Hearing in passerine and psittacine birds: A comparative study of absolute and masked auditory thresholds.

Operant conditioning and a psychophysical tracking procedure were used to measure auditory thresholds for pure tones in quiet and in noise for seven species of small birds—the budgerigar, canary, cockatiel, European starling, song sparrow, swamp sparrow, and the zebra finch. Audibility curves are roughly similar among the seven birds, with the maximum sensitivity between 2 and 5 kHz and poorer sensivitity outside this narrow region. Critical ratios (signal-to-noise ratio at masked threshold) were calculated from pure-tone thresholds in noise. Except for the budgerigar, the critical ratio functions of all birds increase at the rate of 3 dB/octave. This pattern is typical of that observed in most vertebrates. Critical ratios in the budgerigar, on the other hand, decrease gradually from 0.5 kHz to 2.8 kHz and increase dramatically above 2.8 kHz. The present research demonstrates that the critical ratio function for the budgerigar is not only different from other vertebrates but also different from other birds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maturation of spatial delayed responses to auditory cues in kittens.

Tested 40 mongrel cage-reared kittens in 4 age groups (45, 60, 120, or 180 days) for locomotor delayed responses to auditory cues in a 2-choice situation. Each S was trained for 15 days (300 trials); delays of 5 different durations (0-27 sec) were randomly given in each session. Performance did not improve as a function of age. All groups showed some immediate capacity for the task, all improved with training, and in all ages more errors were made after longer than after shorter delays. The ability to remember the locus of a brief sound over short periods of time appears to be mature before weaning in kittens. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypoxia and auditory thresholds

Two cases are presented of bilateral ureteral obstruction and uremia due to pressure from nodes involved in disseminated lymphoma. Their successful managment is reported.     

Effect of restricted cortical lesions on absolute thresholds and aphasia-like deficits in Japanese macaques.

The effect of small bilateral cortical lesions on pure-tone audiograms and on the ability to discriminate between two types of Japanese macaque coo vocalizations was determined in 4 Japanese macaques. A lesion that included the middle portion of the superior temporal gyrus of both hemispheres, that is, the primary and secondary auditory areas, resulted in a partial hearing loss as well as an inability to discriminate the vocalizations. Lesions that included the ventral portions of the superior temporal gyrus of both hemispheres but spared auditory cortex on one side also resulted in a partial hearing loss but had either a small effect or no effect on the ability to discriminate the vocalizations. Bilateral ablation of the dorsal superior temporal gyrus and adjacent parietal and occipital areas did not result in a hearing loss and had no effect on the ability to discriminate the vocalizations. Results suggest that a hearing loss may be produced by lesions that involve small portions of the ventral two-thirds of the superior temporal gyrus bilaterally although the resulting loss is not as great as that observed with larger lesions. However, the aphasia-like deficit appears to result from a lesion of primary and/or secondary auditory cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral auditory thresholds for sinusoidal electrical stimuli in the cat

Behavioral thresholds were measured in four cats by training them to respond behaviorally to acoustic auditory stimuli using food as a reward in an operant reinforcement paradigm. Following training, the subjects were implanted unilaterally with either a scaled-UCSF electrode containing four contacts or an electrode array containing eight intracochlear contacts and one extracochlear contact under temporalis muscle. Behavioral thresholds for electrical stimuli were obtained as a function of sinusoidal frequency, duration, and electrode configuration. Threshold functions for both electrode types and all animals had minima between 48 and 125 Hz and, in general, were relatively flat below this minima; functions increased at 3-6 dB/octave from 96 Hz to 1 kHz. Threshold varied predictably as a function of electrode configuration, with thresholds decreasing as much as 20 dB as electrode spacing was widened from a radial bipolar (200-microns separation) to a monopolar configuration (apical stimulating and temporalis return). With long-duration stimuli, increasing the electrode separation systematically increased the slope of the threshold-versus-frequency contours in all animals. Irrespective of electrode type or configuration, charge/phase thresholds for single-cycle sinusoids were relatively flat for stimulus periods up to 1-5 ms, approximating a constant charge/phase determination of threshold. At phase durations greater than 5 ms, charge thresholds increased at a rate slightly above 6 dB/octave (constant peak current), which was suggestive of neural accommodation. Thresholds for the cat share many features with those reported for implanted humans and monkeys.     

The development of basic auditory processes in infants.

Reviews studies of basic auditory processes (absolute and differential thresholds, masking) in infants. It is argued that autonomic and physiological responses to sounds may measure "attentional" thresholds rather than thresholds of hearing. A behavioral technique for threshold assessment involving reinforcement of a head turn to a sound source is described and used to determine thresholds for sounds in quiet and in background noise. (French abstract) (84 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of auditory feedback in canary song development.

Describes studies conducted with an inbred strain of Belgian "Wasserschlager" canaries bred selectively by aviculturalists in Europe for particular patterns of singing behavior. As in other songbirds, early deafening had drastic effects on the song of the roller canary, a caudueline finch, resulting in a song that was much simpler and more variable than the normal. The repertoire of syllable types was reduced from 30 to a mean of 5.0. Loud white noise was successfully used as a reversible method of cutting off auditory feedback from vocal behavior. Although suffering permanent elevation of hearing thresholds, Ss reared in noise to 200 days, singing at first like deaf Ss, subsequently increased their syllable repertoires significantly. Ss reared in noise to weaning at 40 days, again partly deaf, achieved a normal repertoire size when stimulated with a singing adult. Without such stimulation the repertoire was significantly reduced, showing that canary song is not fully innate. Although abnormal, the song of deaf canaries retained more species-specific features than did the song of emberizine sparrows when the songs developed without auditory feedback. Results are interpreted in terms of a sensory template theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aversive conditioning in neonatal kittens.

Trained 45 kittens less than 10 days of age to crawl over a barrier in a 1-way shuttle box either to escape or avoid pressurized air. Both instrumental escape and avoidance learning occurred. Escape performance was an increasing negatively accelerated function of air pressure. Avoidance behavior was not as stable or of the same form as that previously observed in infant dogs. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of auditory strategies of attention.

Investigated focused and divided attention in right-handed children in 2 age groups: 6.5–7.5 and 10–11 yrs. Ss listened to lists of simultaneous word pairs that were monitored for the presence of designated target words. An analysis of correct and incorrect response rates showed that there was a general increase in the efficiency of both attention tasks with age, although selective listening performance improved to a greater extent than divided attention. In focused attention, selecting one input and ignoring another developed at different rates. In divided attention, there was a right ear advantage that remained constant across the 2 age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postnatal development of delta-opioid receptor subtypes in mice

1. The density and affinity of binding sites for the delta-selective opioid ligands [3H]-[D-Ala2, Asp4]deltorphin (DELT-I), [3H]-[D-Ala2Glu4]-deltorphin (DELT-II), [3H]-[D-Pen2,D-Pen5]enkephalin (DPDPE), and [3H]-naltrindole (NTI) were determined in whole brain from 10, 15, 25 and 60 day-old C57BL mice. 2. At all ages, the analyses of the homologous displacement curves, gave best fits to single rather than to multiple site models. The binding capacity (Bmax) labelled by [3H]-NTI was about one half that labelled by [3H]-DELT-I, [3H]-DELT-II and [3H]-DPDPE. In 25 and 60 day-old mouse brain the DPDPE Bmax was 25% less than the deltorphin-II Bmax. 3. In saturation experiments, specific binding of [3H]-DELT-I on adult mouse brain homogenates was best fitted by a two-site model (34%, high affinity site, Kd = 1.08 nM and 66% low affinity sites, Kd = 39.9 nM). 4. DPDPE produced a biphasic inhibition of specific [3H]-DELTI-I binding, from 15 days of age onwards. The relative percentage of high and low affinity sites was 72% and 28% in 15 day-, 65% and 35% in 25 day- and 30% and 70% in 60 day-old mice. 5. In adult mouse brain labelled with [3H]-DELT-I, DELT-II recognized 71% of high-affinity and 29% of low-affinity sites DELT-I and DPDPE produced monophasic inhibition of specific [3H]-DELT-II binding to brain homogenates of adult mice. 6. These data suggest that a sub-population of delta-sites (probably the delta 2-subtype), recognized by DELT-I, with high affinity for DELT-II and low affinity for DPDPE develops from 25 days onward. 7. In electrically stimulated mouse vas deferens (MVD) the rank order of potency of the three delta-agonists was: DELT-I > DELT-II > DPDPE in 10 day-old mice: and DELT-I- DELT-II > DPDPE, from 25 days onward. During this time, the potency of DELT-II increased about 15 fold whereas the potency of DELT-I and DPDPE increased only 5 times. The higher efficacy of DELT-II could depend on receptor maturation towards the delta 2-subtype.     

Sensation seeking, augmenting-reducing, and absolute auditory threshold: A strength-of-the-nervous-system perspective.

Tested 40 male and female high school and college students on the General and the Disinhibition subscales of the Sensation Seeking Scale (Form IV), the Reducer-Augmenter Scale (RAS), and the absolute auditory threshold (AAT). General sensation seeking correlated significantly with the RAS and the AAT. Both results were general across sex. These findings, that high-sensation seekers tend to be reducers and to lack sensitivity to weak stimulation, are interpreted as supporting strength-of-the-nervous-system theory more than the formulation of M. Zuckerman et al (see record 1975-02479-001). (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Normal and abnormal visual development in kittens: Insights into the mechanisms that underlie visual perceptual development in humans.

Examines certain anatomical peculiarities of the cat visual system and summarizes some of the parallels (e.g., possession of stereopsis) and differences (e.g., in various spatial thresholds) between the perceptual abilities of cats and humans. These similarities and the larger number of parallels between the 2 species that can be drawn during development, reinforce the validity of choosing the cat for study of the mechanisms that underlie human visual development. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postnatal growth and psychomotor development in small for gestational age Brazilian infants.

Early psychomotor development (PD), as measured by the Gesell Developmental Schedules, of 29 infants that were small for gestational age (SGA) was more dependent on postnatal growth than the PD of 51 infants whose birth weight was appropriate for gestational age. The significant association of postnatal growth with PD in SGA Ss at 4, 8, and 12 mo of age was not explained by birth weight or SES. Findings support the hypothesis that the factors that determine postnatal growth in SGA infants also affect neurointegrative development. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The automated prediction of hearing thresholds in sleeping subjects using auditory steady-state evoked potentials

OBJECTIVE: To examine the relationship between auditory steady-state evoked potentials (SSEPs) and behavioral thresholds in sleeping subjects. DESIGN: 60 adults and children with hearing thresholds ranging from normal to profound were selected on the basis of appropriate audiograms. Behavioral audiograms were determined at the octave frequencies 250-4000 Hz. These behavioral thresholds were then compared with the SSEP thresholds obtained during natural sleep for adults, or natural or sedated sleep for children. RESULTS: A strong relationship between behavioral and SSEP thresholds was observed. The strength of the relationship increased with increasing frequency and increasing degree of the loss. On the basis of these data, the prediction of behavioral thresholds from SSEP levels was determined. It was found that the standard deviation of the error in this prediction decreased with increasing frequency and increasing degree of the loss. There was no significant age effect in the results obtained at any of the frequencies. CONCLUSION: The results suggest the SSEP technique can be used as a predictor of behavioral threshold in adults and children at the frequencies 250-4000 Hz.     

Strain differences in auditory thresholds in the canary (Serinus canarius).

Canaries (Serinus canarius) of the Belgian waterslager strain from two different colonies were trained with operant techniques for audiometric testing. For both young and old birds, absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB (SPL) higher than those of other song birds, including canaries of other strains. Thus the Belgian waterslager canary, selectively bred for loud, low-pitched song, has also developed poor high-frequency hearing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive development in kittens (Felis catus): A cross-sectional study of object permanence.

Administered tests of object permanence to 28-, 35-, 48-, and 150-day-old kittens (Felis catus) in order to assess as accurately as possible the developmental level reached at each age group in this Piagetian cognitive capacity. The results indicate that 28-day-old-kittens visually tracked a moving object in their perceptual field (Stage 2); 35-day-olds recovered a hidden object only if they had initiated a search movement at the time of disappearance (Stage 4a); 48- and 150-day-olds mastered multiple visible displacements (Stage 5b). The study showed that the upper limit, Stage 5b, observed in adult cats was reached by Day 48, which indicates a rapid development of object permanence in this species. Results are discussed in relation to object permanence in human babies and in terms of the relevance of object permanence to predatory behavior in the domestic cat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)