Studies in several mammalian species have demonstrated that bilateral ablations of the auditory cortex have little effect on simple sound intensity and frequency-based behaviors. In the rat, for example, early experiments have shown that auditory ablations result in virtually no effect on the rat's ability to either detect tones or discriminate frequencies. Such lesion experiments, however, typ...

Multiunit recordings with microelectrodes were used to identify and delimit subdivision of auditory cortex in squirrels. In the same animals, cortical connections of subdivisions of auditory cortex were determined by placing injections of the tracer wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) into electrophysiologically defined locations. The electrophysiological resu...

Auditory attention has been examined extensively over the years, primarily by means of event-related brain potentials (ERPs). Sustained attention to specific targets embedded in a series of non-targets (e.g. the ‘oddball’ paradigm) causes an increase in the amplitudes of various components of the auditory ERP after about 80 ms and results in the appearance of new waveforms, such as the N2B and ...

Neuronal responses in auditory cortex show a fascinating mixture of characteristics that span the range from almost perfect copies of physical aspects of the stimuli to extremely complex context-dependent responses. Fast, highly stimulus-specific adaptation and slower plastic mechanisms work together to constantly adjust neuronal response properties to the statistics of the auditory scene. Evid...

Damage to the medial temporal lobe impairs the encoding of new memories and the retrieval of memories acquired immediately before the damage in human. In this study, we demonstrated that artificial visuoauditory memory traces can be established in the rat auditory cortex and that their encoding and retrieval depend on the entorhinal cortex of the medial temporal lobe in the rat. We trained rats...

Speech is a complex acoustic signal showing a quasiperiodic structure at several timescales. Integrated neural signals recorded in the cortex also show periodicity at different timescales. In this chapter we outline the neural mechanisms that potentially allow the auditory cortex to segment and encode continuous speech. This chapter focuses on how the human auditory cortex uses the temporal str...

The function of the profuse descending innervation from the auditory cortex is largely unknown; however, recent studies have demonstrated that focal stimulation of auditory cortex effects frequency tuning curves, duration tuning, and other auditory parameters in the inferior colliculus. Here we demonstrate that, in an anesthetized guinea pig, nonfocal deactivation of the auditory cortex alters ...

Objectives: The present project aimed at demonstrating that novelty detection is a basic principle of the functional organization of the auditory system, expanding from lower levels along the auditory pathway in the brainstem up to higher-order areas of the cerebral cortex. Traditionally, auditory novelty detection has been studied by means of the mismatch negativity (MMN) evoked potential, gen...