Women process multisensory emotion expressions more efficiently than men.

Despite claims in the popular press, experiments investigating whether female are more efficient than male observers at processing expression of emotions produced inconsistent findings. In the present study, participants were asked to categorize fear and disgust expressions displayed auditorily, visually, or audio-visually. Results revealed an advantage of women in all the conditions of stimulus presentation. We also observed more nonlinear probabilistic summation in the bimodal conditions in female than male observers, indicating greater neural integration of different sensory-emotional informations. These findings indicate robust differences between genders in the multisensory perception of emotion expression.

Electrophysiological study of auditory development.

Cortical auditory evoked potential (CAEP) testing, a non-invasive technique, is widely employed to study auditory brain development. The aim of this study was to investigate the development of the auditory electrophysiological signal without addressing specific abilities such as speech or music discrimination. We were interested in the temporal and spectral domains of conventional auditory evoked potentials. We analyzed cerebral responses to auditory stimulation (broadband noises) in 40 infants and children (1 month to 5 years 6 months) and 10 adults using high-density electrophysiological recording. We hypothesized that the adult auditory response has precursors that can be identified in infant and child responses. Results confirm that complex adult CAEP responses and spectral activity patterns appear after 5 years, showing decreased involvement of lower frequencies and increased involvement of higher frequencies. In addition, time-locked response to stimulus and event-related spectral pertubation across frequencies revealed alpha and beta band contributions to the CAEP of infants and toddlers before mutation to the beta and gamma band activity of the adult response. A detailed analysis of electrophysiological responses to a perceptual stimulation revealed general development patterns and developmental precursors of the adult response.

Auditory processing in a patient with a unilateral lesion of the inferior colliculus.

The role of the inferior colliculus (IC) in human auditory processing is still poorly understood. We report here the results obtained with a 12-year-old boy (FX) who suffered a very circumscribed lesion of the right IC without additional neurological damage. The child underwent an extensive battery of psychophysical hearing tests. Results revealed normal peripheral auditory functioning, bilaterally. Furthermore, masking-level differences and frequency-pattern recognition were normal for each ear. When the right ear was stimulated, behavioural tests assessing central auditory processing yielded normal results. However, when the left ear was stimulated, speech recognition in the presence of a competing ipsilateral signal and duration-pattern recognition were impaired. Similarly, performance on two dichotic speech recognition tests was poor when the target stimulus was presented in the left and the competing signal in the right ear. Finally, sound-source localization in space was deficient for speakers located on the side contralateral to the lesion. The pattern of results suggests that auditory functions such as recognition of low-redundancy speech presented monaurally, recognition of tone duration patterns, binaural separation and integration, as well as sound-source localization in space, depend on the integrity of the bilateral auditory pathways at the IC level.

Hyperbaric oxygen for children with cerebral palsy: a randomised multicentre trial. HBO-CP Research Group.

BACKGROUND: The use of hyperbaric oxygen for children with cerebral palsy has spread worldwide, despite little scientific evidence of efficacy. We did a randomised trial to assess the efficacy and side-effects of this form of therapy in children with cerebral palsy. METHODS: 111 children with cerebral palsy aged 3-12 years were randomly assigned hyperbaric oxygen (n=57) or slightly pressurised room air (n=54). All children received 40 treatments over 2 months. Hyperbaric oxygen treatment was 1 h in 100% oxygen at 1.75 atmospheres absolute (ATA); children on slightly pressurised air received air at 1.3 ATA (the lowest pressure at which pressure can be felt, thereby ensuring the maintenance of masking). The main outcome measure was gross motor function. Secondary outcomes included performance in activities of daily living, attention, working memory, and speech. FINDINGS: For all outcomes, both groups improved over the course of the study, but without any difference between the two treatments. The score on the global gross motor function measure increased by 3.0% in the children on slightly pressurised air and 2.9% in those on hyperbaric oxygen. The mean difference between treatments was -0.40 (95% CI -1.69 to 0.90, p=0.544). Other changes were seen in speech, attention, memory, and functional skills. Ear problems occurred in 27 children treated by hyperbaric oxygen and in 15 treated with hyperbaric air (p=0.004). INTERPRETATION: In this study, hyperbaric oxygen did not improve the condition of children with cerebral palsy compared with slightly pressurised air. The improvement seen in both groups for all dimensions tested deserves further consideration.

Localization of moving sounds by hemispherectomized subjects.

The objective of the present study was to evaluate the localization abilities of the residual auditory structures in hemispherectomized subjects (Hs) during monaural and binaural listening. The monaural stimulus presentations were aimed at evaluating the relative contribution of crossed and uncrossed afferents to the perception of a moving auditory target. Three Hs and ten control subjects (Cs) were asked to localize a simulated moving sound source of fixed intensity presented on the horizontal plane. The moving stimulus was delivered randomly through 16 loudspeakers which were mounted at 10 degree intervals on a calibrated perimeter frame located inside an anechoic chamber. The apparent movement traveled in either direction over three different distances in the peri-central and lateral fields. Listeners had to report the movement trajectory by pointing with the index finger where they thought the beginning and the ending of the stimulus occurred on the perimeter. Hs were less accurate than Cs in the binaural condition, suggesting that the residual hemisphere and/or subcortical structures are not by themselves as efficient to accurately analyze motion as when the two hemispheres are present. In the monaural testing conditions, most of the subjects showed a prominent lateral displacement of the perceived localization towards the functional ear. However, all subjects, particularly the Cs, were able to perceive different lengths of trajectories although they did not discriminate the direction of the motion. For the Hs, the pattern of performance differed for each subject. One right Hs was more accurate for localizing the sources delivered on the side of the functional ear when relying on crossed-input. A left Hs was able to detect the appropriate side of the moving sound source even when it was presented on the side to the obstructed ear. The other left Hs who had developed normally until the age of 5, was more affected by the hemidecortication in both the binaural and the monaural listening conditions. These findings suggest that it is possible to detect moving sounds in the absence of binaural cues and without the integration carried out by both cerebral hemispheres. However it appears that interaural disparities and bihemispheric integration are required for finer analysis.

Psychological stress and psoriasis: experimental and prospective correlational studies.

Using a dismantled time-series design, 18 subjects with psoriasis symptoms on the scalp were randomly assigned to four groups and six dropped out: meditation (N = 5); meditation and imagery (N = 4); waiting list (N = 5); and no treatment control group (N = 4). Treatment lasted 12 weeks, with 4 weeks pre- and post-baseline periods. An assessment control group was also used during baseline periods (N = 4). The severity of psoriasis symptoms was reliably rated by dermatologists. A time-series multivariate regression analysis controlling for extraneous factors influencing psoriasis symptoms, revealed a significant difference between the mean psoriasis ratings of treatment and control groups after treatment (partial r = 0.30, p less than 0.01). No additional impact was associated with the use of the imagery technique (partial r = 0.06, p less than 0.05). Four subjects in the treatment groups, two in each condition, succeeded in clinically improving their psoriasis symptoms and none deteriorated. The practice of meditation may be clinically effective for some patients in reducing their psoriasis symptoms. For one of the control groups, the relation between psychological stress and psoriasis was examined prospectively over a period of 20 weeks using standardized measures. A time-series multivariate statistical method indicated an average positive correlation between the severity of psoriasis symptoms and psychological distress (partial r = 0.31, p less than 0.01) and the impact of adverse life events (partial r = 0.23, p less than 0.05); there were, however, important individual differences. Stress reduction techniques can thus be regarded as part of the treatment offered to some patients suffering from psoriasis.

Intracerebral influences on the microstructure of receptive fields of cat visual cortex.

Effects of electrical stimulation of the basal ganglia (caudate nucleus and putamen) and cortex (gyrus proreus and compositus) on the receptive fields and response properties of units in the visual cortex of cats were assessed using single lines, double lines and multiple lines (gratings). In the single line experiment caudate stimulation, significantly increased the spontaneous activity, optimal firing rate and receptive field size of visual cortex neurons whereas putamen stimulation decreased these parameters. Stimulation of gyrus proreus enhanced, while that of gyrus compositus diminished optimal firing rate without affecting spontaneous activity; in addition, stimulation of ipsilateral proreus and compositus increased the receptive field size whereas their contralateral homologues decreased it. In the double line experiment, proreus and caudate stimulation increased the magnitude of the facilitatory effect of progressive separation of the lines over certain ranges whereas compositus and putamen stimulation increased the inhibitory influences. Orientation selectivity and spatial frequency tuning characteristics were unaffected by the electrical stimulation of any of the four sites. Thus three categories of network properties were delineated: those characterized by remaining invariant to any cerebral stimulation; those characterized by overall activation as by basal ganglia stimulation; and those characterized as interactive which were responsive especially to cortical stimulation.

A recording procedure for chronic microelectrodes in the paralyzed cat.

A method is described for repeated recording sessions of cortical thalamic units in the unanaesthetized but paralyzed animal. Because the recording chamber is miniaturized, it is well tolerated by the subject between sessions. The system also permits painless and stable immobilization of the head without the use of earbars, avoiding surgical preparation during the actual recording sessions and allowing long periods of recording. Between sessions the animals always display normal behavior.