Binaural response-specific bands in primary auditory cortex (AI) of the cat: Topographical organization orthogonal to isofrequency contours

Middlebrooks, John C.; Dykes, Robert W.; Merzenich, Michael M.

doi:10.1016/0006-8993(80)91257-3

Cited by 255 publications

(117 citation statements)

References 25 publications

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…All subthreshold auditory effects were generated with stimuli presented in the contralateral auditory field, which is consistent with known binaural inputs to auditory cortex (Brugge and Merzenich, 1973;Imig and Adrian, 1977;Middlebrooks et al, 1980). Furthermore, progressive increases in auditory stimulus intensity resulted in concomitant response changes, which is also a common response feature observable in many auditory cortices.…”

Section: Discussionsupporting

confidence: 76%

Subthreshold auditory inputs to extrastriate visual neurons are responsive to parametric changes in stimulus quality: Sensory-specific versus non-specific coding

2008

View full text Add to dashboard Cite

A new subthreshold form of multisensory processing has been recently identified that results from the convergence of suprathreshold excitatory inputs from one modality with subthreshold inputs from another. Because of the subthreshold nature of the second modality, descriptive measures of sensory features such as receptive field properties or location are not directly apparent as they are for traditional bimodal neurons. This raises the question of whether or not subthreshold signals actually convey sensory-specific receptive field information as seen in their bimodal counterparts, or if they represent non-specific effects such as arousal. The present experiment addressed this issue in visually-responsive neurons from the cat posterolateral lateral suprasylvian cortex (PLLS). Singleunit electrophysiological techniques were used to record neuronal responses to visual, auditory and combined visual-auditory stimuli while the intensity of stimulation in the subthreshold auditory modality was systematically altered. The results showed that subthreshold multisensory neurons were sensitive to changes in auditory stimulus intensity. These receptive field sensitivities are similar to those observed in bimodal neurons and thereby represent sensory-specific, not arousal-related responses. In addition, these results provide further support for the notion that multisensory processing occurs along a dynamic continuum of neuronal convergence patterns from bimodal to purely sensory-specific.

show abstract

Section: Discussionsupporting

confidence: 76%

Subthreshold auditory inputs to extrastriate visual neurons are responsive to parametric changes in stimulus quality: Sensory-specific versus non-specific coding

2008

View full text Add to dashboard Cite

show abstract

“…In the present study, clusters of binaural regions were found within AI composed of EE, EO, or EI response types, which crossed isofrequency contours. The distribution of binaural classes in the rabbit AI is similar to what has been described in AI of several other species, such as the cat (Imig and Adrian, 1977;Middlebrooks et al, 1980;Schreiner, 1991Schreiner, , 1995 and rat (Kelly and Sally, 1988), but has not been reported before in this species. TC patches were also associated with the clustered distribution of binaural classes in AI.…”

Section: Auditory Fields and Tc Patchessupporting

confidence: 85%

“…Although physiological (Colwell and Merzenich, 1975;Middlebrooks et al, 1980) and anatomical (Middlebrooks and Zook, 1983;Angelucci et al, 1993;McMullen and de Venecia, 1993;de Venecia and McMullen, 1994;Hashikawa et al, 1995;Cetas et al, 1999) evidence for the existence of multiple parallel pathways linking the auditory thalamus and AI has existed for years, there have been few attempts to correlate auditory physiological maps with TC circuits (Middlebrooks and Zook, 1983). In the present study, focal tracer injections in the MGV frequently resulted in a band of TC axons composed of multiple patches (McMullen and de Venecia, 1993).…”

Section: Auditory Fields and Tc Patchesmentioning

confidence: 52%

“…We conclude that functionally defined isofrequency contours in AI derive from the patchy divergent projections of auditory thalamic neurons. Binaural interaction bands form an additional functional map in AI (Imig and Adrian, 1977;Middlebrooks et al, 1980). Neuronal groups projecting to either EE or EI bands are spatially segregated from one another within the MGV (Middlebrooks and Zook, 1983), suggesting the existence of several classes of MGV neurons with unique projections to AI.…”

Section: Auditory Fields and Tc Patchesmentioning

confidence: 99%

“…The first tonotopic auditory neocortical map was demonstrated by Woolsey and Walzl (1942) in the form of a cochleotopic organization in the primary auditory cortex (AI) of the cat. Other functional maps in AI include binaural interaction bands (Imig and Adrian, 1977;Middlebrooks et al, 1980), threshold/intensity (Tunturi, 1950;Schreiner et al, 1992), and sharpness of tuning (Schreiner and Mendelson, 1990). Interestingly, these maps are patchy or discontinuous in their distribution relative to the frequency map Brugge and Imig, 1978;Middlebrooks et al, 1980;Reale and Imig, 1980;Redies et al, 1989;Schreiner, 1991Schreiner, , 1992Schreiner et al, 1992Schreiner et al, , 2000Mendelson et al, 1993Mendelson et al, , 1997Fitzpatrick et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

et al. 2003

View full text Add to dashboard Cite

Several functional maps have been described in primary auditory cortex, including those related to frequency, tuning, latency, binaurality, and intensity. Many of these maps are arranged in a discontinuous or patchy manner. Similarly, thalamocortical projections arising from the ventral division of the medial geniculate body to the primary auditory cortex are also patchy. We used anterograde labeling and electrophysiological methods to examine the relationship between thalamocortical patches and auditory cortical maps. Biotinylated dextran-amine was deposited into physiologically characterized sites in the ventral division of the medial geniculate body of New Zealand white rabbits. Approximately 7 d later, the animal was again anesthetized and the ipsilateral auditory cortex was mapped with tungsten microelectrodes. Multi-unit physiological data were obtained for the following characteristics: best frequency (BF), binaurality, response type, latency, sharpness of tuning, and threshold. Immunocytochemical methods were used to reveal the injection site in the ventral division of the medial geniculate body as well as the anterogradely labeled thalamocortical afferents in the auditory cortex. In 86% of the cases (12 of 14), entry into a thalamocortical patch was associated with a marked change in physiological responses. A consistent BF and binaural class were usually observed within a patch. The patches appear to innervate distinct functional regions coding frequency and binaurality. A model is presented showing how patchy thalamocortical projections participate in the formation of tonotopic and binaural maps in primary auditory cortex.

show abstract

The Importance of Auricular Prostheses for Speech Recognition

Walsh

Reisberg

Applebaum

et al. 2008

Archives of Facial Plastic Surgery

View full text Add to dashboard Cite

Objectives: To examine the effects of an auricular prosthesis on sound levels at the entrance of the ear canal by measuring the auricular prosthesis transfer function (APTF) and to determine the effect of the prosthesis on speech recognition in noisy hearing conditions. Methods: Eight prostheses were used to measure the APTF. A microphone at the entrance of the ear canal measured sound pressure levels with the prosthesis present or absent while the head was rotated 360°at 30°increments. The Hearing in Noise Test was modified by the APTF to simulate the absence of an auricular prosthesis. Speech recognition was measured by testing 11 subjects with the unmodified Hearing in Noise Test and the modified Hearing in Noise Test. Results: The APTF changed with the head's position relative to the speaker. The mean (SD) maximal gain provided by an auricular prosthesis was 8.1 (2.7) dB at 4.6 (1.0) kHz and 9.7 (1.7) dB at 11.5 (0.9) kHz at 0°rotation. During speech testing, the auricular prosthesis improved the mean (SD) signal to noise ratio by 1.7 (1.7) dB at 0°(PϽ .001), 0.9 (2.2) dB at 90°(P =.04), and 0.5 (2.3) dB at 180°(P=.52). Conclusions: The acoustic gain provided by an auricular prosthesis increases speech recognition in noisy environments. Auricular prostheses not only restore aesthetics but also improve hearing.

show abstract

Binaural response-specific bands in primary auditory cortex (AI) of the cat: Topographical organization orthogonal to isofrequency contours

Cited by 255 publications

References 25 publications

Subthreshold auditory inputs to extrastriate visual neurons are responsive to parametric changes in stimulus quality: Sensory-specific versus non-specific coding

Subthreshold auditory inputs to extrastriate visual neurons are responsive to parametric changes in stimulus quality: Sensory-specific versus non-specific coding

Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

The Importance of Auricular Prostheses for Speech Recognition

Contact Info

Product

Resources

About