Peripheral responses to attended and unattended angry prosody: A dichotic listening paradigm

We investigated the effects of angry prosody, varying focus of attention, and laterality of presentation of angry prosody on peripheral nervous system activity. Participants paid attention to either their left or their right ear while performing a sex discrimination task on dichotically presented pseudo‐words. These pseudo‐words were characterized by either angry or neutral prosody and presented stereophonically (anger/neutral, neutral/anger, or neutral/neutral, for the left/right ear, respectively). Reaction times and physiological responses (heart period, skin conductance, finger and forehead temperature) in this study were differentially sensitive to the effects of anger versus neutral prosody, varying focus of attention, and laterality of presentation of angry prosody.     

Autonomic responses to familiar faces without autonomic responses to familiar voices: Evidence for voice-specific Capgras delusion

Introduction: Patients with Capgras delusion believe that certain individuals have been replaced by duplicates. Unlike normal people, these patients also show reduced autonomic responses to familiar faces, indicating the possibility that it is the covert processes of recognition that are impaired (Ellis, et al., 1997). It has been suggested that such patients would show normal autonomic responses to voices. An auditory parallel of this typical delusion, therefore, is theoretically possible. That is, a delusion whereby mis-recognition of the voice produces the delusional belief of duplication. Such a delusion would only occur in situations where the person is recognised by voice only; and so, even where it does exist, it would often escape diagnosis. Method: We present here a case, H.L., of what appears to be the Capgras delusion for voices in a sighted person. This case was investigated using standard skin conductance tests for face and voice recognition. Results: Consistent with this diagnosis, H.L. displays normal autonomic responses for faces but reduced autonomic responses for famous voices. Discussion: H.L. represents a previously unreported form of Capgras delusion and, further, shows dissociation between autonomic responses to faces and voices. Implications for cognitive models of person recognition are discussed.     

The shopping brain: math anxiety modulates brain responses to buying decisions

Metacognitive theories propose that consumers track fluency feelings when buying, which may have biological underpinnings. We explored this using event-related potential (ERP) measures as twenty high-math anxiety (High MA) and nineteen low-math anxiety (Low MA) consumers made buying decisions for promoted (e.g., 15% discount) and non-promoted products. When evaluating prices, ERP correlates of higher perceptual and conceptual fluency were associated with buys, however only for High MA females under no promotions. In contrast, High MA females and Low MA males demonstrated greater FN400 amplitude, associated with enhanced conceptual processing, to prices of buys relative to non-buys under promotions. Concurrent late positive component (LPC) differences under no promotions suggest discrepant retrieval processes during price evaluations between consumer groups. When making decisions to buy or not, larger (smaller) P3, sensitive to outcome responses in the brain, was associated with buying for High MA females (Low MA females) under promotions, an effect also present for males under no promotions. Thus, P3 indexed decisions to buy differently between anxiety groups, but only for promoted items among females and for no promotions among males. Our findings indicate that perceptual and conceptual processes interact with anxiety and gender to modulate brain responses during consumer choices.     

Recognition of affective prosody: continuous wavelet measures of event-related brain potentials to emotional exclamations

The affective state of a speaker can be identified from the prosody of his or her speech. Voice quality is the most important prosodic cue for emotion recognition from short verbal utterances and nonverbal exclamations, the latter conveying pure emotion, void of all semantic meaning. We adopted two context violation paradigms-oddball and priming-to study the event-related brain potentials (ERP) reflecting this recognition process. We found a negative wave, the N300, in the ERPs to contextually incongruous exclamations, and interpreted this component as analogous to the well-known N400 response to semantically inappropriate words. The N300 appears to be a real-time psychophysiological measure of spontaneous emotion recognition from vocal cues, which could prove a useful tool for the examination of affective-prosody comprehension. In addition, we developed a new ERP component detection and estimation method that is based on the continuous wavelet transform (CWT), does not rely on visual inspection of the waveforms, and yields larger statistical difference effects than classical methods.     

A single administration of testosterone induces cardiac accelerative responses to angry faces in healthy young women

Recently, it was demonstrated how individuals with high levels of testosterone selectively attend toward angry faces. It was argued that this suggests that high levels of testosterone are associated with an aggressive, dominating personality style. In this study, the authors used a double-blind, placebo-controlled design to examine whether exogenous testosterone would induce cardiac acceleration in response to angry faces. Participants (healthy young women) were exposed to neutral, happy, or angry faces. Administration of a single dosage of testosterone (0.5 mg) induced an accelerative cardiac response to angry faces. It is argued that this effect is due to the encouragement of dominance behavior and the inclination toward aggression. Possible mechanisms behind testosterone-driven changes in behavior are discussed with relevance to steroid-responsive networks in the limbic system that drive and control motivational and physiological aspects of social behavior.     

Estimated cardiac vagal tone predicts fetal responses to mother's and stranger's voices

Heart rate responses of 84 near-term fetuses to recorded female voices were examined in 166 trials of auditory stimulation. Each fetus was presented with a 2-min recording of their mother's voice and a 2-min recording of a female stranger's voice, in counterbalanced order, with a 10-min rest period between trials. High frequency heart rate variability during a 2-min baseline period was used to estimate cardiac vagal tone for each trial. Differential heart rate responses to familiar and unfamiliar voice recordings were observed during a 2-min poststimulus period, only when estimated cardiac vagal tone was high. This finding suggests that vagal tone plays a moderating role in the cardiac responses of term fetuses to familiar and unfamiliar stimuli.     

Relating to voices: Exploring the relevance of this concept to people who hear voices

Objectives Conceptualizing interactions between voice hearers and their voices as a ‘relationship’ has recently become an area of psychological inquiry. To date the literature exploring the details of a hearer–voice relationship has arguably privileged the researchers' account of voice hearing at the expense of the individual's explanatory framework and perspective. The present study aimed to establish the perspectives of voice hearers regarding any ‘relationship’ they may have developed with their voices. Method. In‐depth interviews were conducted with 10 service users who had heard voices for at least 12 months. The interviews were transcribed and analysed using interpretative phenomenological analysis (IPA). Results. Analysis resulted in five major themes, three of which are discussed here: Defining the ‘other’ which detailed the personification process; ‘Me vs. the Voice’ which explored oppositional positioning between participants and their voice and strategies employed to retain power and ‘the Voice and Me’ which considered the union that was apparent, as well as participants' rejection of a relational concept. The concept of a ‘relationship’ was both accepted and rejected by participants. Acceptance of relating was relative to the poverty of social relationships. Rejections were considered in terms of preservation of self‐hood, conflict with personal explanatory models and constructions of the term ‘relationship’. Conclusions. This study has provided evidence that supports new developments in working relationally with voices. Working within this frame may help to emphasize hearers' strengths whilst ameliorating distress. However, this concept needs to be posed as a possible rather than an established conceptualization.     

Brain responses to semantic anomaly in natural, continuous speech

In the present study, brain responses were recorded during the presentation of naturally spoken sentences. In two separate experiments, the same set of stimulus sentences was presented with subjects either being asked to pay close attention in order to answer content questions following the run ('memory instruction' - MI) or to press one of two buttons to indicate a normal or unusual ending to a sentence ('response instruction' - RI). Brain event-related potentials were not averaged across the exact same acoustic information but across 49 different words spoken in natural, uninterrupted sentences. There was no attempt to standardize the acoustic features of stimulus words by electronic means. Rather than splicing stimulus words (and trigger pulse needed for computer averaging) onto sentence stems, consonant-vowel-consonant (CVC) monosyllablic words were selected with voiceless stop consonants in the word initial position. This not only avoids acoustic overlap with the preceding word of the sentence but also allows the point of stimulus word onset to be precisely located. In the MI group, brain responses to the semantically anomalous endings were distinguished by the presence of a late negative wave (N300) followed by a sustained positive wave (P650). Responses to anomally in the RI group data was not consistently differentiated from normal in the 650-1000 ms range. Within conditions, the MI and RI waveforms were differentiated by the presence of an augmented positive-going slow wave in the RI condition which may reflect an augmented CNV release. The feasibility of averaging brain electrical responses across non-isolated words which differed acoustically but were of similar phonemic structure was demonstrated. This paradigm provides a means of studying speech-activated neurolinguistic processes in the stream of speech and may make complex spoken language contexts available for event-related potential investigations of brain and language functions.     

Topographic recordings of auditory evoked potentials to speech: Subcortical and cortical responses

Topographies of speech auditory brainstem response (speech ABR), a fine electrophysiological marker of speech encoding, have never been described. Yet, they could provide useful information to assess speech ABR generators and better characterize populations of interest (e.g., musicians, dyslexics). We present here a novel methodology of topographic speech ABR recording, using a 32‐channel low sampling rate (5 kHz) EEG system. Quality of speech ABRs obtained with this conventional multichannel EEG system were compared to that of signals simultaneously recorded with a high sampling rate (13.3 kHz) EEG system. Correlations between speech ABRs recorded with the two systems revealed highly similar signals, without any significant difference between their signal‐to‐noise ratios (SNRs). Moreover, an advanced denoising method for multichannel data (denoising source separation) significantly improved SNR and allowed topography of speech ABR to be recovered.     

The processing of emotional prosody and semantics in schizophrenia: relationship to gender and IQ

BACKGROUND: Female patients with schizophrenia are less impaired in social life than male patients. Because social impairment in schizophrenia has been found to be associated with deficits in emotion recognition, we examined whether the female advantage in processing emotional prosody and semantics is preserved in schizophrenia. METHOD: Forty-eight patients (25 males, 23 females) and 46 controls (23 males, 23 females) were assessed using an emotional language task (in which healthy women generally outperform healthy men), consisting of 96 sentences in four conditions: (1) neutral-content/emotional-tone (happy, sad, angry or anxious); (2) neutral-tone/emotional-content; (3) emotional-tone/incongruous emotional-content; and (4) emotional-content/incongruous emotional-tone. Participants had to ignore the emotional-content in the third condition and the emotional-tone in the fourth condition. In addition, participants were assessed with a visuospatial task (in which healthy men typically excel). Correlation coefficients were computed for associations between emotional language data, visuospatial data, IQ measures and patient variables. RESULTS: Overall, on the emotional language task, patients made more errors than control subjects, and women outperformed men across diagnostic groups. Controlling for IQ revealed a significant effect on task performance in all groups, especially in the incongruent tasks. On the rotation task, healthy men outperformed healthy women, but male patients, female patients and female controls obtained similar scores. CONCLUSION: The advantage in emotional prosodic and semantic processing in healthy women is preserved in schizophrenia, whereas the male advantage in visuospatial processing is lost. These findings may explain, in part, why social functioning is less compromised in women with schizophrenia than in men.     

Mechanisms of general anesthesia: brain regional responses to baclofen

The GABAB agonist baclofen is reported to produce general anesthesia when administered either centrally into the lateral ventricles of rats or peripherally to mice. Previously we demonstrated that beta-endorphin given intracerebrally produces anesthesia in rats, a response localized to sites in or adjacent to the inferior third and fourth ventricles. In order to compare the anatomical localization of these two anesthetic responses, we administered baclofen into the inferior or superior lateral or third ventricles, the aqueduct, or fourth ventricle in rats. Although 10 micrograms baclofen infusions into several regions caused loss of the righting reflex, in no case did animals exhibit an unconscious state which satisfied strict criteria of anesthesia. Infusions of 20 micrograms into the inferior third and fourth ventricles elicited seizures followed by a postictal depression. Although unresponsive to some stimuli, these animals showed no impairment in the corneal reflex. Since this dose was often lethal, higher doses not tested. Baclofen, given to mice intraperitoneally at doses of 25, 50, or 75 mg/kg, failed to elicit strictly defined anesthesia, although, to varying degrees, animals exhibited analgesia, loss of the righting reflex, and loss of behavioral responses to loud sounds. Animals continued to show motor responses when handled and retained corneal reflexes. Baclofen does not evoke an unconscious anesthetic state when administered centrally or systemically, emphasizing the need for strict criteria to define general anesthesia and to categorize drugs that promote this state.     

The power and omnipotence of voices: subordination and entrapment by voices and significant others

BACKGROUND: Cognitive therapy for psychotic symptoms often embraces self-evaluative beliefs (e.g. self-worth) but whether and how such beliefs are related to delusions remains uncertain. In previous research we demonstrated that distress arising from voices was linked to beliefs about voices and not voice content alone. In this study we examine whether the relationship with the voice is a paradigm of social relationships in general, using a new framework of social cognition, 'ranking' theory. METHOD: In a sample of 59 voice hearers, measures of power and social rank difference between voice and voice hearer are taken in addition to parallel measures of power and rank in wider social relationships. RESULTS: As predicted, subordination to voices was closely linked to subordination and marginalization in other social relationships. This was not the result of a mood-linked appraisal. Distress arising from voices was linked not to voice characteristics but social and interpersonal cognition. CONCLUSION: This study suggests that the power imbalance between the individual and his persecutor(s) may have origins in an appraisal by the individual of his social rank and sense of group identification and belonging. The results also raise the possibility that the appraisal of voice frequency and volume are the result of the appraisal of voices' rank and power. Theoretical and novel treatment implications are discussed.     

Habituation,sensitization, and infants' responses to motherse speech

Four-month-old infants were tested for their visual responses to infant-directed (ID) speech versus adult-directed (AD) speech in a fixed-trial habituation procedure. In Experiment I, infants looked significantly longer in response to a 4 × 4 checkerboard pattern that was compounded with an ID speech segment than an AD speech segment. Looking times increased significantly between the first and second presentations of the ID speech segment only. In Experiment II, infants looked slightly more during ID than AD trials when the two were alternated from trial to trial. Responding to the first AD speech segment was significantly greater than when it was preceded by ID speech than when it was not, while responding to the first ID speech segment was significantly less when it was preceded by AD speech than when it was not. These findings are discussed in relation to the hypothesized differential arousing properties of ID and AD speech. © 1995 John Wiley & Sons, Inc.     

Temperature-sensitive neurons in the brain stem: Their responses to brain temperature at different ambient temperatures

Summary Unit recordings have been made in the hypothalamus of cats and rabbits under urethane anaesthesia. The final position of each electrode penetration was marked by the ejection of a dye. Techniques used enabled brain temperature and ambient temperature to be controlled.Neurons were found whose mean firing rate was positively or negatively correlated with changes of brain temperature over a range of 4°C. Some of these neurons also responded when ambient temperature over a range of 4°C. Some of these neurons also responded when ambient temperature was raised to 40°C or lowered to 10°C. In four cases, lowering, but not raising, ambient temperature was found to modify the neuron's responses to brain temperature changes. Two forms of modulation were found. In one, the curve relating brain temperature and firing rate was shifted without showing a change in slope (sensitivity). In the other, the slope of curve changed, so that the sensitivity of the neuron to brain temperature was altered. Both types of modulation are consistent with current models of temperature regulation involving receptors in the hypothalamus and in the skin.     

Neuroticism and brain responses to anticipatory fear

Personality is known to influence cognitive and affective functioning as well as the risk of psychiatric disorders. Exploration of the neurobiological correlates of personality traits has the potential to enhance understanding of their significance in development of related psychopathological states. The authors examined the association between individual differences in neuroticism and brain activity in response to threat of electric shocks. Fourteen right-handed healthy men underwent functional MRI during a 5-min experiment that involved repeated presentations of two 30-s alternating conditions. In 1 of these conditions, subjects were told to expect mild but painful electric shocks; there was no possibility of receiving shocks in the other condition. The results revealed that neuroticism correlated positively with the ratings of fear of shock and negatively (indicating suppression) with brain activity from safe to shock conditions in the anterior and posterior cingulate, superior/middle temporal gyrus extending to the hippocampus, precuneus, putamen, thalamus, and middle occipital gyrus. The observations support recent psychophysiological research that has demonstrated reduced processing of pain in subjects with higher levels of neuroticism, especially the anxiety component of this trait.     

Cardiovascular responses to rewarding brain stimulation.

In awake rats, rewarding stimulation of 155 electrodes spread throughout the forebrain, hypothalamus, and midbrain led to heart rate (HR) deceleration at almost all sites. Stimulation of those animals with forebrain electrodes that were fitted with a carotid catheter produced mean arterial pressure increases acompanying the HR changes. The relative latencies of the cardiovascular responses suggested that rewarding stimulation, in some instances at least, may produce a mixture of autonomic effects that rarely if ever occur in the normal waking animal in the absence of such stimulation. The data obtained when the rats with forebrain electrodes were anesthetized indicated that stimulation caused mean arterial pressure to fall and HR either not to change or to decelerate slightly. These differences between data from the same animals under waking and anesthetized conditions caution against premature generalizations concerning the effects of brain stimulation on cardiovascular changes.     

Control of complex motor gestures: orofacial muscle responses to load perturbations of lip during speech

The contribution of ascending afferents to the control of speech movement was evaluated by applying unanticipated loads to the lower lip during the generation of combined upper lip-lower lip speech gestures. To eliminate potential contamination due to anticipation or adaptation, loads were applied randomly on only 10-15% of the trials. Physical characteristics of the perturbations were within the normal range of forces and movements involved in natural lip actions for speech. Compensatory responses in multiple facial muscles and lip movements were observed the first time a load was introduced, and achievement of the multimovement speech goals was never disrupted by these perturbations. Muscle responses were seen in the lower lip muscles, implicating corrective, feedback processes. Additionally, compensatory responses to these lower lip loads were also observed in the independently controlled muscles of the upper lip, reflecting the parallel operation of open-loop, sensorimotor mechanisms. Compensatory responses from both the upper and lower lip muscles were observed with small (1 mm) as well as large (15 mm) perturbations. The latencies of these compensatory responses were not discernible by conventional ensemble averaging. Moreover, responses at latencies of lower brain stem-mediated reflexes (i.e., 10-18 ms) were not apparent with inspection of individual records. Response latencies were determined on individual loaded trials through the use of a computer algorithm that took into account the variability of electromyograms (EMG) among the control trials. These latency measures confirmed the absence of brain stem-mediated responses and yielded response latencies that ranged from 22 to 75 ms. Response latencies appeared to be influenced by the time relation between load onset and the initiation of muscle activation. Examination of muscle activity changes for individual loaded trials revealed complementary variations in the magnitude of responses among multiple muscles contributing to a movement compensation. These observations may have implications for limb movement control if multimovement speech gestures are considered analogous to a limb action requiring coordinated movements around multiple joints. In this context, these speech motor control data might be interpreted to suggest that for complex movements, both corrective feedback and open-loop predictive processes are operating, with the latter involved in the control of coordination among multiple movement subcomponents.     

Regional brain responses to serotonin in major depressive disorder

BACKGROUND: Positron Emission Tomography (PET) studies have reported altered resting regional brain glucose metabolism in mood disorders. This study examines the relationship of such changes to serotonin system abnormalities associated with depression. METHODS: Thirteen male medication free subjects who were inpatients with a DSM-IIIR major depressive disorder and seven healthy male subjects underwent an [18F]-fluorodeoxyglucose (18FDG) PET scan on consecutive days. Three hours prior to 18FDG subjects received single blind placebo or fenfluramine. Comparisons of voxel level regional glucose metabolic rate responses (rCMRglu) between groups in the two states were performed with SPM99. RESULTS: Unlike healthy male subjects who have significant increases in rCMRglu in prefrontal and parietal cortical regions after receiving fenfluramine, depressed male subjects have no significant increases in rCMRglu. CONCLUSIONS: Blunted increases in rCMRglu in response to fenfluramine in prefrontal and parietal cortex are consistent with our previous pilot study and the indoleamine hypothesis of depression. Differences in specific brain regions affected between this study and previous studies may be attributable to gender differences.     

Mindfulness for voices: An experimental analogue study of the effect of manipulating response style to simulated voices in a non-clinical population

Objectives

We aimed to investigate the effects of directly manipulating response style to simulated voice hearing on emotional and cognitive outcomes in a non-clinical population.

Design

A between-subjects design with one independent variable, response style (with two levels: mindful acceptance vs attentional avoidance). The dependent variables were subjective distress and anxiety (primary outcomes) and performance on a sustained attention task (secondary outcomes).

Methods

Participants were randomly assigned to one of two response styles (mindful acceptance vs. attentional avoidance). They completed a computerised attention task (continuous performance task) whilst listening to a simulation of voice hearing. Participants rated their experience of anxiety and distress before and after completing the sustained attention task which was used to measure their accuracy and response times.

Results

One hundred and one participants took part (mindful acceptance (n = 54); attentional avoidance (n = 47)). There were no statistically significant group differences on post-test distress and anxiety scores, correct response rate or response times on the computerised attention task. Participants reported a range of different response styles along the spectrum of avoidance to acceptance, but this had no association with their assigned experimental condition. Adherence to task instructions was therefore low.

Conclusions

We are unable to conclude from this study whether experimentally inducing people to respond to voices under cognitively demanding conditions in an avoidant or accepting way has an impact on their emotional or cognitive outcomes. Further research should focus on the development of more robust and reliable procedures for inducing differences in response style under experimental conditions.