Normal Tempo Research Articles

A biomimetic controller for a multifinger prosthesis.

A novel controller for a multifinger hand prosthesis was developed and tested to measure its accuracy and performance in transducing volitional signals for individual "phantom" fingers. Pneumatic sensors were fabricated from open-cell polymeric foam, and were interposed between the prosthetic socket and superficial extrinsic tendons associated with individual finger flexion. Test subjects were prompted to move individual fingers or combinations thereof to execute either taps or grasps. Sensor outputs were processed by a computer that controlled motions of individual fingers on a mechanical prosthesis. Trials on three upper-limb amputees showed that after brief training sessions, the TAP controller was effective at producing voluntary flexions of individual fingers and grasping motions. Signal energies were between 5 and 25 dB relative to noise from all sources, including adjacent sensors, indicating high degrees of both sensitivity and specificity for tendon-associated transduction. Finger flexions at up to three repetitions per second, and rhythmic tapping of sequential fingers were readily transduced. One amputee subject was able to play a short piano piece with three fingers, at approximately one-quarter normal tempo. TAP sensors responded linearly to graded forces from individual fingers, indicating proportional force control. Our results demonstrate the feasibility of restoring some degree of finger dexterity by noninvasive sensing of extrinsic tendons.

Internal temporal structure of Mandarin syllables

The durational interactions among different combinations of onsets, nuclei, and codas in Mandarin Chinese syllables are examined, based on data from six speakers at normal and fast rates of speech. This report extends and refines preliminary results, based on four speakers at a normal tempo, that were reported earlier [A. Bell and M. Liu, J. Acoust. Soc. Am. Suppl. 1 87, S67 (1990)]. Effects of different onsets (/n t shtsh/), vowels (/a i u/), diphthongs (/ai au ou ia iau/), and nasal codas (/n sh/) were considered. Consistent effects of onsets, vowel height, complex nuclei, and nasal codas on both syllable and rhyme durations were found. These effects, however, were relatively small, of the order of 15% for rhyme durations, and from about 5% to 10% for syllables, apparently consistent with a hypothesis that Mandarin rhymes and syllables are perceptually invariant. On the other hand, the nature of segment compensations was more consistent with segment-local and universal mechanisms than with language-particular global timing units of rhyme or syllable. [Work supported by the University of Colorado Council on Research and Creative Work.]

Do Female Stickleback Care About Male Courtship Vigour? Manipulation of Display Tempo Using Video Playback

[Reproductive ♂ and ♀ threespine stickleback Gasterosteus aculeatus were presented with a videotaped sequence of a zigzag dancing ♂ played back at normal (T), half (0.5T), one-and-a-half (1.5T), double (2T) and triple (3T) tempo. Playbacks were displayed pairwise (T/0.5T; T/ 1.5T; T/2T; T/3T) on monitors placed at opposite ends of the test tank. Each playback pair was displayed to subjects for 4 min, with display locations switched to opposite ends of the test tank at 2 min to control for position preference. Both ♂ and ♀ subjects responded to playback images much like they do to live ♂♂, ∏demonstrating the potential of video playback for analysing visual communication in stickleback. Male and ♀ subjects contacted 1.5T and 2T images as much as images moving at normal tempo but they contacted 0.5T and 3T images less. Thus, subjects were more attracted to ♂♂ displaying at normal to slightly faster tempo than to ♂♂ displaying outside that range. The stabilizing selection that such effects might impose on animals could contribute to the typical intensity that characterizes much of their display behaviour., Reproductive ♂ and ♀ threespine stickleback Gasterosteus aculeatus were presented with a videotaped sequence of a zigzag dancing ♂ played back at normal (T), half (0.5T), one-and-a-half (1.5T), double (2T) and triple (3T) tempo. Playbacks were displayed pairwise (T/0.5T; T/ 1.5T; T/2T; T/3T) on monitors placed at opposite ends of the test tank. Each playback pair was displayed to subjects for 4 min, with display locations switched to opposite ends of the test tank at 2 min to control for position preference. Both ♂ and ♀ subjects responded to playback images much like they do to live ♂♂, ∏demonstrating the potential of video playback for analysing visual communication in stickleback. Male and ♀ subjects contacted 1.5T and 2T images as much as images moving at normal tempo but they contacted 0.5T and 3T images less. Thus, subjects were more attracted to ♂♂ displaying at normal to slightly faster tempo than to ♂♂ displaying outside that range. The stabilizing selection that such effects might impose on animals could contribute to the typical intensity that characterizes much of their display behaviour.]

The early adaptive evolution of calmodulin.

Interaction between gene duplication and natural selection in molecular evolution was investigated utilizing a phylogenetic tree constructed by the parsimony procedure from amino acid sequences of 50 calmodulin-family protein members. The 50 sequences, belonging to seven protein lineages related by gene duplication (calmodulin itself, troponin-C, alkali and regulatory light chains of myosin, parvalbumin, intestinal calcium-binding protein, and glial S-100 phenylalanine-rich protein), came from a wide range of eukaryotic taxa and yielded a denser tree (more branch points within each lineage) than in earlier studies. Evidence obtained from the reconstructed pattern of base substitutions and deletions in these ancestral loci suggests that, during the early history of the family, selection acted as a transforming force on expressed genes among the duplicates to encode molecular sites with new or modified functions. In later stages of descent, however, selection was a conserving force that preserved the structures of many coadapted functional sites. Each branch of the family was found to have a unique average tempo of evolutionary change, apparently regulated through functional constraints. Proteins whose functions dictate multiple interaction with several other macromolecules evolved more slowly than those which display fewer protein-protein and protein-ion interactions, e.g., calmodulin and next troponin-C evolved at the slowest average rates, whereas parvalbumin evolved at the fastest. The history of all lineages, however, appears to be characterized by rapid rates of evolutionary change in earlier periods, followed by slower rates in more recent periods. A particularly sharp contrast between such fast and slow rates is found in the evolution of calmodulin, whose rate of change in earlier eukaryotes was manyfold faster than the average rate over the past 1 billion years. In fact, the amino acid replacements in the nascent calmodulin lineage occurred at residue positions that in extant metazoans are largely invariable, lending further support to the Darwinian hypothesis that natural selection is both a creative and a conserving force in molecular evolution.

Discrimination of Modulated Music Tempo by String Students

The purpose of this study was to investigate the influence of musical training and age on the ability of string students to discriminate tempo change, and the effect of musical style, speed of a musical composition, and the direction of tempo change on the ability to detect tempo change. Subjects were 116 string students, age 7 through 18 years. Musical stimuli were chosen from familiar string literature. Each excerpt was generated by using synthesized tones and was recorded at a normal tempo, slower than normal tempo, and faster than normal tempo. Three presentations were made at each speed: tempo increase, tempo decrease, and no tempo change. The subjects' task was to identify the direction of the tempo change or no-change. Statistical analyses revealed a significant curvilinear relationship between score and years of musical training, and between score and age. Additional regression analyses indicated that speed, direction of change, and musical style each contributed significantly to tempo perception over and above musical training and individual differences. These findings confirm that tempo perception is a complex phenomenon and that several parameters of tempo discrimination have yet to be identified.

Complex motor functions of the preferred and non-preferred hands in brain-damaged and normal children.

A previous study of early school-age children indicated that a brain-damaged group took more time in normal name-writing than did a group of normal children with both the preferred hand and the non-preferred hand. In addition, the difference between the 2 hands was greater for the brain-damaged children. These results could have been attributed at least in part, considering the age range of 6 to 8 yr., to lack of development of skill in name-writing. Therefore, the study was replicated using children in the 9- to 14-yr. age range since name-writing should have been a practiced and perhaps over-learned skill for older children. Groups were formed by matching pairs of brain-damaged and normal children for race, sex, and age. The results, found by applying converted scores derived from the study of younger children, confirmed the findings with younger children and permitted differentiation of the brain-damaged and normal groups with almost the same degree of accuracy achieved in the prior study. The results suggest that the findings are not due to lack of development of name-writing skill but instead reflect a difference in normal tempo, associated with brain damage, in a highly practiced, complex motor function.

Perceived nasality in the speech of the deaf.

Listener ratings of nasality were obtained from samples of deaf and normal speech presented in the backward play mode. In order to investigate the influence of rhythmic patterning on the perception of nasality, seven of the normal speakers also produced the samples in a word-by-word fashion. Statistically significant differences in mean ratings of nasality were found between the experimental and control groups and between the reduced-tempo and normal-tempo groups. In general, deaf speakers are perceived as more nasal than normal speakers. Furthermore, normal speakers are perceived as more nasal when speaking at a reduced tempo than when speaking at a normal tempo. Much of the perceived nasality in the speech of the deaf may be a natural consequence of reduced speaking tempo, and therapeutic techniques designed to increase speaking tempo may produce a concomitant reduction in perceived nasality.

A Comparison of Thymectomized and Antithymocyte Serum-Treated Mice in Their Development of Hypersensitivity to Protein Antigens

Summary Mice of CF1 strain thymectomized at birth were compared with similar mice which had been sham-operated, treated with normal rabbit serum, or treated with rabbit antiserum to mouse thymus for various time intervals after birth, with respect to ability to develop immediate and delayed hypersensitivity to ovalbumin and bovine serum albumin, and delayed hypersensitivity to tuberculoprotein. Hematologic and histologic changes in these various mice also were evaluated. Mice treated with antiserum or thymectomized at birth either failed to develop hypersensitivities to antigens injected early in the experiment, or they developed these hypersensitivities with slower than normal tempo. Suppression of hypersensitization in antiserum-treated animals was proportional to the length of time over which they were treated with this antiserum. Neither thymectomy nor antiserum treatments interfered with development of anamnestic responsiveness to these initially injected antigens, nor was the immunosuppressive effect more than temporary; thymectomized and treated animals responded normally, developing immediate and delayed hypersensitivities to bovine serum albumin when this was injected into them at the end of the experiment 6 months after thymectomy and approximately 4 months after the last antiserum treatment. None of the animals developed wasting disease. Single or multiple treatments with antiserum to mouse thymocytes caused peripheral lymphocyte counts to drop significantly while numbers of tissue plasma cells and peripheral large lymphocytes remained normal. In vitro examination of the properties of this antiserum revealed that although it would fix complement in the presence of thymus antigens it did not cause thymocyte agglutination or lysis. In long-term treated mice there were, in addition to depressed peripheral lymphocyte counts, histologic changes consisting of decreased lymphoid mass and loss of splenic germinal centers. But thymus glands in these animals remained anatomically intact. Hence, immunosuppression effected by anti-thymus antiserum treatments may be viewed either as due to lymphocyte suppression or as evidence supporting recent reports that a humoral thymic factor may control immunocompetence. If the latter alternative proves true, then rabbit anti-mouse thymus antiserum may contain antibody to this humoral factor which neutralizes its biologic effects.

I Want to Be in Your Class When I'm Older

It began this way: Teach us some songs like in my brother's college class! exclaimed little seven-year old Barbara Pepper when she recognized me as her big brother's professor on a visit to Pennsylvania's Glenside-Weldon Elementary School. Barbara's teacher, Mrs. Virginia Holmstrom, and Principal T. R. Frank liked the idea too, so the Glenside-Weldon venture got under way before Christmas, 1952. In an experimental frame mind, I conducted two fifteen-minute sessions a week. Shortly we shall see what grew out this. Children's marked facility for learning a foreign language is a fact which hardly needs further proof.' The means achieving this proof will continue to improve through systematic experimentation. Procedures vary from teacher to teacher. As Sancho would say, Cada quien tiene su modito de matar pulgas. Procedures in the Glenside-Weldon venture have methodological bearing upon other similar programs. Several weeks after that first stir childish enthusiasm for Spanish, thirty second-grade children were singing Adelita, Las gaviotas, Las posadas, and Fray Felipe, with no American accent. Parents came to visit the class and were amazed when their children carried on simple conversations involving questions like C6mo estas? CC6mo te llamas? CCuantos afios tienes? DD6nde vives? The children became locally famous during two appearances on my Spanish is Fun TV program (WFIL, Philadelphia) in 1953. These two programs brought more fan mail than all other thirteen TV programs combined! Particularly parents were impressed and wanted to have their children learn some Spanish. One class children was presented as a surprise feature the 1952 Penn State University Christmas program, singing Las posadas, Noche de paz, Cascabeles, and Venid, fieles is ay: Teach us some songs rother's col ege clas ! exclaimed ear old Barbara Pep er when she e as her big brother's a visit to Pennsylvania's Glenl Ele entary Scho l. Barbara's s. irginia Holmstrom, and Princi. a liked the idea to , so the Glenl venture got under way ist as, 1952. In an experimental i d, I conducted two fifte n-minute ee . Shortly we shall se what t is. ' arked facility for learning a l age is a fact which hardly ne ds of.' The eans achieving this ill co tinue to improve through syseri entation. Procedures vary er to teacher. As Sancho would say, i tie e su odito de matar pulgas. todos. Again in the 1953 Christmas assembly program, nearly sixty children were PSU guest artists. Nine principles or aspects have been stressed in the Glenside-Weldon venture in Spanish: 1) motivation, 2) repetition, 3) consolidation, 4) simple materials, 5) self-confidence, 6) interest span, 7) informality, 8) civilization study, and 9) singing. 1) The children have always been strongly motivated, having appeared on TV programs, in college and their own assembly programs as well as in demonstrations for visiting parents. These experiences accentuated their interest in learning Spanish. One might superficially ascribe their interest to a pig-latin impulse to say and sing things of the elite few. The interest must go more deeply than this, however. 2) The ideal number repetitions, immediately after the pattern is given, is three. The phrase must be expressed at a clear normal tempo and should not be slowed down excessively; it is preferable to shorten the phrase to enable the child to repeat it easily. Choral drill has been used almost exclusively in assuring the necessary number repetitions. 3) The child must incorporate language materials into his speech patterns as his contact with them increases. Emile De Sauz62 would express this in terms a necessity for an period. One does not go to the breakfast table, eat breakfast, then say to himself, To save time, since I'm already here, I'll just eat lunch and supper too. There must be an interim after first exposures so that the materials are mentally and vocally consolidated. The most skeptical observer will be surprised at the child's unusual progress after an incubation period has passed-providing the first presentation has been methodologically sound. os. Again in the 1953 Christmas assembly ogram, nearly sixty children were PSU est artists. 222 HISPANIA