Neuronal bases of categorization in starling song

WOS:000089176400011International audiencePrevious studies on starling song had shown that different categories of songs are produced and discriminated. In the present study, both playback experiments in the field and electrophysiological recordings of single cells in field L (main central auditory area) were used in order to understand the perceptual bases of category recognition. In both cases, synthesized variants were used where different parameters could be changed. A method of backward correlation was used in order to visualize and determine the precise elements in song towards which the neurons responded. A high proportion of neurons was found that responded selectively to particular features in the species-specific songs. Series of neurons with similar or complementary selectivities were found. We did not find any 'category-detector' as such but key elements appeared both in neuronal selectivity and in behavioural discriminations. The data favour the propositions of the pattern recognition theory, with a multiple feature model. (C) 2000 Elsevier science B.V. All rights reserved

Analyse fonctionnelle des réponses neuronales aux chants naturels chez l'étourneau

National audienc

Functional organization of the forebrain auditory centres of the European starling: A study based on natural sounds

WOS:000232320100002International audienceThe field L complex is thought to be the highest auditory centre and the input in the song vocal nuclei. Different anatomical and functional subdivisions have been described in field L. Auditory neurons of field L are well activated by natural sounds and especially by species-specific sounds. A complex sound coding appears to exist in field L. However, until now, the spatial organization of the different functional subdivisions has been described only using artificial sounds. Here, we investigated the spatial distribution of neuronal responses in field L to species-specific songs. Starlings seemed to be a very appropriate species for this investigation, both because of their complex vocal behaviour that implies different levels of categorization and their neuronal responses towards complex song elements. Multi-unit recordings were performed in wild starlings that were awake. The method of backward correlation was used to visualize the functional organization and we represented the neuronal responses as both activity maps and correlation maps. The use of natural sounds allowed us to define several functional sub-areas with different neuronal processing. These results show that field L is involved in a more complex task than simple frequency processing

Flash evoked responses in a song control nucleus of the zebra finch (Taeniopygia guttata castanotis)

Bischof H-J, Engelage J. Flash evoked responses in a song control nucleus of the zebra finch (Taeniopygia guttata castanotis). Brain Research. 1985;326(2):370-374.The song of the zebra finch is facilitated and altered by the presence of a female. Thus, visual information should affect the song system of the bird. Visually evoked potentials can be recorded from n. hyperstriatum ventrale pars caudale (HVc). The long latency of this potential and its variability indicate several processing steps between primary sensory areas of the telencephalon and HVC. Within HVc, under these experimental conditions no interaction between acoustic and visual input could be demonstrated. However, at the dorsal border and within the shelf below HVc, visual information seems to enhance acoustically evoked potentials

Ergebnisse aus der sozialwissenschaftlichen Umweltforschung

SIGLEBibliothek Weltwirtschaft Kiel C 142833 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A Rapid Correlation Method for the Analysis of Spectrotemporal Receptive-Fields of Auditory Neurons

WOS:A1995TG02300013International audienceThe evaluation of spectre-temporal receptive fields in auditory neurons makes use of a correlation technique that needs a high amount of calculation time. We present a method in which 2-ms time bins of post-stimulus time histograms, rather than every action potential, are the basis for correlation with the acoustic spectrum of the stimulus. In a t test the content of each bin is classified as excitatory, inhibitory or responseless. The bin width is adjusted to the temporal resolution of the units as determined in a gap detection analysis. The method presented here saves a substantial amount of analysis time and reveals adequately spectre-temporal receptive fields

Role of the Zebra Finch Auditory Thalamus in Generating Complex Representations for Natural Sounds

We estimated the spectrotemporal receptive fields of neurons in the songbird auditory thalamus, nucleus ovoidalis, and compared the neural representation of complex sounds in the auditory thalamus to those found in the upstream auditory midbrain nucleus, mesencephalicus lateralis dorsalis (MLd), and the downstream auditory pallial region, field L. Our data refute the idea that the primary sensory thalamus acts as a simple, relay nucleus: we find that the auditory thalamic receptive fields obtained in response to song are more complex than the ones found in the midbrain. Moreover, we find that linear tuning diversity and complexity in ovoidalis (Ov) are closer to those found in field L than in MLd. We also find prevalent tuning to intermediate spectral and temporal modulations, a feature that is unique to Ov. Thus even a feed-forward model of the sensory processing chain, where neural responses in the sensory thalamus reveals intermediate response properties between those in the sensory periphery and those in the primary sensory cortex, is inadequate in describing the tuning found in Ov. Based on these results, we believe that the auditory thalamic circuitry plays an important role in generating novel complex representations for specific features found in natural sounds