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The definition of the face.
There is no generally agreed definition of the human and subhuman face. For primatologists the definition forwarded by PERKNOPF (1957) is most agreeable: all structures of the head which can be seen from en face belong to the human face. The face is a combination of structures heterogeneous in both anatomy and function (forehead, eyes, mouth, pelage, etc.). They are different in qualities (e.g., color of the skin or the hair) and quantities as well (length of the jaw or the hairs of the mane). Despite the heterogeneity in form and function, the face as a whole appears as a unit, because in facial expressions there is always more than one structure involved. Blage, etc.). They are different in qualities (e.g., color of the skin or the hair) and quantities as well (length of the jaw or the hairs of the mane). Despite the heterogeneity in form and function, the face as a whole appears as a unit, because in facial expressions there is always more than one structure involved. Blage, etc.). They are different in qualities (e.g., color of the skin or the hair) and quantities as well (length of the jaw or the hairs of the mane). Despite the heterogeneity in form and function, the face as a whole appears as a unit, because in facial expressions there is always more than one structure involved. Because of the frontally oriented eyes and the stereoscopic vision, the facial structures are situated on the head so that they can be seen from in front. This is the reason why primate display mainly face to face. The concepts of the internal and external face are justified only in terms of topographical anatomy.
Recognition of upright and inverted faces: a correlational study.
An investigation of ninety-five university admission candidates failed to replicate the finding by Yin of a negative correlation between the ability to recognise upright and inverted faces. A zero correlation was obtained when unknown faces were both learned and recognised upside down, but when well-known faces were presented normally and upside down for identification, a significant positive correlation appeared. Rock has suggested that inverted faces are difficult to recognise because they overtax a mechanism for correcting disoriented stimuli. This explanation satisfactorily accounts for the data with the proviso that, when inverted faces are to be remembered, the best strategy is not to attempt to correct their orientation, but to learn isolated features of the face. This describes the data more parsimoniously than Yin's face-specific mechanism.
Methods for precisely trimming block faces for ultramicrotomy.
Two devices are described to aid in trimming block faces of embedded tissue for ultramicrotomy. The first, a reticle to fit the ocular of a stereomicroscope, can be manufactured by the ultramicrotomist and is designed to outline the edges of the block face so that it can be trimmed to a standard size and shape with the area of interest centered in it. The second, a rectangular "trimalign" block mounted in the knife holder of the ultramicrotome, is, with the block face, aligned to the plane of sectioning, and aids in retrimming the top and bottom edges of the block face. This is the simplest trimming device yet described and the first which will, from any sort of embedded material, produce a block face with parallel top and bottom edges even if the block face is not perpendicular to the axis of the specimen holder. If the edge of the diamond knife used for sectioning is parallel to the axis of rotation of the knife holder, the block face has also been automatically aligned to the kinfe as a consequence of this aligning and trimming procedure. As a result, sectioning can begin immediately without further adjustments.
Reaction-time differences between the left and right hemispheres for face and letter discrimination in children and adults.
Twenty boys at each age level 7, 10, and 13 years and 20 adult males were tested for choice manual reaction times to photographs of faces or letter pairs tachistoscopically presented 3 1/2 degree to the left or 3 1/2 degree to the right of a central fixation point, in the left visual field (LVF) or the right visual field (RVF) respectively. All subjects were right-handed. Subjects were tested monocularly. They used a different hand and a different eye in the first and second half of trials. Eye order and hand order were randomized across subjects. Seven- and 10-year-olds were intermittently rewarded with a poker chip following fast correct responses. Analysis of correct reaction time scores indicated an overall LVF superiority for the speed of response to faces, but no significant field differences for responses to letter pairs. The interaction of these field-stimulus effects with age was not significant, suggesting that the obtained field effects with faces and letter pairs were consistent across the range of ages tested. The results of comparisons of field differences within individual subjects suggested a "switchover" from a left-field advantage with letter pairs at age 7 to a right-field advantage at the adult level; this tendency, however, was not significant. None of these results was influenced by the use of different hands or eyes or to frequencies of commission of errors. The results suggested that a left-field advantage in speed of response to familiarized faces is found as early as 7 years of age and does not change appreciably thereafter. The finding of a significant left-field advantage for faces in the 7-year-old group represented an earlier age of left-field, right hemisphere lateralization for face stimuli than that previously obtained by other investigators. The failure to find over field differences with letter pairs was attributed to a possible tendency among subjects to process to letters visually (i.e., graphemically), a tendency which may have been more marked in the 7-year-old group due to the relative inexperience of children of this age with alphabetical material.
Open loop increase in trunk temperature produced by face cooling in working humans.
1. Five human subjects pedalled on a bicyle ergometer for at least two 74 min periods at 10 degrees C ambient temperature. During the first period the subjects cycled for 42 min with face fanning, followed by 32 min with the head thermally insulated. In the second period, this procedure was reversed. Oesophageal (tes), tympanic (Tty), forehead and hand skin temperatures were recorded. In addition, heart rate (H.R.) was counted throughout the experiments, and the technique of perceptual rating of cool and warm stimuli was used in order to appreciate whether the subjects were hypo-, normo-, or hyperthermic. 2. Face fanning resulted in decreased Tty, decreased H.R., mild skin vasoconstriction but increased Tes. 3. Head covering resulted in increased Tty and H.R., while Tes decreased slightly, due to peripheral vasodilatation. 4. When their faces were being fanned so that Tty was low and Tes was high, the subjects gave slightly hypothermic ratings. Ratings were clearly hyperthermic when their heads were covered and Tty was high and Tes was low. 5. The close correlation between vasomotor response and H.R. on the one hand and Tty on the other confirms that this variable is a better approximation of regulated core temperature than Tes. 6. Increase in Tes during face fanning and decrease in Tes during face insulation is new evidence for the possibility of the human brian being cooled during exercise by cool blood returning from the face. 7. We suggest that this selective brain cooling determines the apparent upper resetting of core temperature during exercise while brain temperature remains precisely regulated and constant.
Genome wide association study reveals novel associations with face morphology.
Genome-wide association studies (GWAS) on the Middle Eastern population, including the United Arab Emirates (UAE), have been relatively limited. The present study aims to investigate genotype-face morphology associations in the UAE population through Genome Wide Association Studies (GWAS). Phenotypic data (44 face measurements) from 172 Emiratis was obtained through three-dimensional (3D) scanning technology and an automatic face landmarking technique. GWAS analysis revealed associations of 19 genetic loci with six face features, 14 of which are novel. The GWAS analysis revealed 11 significant relationships between 44 face parameters and 242 SNPs, exceeding the GWAS significance threshold. These phenotypes were previously associated with body height, craniofacial defects, and facial characters. The most significant associations of these genetic variations were related to six main facial features which were facial convexity, left orbital protrusion, mandibular contour, nasolabial angle D, inferior facial angle B, and inferior facial angle A. To the best of our knowledge, this is the first GWAS study to investigate the association of SNP variations with face morphology in the Middle Eastern population.
A cephalometric evaluation of high-pull molar headgear and face-bow neck strap therapy.
The effects of two different extraoral appliances were evaluated over a 1-year period. Of the thirty-seven cases selected for study, twenty were treated with a face-bow neck strap and seventeen were treated with a high-pull molar headgear. Patients ranged in age from 10.10 to 16.6 years and averaged 13.4 years. The appliances exerted less than 600 Gm. of force per side and were worn for 12 to 16 hours per day. All cases were fully banded, and extraction and nonextraction treatment were included. An analysis of pretreatment data revealed a high degree of selection. Patients selected for high-pull treatment generally exhibited larger anterior face heights, steeper mandibular plane angles, and a greater amount of tooth eruption of the upper first molars than the patients selected for neck strap therapy. A control group of ten untreated subjects was matched to each treatment group to permit assessment of the impact of treatment on growth. Relative to normal growth, treatment with face-bow neck strap traction tended to direct the maxilla and mandible downward and backward. The palatal plane was lowered anteriorly and point A was retracted. The maxillary molars were extruded, and concomitantly an increase in anterior face height and mandibular plane angle was observed. On the other hand, the high-pull molar headgear traction resulted only in increased mandibular molar eruption. However, there was also a nonsignificant tendency for point A to be held back and for lower anterior face height to increase. The comparison of the two treatment samples revealed that the functional occlusal plane was tipped down at the back as the maxillary molars were more extruded in the neck strap sample. In the high-pull sample, the functional occlusal plane was unchanged and the mandibular molars were more extruded than they were in the neck strap group.
Upright and inverted faces: the right hemisphere knows the difference.
The existence of a right hemisphere capacity, specific to upright faces was investigated. Upright and inverted faces, equally complex as patterns, were presented under lateralized tachistoscopic conditions to two groups of normal adult subjects. A significant orientation by visual field advantage was found. While there was a highly significant left visual field advantage for upright faces, the visual field difference for inverted faces failed to reach significane. This pattern of results supports the hypothesis that the right hemisphere is specialized for the perception of faces in particular, in addition to its specialization for the perception of visuospatial patterns in general.
Visual and cardiac responses to animate and inanimate faces by young term and preterm infants.
Infants' looking and looking-away behaviors, as well as cardiac responses to mothers' spontaneous and imitative and to dolls' animated and still faces, were recorded for 18 term and 18 preterm infants when they were 3 months old. Infants spent less time looking at their mothers' than at the doll's faces, and their heart-rate levels were elevated while looking at mothers' faces. These effects were most pronounced for the preterm infants whose inferior scores on the animate visual item of the Brazelton neonatal scale suggested a continuity of visual inattentiveness to animate stimuli. Both groups also looked at the inanimate more than the animate doll's face and evidenced lower heart-rate levels during that situation. An information-processing/arousal-modulation interpretation was made for infant looking-away behavior and elevated heart rate during the more arousing mother's-face situations.
A developmental study of hemisphere specialization for recognition of faces in normal subjects.
In a developmental study of hemisphere lateralization for recognition of faces in normal subjects three groups of subjects (mean ages: 7 years 9 months; 13 years 10 months; and 19 years 6 months) were tested. The procedure was a go-no go reaction time task in which the subject responded to faces tachistoscopically presented to the right or left visual field. A left visual field superiority was found for the two older age groups, which is interpreted as a right hemisphere dominance for recognition of faces. However, the 7 and 8 year old group did not demonstrate a significant visual field difference. These results indicate that the hemisphere specialization (lateralization) for recognition of faces involves processes which develop with increasing age through childhood and is not well-established until some time after the age of 8 and before age 13.
Asymmetry in perception of the sides of the human face.
The objective of this research was to determine if systematic differences occur in the way people ascribe meaning to right and left sides of the human face. Twenty-two faces, bilaterally symmetrical, were constructed from 11 photographs. These left- and right-constructed faces were rated 1 wk. apart by 26 raters on nine bipolar adjective scales selected for the evaluative, potency, and activity dimensions of the semantic differential (Osgood, 1961). Multivariate F tests indicated that on seven of the nine bipolar scales the left- and right-sided faces received significantly different ratings. Left facial constructions were rated as healthier, stronger, harder, more active, more excitable, and in the direction of bad on the good-bad scale. Right facial constructions were rated more sickly, weaker, more feminine, softer, more passive, calmer, and in the good direction on the good-bad scale.
Anthropometry of the face in lateral facial dysplasia: the bilateral form.
The morphology of the head, face, and ears was studied in 26 patients with bilateral lateral facial dysplasia in The Hospital for Sick Children, Toronto, using anthropometric and cephalometric methods. The anthropometric data of the maxilla and mandible were compared to the cephalometric findings. The study showed that, in the majority of the patients, one side of the face was more damaged than the other was was associated with a high frequency of defects in all areas of the face. The microtic ear was not necessarily part of this syndrome. The anthropometry proved to be a valuable supplement to the x-ray cephalometry assessment of the malformed face.
Evaluation of the use of a face-bow in complete denture occlusion.
A study was conducted that compared three arbitrarily located axes to the true hinge axis location on ten subjects. Of the 60 different arbitrary axis locations registered, 55% were within 6 mm of the true hinge axis. The results of this study revealed very small differences between a hinge axis face-bow. Hanau 132-SM face-bow, and the Whip-Mix ear face-bow. A linear deviation range of 0.116 to 0.268 mm is of doubtful clinical significance to complete denture construction. If an articulator like the New Simplex is used without a face-bow and with a 3 mm interocclusal wax record, it can be anticipated that there will be a 1 mm deviation in the anterior direction in centric occlusion. This discrepancy, incorporated with errors due to processing, can be eliminated by remounting the finished complete dentures with a new centric relation record for occlusal correction.
Psychological factors in the face-hand test.
Young children's failure to report double-simultaneous stimulations of the side of the face and the contralateral hand has been attributed to cerebral deficiencies. When tested under optimal psychological conditions, 3- to 6-year-old children correctly report simultaneous stimulations of the face and contralateral hand. Performance on the face-hand test, which has been used as an index of cerebral functioning, is influenced in a significant way by the child's ease in the testing situation and understanding of the task.
II. Functional properties of cells in anterolateral part of area 7 associative face area of awake monkeys.
The most anterior part of area 7 of awake, behaving macaque monkeys was investigated using single cell recording technique. Eighty-five cells from three hemispheres of two monkeys were isolated and studied. These cells showed more complex functional properties than the cells in the primary and secondary cortical fields. Of the cells 61% responded to somatosensory (26%) or visual (2%) or both somatosensory and visual (33%) stimulation; 39% of the cells were active only during the monkey's own movements. Most of the cells studied were active while the monkey was bringing an object to the mouth with its hand, when reaching for an object with lips, or while chewing. The neurons responded selectively to, e.g., palpation of the flexors of the arm, a visual stimulus approaching the face, passive movement of the monkey's hand towards the mouth, or they were active only when the monkey was reaching for an object with its lips or was mouthing it. The cellular activity in the anterolateral part of area 7 was prominently related to the stimulation or motor activity of the face (especially the mouth). In this respect, it differed from the more posterior part of area 7 adjacent to it. The results thus indicate that there is a separate and rather extensive mouth (or face) area in the parietal association cortex of the monkey.
Surgical correction of the long face syndrome.
The combined efforts of different specialists are needed for the successful treatment of patients with the long face syndrome. Both surgeons and orthodontists who recognize their own capabilities and limitations must combine their skills to achieve the best possible occlusion and facial esthetics. The surgical and orthodontic plan of therapy is designed to correct the patient's dentofacial deformity. Surgical reduction of facial height and proper alignment of the teeth by orthodontic means are common denominators of successful treatment. By properly planned and executed Le Fort I maxillary osteotomies, the vertical dimensions of the face can be shortened to improve the esthetic balance between the nose, upper lip, teeth, and chin and achieve lip competency. Variable open-bite and nonopen-bite maxillary deformities in forty adults with the long face syndrome were corrected by Le Fort I osteotomy and orthodontic treatment. The technical problems encountered in planning and executing treatment are discussed and illustrated by selected case reports.
Inverted writing in right- and left-handers in relation to lateralization of face recognition.
In a study with 157 right-handed and 69 left-handed college students, Gilbert's two-face choice task, which was used as an indicator of cerebral lateralization for face recognition, distinguished left-handers from right-handers. Right-handers primarily attended to the right side of the face (left visual field), while the group of left-handers had no visual field preference. Levy's hypothesis that inverted-writing left-handers are cortically lateralized like right-handers, and that inverted-writing right-handers are lateralized like left-handers found some support among the males. However, the females in both handedness groups performed in an opposite manner to that predicted by Levy's hypothesis.