role of f0 alignment in distinguishing intonation categories: evidence from American english

Under the autosegmental-metrical (AM) theory of intonation, the temporal alignment of fundamental frequency (F0) patterns with respect to syllables has been claimed to distinguish pitch accent categories. Several experiments test whether differences in F0 peak or valley alignment in American English phrases would produce evidence consistent with a change from (1) a H* to a H+L* pitch accent, and (2) a L* to a L+H* pitch accent. Four stimulus series were constructed in which F0 peak or valley alignment was shifted across portions of short phrases with varying stress. In Experiment 1, participants discriminated pairs of stimuli in an AX task. In Experiment 2, participants classified stimuli as category exemplars using an AXB task. In Experiment 3, participants imitated stimuli; the alignment of F0 peaks and valleys in their productions was measured. Finally, in Experiment 4, participants judged the relative prominence of initial and final syllables in stimuli to determine whether alignment differences generated a stress shift. The results support the distinctions between H* and H+L* and between L+H* and L*. Moreover, evidence consistent with an additional category not currently predicted by most AM theories was obtained, which is proposed here to be H*+H. The results have implications for understanding phonological contrasts, phonetic interpolation in English intonation, and the transcription of prosodic contrasts in corpus-based analysis.

Gradients of Facial EMG and Cardiac Activity During Emotional Stimulation

We investigated the effects of a serial presentation of short emotional stimuli on facial EMG, mood and autonomic functioning including total respiratory resistance (TRR). Twenty asthmatic and 20 nonasthmatic subjects viewed series of happy and depressing pictures and Velten statements. Each series consisted of nine affectively homogeneous stimuli plus one neutral stimulus. During prestimulus, presentation and imagination intervals of each stimulus presentation, heart period (HP) and EMG activity over corrugator supercilii, orbicularis oculi and zygomaticus major muscle sites were recorded. Each series was followed by 1 min measurements of TRR, HP, respiratory sinus arrhythmia, ventilation, and mood. Each stimulus was rated with respect to pleasure and arousal. Successive increases of corrugator EMG were observed throughout the series of depressing and happy stimuli. These gradients were comparable for prestimulus, presentation or imagination intervals, thus yielding no evidence for response habituation or sensitization. Other muscle sites showed only negligible EMG gradients, while HP revealed successive shortening over each stimulus series. Marginal evidence was found to support the suggestion that successive corrugator increases affected mood and stimulus evaluations. Subjects with significant positive corrugator EMG gradients throughout depressing pictures revealed significantly lower TRR following the stimulus series. The observed changes in HP and TRR are compatible with an economical model of autonomic-somatic coupling.

Changes in the response states of primate spinothalamic tract cells caused by mechanical damage of the skin or activation of descending controls

1. The responses of a population of 318 spinothalamic tract (STT) cells to mechanical stimulation of the skin were recorded in anesthetized macaque monkeys by several teams of investigators. The responses were subjected to k-means cluster analysis, a multivariate statistical procedure. 2. For an analysis that pertained to the responsiveness of the neurons, the mean responses to four standard mechanical stimuli (Brush, Pressure, Pinch, and Squeeze) were used. Although no true clusters were found, the cells could be partitioned into four groups (called clusters a, b, c, and d) that responded progressively more vigorously to the stimuli. 3. For an analysis that pertained to the selectivity of the cells for various stimulus intensities, from innocuous to highly noxious, the data were normalized by taking the ratio of the mean response evoked by each stimulus to the sum of the responses and multiplying by 100. This procedure does not have a bias toward selection of any particular number of clusters and resulted in three clusters of STT cells. 4. Cluster 1 STT cells responded best to Brush. Cluster 2 cells responded weakly to Brush and Pressure and maximally to Pinch. Cluster 3 cells responded weakly to Brush, Pressure, and Pinch and maximally to Squeeze. 5. The response states of STT cells with respect to mechanical stimulation of the skin can be defined by their cluster assignments on the basis of the responsiveness (clusters a-d) and selectivity (clusters 1-3) of the cells. The response states of newly recorded STT cells can be determined by discriminant analysis from the nearest centroids of the two types of clusters in the reference population of STT cells. 6. No consistent changes in response state were detected when a second series of mechanical stimuli was applied 1 cm from the site stimulated initially or when the stimulus series was alternately repeated at the initial site and at progressively more proximal sites. However, when the stimulus series was applied five times to the initial site, the response state of five of eight cells tested showed a change. Although a change in response state required repetitive damage, even a single stimulus series increased background activity and responses to Brush at undamaged sites. 7. The background activity and responses to Brush and Pressure of all five STT cells recorded in the superficial laminae increased after repeated testing. The background activity of five STT cells recorded in the nucleus proprius also increased, but the responses of only three of the cells to Brush and Pressure increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Present Vestibular Status of Subjects Implanted with Auditory Prostheses

Electronystagmographic studies were performed on all 13 patients with the caloric stimulus series, omitted in two subjects with external otitis. Eleven of the 13 subjects exhibited normal eye movement screening tests. Of the remaining nine subjects who could be evaluated, all demonstrated markedly reduced or absent caloric-induced nystagmus responses. These results confirmed preoperative vestibular test findings performed by implant surgery teams and indicated that the vestibular systems of the patients were severely damaged.