Perceiving Rhythmic Repetition and Change Across Development: Effects of Concurrent Pitch

The ability to perceive repetition and change in rhythm is fundamental to music understanding. How is this ability affected by other musical dimensions, such as pitch? We compared the perception of rhythmic repetition and change in rhythm-only stimuli versus rhythm-and-pitch stimuli. A sample of 357 participants, aged from 6 to 22 years, performed Same (repetition) versus Different (change) judgments on rhythmic stimuli with and without concurrent pitch variation. Rhythm-and-pitch stimuli impaired the perception of rhythmic repetition but not the perception of change, and this was independent from participants’ age. Our findings are consistent with two concurrent effects of pitch on rhythmic perception: a change-highlighting effect, acting only in rhythmic change, and a working-memory-overload effect that acts in both repetition and change. We discuss the implications regarding composer–listener communication across development.

Middle-ear myoclonus

Tinnitus produced by repetitive contraction of the middle-ear muscles is a rare condition. We present an interesting case of bilateral middle-ear myoclonus causing incapacitating tinnitus in a patient with multiple sclerosis. Otological examination demonstrated rhythmic involuntary movement of the tympanic membrane. These movements correlated with a rhythmic ‘rushing wind’ noise perceived by the patient. Oropharyngeal examination showed no evidence of palatal myoclonus. Impedance audiometry confirmed rhythmic change in the middle-ear volume. Medical management was unsuccessful. The patient’s tinnitus was subsequently cured with bilateral sectioning of the tensor tympani and stapedial tendons.

Deficient pulsatile thyrotropin secretion in the low-thyroid-hormone state of severe non-thyroidal illness

Custro N, Scafidi V, Gallo S, Notarbartolo A. Deficient pulsatile thyrotropin secretion in the low-thyroid-hormone state of severe non-thyroidal illness. Eur J Endocrinol 1994;130:132–6. ISSN 0804–4643. Twenty-four-hour thyrotropin (TSH) profiles in eight severely ill patients were compared with those of six healthy subjects. The profiles were assessed using the cosinor method to evaluate circadian variations and using the Pulsar algorithm to analyze episodic secretion. In the normal subjects, the typical periodicity of TSH secretion showed a mean level in the rhythm (mesor) of 2.03 mU/l, The amplitude (half the extent of rhythmic change in the cycle) was 0.58 mU/l; the acrophase (the delay from midnight (0 degrees) of the highest level in the rhythm) was −9.9 degrees. In contrast, severely ill patients showed only slight and anticipated elevations of serum TSH levels (mesor 0.93 mU/l, amplitude 0.22 mU/l, acrophase +82.4 degrees). Moreover, whereas the episodic TSH secretion in healthy individuals consisted of 5–8 pulses/24 h, mainly clustered around midnight, only one pulse of reduced amplitude was detected in two of the eight severely ill patients and no pulses in the other six. Since earlier studies have indicated that the loss of TSH pulsatility is associated with the relative insensitivity of the thyrotrophs to low thyroid hormone levels and our analytical procedures have demonstrated that 24 h pulsatile pattern of TSH closely overlapped with baseline TSH secretion, it seems reasonable to assume that low-thyroid-hormone state, deficient pulsatile TSH secretion and altered nyctohemeral TSH periodicity do not coincide by chance, but that there is a causal relationship between such abnormalities in severely ill patients. Nicola Custro, Cattedra di Patologia Medica, Via del Vespro, n.141, 90127 Palermo, Italy