The clearest mirror : the science of laughing and crying

Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 44-48).There are few things as familiar to us as the experience of laughing and crying. Studying the two emotional expressions side to side is a way to see our species anew. A way of linking what we share with other mammals to that which sets us apart from all other species. Pulling laughing and crying onto center stage in all their theatrical glory creates a scene of which philosophers and anthropologists have long dreamt: a vision that is uniquely human. Laughing and crying are in many ways physiological and psychological opposites, but these complex behaviors are not exact reversals of the same bodily processes. Nor have researchers told me that they are connected in any biologically relevant way. But zooming out of narrow scientific definitions, digging into our evolutionary history, focusing on the disorders of laughing and crying, looking to the stage where actors and actresses come alive through their tears, there emerges a puzzle of psychology, neuroscience, evolutionary theory, and neurology slowly snapping together.by Genevieve M. Wanucha.S.M.in Science Writin

Eye-to-face Gaze in Stuttered Versus Fluent Speech

The present study investigated the effects of viewing audio-visual presentations of stuttered relative to fluent speech samples on the ocular reactions of participants. Ten adults, 5 males and 5 females, aged 18-55 who had a negative history of any speech, language and hearing disorders participated in the study. Participants were shown three 30 second audio-visual recordings of stuttered speech, and three 30 second audio-visual recordings of fluent speech, with a three second break (black screen) between the presentation of each video. All three individuals who stutter were rated as ‘severe’ (SSI-3, Riley, 1994), exhibiting high levels of struggle filled with overt stuttering behaviors such as repetitions, prolongations and silent postural fixations on speech sounds, in addition to tension-filled secondary behaviors such as head jerks, lip protrusion, and facial grimaces. During stuttered and fluent conditions, ocular behaviors of the viewers including pupillary movement, fixation time, eye-blink, and relative changes in pupil diameter were recorded using the Arrington ViewPoint Eye-Tracker infrared camera and the system’s data analysis software (e.g., Wong & Cronin-Colomb & Neargarder, 2005) via a 2.8GHz Dell Optiplex GX270 computer. For all ocular measures except fixation time, there were significant (p\u3c.05) differences for stuttered relative to fluent speech. There was an increase in the number of pupillary movements, blinks, and relative change in pupil diameter and a decrease in time fixated when viewing stuttered relative to fluent speech samples. While not significant, participants fixated or directed their attention for less time during stuttered than fluent conditions, indicating decreased attention overall during stuttered speech samples. Increases in eye-blink data and pupil-dilation data were also significant. Because both eye-blink, as a measure of the startle reflex, and pupil-dilation are resistant to voluntary control or are completely under the control of the autonomic nervous system, significant increases in both for stuttered relative to fluent speech indicate a visceral reaction to stuttering

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Cephalometric Evaluation of Bionator Therapy in the Early Treatment of Class II Malocclusions

Early or two-phase orthodontic treatment of Class II malocclusions is a debated topic in orthodontic circles primarily because the benefits of early intervention have not been consistently reproduced among researchers. The present study was a retrospective analysis of cephalograms from patients with Class II, division 1 malocclusions at the start of treatment. These were 50 consecutively treated youths who received phase 1 (early) treatment with a Bionator appliance and later treatment with full appliances (all treated by a single clinician). The comparison group consisted subjects treated in a single phase with fixed Edgewise appliances only. Importantly, subjects in the two samples were matched, on a one-to-one basis, for demographic and cephalometric variables (ANB, SNA, SNB, NAP, FMA) to ensure comparability in the nature and severity of the malocclusions. The key question was whether the cephalometric results at the end of treatment were comparable between groups. Two-phase subjects were treated on average 1.4 years longer than the one-phase group, though this measure of clock time may obscure the greater ease of treatment chair side. Neither of out two integumental variables (Z angle, E plane) differed statistically, but two key skeletal variables did differ, namely ANB and NAP. ANB was significantly smaller ( = 2.6°) in the two-phase group than in the one-phase group ( = 3.7°), and NAP averaged 2.7º in the two-phase group compared to a mean of 4.8º in the one-phase group. Consequently, the two-phase group was discernibly more orthognathic at the end of treatment, with most of the correction coming from mandibular growth rather than maxillary restriction. None of the dental variables differed statistically except the position of the maxillary incisors which were slightly more proclined in the two-phase group, and this was due to operator preference. The two-phase subjects had a lower rate of premolar extraction (12% vs 84%) than the one-phase subjects. Overall, the two-phase group achieved a better bony facial profile, with the majority of the skeletal and dental correction occurring during the first phase of treatment. These favorable results contrast with published randomized clinical trials, possibly because of differences in patient selection and appliance design. Our results do support the value of early intervention, though it is not known whether the statistically significant improvements in the facial profile are large enough to be perceptible to the patient and parents

Associative learning alone is insufficient for the evolution and maintenance of the human mirror neuron system

AbstractCook et al. argue that mirror neurons originate from associative learning processes, without evolutionary influence from social-cognitive mechanisms. We disagree with this claim and present arguments based upon cross-species comparisons, EEG findings, and developmental neuroscience that the evolution of mirror neurons is most likely driven simultaneously and interactively by evolutionarily adaptive psychological mechanisms and lower-level biological mechanisms that support them.</jats:p

Architecture and the Senses: A Sensory Musing Park

This thesis studies the relationship of architecture and the senses. The first part of the document explores sensory characteristics and how they work. It defines their importance in allowing humans to navigate complex environments. The second part of the thesis looks directly at environmental stimuli. It seeks to qualify and associate physical variables with particular sensory responses. The goal of the research is to create a set of standards by which architecture can design "for the senses". The design project will put to test the principles organized from research through a series of architectural installations that harness both natural and man-made stimuli. The methodology with which stimuli are engaged will highlight time, place, and the awareness of being. Each installation is part of a greater constellation that can be sequenced in a variety of ways, experienced uniquely each time, and even added to by visitors and artists

Cephalometric Evaluation of One-Phase and Two-Phase Treatment Alternatives in Matched Class Ii Subjects

“Early” or two-phase orthodontic treatment of Class II malocclusions is a highly debated topic in the orthodontic literature. We report here on a retrospective cephalometric study of patients with Class II, division 1 malocclusions. One group consisted of 32 consecutively treated patients who received “early” treatment with a Fränkel II appliance followed by treatment with full fixed appliance. These subjects were “matched” by sex and cephalometric value, to a subject treated with standard edgewise appliances in a single phase. Matching criteria focused on the bony facial characteristics, notably ANB, NAP, Y Axis, AOBO, FMA, overjet, and overbite. The question was whether the cephalometric results at the end of treatment were comparable. Two-phase subjects were treated on average 2 years longer than the one-phase edgewise group. Neither integumental variable (Z angle, E plane) differed statistically. Two of eight skeletal variables differed statistically, namely ANB and FMA. ANB was on average 1.3° smaller in the two-phase group, while the FMA was on average 1.8° steeper in the one-phase group. Four of the eleven dental variables differed statistically between the two groups. These variables were related to incisor position. Overall, the incisors in both treatment groups proclined during treatment. The two-phase subjects had a lower rate of premolar extraction (3% vs. 56%) than the one-phase subjects. Similar skeletodental endpoints were achieved regardless of treatment protocol; indicating the treatments can be viewed as equivalent approaches to a common problem