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Experimental Aging Research
An International Journal Devoted to the Scientific Study of the Aging Process
Volume 22, 1996 - Issue 2
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Original Articles

Aging Effects on Auditory Processing: An Event-Related Potential Study

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Pages 171-184 | Received 29 Sep 1994, Accepted 17 Jun 1995, Published online: 28 Sep 2007

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T. Kojima, S. Karino, M. Yumoto & M. Funayama. (2014) A stroke patient with impairment of auditory sensory (echoic) memory. Neurocase 20:2, pages 133-143.
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Risto Näätänen. (2008) Mismatch negativity (MMN) as an index of central auditory system plasticity. International Journal of Audiology 47:sup2, pages S16-S20.
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Gunvant K Thaker. (2007) Schizophrenia endophenotypes as treatment targets. Expert Opinion on Therapeutic Targets 11:9, pages 1189-1206.
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Saravanan Elangovan, Jerry L. Cranford, Letitia Walker & Andrew Stuart. (2005) A Comparison of the mismatch negativity and a differential waveform response. International Journal of Audiology 44:11, pages 637-646.
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Articles from other publishers (87)

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Niels Trusbak Haumann, Bjørn Petersen, Peter Vuust & Elvira Brattico. (2023) Age differences in central auditory system responses to naturalistic music. Biological Psychology 179, pages 108566.
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Roberta Bianco & Maria Chait. (2023) No Link Between Speech-in-Noise Perception and Auditory Sensory Memory – Evidence From a Large Cohort of Older and Younger Listeners. Trends in Hearing 27.
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Roberta Bianco, Edward T.R. Hall, Marcus T. Pearce & Maria Chait. (2023) Implicit auditory memory in older listeners: From encoding to 6-month retention. Current Research in Neurobiology 5, pages 100115.
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Yiru Yang, Dandan Wang, Wenjie Hou & He Li. 2023. Cognitive Aging and Brain Health. Cognitive Aging and Brain Health 25 46 .
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Chiara Avancini, Sally Jennings, Srivas Chennu, Valdas Noreika, April Le, Tristan A. Bekinschtein, Madeleine J. Walpert, Isabel C. H. Clare, Anthony J. Holland, Shahid H. Zaman & Howard Ring. (2022) Exploring electrophysiological markers of auditory predictive processes and pathological ageing in adults with Down's syndrome. European Journal of Neuroscience 56:9, pages 5615-5636.
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Jonathan Lassen, Bob Oranje, Martin Vestergaard, Malene Foldager, Troels W. Kjær, Sidse Arnfred & Bodil Aggernæs. (2022) Reduced mismatch negativity in children and adolescents with autism spectrum disorder is associated with their impaired adaptive functioning. Autism Research 15:8, pages 1469-1481.
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Jiali Chen, Xiaomin Huang, Xianglong Wang, Xuefei Zhang, Sishi Liu, Junqin Ma, Yuanqiu Huang, Anli Tang & Wen Wu. (2022) Visually Perceived Negative Emotion Enhances Mismatch Negativity but Fails to Compensate for Age-Related Impairments. Frontiers in Human Neuroscience 16.
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Sandeepa Sur & Edward J. Golob. (2020) Neural correlates of auditory sensory memory dynamics in the aging brain. Neurobiology of Aging 88, pages 128-136.
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Elisa M. Ruohonen, Saara Kattainen, Xueqiao Li, Anna-Elisa Taskila, Chaoxiong Ye & Piia Astikainen. (2020) Event-Related Potentials to Changes in Sound Intensity Demonstrate Alterations in Brain Function Related to Depression and Aging. Frontiers in Human Neuroscience 14.
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Tufikameni Brima, Sophie Molholm, Ciara J. Molloy, Olga V. Sysoeva, Eric Nicholas, Aleksandra Djukic, Edward G. Freedman & John J. Foxe. (2019) Auditory sensory memory span for duration is severely curtailed in females with Rett syndrome. Translational Psychiatry 9:1.
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Shiou-Han Yang, Pei-Ning Wang & Chia-Hsiung Cheng. (2019) Altered auditory repetition suppression and MMNm in relation to cognitive tests in older adults. Biological Psychology 146, pages 107725.
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Peter Vuust, Lari Liikala, Risto Näätänen, Pauli Brattico & Elvira Brattico. (2016) Comprehensive auditory discrimination profiles recorded with a fast parametric musical multi-feature mismatch negativity paradigm. Clinical Neurophysiology 127:4, pages 2065-2077.
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Chia-Hsiung Cheng, Pei-Ying S. Chan, Yu-Wei Hsieh & Kuan-Fu Chen. (2016) A meta-analysis of mismatch negativity in children with attention deficit-hyperactivity disorders. Neuroscience Letters 612, pages 132-137.
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Lisa Bartha‐Doering, Dirk Deuster, Vito Giordano, Antoinette am Zehnhoff‐Dinnesen & Christian Dobel. (2015) A systematic review of the mismatch negativity as an index for auditory sensory memory: From basic research to clinical and developmental perspectives. Psychophysiology 52:9, pages 1115-1130.
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Anthoula Tsolaki, Vasiliki Kosmidou, Leontios Hadjileontiadis, Ioannis (Yiannis) Kompatsiaris & Magda Tsolaki. (2015) Brain source localization of MMN, P300 and N400: Aging and gender differences. Brain Research 1603, pages 32-49.
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Jerome Daltrozzo & Christopher M. Conway. (2014) Neurocognitive mechanisms of statistical-sequential learning: what do event-related potentials tell us?. Frontiers in Human Neuroscience 8.
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Stephan Bender, Annet Bluschke, Gabriel Dippel, André Rupp, Matthias Weisbrod & Christine Thomas. (2014) Auditory post-processing in a passive listening task is deficient in Alzheimer’s disease. Clinical Neurophysiology 125:1, pages 53-62.
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A.K. Pandey, C. Kamarajan, Y. Tang, D.B. Chorlian, B.N. Roopesh, N. Manz, A. Stimus, M. Rangaswamy & B. Porjesz. (2012) Neurocognitive deficits in male alcoholics: An ERP/sLORETA analysis of the N2 component in an equal probability Go/NoGo task. Biological Psychology 89:1, pages 170-182.
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R. Naatanen, T. Kujala, K. Kreegipuu, S. Carlson, C. Escera, T. Baldeweg & C. Ponton. (2011) The mismatch negativity: an index of cognitive decline in neuropsychiatric and neurological diseases and in ageing. Brain 134:12, pages 3435-3453.
Crossref
Fabrizio Vecchio & Sara Määttä. (2011) The Use of Auditory Event-Related Potentials in Alzheimer's Disease Diagnosis. International Journal of Alzheimer's Disease 2011, pages 1-7.
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Risto Näätänen, Teija Kujala & István Winkler. (2010) Auditory processing that leads to conscious perception: A unique window to central auditory processing opened by the mismatch negativity and related responses. Psychophysiology 48:1, pages 4-22.
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Patrick J. C. May & Hannu Tiitinen. (2010) Mismatch negativity (MMN), the deviance-elicited auditory deflection, explained. Psychophysiology 47:1, pages 66-122.
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Michael Kiang, David L. Braff, Joyce Sprock & Gregory A. Light. (2009) The relationship between preattentive sensory processing deficits and age in schizophrenia patients. Clinical Neurophysiology 120:11, pages 1949-1957.
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Elisabeth Glass. (2009) Ereigniskorrelierte Potenziale und auditives sensorisches Gedächtnis. Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie 37:6, pages 513-523.
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Sami Schiff, Pietro Valenti, Pellegrini Andrea, Maria Lot, Patrizia Bisiacchi, Angelo Gatta & Piero Amodio. (2008) The effect of aging on auditory components of event-related brain potentials. Clinical Neurophysiology 119:8, pages 1795-1802.
Crossref
Elisabeth Glass, Steffi Sachse & Waldemar von Suchodoletz. (2008) Development of auditory sensory memory from 2 to 6 years: an MMN study. Journal of Neural Transmission 115:8, pages 1221-1229.
Crossref
Johanna G. Barry, Mervyn J. Hardiman, Elizabeth Line, Katherine B. White, Ifat Yasin & Dorothy V.M. Bishop. (2008) Duration of auditory sensory memory in parents of children with SLI: A mismatch negativity study. Brain and Language 104:1, pages 75-88.
Crossref
R. Näätänen, P. Paavilainen, T. Rinne & K. Alho. (2007) The mismatch negativity (MMN) in basic research of central auditory processing: A review. Clinical Neurophysiology 118:12, pages 2544-2590.
Crossref
J. Marco-Pallarés, G. Ruffini, M.D. Polo, A. Gual, C. Escera & C. Grau. (2007) Mismatch negativity impairment associated with alcohol consumption in chronic alcoholics: A scalp current density study. International Journal of Psychophysiology 65:1, pages 51-57.
Crossref
Kelly C. Harris, John H. Mills & Judy R. Dubno. (2007) Electrophysiologic correlates of intensity discrimination in cortical evoked potentials of younger and older adults. Hearing Research 228:1-2, pages 58-68.
Crossref
D. Borghetti, C. Pizzanelli, P. Maritato, M. Fabbrini, S. Jensen, A. Iudice, L. Murri & F. Sartucci. (2007) Mismatch negativity analysis in drug-resistant epileptic patients implanted with vagus nerve stimulator. Brain Research Bulletin 73:1-3, pages 81-85.
Crossref
Satu Pakarinen, Rika Takegata, Teemu Rinne, Minna Huotilainen & Risto Näätänen. (2007) Measurement of extensive auditory discrimination profiles using the mismatch negativity (MMN) of the auditory event-related potential (ERP). Clinical Neurophysiology 118:1, pages 177-185.
Crossref
Teija Kujala, Mari Tervaniemi & Erich Schröger. (2007) The mismatch negativity in cognitive and clinical neuroscience: Theoretical and methodological considerations. Biological Psychology 74:1, pages 1-19.
Crossref
JingTian Wang, David Friedman, Walter Ritter, Michael Bersick & Letecia Latif. (2006) Aging effects on the ERP correlates of involuntary attentional capture in speech sound analysis. Neurobiology of Aging 27:8, pages 1164-1179.
Crossref
Rowena J. Cooper, Juanita Todd, Katherine McGill & Patricia T. Michie. (2006) Auditory sensory memory and the aging brain: A mismatch negativity study. Neurobiology of Aging 27:5, pages 752-762.
Crossref
Monica Fabiani, Kathy A. Low, Emily Wee, Jeffrey J. Sable & Gabriele Gratton. (2006) Reduced Suppression or Labile Memory? Mechanisms of Inefficient Filtering of Irrelevant Information in Older Adults. Journal of Cognitive Neuroscience 18:4, pages 637-650.
Crossref
Kirk R. Daffner, Katherine K. Ryan, Danielle M. Williams, Andrew E. Budson, Dorene M. Rentz, Leonard F.M. Scinto & Phillip J. Holcomb. (2005) Age-related differences in novelty and target processing among cognitively high performing adults. Neurobiology of Aging 26:9, pages 1283-1295.
Crossref
R. Mager, M. Falkenstein, R. Störmer, S. Brand, F. Müller-Spahn & A. H. Bullinger. (2004) Auditory distraction in young and middle-aged adults: a behavioural and event-related potential study. Journal of Neural Transmission 112:9, pages 1165-1176.
Crossref
Shotaro Karino, Masato Yumoto, Kenji Itoh, Keiko Yamakawa, Tomomi Mizuochi & Kimitaka Kaga. (2005) A modified parallel paradigm for clinical evaluation of auditory echoic memory. NeuroReport 16:7, pages 683-687.
Crossref
Laura Lorenzo-López, Elena Amenedo, Paula Pazo-Alvarez & Fernando Cadaveira. (2004) Pre-attentive detection of motion direction changes in normal aging. NeuroReport 15:17, pages 2633-2636.
Crossref
Gerene K Starratt & Allan J Nash. (2004) An alternative baseline measure for calculation of the mismatch negativity (MMN) component of the event-related potential (ERP). International Journal of Psychophysiology 51:3, pages 201-208.
Crossref
Kelly L Tremblay, Michael Piskosz & Pamela Souza. (2003) Effects of age and age-related hearing loss on the neural representation of speech cues. Clinical Neurophysiology 114:7, pages 1332-1343.
Crossref
Ilan Laufer & Hillel Pratt. (2003) Evoked potentials to auditory movement sensation in duplex perception. Clinical Neurophysiology 114:7, pages 1316-1331.
Crossref
Ilan Laufer & Hillel Pratt. (2003) The electrophysiological net response (‘F-complex’) to spatial fusion of speech elements forming an auditory object. Clinical Neurophysiology 114:5, pages 818-834.
Crossref
Risto Näätänen. (2003) Mismatch negativity: clinical research and possible applications. International Journal of Psychophysiology 48:2, pages 179-188.
Crossref
Urte Roeber, Stefan Berti & Erich Schröger. (2003) Auditory distraction with different presentation rates: an event-related potential and behavioral study. Clinical Neurophysiology 114:2, pages 341-349.
Crossref
C. Engeland, C. Mahoney, E. Mohr, V. Ilivitsky & Verner J. Knott. (2002) Acute nicotine effects on auditory sensory memory in tacrine-treated and nontreated patients with Alzheimer's disease. Pharmacology Biochemistry and Behavior 72:1-2, pages 457-464.
Crossref
Sibylle Bertoli, Jacek Smurzynski & Rudolf Probst. (2002) Temporal resolution in young and elderly subjects as measured by mismatch negativity and a psychoacoustic gap detection task. Clinical Neurophysiology 113:3, pages 396-406.
Crossref
Carles Grau, M.Dolores Polo, Elena Yago, Antoni Gual & Carles Escera. (2001) Auditory sensory memory as indicated by mismatch negativity in chronic alcoholism. Clinical Neurophysiology 112:5, pages 728-731.
Crossref
M Onofrj, A Thomas, D Iacono, G DˈAndreamatteo & C Paci. (2001) Age-related changes of evoked potentials. Neurophysiologie Clinique/Clinical Neurophysiology 31:2, pages 83-103.
Crossref
Helen Gaeta, David Friedman, Walter Ritter & Jeff Cheng. (2001) An event-related potential evaluation of involuntary attentional shifts in young and older adults.. Psychology and Aging 16:1, pages 55-68.
Crossref
J. Huttunen, H. Wikström, O. Salonen & R.J. Ilmoniemi. (1999) Human somatosensory cortical activation strengths: comparison between males and females and age-related changes. Brain Research 818:2, pages 196-203.
Crossref
Helen Gaeta, David Friedman, Walter Ritter & Jeff Cheng. (1998) An event-related potential study of age-related changes in sensitivity to stimulus deviance. Neurobiology of Aging 19:5, pages 447-459.
Crossref
E Amenedo & F Dı́az. (1998) Automatic and effortful processes in auditory memory reflected by event-related potentials. Age-related findings. Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section 108:4, pages 361-369.
Crossref
Victoria A. Kazmerski, David Friedman & Walter Ritter. (1997) Mismatch negativity during attend and ignore conditions in Alzheimer's disease. Biological Psychiatry 42:5, pages 382-402.
Crossref

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