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PubMed2005

Unconscious word-stem completion priming in a mirror-masking paradigm.

The aim of this study was to investigate unconscious priming by the use of a spatial mirror-masking paradigm. Words and nonwords with no under-length letters are mirrored at their horizontal axis. The results are figures of geometric-like forms that contain letters in their upper part. In the three experiments reported in this study, a priming procedure used such mirrored words and nonwords as primes. Participants were ignorant of the nature of the construction of the stimuli. Perceptual reports of the participants revealed that they did not realize that words were hidden in the primes. Nevertheless, they showed priming in all three experiments. Priming effects were replicated with prime-target SOAs of between 1 and 3 s. Functional dissociations were found between ignorant and informed participants. Informed groups showed perceptual and semantic priming, while ignorant groups showed only perceptual priming.

Female↗
PubMed2006

Empathy and the somatotopic auditory mirror system in humans.

How do we understand the actions of other individuals if we can only hear them? Auditory mirror neurons respond both while monkeys perform hand or mouth actions and while they listen to sounds of similar actions . This system might be critical for auditory action understanding and language evolution . Preliminary evidence suggests that a similar system may exist in humans . Using fMRI, we searched for brain areas that respond both during motor execution and when individuals listened to the sound of an action made by the same effector. We show that a left hemispheric temporo-parieto-premotor circuit is activated in both cases, providing evidence for a human auditory mirror system. In the left premotor cortex, a somatotopic pattern of activation was also observed: A dorsal cluster was more involved during listening and execution of hand actions, and a ventral cluster was more involved during listening and execution of mouth actions. Most of this system appears to be multimodal because it also responds to the sight of similar actions. Finally, individuals who scored higher on an empathy scale activated this system more strongly, adding evidence for a possible link between the motor mirror system and empathy.

Acoustic Stimulation↗
PubMed2006

Difference in sensorimotor adaptation to horizontal and vertical mirror distortions during ballistic arm movements.

When learning a novel motor task, the sensorimotor system must develop new strategies to efficiently control the limb(s) involved, and this adaptation appears to be developed through the construction of a behavioral map known as an 'internal model'. A common method to uncover the mechanisms of adaptation and reorganization processes is to expose the system to new environmental conditions, typically by introducing visual or mechanical distortions. The present study investigated the adaptation mechanisms of the human sensorimotor system to horizontal and vertical mirror distortions (HMD and VMD) during the execution of fast goal-directed arm movements. Mirror distortions (MDs) were created by means of virtual visual feedback on a computer screen while the movement was executed on a graphics tablet. Twenty healthy adult participants were recruited and assigned to one of two groups of 10 people each. Tests were divided in two subsequent blocks of five trials. The first block consisted of trials with no mirror distortion (NMD), while the second block was recorded when exposing one group to HMD and the other to VMD. Both MDs resulted in kinematic changes: during the tests with the MDs the participants did not reach the performance level found at the NMD test. Motor performance during HMD appeared to be globally better than during VMD and the adaptation process to VMD appeared to be slower than to HMD, but data interpretation was hampered by large within-participant and between-participant variability. In-depth analyses of the data revealed that most of the motor performance information was contained in the direction of movement. The data supported the idea that the internal model for HMD was already partially built.

Adult↗
PubMedDate not supplied

Development and validation of a home-based, mirrored, gynecologic laparoscopy trainer.

STUDY OBJECTIVE: To develop and evaluate the usefulness of a home-based laparoscopy practice tool in terms of skills acquisition and practice pattern. DESIGN: Six mirrored laparoscopy trainers were designed and built. Participants were enrolled in a prospective randomized controlled trial and performed a series of skills with a video-endoscopic training tower and laparoscopic training box in timed pre- and post-tests over 5 weeks. Control and experimental cohorts practiced skills tests in different settings with different equipment. Data analysis used the t test and Wilcoxon rank-sum test. Analysis of variance/analysis of covariance models were used for independent variables. (Canadian Task Force classification I.) SETTING: Midwestern tertiary care teaching hospital. PARTICIPANTS: Third-year medical students rotating through their obstetrics and gynecology clerkship. INTERVENTIONS: Control cohort participants (n = 13) practiced the skills in the video-endoscopic laboratory while the experimental cohort (n = 13) received mirrored training boxes and practiced at home. MEASUREMENTS AND MAIN RESULTS: Both groups demonstrated significant improvement, with a trend favoring the control group (p = .08). Randomization group and number of practice sessions were significant variables favoring the control group and experimental group, respectively. CONCLUSION: Home-based practice on a mirrored laparoscopy trainer improves hand-eye coordination in inexperienced surgeons and results in more frequent practice.

Adult↗
PubMed2006

Out of time: a possible link between mirror neurons, autism and electromagnetic radiation.

Recent evidence suggests a link between autism and the human mirror neuron system. In this paper, I argue that temporal disruption from the environment may play an important role in the observed mirror neuron dysfunction, leading in turn to the pattern of deficits associated with autism. I suggest that the developing nervous system of an infant may be particularly prone to temporal noise that can interfere with the initial calibration of brain networks such as the mirror neuron system. The most likely source of temporal noise in the environment is artificially generated electromagnetic radiation. To date, there has been little evidence that electromagnetic radiation poses a direct biological hazard. It is clear, however, that time-varying electromagnetic waves have the potential to temporally modulate the nervous system, particularly when populations of neurons are required to act together. This modulation may be completely harmless for the fully developed nervous system of an adult. For an infant, this same temporal disruption might act to severely delay or disrupt vital calibration processes.

Autistic Disorder↗
PubMed2005

Intracisternal administration of mitogen-activated protein kinase inhibitors reduced IL-1beta-induced mirror-image mechanical allodynia in the orofacial area of rats.

The present study investigated the role of central mitogen-activated protein kinases (MAPKs) in interleukin-1beta (IL-1beta)-induced mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on Sprague-Dawley rats. Under pentobarbital sodium anesthesia, a polyethylene tube was implanted in the subcutaneous area of one vibrissa pad, which enabled us to inject IL-1beta. For an intracisternal injection, each anesthetized rat was mounted on a stereotaxic frame and a polyethylene tube was implanted. Animals were given a recovery time of at least 72 h from surgery. After a subcutaneous administration of 0.01, 0.1, 1, or 10 pg of IL-1beta, we examined the face withdrawal behavioral responses produced by 10 successive trials of air puffs ipsilateral or contralateral to the IL-1beta injection site. Normal animals did not respond to pressure less than 40 psi. The thresholds of air puffs ipsilateral and contralateral to the IL-1beta injection site were significantly lower in the IL-1beta-treated group, compared with the vehicle-treated group. The decrease in the threshold of air puffs appeared 10 min after an IL-1beta injection and persisted for over 3h. Intracisternal pretreatment with PD98059, a p44/42 MAPK inhibitor, or SB203580, a p38 MAPK inhibitor, significantly reduced the decrease in the threshold of air puffs ipsilateral to the IL-1beta injection site produced by 10 pg of IL-1beta. IL-1beta-induced mirror-image mechanical allodynia was also reduced significantly by intracisternal pretreatment with both PD98059 and SB203580. These results indicate that central MAPK pathways mediate IL-1beta-induced mirror-image mechanical allodynia in the orofacial area.

Afferent Pathways↗
PubMed2003

"Mirror-lake" serial relationship of electrocardiographic and biochemical indices for the detection of reperfusion and the prediction of salvage in patients with acute myocardial infarction.

BACKGROUND: Serial observations of biochemical markers in the blood and bioelectric markers on the electrocardiogram (ECG) have been used to evaluate the effectiveness of reperfusion therapy in acute myocardial infarction (AMI). This study presents a combined method for clinical use, based on the "mirror-lake" tendency of the serial changes in these markers. METHODS: Consecutive thrombolytic-treated patients with AMI (n = 43) had ST-segment monitoring (Mortara Eli 100) and frequent serum sampling of myoglobin (MG) concentration. Their acutely predicted and finally estimated AMI sizes and myocardial salvage extents were calculated from the 12-lead standard ECG. Patients having 2 positive reperfusion indices (ST resolution at least 50%, and an increase in MG at least 2.4 fold) at 2 hours after initiation of thrombolytic therapy were considered the "complete reperfusion" group, and patients with discordant or 2 negative reperfusion indices after 2 hours of thrombolytic therapy were considered the "limited reperfusion" group. RESULTS: Patients with complete reperfusion (n = 22) versus patients with limited reperfusion (n = 21) had +12% versus -1% myocardial salvage (P <.0001). The serial changes in the ST segment mirrored the serial changes in the MG concentration, and the rates of increase in MG correlated with the rates of resolution of the ST-segment elevation. CONCLUSION: Myocardial salvage (measured by ECG indices) is greatest when an early increase in serum MG is "mirrored" by early resolution of ST-segment elevation.

Aged↗
PubMed1976

Sinistrad mirror writing and reading after brain concussion in a bi-systemic (oriento-occidental) polyglot.

The problem of mirror writing and reading is discussed in the light of a clinical case, where this disturbance appeared after an apparently minor head injury. Mirror writing and reading in this polyglot individual affected only the sinistrad (Hebrew) writing and reading system, leaving the dextrad (Latin) system unimpaired. This disturbance appeared together with dyscalculia, left-right disorientation and slight temporal confusion, suggestive of parieto-occipital lobe pathology. The clinical picture also showed apparently "conversional" traits, such as are sometimes seen in incomplete parietal lobe syndromes. The relevant literature is reviewed and patho-physiological mechanisms of mirror reversal are discussed.

Brain Concussion↗
PubMed2004

The mirror neuron system and action recognition.

Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been also found. In humans, through an fMRI study, it has been shown that the observation of actions performed with the hand, the mouth and the foot leads to the activation of different sectors of Broca's area and premotor cortex, according to the effector involved in the observed action, following a somatotopic pattern which resembles the classical motor cortex homunculus. These results strongly support the existence of an execution-observation matching system (mirror neuron system). It has been proposed that this system is involved in action recognition. Experimental evidence in favor of this hypothesis both in the monkey and humans are shortly reviewed.

Animals↗
PubMed2003

Choral speech: the amelioration of stuttering via imitation and the mirror neuronal system.

'Choral' speech or speaking in unison is an undeniable phenomenon that immediately induces fluent and natural sounding speech in almost all people who stutter, regardless of linguistic content, situation or audience size. We propose that the choral speech effect is a form direct imitation, a primitive and innate human capacity that is possibly mediated at the neuronal level by 'mirror neurons'. Mirror systems link observations and actions are considered by many to be a neuronal substrate for gestural language acquisition, as well as forming the basis for many learned behaviors, thus possibly playing a vital role in ensuring survival during infancy. The engagement of these systems allows gestural sequences, including speech, to be fluently replicated. Choral speech and its permutations use the capacity for fluent imitation in people who stutter via a 'loose' gestural matching system in which gestures in the external signal possessing cues found in the intended utterance can serve as stuttering inhibitors. We suggest implementing these innate gestural mirrors to provide immediate and effective amelioration for stuttering.

Animals↗
PubMed1999

Roots of brain specializations: preferential left-eye use during mirror-image inspection in six species of teleost fish.

It has recently been reported that predator inspection is more likely to occur when a companion (i.e. the mirror image of the test animal) is visible on the left rather than on the right side of mosquitofish Gambusia holbrooki. This very unexpected outcome could be consistent with the hypothesis of a preferential use of the right eye during sustained fixation of a predator as well as of a preferential use of the left eye during fixation of conspecifics. We measured the time spent in monocular viewing during inspection of their own mirror images in females of six species of fish, belonging to different families-G. holbrooki, Xenotoca eiseni, Phoxinus phoxinus, Pterophyllum scalare, Xenopoecilus sarasinorun, and Trichogaster trichopterus. Results revealed a consistent left-eye preference during sustained fixation in all of the five species. Males of G. holbrooki, which do not normally show any social behaviour, did not exhibit any eye preferences during mirror-image inspection. We found, however, that they could be induced to manifest a left-eye preference, likewise females, if tested soon after capture, when some affiliative tendencies can be observed. These findings add to current evidence in a variety of vertebrate species for preferential involvement of structures located in the right side of the brain in response to the viewing of conspecifics.

Animals↗
PubMed2003

Phased mirror tracing outcomes correlate with several hemisphericity measures.

Recently, subjects, separated into two large groups by the Dichotic Deafness Test (DDT), a new brain laterality measure. These were significantly correlated with groups separated by two preference-based hemisphericity-type questionnaires, the Preference Questionnaire (PrefQ) and Polarity Questionnaire (PolQ). Here, Mirror-Tracing, another potential biophysical measure of hemisphericity earlier reported to be weakly correlated with laterality, was tested using 171 subjects, the DDT, and both questionnaires. No correlations between the DDT, PrefQ, and PolQ separation methods and Mirror Tracing outcomes were found until individuals identified as having left brain affect were removed from the population. Then, robust correlations appeared for the remaining right-affect subjects alone (n=82). These correlations became even higher when the left brain affect subjects that had been removed (n=89) were "phase corrected" from a contralateral to an ipsilateral connectivity for motor dominance and then returned to the sample (n=171). These Phased Mirror-Tracing (PMT) outcomes were also significantly correlated with 10 of the 11 statements of the PolQ. Thus, PMT joins the DDT as a second performance-based measure of laterality whose outcomes significantly correlated with those of preference-based hemisphericity questionnaires.

Adult↗
PubMed2001

Mirror image processing in three marine mammal species: killer whales (Orcinus orca), false killer whales (Pseudorca crassidens) and California sea lions (Zalophus californianus).

Dolphins (Tursiops truncatus) and their relatives might be expected to show mirror-induced contingency checking, a prerequisite to self-recognition, because of their high brain development, their complex social life and their demonstrated abilities in bodily imitation. A study of killer whales'(Orcinus orca) behaviour in front of a mirror is presented, including a mark test. Shorter investigations of mirror behaviour are also described in false killer whales (Pseudorca crassidens) and California sea lions (Zalophus californianus). Contingency checking was present in killer whales and possibly also in false killer whales, but no clear contingency checking was observed in sea lions. The mark test on killer whales suggested that the marked animal anticipated that its image would look different. This study shows that killer whales and false killer whales, like bottlenose dolphins, appear to possess the cognitive abilities required for self-recognition.

Journal Article↗
PubMed1998

Accurate binaural mirroring of spontaneous otoacoustic emissions suggests influence of time-locking in medial efferents.

Spontaneous otoacoustic emissions (SOAEs) of nearly identical acoustic frequency in both ears are a common observation, but it is unknown if this binaural mirroring effect is random, artefactual, genetic, developmental, or of other origin. The available raw data of all human SOAE surveys were pooled, and the intervals of all possible binaural emission pairs (N = 9555) were listed according to size on the Cent-scale (1 Cent = 1/100 semitone = 1/1200 octave). Statistical analysis showed (1) a slight broad-band mirroring in the 0-100 Cent range (P < 0.05), and (2) a strong narrow-band mirroring (NBM) in the 0-20 Cent range (P < 0.001). Negative results in a detailed SOAE cluster detection program excluded experimental artefacts as causes of NBM. Analysis of the large subgroup of twin data excluded genetic and intrauterine developmental causes. Systemic developmental causes are unrealistic, as 20 Cent corresponds to only approximately 80 microm on the cochlear map. Analysis of infant data indicated that the effect may be introduced after birth by secondary factors. Interaural crosstalk was examined but had to be rejected. It is suggested that bilaterally spreading period information in the medial olivocochlear system influences outer hair cells of the same best frequency in both ears very similarly. Evidence concerning possible effects on electromotility is discussed, and experimental tests are proposed.

Artifacts↗
PubMed2000

Simple cylindrical ion mirror with three elements.

A new cylindrical ion mirror has been designed to create an electric field that is non-linear or curved along the flight path axis for general-purpose time-of-flight mass spectrometers. The inclusion of one or two grids is found to improve the radial field homogeneity especially around the aperture. Only three cylindrical electrodes are used in the design. Changing the electrode dimensions and voltages affects the electric field distribution. Once the electrode dimensions are fixed, there are only two adjustable parameters for achieving optimum nonlinear electric field shape. Resolving powers of 7,000 and 16,100 have been achieved with kinetic energy variations of 34 and 10.5%, respectively. Simulations show that the electric field homogeneity in the radial direction enables the use of ion beam diameters up to 15 mm with only modest loss of resolving power. Increasing the mirror diameter could further increase the practical ion beam diameter. This article details the electric field distribution within the cylindrical mirror in both axial and radial directions. The voltages of the middle and rear electrodes affect the resolving power and the kinetic energy range over which focus can be achieved. The predicted arrival time spread for a single m/z value is narrower than that caused by the turn-around time of ions in a gas-phase ion source. In this case, the broad energy range over which good focus is achieved enables the use of higher extraction fields for turn-around time reduction.

Chemical Phenomena↗
PubMed2003

Activations related to "mirror" and "canonical" neurones in the human brain: an fMRI study.

In the macaque monkey ventral premotor cortex (F5), "canonical neurones" are active when the monkey observes an object and when the monkey grasps that object. In the same area, "mirror neurones" fire both when the monkey observes another monkey grasping an object and when the monkey grasps that object. We used event-related fMRI to investigate where in the human brain activation can be found that reflects both canonical and mirror neuronal activity. There was activation in the intraparietal and ventral limbs of the precentral sulcus when subjects observed objects and when they executed movements in response to the objects (canonical neurones). There was activation in the dorsal premotor cortex, the intraparietal cortex, the parietal operculum (SII), and the superior temporal sulcus when subjects observed gestures (mirror neurones). Finally, activations in the ventral premotor cortex and inferior frontal gyrus (area 44) were found when subjects imitated gestures and executed movements in response to objects. We suggest that in the human brain, the ventral limb of the precentral sulcus may form part of the area designated F5 in the macaque monkey. It is possible that area 44 forms an anterior part of F5, though anatomical studies suggest that it may be a transitional area between the premotor and prefrontal cortices.

Adult↗
PubMed2003

Lead-tin mirror formation from mixtures of red lead and tin sulphide.

Mosaic gold, tin (IV) sulphide, is a yellow pigment which was known in antiquity but whose use was superseded by other more easily obtainable yellow pigments by the Renaissance. The identification of mosaic gold residues in a burnished golden mirror decoration on a XIIIth Century Spanish polychrome statue is important in that the first reference to the use of mosaic gold in the European literature dates from the XIVth Century, although the use of this material in China had been recorded some time before. In this paper, Raman spectroscopy, XRD and SEM are used in the analysis of the conditions required for the formation of golden mirrors using tin (IV) sulphide in admixture with dilead (II) lead (IV) tetroxide and mercury (II) sulphide. From these results, it is proposed that the major reactions are the reduction of Sn(IV) to Sn(0) with the accompanying oxidation of lead (II) oxide to lead (IV) oxide and the formation of lead (0) and lead (II) sulphide. From these results it was possible to explain the process of creation of the golden mirror from mosaic gold in the XIIIth Century.

Lead↗
PubMed1984

The effects of mirror confrontation on self-estimation of body dimensions in anorexia nervosa, bulimia and two control groups.

Using an apparatus which provides a continuous horizontal slit of light of variable length, self-estimations of 4 body widths were carried out before and after a mirror confrontation procedure on 4 groups of young female subjects--anorexic, bulimic, emotionally disturbed and normal. The results confirm that anorexic subjects overestimate body size, although in this study the hip diameter was frequently underestimated. Bulimic and emotionally disturbed subjects overestimate to much the same degree as anorexics, whereas normal subjects are remarkably accurate with the exception of the head width. Mirror confrontation resulted in reduced estimations in the majority of subjects, but significant differences were found in the degree to which this occurred in the 4 groups; anorexic subjects showed the greatest change and normal subjects the least. This relative instability of the anorexic subject's body image cannot be explained simply on the basis of a self-correcting experience, as many estimations which were initially below actual width were even lower on re-testing. In the anorexic and bulimic groups a significant correlation was found between the degree of overestimation after mirror confrontation and progress in treatment, as measured on a specially devised rating scale. Possible explanations for these findings and their diagnostic and prognostic implications are discussed.

Adult↗