Pitch and rhythmic patterns affecting infants' sensitivity to musical phrase structure.

The present studies were undertaken to learn more about the nature of the cues that underlie infants' perception of musical phrase structure. Exp 1 demonstrated that infants in C. L. Krumhansl and P. W. Jusczyk's (1990) study were responding to the phrase structure instead of to the beginnings and endings of Mozart minuet stimuli. Exp 2 showed that infants treat musical passages with pauses inserted at phrase boundaries much as they do unaltered versions of the same passages. Exps 3 and 4 indicated that the direction of change in pitch height and tone duration is critical to obtaining longer orientation times to musical passages that are segmented at phrase boundaries. Finally, Exp 5 demonstrates that different effects found for the forward and reversed versions of the passages with inserted pauses are not the result of an intrinsic preference for the forward versions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation of young infants' perceptual representations of speech sounds.

The present study examined the ability of newborns and 2-month-olds to detect phonetic differences between syllables. By relying on the modified high-amplitude sucking procedure, which did not permit the infants to use a simple same–different response, the present experiments tapped the perceptual representations of the speech sounds. Infants as young as a few days old displayed some capacity to represent differences in a set of syllables varying in their phonetic composition, although there was no convincing evidence that their representations were structured in terms of phonetic segments. Finally, evidence of developmental changes in speech processing were noted for the first time with infants in this age range. The change noted was a tendency from global toward more specific representations on the part of the older infants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An implantable electromagnetic sound source for speech production

Many operative and nonsurgical procedures have been designed for vocal rehabilitation following laryngectomy, but as yet a consistently successful solution with a negligible complication rate has failed to materialize. In our laboratory during the last two years, experiments have been carried out in dogs using active electromagnetic devices placed in the retropharynx as an energy source for speech production. An implantable porous coated stainless steel electromagnetic device energized from an externally controlled oscillator has been developed. Factors under investigation included biocompatibility of materials, durability, noise quality and intensity, together with the efficiency of the system. As a result of the favorable findings, it is envisaged that this system will soon be used in a carefully designed restricted clinical trial as a secondary procedure in those consenting cured laryngeal cancer patients who have failed to develop esophageal speech.     

Young infants' sensitivity to optical information for collision.

Four experiments explored the properties of the stimulus event that will evoke blinking and backward head movements in 100 3–4 wk old infants. Measured by a sensitive pressure transducer, backward head movements did not occur when Ss viewed displays that specified an object approaching on a collision course, except when some of the object's contours rose in the S's visual field. Thus, such head movements may reflect a tendency of young infants to fixate and pursue contours that move upward. In contrast, displays specifying collision evoked more frequent blinking than displays specifying an object's withdrawal, whether or not rising contours were present. The reliability of the blink response suggests that very young infants are sensitive to some optical information for collision. (French abstract) (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of infants' and adults' sensitivity to Western musical structure.

28 adults and 48 8-mo-old infants listened to repeated transpositions of a 10-note melody exemplifying the rules of Western tonal music. They were tested for their detection of 2 types of changes to that melody: (1) a 4-semitone change in 1 note that remained within the key and implied dominant harmony (diatonic change) or (2) a 1-semitone change in the same note that went outside the key (nondiatonic change). Adults easily detected the nondiatonic change but had difficulty with the diatonic change. Infants detected both changes equally well, performing better than adults in some circumstances. These findings imply that there are qualitative differences in infants' and adults' processing of musical information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of the ability to locomote on infants' social and exploratory behaviors: An experimental study.

In Exp I, 20 normal 6.5–10 mo old infants who were unable to locomote independently were observed for 10 min in an infant "walker" and for 10 min out of the walker. Exp II compared effects of walker-assisted locomotion with effects of independent locomotion in 16 7–20 mo olds who were able to creep or crawl. Age parameters were closely similar to those of the 1st sample. Results indicate that the 2 modes of locomotion, walker-assisted or independent, afforded similar experiences within a standard environment, but experiences quite different from those of the nonlocomoting infant. Some behaviors actually emerged as a function of the ability to locomote; others changed in frequency or were extended to new features of the environment. In addition, all classes of behaviors measured were known from other studies to affect adults' behavior toward infants. Therefore, changes in these behaviors should lead to changes in infants' social experiences. The systematic reorganization of experiences, both social and nonsocial, as a result of locomotion has implications for social, perceptual, cognitive, and language development. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An electrophysiological study of the insertion of overt response choice.

Using electrophysiological measures, the authors studied changes in prestimulus state, stimulus identification, and response-related processing when, in a go/no-go task, forced choice between 2 overt go responses was inserted. The authors observed decreased prestimulus motor preparation (electromyogram), no change in stimulus identification time (selection negativity), a minor increase in response selection time (lateralized readiness potential), a large increase in response preparation time (lateralized readiness potential), a minor effect on response execution time (electromyogram), and a decrease in the activation of a response-inhibition process on no-go trials (frontal event-related potential). The existence of the response-inhibition process was verified by the presence of inverted lateralized readiness potentials on no-go trials. Pure insertion of response choice in a task seems impossible because the choice between activation and inhibition (go/no-go) always seems already present. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An electrophysiological study of the action of crude Enhydrina schistosa venom

Complementary techniques to laparotomy are required to monitor patients with lymphomas both before and after treatment. Our preliminary experience with grey-scale ultrasonography is presented. Fifty-two patients, themajority with Hodgkin's disease or other lymphomas, were examined with ultrasound equipment which was custom built. The essential difference between grey-scale equipment and conventional machines is the ability to display the internal consistency of soft organs. Of 20 spleens examined prior to splenectomy, the ultrasonic scan was considered suggestive of involvement in seven of nine that showed histological evidence of Hodgkin's disease. Threeof 11 histologically negative spleens were considered to be positive preoperatively and two of nine read as negative on the scan contained histological disease. Fifty livers were examined with ultrasound. Of seven patients with histological involvement four were read as positive and three as negative and six of 43 patients with no macroscopic or microscopic evidence of liver infiltration were also considered to have a positive ultrasonic scan. Ultrasonic scanning has proved useful for demonstrating enlarged lymph nodes in the porta hepatis, upper para-aortic lymph nodes and bulky mesenteric nodes. On the basis of these preliminary observations the potential value and application of the technique is discussed.     

An electromyographic study of velopharyngeal function in speech

Electromyographic (EMG) recordings were obtained from the levator palatini, superior pharyngeal constrictor, middle pharyngeal constrictor, palatoglossus, and palatopharyngeus muscles of three talkers of American English. Bipolar hooked-wire electrodes were used. Each subject read nonsense words composed of three vowels (/i, a, u/), six stop consonants (/p, b, t, d, k, g/), and two nasal consonants (/m, n/) to form various stop-nasal and nasal-stop contrasts. Multiple repetitions of each utterance type were recorded and subsequently processed by computer. The levator palatini was found to be the primary muscle of velopharyngeal closure for each of the subjects. The palatopharyngeus also showed consistent oralization activity for each of the subjects, although the activity of this muscle was strongly affected by vowel environment. Two subjects showed pharyngeal constrictor muscle activity related to oral articulation, but pharyngeal constrictor activity for the third subject was related to vowel quality. Nasal articulation was accomplished by suppression of oral articulation for each subject. Vowel quality affected the strength of EMG signals for lateral and posterior pharyngeal wall muscles. In those cases where activity was different for the three vowels, activity was greatest for /a/.     

An electrophysiological study on the vagal innervation of the thymus in the rat

Vagal innervation of the thymus was studied by means of electrophysiological technique in the rat. Under urethane anesthesia, evoked action potentials originated from cervical vagus by electrical stimulations were recorded from the central cut end of the thymic branch of the vagus nerve after averaging for 32 times. It was observed that the conduction velocities are distributed in the range of 0.56-6.84 m/s, and the majority of vagal fibers in the thymic branch of the vagus nerve belong to a nonmyelinated C-fiber group. Further, it was confirmed that the right and left lobes of the thymus are innervated by cervical vagi bilaterally. The results suggest that the thymic branch of the vagus nerve plays a role in modulation of thymic function.     

Medullary actions of tetanus toxin. An electrophysiological study in man

Brain-stem reflexes have been studied in four patients with generalized tetanus. Inhibitory cutaneous reflexes were abolished or severely depressed. The same held true, to a lesser degree, for excitatory cutaneous reflexes with long polysynaptic pathways. Proprioceptive reflexes behaved variably. The observations are discussed in regard to the possible sources of enhanced motoneuronal activity in tetanus. It is concluded that, besides depression of inhibitory synapses on motoneurons, interneuronal damage may contribute to the tetanus symptomatology.     

An electrophysiological study of the postnatal development of the corticospinal system in the macaque monkey

We characterized toxin-insensitive calcium currents expressed by acutely dissociated embryonic dorsal root ganglion neurons. In the presence of 3 microM omega-conotoxin-GVIA, 3 microM nitrendipine and either 500 nM omega-agatoxin-IVA or 500 nM omega-conotoxin-MVIIC to inhibit N-, L- and P/Q-type currents, respectively, all neurons expressed two residual currents: a T-type and another which we referred to as toxin-resistant current. The toxin-resistant current (i) consisted of an inactivating and a sustained components, (ii) had a threshold of activation and a steady-state inactivation comprised between that of the T-type current and that of the other high-voltage-activated currents, (iii) had the same permeability for barium and calcium used as charge carriers, (iv) was highly sensitive to both cadmium and nickel; and (v) was insensitive to 500 microM amiloride which abolished the T-type at this concentration. The properties of the toxin-resistant current are very similar to those of the currents expressed in oocytes following injection of alpha(1E) subunits which we demonstrated to be present in these neurons. Therefore a component of the toxin-resistant current calcium channels in sensory neurons may be closely related to those calcium channels formed by alpha(1E) subunits.     

An event-related potential study of age-related changes in sensitivity to stimulus deviance

The mismatch negativity (MMN) of the event-related (brain) potential (ERP) has been shown to reflect the storage of information in sensory memory and is thought to reflect the operation of a mechanism that compares frequently occurring standard with infrequently occurring deviant acoustic events. The MMN was recorded from young (mean = 23 years) and elderly (mean = 72 years) adults to small (50 Hz) and large (300 Hz) frequency deviants and to a variety of novel, environmental sounds. At each level of deviance, MMN amplitude was smaller in the ERPs of older relative to younger adults. Young, but not older adults showed robust MMNs at the smallest level of deviance. Moreover, a P3 component was observed in the ERPs of the young to both large tonal and novel deviants, whereas a robust P3 component was evident only to the novel deviants in the ERPs of the old. The data suggest that older adults demonstrate less sensitivity to stimulus deviance and that only highly deviant events are likely to involuntarily capture their attention.     

An electrophysiological study on the autonomic innervation of the mesenteric lymph node in the rat

Splanchnic innervation of the mesenteric lymph node was studied by means of electrophysiological technique in the rat. The effect of intravenous (i.v.) injection of recombinant human interleukin-1beta (rhIL-1beta) on the activity of efferent nerve fibers innervating the mesenteric lymph node was observed in the urethane anesthetized rat. An i.v. injection of 10 ng rhIL-1beta caused a gradual increase in efferent activity which lasted longer than 90 min. Dose related responses were observed at doses of 1, 10 and 100 ng. The least effective dose was about 10 ng. The conduction velocities estimated in mesenteric nerve fibers to the lymph node distributed in the range of 1.9-0.9 m/s, and the mean velocity was 1.39+/-0.34 m/s (n = 5). These observations implicate the involvement in the neural modulation of immune function of the mesenteric lymph node.     

Cisplatin ototoxicity. An electrophysiological dose-effect study in albino guinea pigs

Accumulating evidence indicates that the endogenous opioid peptides dynorphinA-(1-17) and dynorphinA-(1-13) interact not only with opioid but also with yet poorly characterized non-opioid receptors. The latter have been implicated in a number of the effects of dynorphins including induction of ACTH release in sheep and in AtT 20 cells, a pituitary-derived mouse cell line. AtT 20 cells do not express opioid receptors and therefore are particularly suitable for search of non-opioid dynorphin receptors. We report here that 3H-dynorphinA-(1-13)-NH2 associates specifically with AtT 20 cells, apparently through an uptake process and a binding site. Within the cell, it binds preferentially to fractions containing secretory vesicles, with a Kd of about 100 nM. DynorphinA-(1-17), and several non-opioid fragments of dynorphin, including A-(2-17), A-(2-16) and A-(2-13), compete with 3H-dynorphinA-(1-13)-NH2 for that site with IC50s ranging from 200 nM to 2 microM. ACTH(1-39) also competes with 3H-dynorphinA-(1-13)-NH2 for the site with an IC50 of about 300 nM. DynorphinA-(2-17) at microM concentrations stimulates release of ACTH from the isolated vesicles. The results indicate the presence of a non-opioid dynorphin binding site on the secretory vesicle fractions of AtT20 cells that might be involved in ACTH release. The ability of ACTH itself to compete for the binding sites associated with the vesicles suggest that those sites may be involved in an autocrine loop.     

Functional motor innervation of brachial plexus roots. An intraoperative electrophysiological study

Human T-lymphocytic virus type 1 (HTLV-1) carriage is associated with a 2% to 5% lifetime risk of developing a severe, if not fatal, disease. In our Inner London antenatal population, we found that the carrier rate was 0.3%. The antenatal transmission rate is known to be very low, but if the infant is breastfed the transmission rate is up to 25%. It is therefore possible to interrupt the transmission cycle by advising against breastfeeding. The ethical and fiscal issues surrounding antenatal testing are addressed.     

Results of systematic speech sound monitoring in children with cleft palate

Two potent inhibitors of nitric oxide synthase (NOS), namely, NG-nitro-L-arginine (NNA) and NG-monomethyl-L-arginine (NMMA) were administered intracerebroventricularly (i.c.v.) in morphine-dependent mice to investigate their effects on abrupt withdrawal and naltrexone-precipitated abstinence signs. Male Swiss-Webster mice were rendered dependent on morphine by subcutaneous implantation of a morphine pellet containing 75 mg of morphine base. Mice implanted with placebo pellets served as controls. NMMA or NNA administered i.c.v. had minimal effects on body weight loss and hypothermia that occur during abrupt withdrawal of morphine. When administered i.c.v., both NNA or NMMA (0.1, 1 and 10 micrograms/mouse) dose-dependently inhibited naltrexone-induced stereotyped jumping behavior in mice. I.c.v. administration of NMMA also attenuated withdrawal induced fecal pellet formation. This effect, however, was not dose-dependent. In conclusion, these results suggest that brain NO plays an important role in the expression of behavioral signs of morphine withdrawal syndrome. In addition, these results support the idea that NOS inhibitors may be potentially useful in the treatment of opioid withdrawal syndrome.