Cancellation model of pitch perception

A model of pitch perception is presented involving an array of delay lines and inhibitory gating neurons. In response to a periodic sound, a minimum appears in the pattern of outputs of the inhibitory neurons at a lag equal to the period of the sound. The position of this minimum is the cue to pitch. The model is similar to the autocorrelation model of pitch, multiplication being replaced by an operation similar to subtraction, and maxima by minima. The two models account for a wide class of pitch phenomena in very much the same way. The principal goal of this paper is to demonstrate this fact. Several features of the cancellation model may be to its advantage: it is closely related to the operation of harmonic cancellation that can account for segregation of concurrent harmonic stimuli, it can be generalized to explain the perception of multiple pitches, and it shows a greater degree of sensitivity to phase than autocorrelation, which may allow it to explain certain phenomena that autocorrelation cannot account for.     

Exfoliative dermatitis due to immunologically confirmed carbamazepine hypersensitivity

A 6-year-old Caucasian girl experienced a generalized erythematous skin rash during carbamazepine therapy. Over the next four days the eruption worsened into erythroderma with fever and generalized lymphadenopathy. Routine laboratory studies revealed increased serum levels of liver enzymes and eosinophilia. Immunologic reactivity to the anticonvulsant carbamazepine and its analogs was investigated both in vivo and in vitro by patch tests and lymphocyte proliferation assays, respectively.     

Reversible dementia due to valproic acid therapy

A progressive dementia syndrome (DSM IV) with frontal-subcortical features developed in a 72-year-old woman during valproate therapy (Depakine). Discontinuation of valproate resulted in complete recovery. Drugs are a common cause of reversible dementia. The association of dementia with valproate therapy is rare. Features of a subcortical dementia are indicative of a reversible cause. In addition, the possible role of drugs should always be considered in patients with cognitive decline.     

Absolute and relative pitch discrimination in serial pitch perception by birds.

Four European starlings (Sturnus vulgaris) were successfully trained to discriminate a set of temporally configured 4-tone sequences that rose in pitch on a whole-tone scale from a set of otherwise identical 4-tone sequences that fell in pitch. A series of transfer tests assessed their ability to maintain the discrimination (a) when the intensity of the tones in the patterns was varied and (b) when the patterns were shortened to 1, 2, or 3 tones. The discrimination was maintained when intensity values changed, which indicated that apparent loudness was not a relevant cue for accurate performance. When sequences were shortened, overall discrimination performance diminished. Shortened sequences produced evidence for both absolute and relative pitch perception in sequence discrimination. The discrimination depended in part on the ability to "name" particular pitches in the sequences and in part on the ability to detect that a given sequence rose or fell in pitch. Results have implications for cognitive processes in serial acoustic pattern perception by animals, for a comparative study of pitch perception guided by theories encompassing absolute and relative pitch, and for research seeking the functionally significant dimensions of natural birdsong. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversible thrombocytosis and anemia due to miconazole therapy

Miconazole was administered intravenously in six consecutive patients with, active coccidioidal infection. Such treatment was associated with progressive anemia and thrombocytosis. The hematological abnormalities appeared to be dose related and potentially reversible. Bone marrow studies demonstrated erythroid hypoplasia and increased or active platelet production in three subjects. No hemorrhagic or thrombotic episodes were identified. It is suggested that careful hematological monitoring be performed in subjects undergoing systemic miconazole therapy.     

Perceptual grouping due to pitch and amplitude in hallucinating schizophrenics

Acquired deficiencies of fibrinogen, antithrombin III and plasminogen are reported in liver disease, and it is known that their plasma levels fluctuate during the day. The aim of this study was to investigate the circadian rhythms of these three factors in chronic liver disease. Five groups of subjects were considered: (A) 15 healthy controls: (B) 15 patients with hepatic alcoholic steatosis; (C) 15 patients with chronic active hepatitis; (D) 15 patients with compensated cirrhosis of the liver, and (E) 15 patients with decompensated cirrhosis with ascites. The levels of fibrinogen, antithrombin III and plasminogen were determined in blood samples drawn in each subject during the span of a day every 3 h starting from midnight. The time-related values were analyzed using the 'population-mean cosinor' method. Groups A and B presented a significant (p < 0.05) circadian rhythm for each variable, group C a significant (p < 0.05) circadian rhythm for fibrinogen and antithrombin III and groups D and E no significant (p > 0.05) circadian rhythms. Statistically significant differences (p < 0.05) were demonstrated among the groups in the mean daily levels of the three variables by ANOVA, the concentrations decreasing with disease severity. These data confirm the existence of a significant diurnal periodicity in the circulating levels of fibrinogen, antithrombin III and plasminogen in controls and suggest that liver disease is associated with progressive circadian modifications in the temporal structure of fibrinogen, antithrombin III and plasminogen, related to the stage of the liver disease. The rhythm derangements may be considered markers of evolution in liver disease.     

Musical pitch perception with electrical stimulation of the cochlea

Studies were undertaken to investigate the ability of a user of the Nucleus multi-electrode cochlear implant to judge pitch in the context of musical intervals. The subject had qualified as a musical instrument tuner before he received his implant, and was able to judge the intervals between electrical sensations with neither training nor the guidance of familiar melodies. The procedures used were interval estimation, and interval production by the method of adjustment. The pitch of the electrical stimulation was controlled by varying the pulse repetition rate, the active electrode position, or two combinations of these parameters. Further studies employed sinusoidally amplitude modulated pulse trains with varying modulation frequency. The results showed that rate or modulation frequency could convey musical pitch information over a limited range (approximately two octaves). The data were directly comparable with the relationship between musical intervals and frequency for normal hearing. The pitch related to electrode place varied in accordance with the tonotopic organization of the cochlea, and also appeared to be able to support musical intervals. When both place and rate varied together, the place-related pitch was generally dominant. In all cases, the judgement of intervals tended to diverge from their acoustic counterparts as the intervals became larger.     

Mechanisms of signal analysis and pattern perception in periodicity pitch

Progress in the knowledge of auditory processing of complex sounds has been made through coordinated psychophysical, physiological and theoretical studies of periodicity pitch and combination tones. Periodicity pitch is the basis for human perception of musical notes and pitch of voiced speech. The mechanism of perception involves harmonic pattern recognition on the complex Fourier frequency spectra generated by auditory frequency analysis. Combination tones are perceptible distortion tones generated within the cochlea by nonlinear interaction of component stimulus tones. Perception of periodicity pitch is quantitatively accounted for by a two-stage process of frequency analysis subject to random errors and significant nonlinearities, followed by a pattern recognizer that operates very efficiently to measure the period of musical and speech sounds. The basic characteristic of the first stage is a Gaussian standard error function that quantifies the randomness in aural estimation of frequencies of component tones in a complex tone stimulus. Efficient aural measurement of neural spike intervals from the eighth nerve provides a physiological account for the psychophysical characteristic of aural frequency analysis with complex sounds. Although cochlear filtering is an essential stage in auditory frequency analysis, neural time following, rather than details of the filter characteristics, is the decisive factor in determining the precision of aural frequency measurement. It is likely that peripheral auditory coding is similar for sounds in periodicity pitch and in speech perception, although the 'second stage' representing central processing would differ.     

Tempo discrimination of musical patterns: effects due to pitch and rhythmic structure

The purpose of this research was to investigate a set of factors that may influence the perceived rate of an auditory event. In a paired-comparison task, subjects were presented with a set of music-like patterns that differed in their relative number of contour changes and in the magnitude of pitch skips (Experiment 1) as well as in the compatibility of rhythmic accent structure with the arrangement of pitch relations (Experiment 2) Results indicated that, relative to their standard referents, comparison melodies were judged to unfold more slowly when they displayed more changes in pitch direction, greater pitch distances, and an incompatible rhythmic accent structure. These findings are suggested to stem from an imputed velocity hypothesis, in which people overgeneralize certain invariant relations that typically occur between melodic and temporal accent structure within Western music.     

Reversible dementia due to dural arteriovenous fistula: a simple surgical option

Dural AVMs can produce a wide variety of symptoms related to raised intracranial pressure, venous congestion, and cerebral ischaemia. We present a unique case of reversible dementia, due to venous hypertension. The cerebral ischaemia was caused by extensive bilateral arteriovenous malformations of the external carotid system, which drained into the superior sagittal and transverse sinuses and resulted in venous hypertension. Although partial occlusion by endovascular embolization and ligation procedures had some effect, only 'scalping and silastic implantation' gave satisfactory amelioration of symptoms.     

Relative pitch perception in Japanese monkeys (Macaca fuscata).

To investigate whether monkeys perceive relative pitch, the author trained 3 Japanese monkeys (Macaca fuscata) to detect changes from rising to falling contours of 3-tone sequences. Tone sequences were presented serially with transposition, so monkeys were urged to attend to cues other than the absolute frequency of a component tone. Results from probe tests with novel sequences showed that monkeys discriminated by the relative pitch when the frequency ranges of sequences were within the training range, showing a similar tendency as birds in previous studies (e.g., S. H. Hulse, J. Cynx, & J. Humpal, 1984). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decreased antidiuretic response in diabetes insipidus during prolonged treatment with carbamazepine presumably due to enzym-induction

Carbamazepine (CA)-induced antidiuresis and fluorescence in urinary cortisol assay was compared during short-term and prolonged treatment in 3 patients with pituitary diabetes insipidus. The fluorescence induced by excreted CA-metabolite(s) (probably CA-10-11 epoxide and its derivatives) was used for the rough clinical estimation of the rate of metabolic elimination of the drug. A marked decrease was observed both in the antidiuretic response induced by CA and excretion of CA metabolite(s) during prolonged treatment - with a fixed dose of CA. These findings suggest that diminishing antidiuretic effectiveness might be due to auto-induction of CA. Auto-induction of CA may explain the delay in improvement of renal concentrating operation in patients with DI during long-term treatment with fixed doses of CA. Another clinical consequence of this mechanism may be the prevention of the development of water intoxication in neuro-psychiatric patients undergoing chronic treatment with CA.     

A dual mechanism for sound pitch perception: new evidence from brain electrophysiology

The N1 component of the auditory brain evoked potential was used as a direct electrophysiological index, to study how the perception of pitch for complex periodic tones can be influenced by the phase of the harmonics that make up a sound, according to their ranks. Results showed that in the low pitch and/or high spectra region, N1 latency was modified by phase, whereas it was not in the high pitch and low spectra region. These data help bring evidence towards a dual mechanism for pitch perception, and demonstrate that these processes take place within 110 ms following stimulus onset. Results are compatible with a model based on the resolvability of components and on the bandwidth of auditory filters.     

Relative pitch perception is constrained by absolute pitch in songbirds (Mimus, Molothrus, and Sturnus).

Assessed the ability of starlings (Sturnus vulgaris), cowbirds (Molothrus ater), and a mockingbird (Mimus polyglottos) to maintain a relative pitch discrimination when the absolute frequencies of a serial pattern of tones were changed. In Exp I, 7 Ss learned a relative pitch discrimination between 4-tone sequences that either ascended or descended in frequency within a 1-octave range. Results show that Ss lost the discrimination completely when the frequency range was shifted an octave above or below the initial training range. Recovery of the discrimination in the novel ranges was slow, and considerable relearning was necessary. Starling Ss, however, easily generalized the relative pitch discrimination to new frequencies within the original training range. In Exp II, 4 starlings were trained on the same relative ascending–descending discrimination in 2 noncontiguous frequency ranges. Ss lost the discrimination when transferred into a novel gap of frequencies between the original training ranges. Findings demonstrate that songbirds can learn a relational discrimination between serial pitch patterns but that their ability to generalize the discrimination is constrained markedly by the frequency range in which the sound sequences are learned initially. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversible left atrial dysfunction possibly due to afterload mismatch in patients with left ventricular dysfunction

OBJECTIVE: The aim of this study was to define the clinical-therapeutical approach to endometrial cancer now being followed in some of the most important centers of reference for gynecological cancer in North America by means of a questionnaire. STUDY DESIGN: The questionnaire focused on four principal areas: (1) surgical staging and therapy; (2) adjuvant treatment; (3) treatment modifications; and (4) management of advanced stages (FIGO III-IV). RESULTS: There were 48 evaluable responses (77%) received by the end of December 1994 which were considered for this analysis. Lymphadenectomy is utilized routinely in 26/48 centers (54.2%) and in selective clinical-pathological conditions in another 21/48 centers (43.5%). In the majority of centers (31/48; 64.6%) radical surgery is utilized for selected indications such as cervical involvement. Only 3/48 (6.2%) centers consider the vaginal approach totally inappropriate. The great majority (40/48; 83.3%) of the centers considered postsurgical adjuvant therapy to be necessary in FIGO Stage Ic. Brachytherapy is routinely performed in 3 centers (6.2%) in postsurgical management of Stage I endometrial cancer, while the majority of the centers (31/48; 64.6%) perform brachytherapy of the vaginal vault in certain clinical-pathological conditions. A wide variety of treatments are used for advanced stages (FIGO III-IV). CONCLUSIONS: It emerges that some controversial aspects exist on endometrial cancer treatment, and these conflicting data need a large-scale multicenter randomized clinical trial.     

Time perception and reproduction in young adults with attention deficit hyperactivity disorder.

Adults with attention deficit hyperactivity disorder (ADHD; n ?=? 104) were compared with a control group (n ?=? 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than did the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)