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PubMed2005

Development of a universal ellipsoidal mirror device for fluorescence detected circular dichroism: elimination of polarization artifacts.

We have developed an ellipsoidal mirror fluorescence detected circular dichroism (FDCD) device with enhanced detection sensitivity that eliminates the polarization artifact; this is applicable to samples with strongly polarized fluorescence. The device, JASCO FDCD465, has an ellipsoidal mirror structure with a framework consisting of three mirrors (one elliptical and two plane mirrors) that maximally collects light in the FDCD. All assemblies on the device including the ellipsoidal mirror, cylindrical cell, and photomultiplier tube (PMT) are aligned on the chamber-fitting sample mount as an attachment compatible with a standard CD spectropolarimeter. The new FDCD465 device eliminates the polarization artifact caused by anisotropic distribution of the emitted light. It represents a convenient, reliable, and sensitive FDCD attachment to the JASCO J-800 CD spectrometer series that can be used under both isotropic and photoselected conditions.

Artifacts↗
PubMed1973

Schedule-induced mirror responding in the pigeon.

Two pigeons that were previously exposed to a multiple schedule of reinforcement in the presence of a stuffed and a live pigeon, and two of three naive pigeons, responded on a mirror during exposure to multiple fixed-ratio, fixed-ratio schedules of reinforcement for key pecking. Both the topography and temporal pattern of mirror responding were comparable to schedule-induced "attack" on live and stuffed targets. Rate of target responding was reduced when either the mirror was covered with paper or when the multiple schedule was removed. A reversal in the relationship between reinforcement schedules and discriminative stimuli demonstrated that mirror responding was controlled by the stimulus correlated with the higher fixed-ratio schedule. With one component of the multiple schedule held constant at fixed ratio 25 and the ratio requirement of the other component varying from 25 to 150, there was an inverted U-shaped relationship between rate of mirror responding and fixed-ratio schedule in the varied component. As in Flory's study (1969b) there was an inverted U-shaped relationship between target responding and inter-food intervals. The combined results of these studies suggest that the relationship between rate of target responding and reinforcement schedules is controlled primarily by the inter-food intervals resulting from the schedules.

Journal Article↗
PubMed1992

Mirror training in three dimensions for dental students.

Dental students have significantly improved skills of indirect vision following mirror exercises in two dimensions. The objective of this study was to assess whether freshmen improved these skills after mirror training in three dimensions. A pretest was given to 60 subjects, maneuvering a handpiece-shaped probe through a brass block maze. Total time, error time, and total errors were recorded for each of three perceptually different mirror positions. Subjects were then randomly divided into two groups. Group A participated in 2 training sessions; Group B (a control) received no training. Both groups then performed a posttest. Transformed time scores examined by analysis of variance indicated a significant difference for total time between Groups A and B at posttest at each mirror position. For error time, Groups A and B were significantly different at posttest at Positions 2 and 3. For total errors, groups were significantly different at posttest at Mirror Position 3 only. Indirect vision skills improved significantly with training in three dimensions.

Dental Equipment↗
PubMed2002

Effect of teaching with mirrors on body image and locus of control in women college ballet dancers.

This preliminary study assessed the effect of mirrors in dance instruction on body image and locus of control of women college ballet dancers. With the same instructor in two beginning ballet classes 8 women were taught using mirrors and 13 women were taught without mirrors. Subjects completed the Cash 69-item Multidimensional Body-Self Relations Questionnaire, and the 40-item Adult Nowicki-Strickland Locus of Control Scale during the first and last classes of a 14-wk. semester. Body-areas Satisfaction increased for the nonmirror class yet decreased for the class taught with mirrors. For the nonmirror class, there were significant increases in Appearance Orientation and Externality. Analysis suggested that the use of a mirror in the teaching of ballet may be an element which contributes to the low body-image scores of the 21 women ballet dancers. Replication with a much larger sample is required to draw conclusions.

Adult↗
PubMed2004

Mirror vision: perceived size and perceived distance of virtual images.

We investigated spatial perception of virtual images that were produced by convex and plane mirrors. In Experiment 1, 36 subjects reproduced both the perceived size and the perceived distance of virtual images for five targets that had been placed at a real distance of 10 or 20 m. In Experiment 2, 30 subjects verbally judged both the perceived size and the perceived distance of virtual images for five targets that were placed at each of five real distances of 2.5-45 m. In both experiments, the subjects received objective-size and objective-distance instructions. The results were that (1) size constancy was attained for a distance of up to 45 m, (2) distance was readily discriminated within this distance range, although virtual images produced by the mirror of strong curvature were judged to be farther away than those produced by the mirrors of less curvature, and (3) the ratio of perceived size to perceived distance was described as a power function of visual angle, and the ratio for the convex mirror was larger than that for the plane mirror. We compared the taking-into-account model and the direct perception model on the basis of a correlation analysis for proximal, virtual, and real levels of the stimuli. The taking-into-account model, which assumes that visual angle is transformed into perceived size by taking perceived distance into account, was supported by an analysis for the proximal level of stimuli. The direct perception model, which assumes that there is no inferential process between perceived size and perceived distance, was partially supported by an analysis for the distal level of the stimuli.

Adult↗
PubMed1989

Mirror reversal by blind subjects in cutaneous perception and motor production of letters and numbers.

A letter drawn on the forehead is often perceived as its mirror reversal. Similarly, people produce mirror reversals when asked to write a letter on the underside of a table at which they are sitting. We varied the orientation and position of the stimulated or inscribed surface, and found several examples of these two mirror-reversal phenomena in blind subjects (who had no, or very little, visual experience), as well as in sighted subjects. Furthermore, the mirror-reversal rate of the two groups of subjects as a function of orientation and position of the surface was highly correlated. Thus, the mirror-reversal phenomena should be attributed to a nonvisual, spatial cognitive scheme that is perhaps shared by sighted and blind subjects.

Adult↗
PubMed1994

Reflections of the mirror effect for item and associative recognition.

In five experiments, participants studied pairs of words and yes/no recognition memory for both item and associative information was tested. Two stimulus manipulations, nouns versus nonnouns and high versus low word concreteness, produced the mirror effect for both item and associative recognition. The mirror effect was reflected in both measures of accuracy and response latency. A word frequency manipulation, however, produced the mirror effect only for item recognition. Two additional experiments showed that the mirror effect could also be obtained between nouns and nonnouns and between high and low concrete words for associative recognition in a forced-choice recognition procedure. The results extend the generality of the mirror effect to measures of response latency and to associative recognition and also suggest that similar retrieval and decision processes underlie recognition of item and associative information.

Humans↗
PubMed2002

Mirror syndrome. A case report.

BACKGROUND: Water retention in a pregnant woman can mirror fetal hydropic changes. This clinical presentation has been named "mirror syndrome." Awareness of the syndrome is important due to the associated fetal and maternal risks. CASE: A 26-year-old woman, gravida 3, para 1011, presented at 31 weeks' gestation with significant edema and a 7-km weight gain in one week. Sonographic evaluation revealed hydramnios and fetal ascites. Maternal workup was negative for preeclampsia, diabetes, or cardiac or renal dysfunction. A workup for nonimmune hydrops was also negative. Over the next three days there was progression of maternal edema. With diagnosis of mirror syndrome, the decision for delivery was made. Both neonate and mother subsequently did well, with normalization of ascites and edema, respectively. CONCLUSION: Our case, along with 19 reviewed in the literature, reiterate the features of mirror syndrome and provide an opportunity to dispel some of the misconceptions in the literature. The condition is frequently mistaken for preeclampsia, although distinguishing characteristics can be identified. Mirror syndrome is a manifestation of extremely severe fetal hydrops. When the specific cause of fetal hydrops cannot be identified and corrected, immediate delivery is necessary in order to avoid fetal death and maternal complications.

Adult↗
PubMedDate not supplied

[Mirror writing secondary to left parietal-occipital infarction].

INTRODUCTION: Mirror writing is a rare disorder in which the patient's handwriting is done backwards and a mirror is needed to be able to read it. Although mirror writing presents both spontaneously and pathologically, it is mainly due to cerebrovascular lesions in the dominant hemisphere. CASE REPORT: A right-handed 62-year-old female who, following a left parietal-occipital infarction, evidenced by computerized tomography scanning, developed mirror writing with the left hand associated with mnemonic, gnosic and praxic disorders. The symptoms continued for a year after the episode. CONCLUSIONS: Mirror writing and other associated disorders are a consequence of a dysfunction of the left parietal-occipital lobe and the optic thalamus on the same side.

Cerebral Infarction↗
PubMed1992

The utilization of a temporal mirror coating on the back surface of the lens as a field enhancement device.

A 37-year-old male had a right homonymous hemianopia due to trauma. During his initial low vision assessment, a small clip-on mirror was dispensed to help him compensate for his field loss. At follow-up, he reported satisfaction with the mirror. He also reported that novelty "look behind you" sunglasses were beneficial to him and less conspicuous than the clip-on mirror. He requested temporal mirror coating on otherwise clear lenses so that he could utilize the glasses at night or on cloudy days. We fabricated this for him and also mounted a small mirror nasally within the vertex distance behind his frame. The fabrication of the two devices will be discussed as well as a comparison of these three field enhancement devices.

Adult↗
PubMed2004

Spatiotemporal analysis of neuromagnetic activation associated with mirror reading.

Our previous report has confirmed that visually presented words can elicit neuromagnetic activities from the visual cortex, angular gyrus and Broca's area. It is not clear how the words are visuospatially transformed and recognized by the human brain. Mirror reading is characterized by reading which runs in the opposite direction to normal reading, with reversals of letters. It would be very interesting to find out if there are any neuromagnetic differences between the mirror reading and normal reading. Four right-handed healthy adults have been studied with a whole cortex Magnetoencephalography (MEG) system. The stimuli consisted of eight normal oriented words and eight inverted exclamation mark section "reversed words" (mirror-image of the words). All stimuli were randomly presented on the screen in front of the subjects using DirectX. MEG data were analyzed using both single dipole modeling and synthetic aperture magnetometry (SAM). Four responses to the reversed words were identified in all four subjects. In comparison to the normally oriented words, the reversed words elicited a stronger response at a latency of 248+/-6 ms. SAM results indicated that the reversed words invoked strong activations in the left and right parietal cortices but the normally oriented words did not. The mirror reading elicited one magnetic response which is different from that of the normal reading. The difference between the mirror reading and the normal reading in terms of neuromagnetic activation may reflect the development of novel representations for reversed words.

Adult↗
PubMed1991

Laryngeal examination: a comparison of mirror examination with a rigid lens system.

Indirect mirror laryngoscopy is the standard screening examination used in patients with complaints referable to the larynx and upper aerodigestive tract. The purpose of this study was to prospectively evaluate, in 100 patients, the diagnostic accuracy and examination success rate of indirect laryngoscopy versus a rigid rod examination. Fifty-two percent of mirror examinations were successful as were 83% of rod exams. This was a significant difference in success rate. From the 29 patients who underwent direct laryngoscopy, one false negative and one false positive mirror examination and one false positive rod examination were found. We conclude that the mirror is a useful screening tool so long as strict examination criteria are used. The rigid rod adds further diagnostic information in those patients who cannot be evaluated with a mirror.

Equipment Design↗
PubMed1990

Do infants use their own images to locate objects reflected in a mirror?

The ability of infants to locate a toy from a mirror reflection was investigated in 3 experiments. In the first, it was found that a minority of 22-month-old infants turned to locate the toy that was the source of the reflection, and that localization of the toy occurred regardless of whether the infants' own image was visible in the mirror. The results of 2 further experiments indicated that younger infants aged 14 and 18 months rarely use mirror information to locate a toy. When they do so, they also turn whether or not images of themselves are visible. It is concluded that tasks involving the localization of objects or events from mirror images are not direct indices of self-recognition. Rather, they indicate the skill of infants in using the mirror as a perceptual tool.

Arousal↗
PubMed1989

[The mirror as a possibility of participation in routine gynecologic examination: effects on the psychological status of the female].

The effect of active participation by means of a hand-mirror during gynecological examination was investigated in that three groups were formed: one that wanted and got the mirror, one that wanted the mirror but was not given it and thirdly refusers. The mirror leads to significantly greater satisfaction, which however does not override preexisting attitudes concerning one's body and sexuality as well as the image of the doctor. In that respect acceptance or refusal of the mirror reflects in some ways the open-mindedness or conservatism of the patients.

Body Image↗
PubMed1980

The observed image velocity of a stationary target reflected by a rotating plane mirror.

An equation is presented describing the angular velocity of an image, viewed by an observer when a plane mirror is undergoing angular velocity. The image velocity is determined at the observer's entrance pupil. An expression to determine the size of the mirror aperture for a given exposure time is also presented. The results indicate that, in general, the image velocity is not constant nor twice the mirror velocity, as is usually assumed. Also, if the mirror extends to an equal length on each side of its axis of rotation, then the time in which the image appears to travel from the mirror's edge to the axis of rotation does not equal the time in which it appears to travel from the axis to the other edge.

Humans↗
PubMed1995

[Mirror movements observed in patients skilled in playing the piano--symptomatological study].

We investigated mirror movements observed in two patients skilled in playing the piano and compared these symptoms with those reported in patients associated with frontal lobe, corpus callosum or cervical cord lesion. We found the following common features in our two patients: 1) mirror movements were observed during skilled finger movements such as playing the piano, 2) these were observed in distal parts of the bilateral upper extremities, 3) contralateral imitative associated movements were seen concomitantly, 4) frontal lobe symptoms and callosal disconnection syndrome were not seen, 5) both patients recalled having mirror movements in their infancy, and one had family history. These characteristics of mirror movements in our patients were similar to those in patients associated with cervical cord lesion, but were different from those in patients associated with frontal lobe or corpus callosum lesion. It is suggested that abnormal pathways in the pyramidal tract or cervical cord lesion elicited mirror movements in our patients.

Adult↗
PubMed2004

Mirror writing, left-handedness, and leftward scripts.

This minireview concerns a new observation on mirror writing. An uncommon form of writing, mirror writing is seen among healthy individuals, but it can also follow a variety of neurological diseases; it is nearly always carried out with the left hand and is more easily undertaken by left-handers. We have found that a particularly high prevalence of left-handed mirror writing has been reported among those whose native languages are traditionally written in a leftward direction, including Chinese, Japanese, and Hebrew. Innate left-handers and those whose languages are written leftward thus share an unusual facility for left-handed mirror writing, an observation that may have implications for understanding hemisphere specialization in relation to handedness.

Dominance, Cerebral↗
PubMed1995

Mirror image duplication of the hands and feet: report of a sporadic case with multiple congenital anomalies.

Mirror image duplication of the hands and feet is a rare entity. Based on 3 previous reports, findings include nasal abnormalities, dimelia of ulna and fibula, tibial hypoplasia and mirror image duplication of hands and feet. We report on a sporadic case in which mirror image duplication was associated with multiple congenital anomalies. Although these cases may represent variable expression of the same dominantly transmitted complex polysyndactyly syndrome, it is possible that mirror image duplication of the hands and feet is a manifestation common to a number of distinct clinical entities. During limb bud development, duplication and aberrant positioning of the zone of polarizing activity in relation to the apical ectodermal ridge may account for the anatomic abnormalities of the hands and feet in these patients.

Abnormalities, Multiple↗