Understanding the neurobiology of emotion perception: implications for psychiatry.
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Bipolar Disorder↗
Biomedical subjects
M L Phillips
Publications and source records attributed to M L Phillips.
Separating depersonalisation and derealisation: the relevance of the "lesion method".
OBJECTIVES: Depersonalisation (DP) and derealisation (DR) are often met with in patients with a wide range of localisable neurological conditions. This suggests that the "lesion method" might be a valid approach to study the neurobiology of DP/DR. However, the fact that anxiety can trigger DP/DR makes it difficult to establish whether the presence of DP/DR in neurological patients is mainly determined by coexisting anxiety or by lesion location. To overcome this difficulty, we suggest the study of neurological phenomena, which although not considered as DP/DR, bear enough phenomenological resemblance with them as to warrant their use as models. METHODS: One patient with "visual hypoemotionality" and another with "hemiasomatognosia" are described in detail together with a selective literature review. RESULTS: Complaints of patients with visual hypoemotionality are indistinguishable from those of patients with "visual derealisation". There is also a phenomenological overlap between "asomatognosia" and the symptom of "body alienation", which is a central feature of depersonalisation. CONCLUSIONS: Phenomenological similarities between visual hypoemotionality and DR suggest that a disruption of the process by means of which perception becomes emotionally coloured may be an underlying mechanism in both conditions. Likewise, phenomenological overlaps with asomatognosia suggest that DP might result from parietal mechanisms disrupting the experience of body ownership and agency. These findings give validity to the notion that DP and DR may have distinct neurobiological mechanisms.
Adult↗
Depersonalization disorder: thinking without feeling.
Patients with depersonalization disorder (DP) experience a detachment from their own senses and surrounding events, as if they were outside observers. A particularly common symptom is emotional detachment from the surroundings. Using functional magnetic resonance imaging (fMRI), we compared neural responses to emotionally salient stimuli in DP patients, and in psychiatric and healthy control subjects. Six patients with DP, 10 with obsessive-compulsive disorder (OCD), and six volunteers were scanned whilst viewing standardized pictures of aversive and neutral scenes, matched for visual complexity. Pictures were then rated for emotional content. Both control groups rated aversive pictures as much more emotive, and demonstrated in response to these scenes significantly greater activation in regions important for disgust perception, the insula and occipito-temporal cortex, than DP patients (covarying for age, years of education and total extent of brain activation). In DP patients, aversive scenes activated the right ventral prefrontal cortex. The insula was activated only by neutral scenes in this group. Our findings indicate that a core phenomenon of depersonalization--absent subjective experience of emotion--is associated with reduced neural responses in emotion-sensitive regions, and increased responses in regions associated with emotion regulation.
Adult↗
Basal activity of the hypothalamic-pituitary-adrenal axis in patients with depersonalization disorder.
Depersonalisation disorder may occur during severe anxiety or following a traumatic event, suggesting a possible role of stress hormones. This study investigated basal activity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with depersonalisation disorder. Salivary cortisol levels were measured at four time points over 12 h in patients with depersonalisation disorder (N=13), major depressive disorder (MDD, N=14) and healthy controls (N=13). Beck Depression Inventory scores were significantly higher in depersonalised subjects than controls, while MDD subjects demonstrated higher scores than both groups. Basal cortisol levels of depersonalised subjects were significantly lower than those of MDD subjects but not healthy controls. These results point to reduced basal activity of the HPA axis in depersonalisation disorder. This pilot study supports the distinction between depersonalisation disorder and major depressive disorder which should be examined in a larger sample.
Adult↗
Polymerization of the SAM domain of TEL in leukemogenesis and transcriptional repression.
TEL is a transcriptional repressor that is a frequent target of chromosomal translocations in a large number of hematalogical malignancies. These rearrangements fuse a potent oligomerization module, the SAM domain of TEL, to a variety of tyrosine kinases or transcriptional regulatory proteins. The self-associating property of TEL-SAM is essential for cell transformation in many, if not all of these diseases. Here we show that the TEL-SAM domain forms a helical, head-to-tail polymeric structure held together by strong intermolecular contacts, providing the first clear demonstration that SAM domains can polymerize. Our results also suggest a mechanism by which SAM domains could mediate the spreading of transcriptional repression complexes along the chromosome.
Amino Acid Sequence↗
Hexagonal ammonium zinc phosphate, (NH4)ZnPO4, at 10 K.
The title compound, (NH(4))ZnPO(4)-HEX, is built up from a three-dimensional network of ZnO(4) and PO(4) tetrahedra [d(av)(Zn-O) = 1.9400 (7) A and d(av)(P-O) = 1.5396 (7) A], fused together via Zn-O-P links [straight theta(av) = 133.47 (4) degrees ]. An undisordered linear Zn-O-P bond occurs (all three atoms lie on a threefold axis). Extra-framework NH(4)(+) cations, which interact with the [ZnPO(4)](-) framework by hydrogen bonds, complete the crystal structure.
Journal Article↗
Time courses of left and right amygdalar responses to fearful facial expressions.
Despite the many studies highlighting the role of the amygdala in fear perception, few have examined differences between right and left amygdalar responses. Using functional magnetic resonance imaging (fMRI), we examined neural responses in three groups of healthy volunteers (n = 18) to alternating blocks of fearful and neutral faces. Initial observation of extracted time series of both amygdalae to these stimuli indicated more rapid decreases of right than left amygdalar responses to fearful faces, and increasing magnitudes of right amygdalar responses to neutral faces with time. We compared right and left responses statistically by modeling each time series with (1) a stationary fit model (assuming a constant magnitude of amygdalar response to consecutive blocks of fearful faces) and (2) an adaptive model (no assumptions). Areas of significant sustained nonstationarity (time series points with significantly greater adaptive than stationary model fits) were demonstrated for both amygdalae. There was more significant nonstationarity of right than left amygdalar responses to neutral, and left than right amygdalar responses to fearful faces. These findings indicate significant variability over time of both right and left amygdalar responses to fearful and neutral facial expressions and are the first demonstration of specific differences in time courses of right and left amygdalar responses to these stimuli.
Adult↗
Arousal dissociates amygdala and hippocampal fear responses: evidence from simultaneous fMRI and skin conductance recording.
The experience and appraisal of threat is essential to human and animal survival. Lesion evidence suggests that the subjective experience of fear relies upon amygdala-medial frontal activity (as well as autonomic arousal), whereas the factual context of threat stimuli depends upon hippocampal-lateral frontal activity. This amygdala-hippocampus dissociation has not previously been demonstrated in vivo. To explore this differentiation, we employed functional magnetic resonance imaging (fMRI) and simultaneous skin conductance response (SCR) measures of phasic arousal, while subjects viewed fearful versus neutral faces. fMRI activity was subaveraged according to whether or not the subject evoked an arousal SCR to each discrete face stimulus. The fMRI-with arousal and fMRI-without arousal data provided a distinct differentiation of amygdala and hippocampal networks. Amygdala-medial frontal activity was observed only with SCRs, whereas hippocampus-lateral frontal activity occurred only in the absence of SCRs. The findings provide direct evidence for a dissociation between human amygdala and hippocampus networks in the visceral experience versus declarative fact processing of fear.
Adult↗
Recognizing one's own face.
We report two studies of facial self-perception using individually tailored, standardized facial photographs of a group of volunteers and their partners. A computerized morphing procedure was used to merge each target face with an unknown control face. In the first set of experiments, a discrimination task revealed a delayed response time for the more extensively morphed self-face stimuli. In a second set of experiments, functional magnetic resonance imaging (fMRI) was used to measure brain activation while subjects viewed morphed versions of either their own or their partner's face, alternating in blocks with presentation of an unknown face. When subjects viewed themselves (minus activation for viewing an unknown face), increased blood oxygenation was detected in right limbic (hippocampal formation, insula, anterior cingulate), left prefrontal cortex and superior temporal cortex. In the partner (versus unknown) experiment, only the right insula was activated. We suggest that a neural network involving the right hemisphere in conjunction with left-sided associative and executive regions underlies the process of visual self-recognition. Together, this combination produces the unique experience of self-awareness.
Adult↗
Primary and secondary depersonalisation disorder: a psychometric study.
INTRODUCTION: Depersonalisation may be part of a symptom-complex, a primary or a secondary disorder. Optimal methods of measurement and diagnosis have not been established. METHODS: We assessed 42 patients with primary or secondary depersonalisation, plus psychiatric and non-psychiatric controls using a variety of self-report questionnaire scales including the Beck depression and anxiety Inventories, and one developed by the authors (the Fewtrell Depersonalisation Scale (FDS)). The correlations between the scales and measures of anxiety and depression were calculated, as were sensitivity and specificity against an operational case definition. RESULTS: All the scales were highly correlated. All could distinguish depersonalisation cases from the rest but none could distinguish between primary and secondary depersonalisation disorder. Anxiety and especially depression were correlated with depersonalisation symptoms. The FDS had high sensitivity (85.7%) and specificity (92.3%) which compared favourably with other instruments. Patients with both derealisation and depersonalisation scored the highest on the FDS. DISCUSSION: Depersonalisation disorder comprises a measurable cluster of symptoms which may be quantified with the help of self-report scales. Primary and secondary forms overlap, with depressed mood a frequent feature.
Adolescent↗
The reliability of multiple regression and an alternative method for extracting task-specific exposure estimates from time-weighted average data.
The reliability of multiple regression analysis as a method for determining task-specific exposures from multi-task time-weighted average data was evaluated in comparison with the alternative P-screen method. The performances of the two methods were tested using simulated sample data that were calculated as averages over six tasks, where task-specific concentrations drawn randomly from lognormal distributions were weighted by randomly generated task time-weights. Data sets consisted of 20 or 100 simulated samples. The simulated data sets conformed to requirements inherent in the P-screen method that at least one task be absent from each sample and each task be absent from at least one sample. In thousands of Monte Carlo trials under various conditions, the two methods were found to perform equally well when dichotomous task measures (occurrence/ nonoccurrence) were used. Combining the two methods did not improve reliability appreciably, suggesting that the methods are effectively equivalent when dichotomous task measures are used. When task durations were used as the regressors or time-weights, multiple regression was found to be more reliable than P-screen. It is well recognized that incidental or fundamental collinearities between regressors may undermine multiple regression analyses. The P-screen-related restrictions on the task structure of data sets reduces the potential for problems arising from such collinearities. However, the use of multivariate analysis of multiple-task samples will always be an imperfect substitute for single-task sampling.
Air Pollution, Indoor↗
Sodium scandium arsenate, Na3Sc2(AsO4)3.
Nasicon-type trisodium discandium tris(arsenate), Na3Sc2(AsO4)3, contains a polyhedral network of vertex-sharing octahedral ScO6 and tetrahedral AsO4 units [d(av)(Sc-O) = 2.089 (2) A and d(av)(As-O) = 1.672 (2) A] encapsulating two types of Na+ species. The sodium site occupancies are similar to those of the equivalent species in beta-Na3Sc2(PO4)3.
Journal Article↗
What is "powder free"? Characterisation of powder aerosol produced during simulated use of powdered and powder free latex gloves.
OBJECTIVES: To characterise the distribution of particle size and mass of glove powder aerosol released from powdered and powder free non-sterile latex gloves under controlled conditions. METHODS: Gravimetric sampling and aerodynamic particle size analysis were performed during simulated use of gloves on a prosthetic hand in a chamber designed to minimise background particle concentrations. RESULTS: Aerosol was detectable for both powdered and powder free gloves under both aggressive and non-aggressive handling conditions. Most of the particles detected had aerodynamic diameter less than 10 microm. CONCLUSION: Powder free gloves were not entirely free of powder aerosol. Particles from both powdered and powder free gloves are sufficiently fine to penetrate into the thoracic region of the respiratory tract.
Air Pollutants, Occupational↗
Resolving conflict realistically in today's health care environment.
Conflict is a natural part of human interaction, and when properly addressed, results in improved interpersonal relationships and positive organizational culture. Unchecked conflict may escalate to verbal and physical violence. Conflict that is unresolved creates barriers for people, teams, organizational growth, and productivity, leading to cultural disintegration within the establishment. By relying on interdependence and professional collaboration, all parties involved grow and, in turn, benefit the organization and population served. When used in a constructive manner, conflict resolution can help all parties involved see the whole picture, thus allowing freedom for growth and change. Conflict resolution is accomplished best when emotions are controlled before entering into negotiation. Positive confrontation, problem solving, and negotiation are processes used to realistically resolve conflict. Everyone walks away a winner when conflict is resolved in a positive, professional manner (Stone, 1999).
Adaptation, Psychological↗
Lamotrigine in the treatment of depersonalization disorder.
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Adult↗
Towards a functional neuroanatomy of self processing: effects of faces and words.
We studied the neural correlates of self vs. non-self judgements using functional magnetic resonance imaging (fMRI). Individually tailored faces and personality trait words were used as stimuli in three experiments (exp.). In the first two experiments, brain activation was measured while subjects viewed morphed versions of either their own (self face exp.) or their partner's face (partner's face exp.), alternating in blocks with presentation of an unknown face. In the self face exp. right limbic areas (hippocampal formation, insula, anterior cingulate), the right middle temporal lobe, left inferior parietal and left prefrontal regions showed signal changes. In the partner's face exp., only the right insula was activated. In the third exp., subjects made decisions about psychological trait adjectives previously categorized as describing their own attributes. Activation was present in the precuneus, the left parietal lobe, left insula/inferior frontal gyrus and the left anterior cingulate. A reaction time advantage was present when subjects responded to self-relevant words. The main area with signal changes during self-reference processing, regardless of the type of stimulus, was the left fusiform gyrus. The self-relevant stimuli engaged to a differential extent long term and working memory, semantic and emotional processes. We suggest that regions activated by these stimuli are engaged in self-processing.
Adult↗
Perception of threat in schizophrenics with persecutory delusions: an investigation using visual scan paths.
BACKGROUND: Cognitive theories of persecutory delusions in schizophrenia include increased attention to threat and reduced re-appraisal of information during decision-making. METHODS: We employed visual scan path measurements, an 'on-line' marker of attention, in schizophrenic patients with persecutory delusions (N = 19), negative symptom- and medication-matched patients with non-persecutory delusions (N = 8), and normal controls (N = 18). Stimuli comprised black-and-white photographs of social scenes rated as depicting either neutral, ambiguous or overtly threatening activity. Foreground areas containing salient information with regard to the overall scene were rated independently as either threatening or non-threatening in both the overtly threatening and ambiguous scenes; all foreground areas were rated as non-threatening in the neutral scene. RESULTS: For the ambiguous scene only, schizophrenics with persecutory delusions directed gaze to less threatening areas, and, for all three scenes, demonstrated reduced re-appraisal of information compared with both control groups. All subjects showed similar viewing strategies for the overtly threatening and neutral scenes. CONCLUSIONS: These findings suggest abnormal information gathering and evaluation in schizophrenics, specifically related to the presence of persecutory delusions. In particular, the results point to biased processing of contextual information in an ambiguous setting in these patients, and perhaps perception of threat in inappropriate places.
Adult↗
A differential neural response in obsessive-compulsive disorder patients with washing compared with checking symptoms to disgust.
BACKGROUND: Patients with obsessive-compulsive disorder (OCD) have symptoms that predominantly concern washing (washers) or checking (checkers), or both. Functional neuroimaging has been used to identify the neural correlates of the urge to ritualize but has not distinguished between washing and checking symptoms in OCD. We used functional magnetic resonance imaging to compare the neural response to emotive pictures in washers and checkers. METHODS: In one of two 5-minute experiments, washers (N = 7), checkers (N = 7) and age-matched normal controls (N = 14) were scanned while viewing alternating blocks of normally disgusting (rated as disgusting by all subjects) and neutral pictures. In the other experiment, all patients and a normal subgroup (N = 8) viewed alternating blocks of washer-relevant (rated as more disgusting by washers than normal controls or checkers) and neutral pictures. RESULTS: In all subjects, normally disgusting pictures activated visual regions implicated in perception of aversive stimuli and the insula, important in disgust perception. Only in washers were similar regions activated by washer-relevant pictures. In checkers, these pictures activated fronto-striatal regions associated with the urge to ritualize in OCD. Normal controls were more similar in neural response to checkers than washers to these pictures. Both normal controls and checkers had frontal regions activated significantly more by washer-relevant than normally disgusting pictures, and had these regions activated significantly more than washers by washer-relevant pictures. CONCLUSIONS: We demonstrate a differential neural response to washer-relevant disgust in washers and checkers: only washers demonstrate a neural response to washer-relevant disgust associated with emotion perception rather than attention to non-emotive visual detail.
Adolescent↗