the picture stimuli were assessed by means of subjective ratings. Viewing affectively arousing (unpleasant and pleasant) pictures was associated with enhanced ssVEP amplitude at parieto-occipital recording sites, as compared with neutral stimuli. Phase information suggested increased coactivation of right occipitotemporal and frontotemporal sources during processing of affectively arousing stimuli. These findings are consistent with reentrant modulation of early visual processing by distributed networks including subcortical and neocortical structures according to a stimulus's motivational relevance.

Adult↗

PubMed2002

Looking at facial expressions: dysphoria and facial EMG.

Previous research on interpersonal deficits among dysphoric individuals has been equivocal, with some studies finding that dysphoric persons show an increase in negative behavior and other studies finding no group differences. Most studies in this area have employed self-report instruments and behavioral coding systems to examine interpersonal displays. Using a different approach, we examined facial electromyography (EMG) reactivity to pictures of happy and unhappy expressions among dysphoric persons. Dysphoric and non-dysphoric persons viewed happy and unhappy facial expressions while zygomatic EMG and corrugator EMG activity was recorded. Results indicated that both groups showed the appropriate increase in corrugator EMG to unhappy expressions; however, dysphoric persons did not show the expected increase in zygomatic EMG activity to happy expressions while the control participants did show this response. Unexpectedly, the dysphoric group displayed an increase in corrugator EMG activity (e.g. frown response) to the happy facial expressions. These findings indicate that dysphoric persons have impaired interpersonal reactivity that is specific to happy facial displays.

Adult↗

PubMed2002

Large-scale neural correlates of affective picture processing.

Hemodynamic and electrophysiological studies indicate differential brain response to emotionally arousing, compared to neutral, pictures. The time course and source distribution of electrocortical potentials in response to emotional stimuli, using a high-density electrode (129-sensor) array were examined here. Event-related potentials (ERPs) were recorded while participants viewed pleasant, neutral, and unpleasant pictures. ERP voltages were examined in six time intervals, roughly corresponding to P1, N1, early P3, late P3 and a slow wave window. Differential activity was found for emotional, compared to neutral, pictures at both of the P3 intervals, as well as enhancement of later posterior positivity. Source space projection was performed using a minimum norm procedure that estimates the source currents generating the extracranially measured electrical gradient. Sources of slow wave modulation were located in occipital and posterior parietal cortex, with a right-hemispheric dominance.

Adult↗