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Buetefisch CM, Revill KP, Haut MW, Kowalski GM, Wischnewski M, Pifer M, Belagaje SR, Nahab F, Cobia DJ, Hu X, Drake D, Hobbs G. Abnormally reduced primary motor cortex output is related to impaired hand function in chronic stroke. J Neurophysiol 2018; 120:1680-1694. [PMID: 29924707 DOI: 10.1152/jn.00715.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Stroke often involves primary motor cortex (M1) and its corticospinal projections (CST). As hand function is critically dependent on these structures, its recovery is often incomplete. The neuronal substrate supporting affected hand function is not well understood but likely involves reorganized M1 and CST of the lesioned hemisphere (M1IL and CSTIL). We hypothesized that affected hand function in chronic stroke is related to structural and functional reorganization of M1IL and CSTIL. We tested 18 patients with chronic ischemic stroke involving M1 or CST. Their hand function was compared with 18 age-matched healthy subjects. M1IL thickness and CSTIL fractional anisotropy (FA) were determined with MRI and compared with measures of the other hemisphere. Transcranial magnetic stimulation (TMS) was applied to M1IL to determine its input-output function [stimulus response curve (SRC)]. The plateau of the SRC (MEPmax), inflection point, and slope parameters of the curve were extracted. Results were compared with measures in 12 age-matched healthy controls. MEPmax of M1IL was significantly smaller ( P = 0.02) in the patients, indicating reduced CSTIL motor output, and was correlated with impaired hand function ( P = 0.02). M1IL thickness ( P < 0.01) and CSTIL-FA ( P < 0.01) were reduced but did not correlate with hand function. The results indicate that employed M1IL or CSTIL structural measures do not explain the extent of impairment in hand function once M1 and CST are sufficiently functional for TMS to evoke a motor potential. Instead, impairment of hand function is best explained by the abnormally low output from M1IL. NEW & NOTEWORTHY Hand function often remains impaired after stroke. While the critical role of the primary motor cortex (M1) and its corticospinal output (CST) for hand function has been described in the nonhuman primate stroke model, their structure and function have not been systematically evaluated for patients after stroke. We report that in chronic stroke patients with injury to M1 and/or CST an abnormally reduced M1 output is related to impaired hand function.
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Duru UB, Pawar G, Barash JA, Miller LE, Thiruselvam IK, Haut MW. An Unusual Amnestic Syndrome Associated With Combined Fentanyl and Cocaine Use. Ann Intern Med 2018; 168:747-748. [PMID: 29379942 DOI: 10.7326/l17-0575] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Hartzell JW, Geary R, Gyure K, Chivukula VR, Haut MW. Completed suicide in an autopsy-confirmed case of early onset Alzheimer's disease. Neurodegener Dis Manag 2018; 8:81-88. [PMID: 29319406 PMCID: PMC6367712 DOI: 10.2217/nmt-2017-0045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report a case of a 57-year-old male with clinically diagnosed and autopsy-confirmed early onset Alzheimer's disease who completed suicide by gunshot wound to the chest. This case has several unique aspects that have not been discussed in previous case reports of completed suicide in Alzheimer's disease. In particular, our patient's death was highly planned with successful compensation for his cognitive deficits. After all firearms had been removed from the home as a safety precaution, he obtained a new weapon, hid it and left himself cues to find and use it. The case is discussed in the context of literature differentiating the neural circuitry propagating impulsive versus planned suicidal acts.
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Kesar TM, Belagaje SR, Pergami P, Haut MW, Hobbs G, Buetefisch CM. Effects of monoaminergic drugs on training-induced motor cortex plasticity in older adults. Brain Res 2017. [PMID: 28633996 DOI: 10.1016/j.brainres.2017.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Primary motor cortex (M1) plasticity is involved in motor learning and stroke motor recovery, and enhanced by increasing monoaminergic transmission. Age impacts these processes but there is a paucity of systematic studies on the effects of monoaminergic drugs in older adults. Here, in ten older adults (age 61+4years, 4 males), we determine the effects of a single oral dose of carbidopa/levodopa (DOPA), d-amphetamine (AMPH), methylphenidate (MEPH) and placebo (PLAC) on M1 excitability and motor training-induced M1 plasticity. M1 plasticity is defined as training related long lasting changes in M1 excitability and kinematics of the trained movement. At peak plasma level of the drugs, subjects trained wrist extension movements for 30min. Outcome measures were motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation at increasing intensity (stimulus response curve, SRC) and peak acceleration of the trained wrist extension movements. Measures were obtained before and after completion of training. The curve parameters plateau (MEPmax), inflection point, and slope were extracted from SRC. At baseline drugs had a differential effect on curve parameters, while kinematics remained unchanged. Training alone (PLAC) increased MEPmax but did not improve kinematics. Drugs affected training-related changes of the curve parameters differently, but did not enhance them or kinematics when compared to PLAC. The results demonstrate that in the older adults, MEPH, DOPA, or AMPH have differential effects on baseline M1 excitability and training-related M1 plasticity but fail to enhance them above the naïve level.
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Haut MW, Hogg JP, Marshalek PJ, Suter BC, Miller LE. Amnesia Associated with Bilateral Hippocampal and Bilateral Basal Ganglia Lesions in Anoxia with Stimulant Use. Front Neurol 2017; 8:27. [PMID: 28228745 PMCID: PMC5296355 DOI: 10.3389/fneur.2017.00027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 01/20/2017] [Indexed: 12/27/2022] Open
Abstract
We report a case of a 55-year-old man with ischemic lesions of the bilateral hippocampus and bilateral basal ganglia following a myocardial infarction during an episode of multiple drug use with subsequent anoxia requiring resuscitation. He presented for a neuropsychological evaluation with an anterograde amnesia for both explicit and procedural memory. There are two main points to this case, the unique aspects of the bilateral multifocal lesions and the functional, cognitive impact of these lesions. We hypothesize that his rare focal bilateral lesions of both the hippocampus and basal ganglia are a result of anoxia acting in synergy with his stimulant drug use (cocaine and/or 3,4-methylenedioxy-methamphetamine). Second, his unique lesions produced an explicit and implicit/procedural anterograde amnesia.
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Wischnewski M, Kowalski GM, Rink F, Belagaje SR, Haut MW, Hobbs G, Buetefisch CM. Demand on skillfulness modulates interhemispheric inhibition of motor cortices. J Neurophysiol 2016; 115:2803-13. [PMID: 26961108 DOI: 10.1152/jn.01076.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 03/08/2016] [Indexed: 11/22/2022] Open
Abstract
The role of primary motor cortex (M1) in the control of hand movements is still unclear. Functional magnetic resonance imaging (fMRI) studies of unimanual performance reported a relationship between level of precision of a motor task and additional ipsilateral M1 (iM1) activation. In the present study, we determined whether the demand on accuracy of a movement influences the magnitude of the inhibitory effect between primary motor cortices (IHI). We used transcranial magnetic stimulation (TMS) to measure active IHI (aIHI) of the iM1 on the contralateral M1 (cM1) in the premovement period of a left-hand motor task. Ten healthy participants manipulated a joystick to point to targets of two different sizes. For aIHI, the conditioning stimulus (CS) was applied to iM1, and the test stimulus (TS) to cM1, with an interstimulus interval of 10 ms. The amount of the inhibitory effect of the CS on the motor-evoked potential (MEP) of the subsequent TS was expressed as percentage of the mean MEP amplitude evoked by the single TS. Across different time points of aIHI measurements in the premovement period, there was a significant effect for target size on aIHI. Preparing to point to small targets was associated with weaker aIHI compared with pointing to large targets. The present findings suggest that, during the premovement period, aIHI from iM1 on cM1 is modulated by the demand on accuracy of the motor task. This is consistent with task fMRI findings showing bilateral M1 activation during high-precision movements but only unilateral M1 activity during low-precision movements.
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Wiener J, Moran MT, Haut MW. Completed suicide in a case of clinically diagnosed progressive supranuclear palsy. Neurodegener Dis Manag 2015; 5:289-92. [PMID: 26295722 DOI: 10.2217/nmt.15.24] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We present the clinical history and the cognitive and behavioral presentations of a male patient with suspected progressive supranuclear palsy (PSP) who fatally shot himself in the head. We believe his act of suicide was the consequence of impulsivity, rather than primary depression or mood disturbance. In cases of suspected PSP and other atypical parkinsonisms, health professionals must be aware of neurobehavioral risk factors for suicide attempts and completions to promote patient safety; however, the literature on this topic is sparse. Our case highlights the potentially lethal consequences of impulsivity and other neuropsychiatric symptoms in PSP and related syndromes.
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Buetefisch CM, Howard C, Korb C, Haut MW, Shuster L, Pergami P, Smith C, Hobbs G. Conditions for enhancing the encoding of an elementary motor memory by rTMS. Clin Neurophysiol 2014; 126:581-93. [PMID: 25113275 DOI: 10.1016/j.clinph.2014.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 06/12/2014] [Accepted: 07/07/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Motor learning results in changes of movement representation in primary motor cortex (M1) a process involving long-term potentiation (LTP). Pairing motor training with repetitive transcranial magnetic stimulation (rTMS) of M1 enhances the formation of a motor memory. Here we determined the effect of pairing M1 stimulation and the execution of training movements at different times and frequencies on the formation of a motor memory. METHODS Formation of a motor memory was defined as increases in motor evoked potentials (MEP) of the training agonist (extensor carpi ulnaris muscle, ECU) and increases in peak acceleration of the trained movements that last more than 60min. Training consisted of auditory-paced ballistic wrist extension movements (30min, 0.5Hz) paired with 0.1, 0.25 or 0.5Hz subthreshold rTMS. The rTMS pulse was applied at either the onset, 100ms prior to or 300ms after the onset of training movement related increases in electromyographic (EMG) activity of ECU. This was compared to a Sham condition. RESULTS Only 0.1Hz rTMS applied at the onset of the training related increase in ECU-EMG activity resulted in increases in MEP amplitudes and peak acceleration when compared to the Sham. CONCLUSIONS The formation of motor memory is enhanced above the naïve level by co-administration of low frequency rTMS at the time of execution of training movements. SIGNIFICANCE These results indicate the importance of time and frequency of rTMS in these settings and should be considered in the design of rehabilitation treatment strategies using rTMS.
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Haut MW, Roberts VJ, Goldstein FC, Martin RC, Keefover RW, Rankin ED. Working Memory Demands and Semantic Sensitivity for Prose in Mild Alzheimer's Disease. AGING NEUROPSYCHOLOGY AND COGNITION 2010. [DOI: 10.1076/anec.5.1.63.25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Haut MW, Chen S, Edwards S. Working Memory, Semantics, and Normal Aging. AGING NEUROPSYCHOLOGY AND COGNITION 2010. [DOI: 10.1076/anec.6.3.179.780] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Haut MW, Kuwabara H, Leach S, Callahan T. Age-Related Changes in Neural Activation During Working Memory Performance. AGING NEUROPSYCHOLOGY AND COGNITION 2010. [DOI: 10.1076/1382-5585(200006)7:2;1-u;ft119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Buckalew N, Haut MW, Aizenstein H, Morrow L, Perera S, Kuwabara H, Weiner DK. Differences in brain structure and function in older adults with self-reported disabling and nondisabling chronic low back pain. PAIN MEDICINE 2010; 11:1183-97. [PMID: 20609128 DOI: 10.1111/j.1526-4637.2010.00899.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The primary aim of this pilot study was to identify structural and functional brain differences in older adults with self-reported disabling chronic low back pain (CLBP) compared with those who reported nondisabling CLBP. DESIGN Cross-sectional. PARTICIPANTS Sixteen cognitively intact older adults, eight with disabling CLBP and eight with nondisabling CLBP. Exclusions were psychiatric or neurological disorders, substance abuse, opioid use, or diabetes mellitus. METHODS Participants underwent: structural and functional brain MRI; neuropsychological assessment using the Repeatable Battery for the Assessment of Neuropsychological Status, Trail Making Tests A and B; and physical performance assessment using the Short Physical Performance Battery. RESULTS In the disabled group, there was significantly lower white matter (WM) integrity (P < 0.05) of the splenium of the corpus callosum. This group also demonstrated activation of the right medial prefrontal cortex at rest whereas the nondisabled demonstrated activation of the left lateral prefrontal cortex. Combined groups analysis revealed a strong positive correlation (r(s) = 0.80, P < 0.0002) between WM integrity of the left centrum semiovale with gait-speed. Secondary analysis revealed a strong negative correlation between total months of CLBP and WM integrity of the SCC (r(s) = -0.59, P < 0.02). CONCLUSIONS Brain structure and function is different in older adults with disabling CLBP compared with those with nondisabling CLBP. Deficits in brain morphology combining groups are associated with pain duration and poor physical function. Our findings suggest brain structure and function may play a key role in chronic pain related disability and may be important treatment targets.
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Adamovich BL, Gualberto G, Roberts T, Haut MW, Gutmann L. Teaching NeuroImages: amnesia due to fornix infarction. Neurology 2009; 73:e86. [PMID: 19858453 DOI: 10.1212/wnl.0b013e3181bd80af] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Abraham J, Haut MW, Moran MT, Filburn S, Lemiuex S, Kuwabara H. Adjuvant chemotherapy for breast cancer: effects on cerebral white matter seen in diffusion tensor imaging. Clin Breast Cancer 2008; 8:88-91. [PMID: 18501063 DOI: 10.3816/cbc.2008.n.007] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE The purpose of this study was to examine the effect of adjuvant chemotherapy on normal-appearing white matter in women with breast cancer. PATIENTS AND METHODS Ten patients with early-stage breast cancer who were treated with adjuvant chemotherapy and 9 age-, education-, and IQ-matched healthy controls were studied with magnetic resonance imaging. Diffusion tensor imaging was used to calculate fractional anisotropy (FA), a measure of white matter integrity. Measurements were made in the genu and splenium of the corpus callosum. Participants also completed measures of processing speed, depression, and anxiety. RESULTS Relative to controls, patients had slower processing speed and lower FA in the genu. Processing speed was positively correlated with FA in the genu. CONCLUSION The results of this pilot study suggest that adjuvant chemotherapy affects normal-appearing white matter in the genu of the corpus callosum and that this is related to the cognitive deficits experienced by patients.
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Carey ME, Haut MW, Reminger SL, Hutter JJ, Theilmann R, Kaemingk KL. Reduced frontal white matter volume in long-term childhood leukemia survivors: a voxel-based morphometry study. AJNR Am J Neuroradiol 2008; 29:792-7. [PMID: 18184841 DOI: 10.3174/ajnr.a0904] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE To our knowledge, no published studies have examined whole-brain regional differences to identify more discrete volumetric changes in the brains of childhood leukemia survivors. We used voxel-based morphometry (VBM) to examine regional gray and white matter differences in a group of long-term survivors of acute lymphoblastic leukemia (ALL) compared with a group of healthy controls. Differences in regional white matter volume were expected, given previous reports of white matter changes during treatment for ALL and reduced brain white matter volumes in long-term survivors. Follow-up analyses examined the relationship of regional brain volumes to cognitive function. MATERIALS AND METHODS We compared 9 long-term survivors of ALL with 14 healthy controls. Survivors of ALL were treated with systemic and intrathecal chemotherapy only. T1-weighted axial 3D spoiled gradient high-resolution images collected on a 1.5T MR imaging scanner were used for the VBM analysis. Neuropsychological evaluations were conducted within 2 months of the MR imaging to assess cognitive function. RESULTS VBM analysis revealed 2 specific regions of reduced white matter in the right frontal lobes of survivors of ALL compared with healthy controls. Survivors of ALL had lower performances on tests of attention, visual-constructional skills, mental flexibility, and math achievement compared with healthy individuals. Decreased performance on neuropsychological measures was associated with decreased regional white matter volumes. No differences were found between the groups with respect to gray matter regions. CONCLUSION These findings are consistent with previous literature describing the long-term cognitive, academic, and imaging findings of survivors of ALL and suggest that right frontal white matter is particularly vulnerable to disruption following intensive chemotherapy for ALL. Future studies should focus on further clarifying the white matter changes observed.
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Buckalew N, Haut MW, Morrow L, Weiner D. Chronic Pain Is Associated with Brain Volume Loss in Older Adults: Preliminary Evidence. PAIN MEDICINE 2008; 9:240-8. [DOI: 10.1111/j.1526-4637.2008.00412.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Swayampakula AK, Alkhouri N, Haut MW, Abraham J. Cognitive impairment with significant brain parenchymal volume loss following standard adjuvant chemotherapy in a patient with breast cancer. CLINICAL ADVANCES IN HEMATOLOGY & ONCOLOGY : H&O 2007; 5:985-988. [PMID: 18277960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Haut MW, Moran MT, Lancaster MA, Kuwabara H, Parsons MW, Puce A. White Matter Correlates of Cognitive Capacity Studied With Diffusion Tensor Imaging: Implications for Cognitive Reserve. Brain Imaging Behav 2007. [DOI: 10.1007/s11682-007-9008-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Haut MW, Kuwabara H, Ducatman AM, Hatfield G, Parsons MW, Scott A, Parsons E, Morrow LA. Corpus Callosum Volume in Railroad Workers With Chronic Exposure to Solvents. J Occup Environ Med 2006; 48:615-24. [PMID: 16766926 DOI: 10.1097/01.jom.0000205211.67120.23] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Changes to cognition and behavior have been reported after long-term exposure to solvents. Solvents are hypothesized to affect brain white matter. To test this, we examined the volume of the corpus callosum in workers with a history of exposure to solvents. METHODS We manually traced (blind to group membership) the volume of the corpus callosum in 31 railroad workers and 31 matched controls. RESULTS There was a decrease in the genu of the corpus callosum in the solvent-exposed workers compared with controls. A smaller volume of the genu of the corpus callosum was associated with greater exposure and worse performance on cognitive tasks. CONCLUSIONS This study supports the hypothesis that occupational exposure to solvents affects the anterior white matter of the brain and is related to extent of exposure and degree of cognitive change.
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Parsons MW, Haut MW, Lemieux SK, Moran MT, Leach SG. Anterior medial temporal lobe activation during encoding of words: FMRI methods to optimize sensitivity. Brain Cogn 2006; 60:253-61. [PMID: 16472901 DOI: 10.1016/j.bandc.2005.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2005] [Indexed: 12/01/2022]
Abstract
The existence of a rostrocaudal gradient of medial temporal lobe (MTL) activation during memory encoding has historically received support from positron emission tomography studies, but less so from functional MRI (FMRI) studies. More recently, FMRI studies have demonstrated that characteristics of the stimuli can affect the location of activation seen in the MTL when those stimuli are encoded. The current study tested the hypothesis that MTL activation during memory encoding is related to the modality of stimulus presentation. Subjects encoded auditorily or visually presented words in an FMRI novelty paradigm. Imaging and analysis parameters were optimized to minimize susceptibility artifact in the anterior MTL. Greater activation was observed in the anterior than posterior MTL for both modalities of stimulus presentation. The results indicate that anterior MTL activation occurred during encoding, independent of stimulus modality and provide support for the hypothesis that verbal-semantic memory processing occurs in anterior MTL. The authors suggest that technical factors are critical for observing the rostrocaudal gradient in MTL memory activation.
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Haut MW, Kuwabara H, Moran MT, Leach S, Arias R, Knight D. The Effect of Education on Age-Related Functional Activation During Working Memory. AGING NEUROPSYCHOLOGY AND COGNITION 2005. [DOI: 10.1080/13825580590969325] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Haut MW, Arias RG, Moran MT, Leach S, Parsons MW, Kuwabara H. Neural activation during frequency-memory performance. Neuropsychology 2002. [PMID: 11761046 DOI: 10.1037//0894-4105.15.4.568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Lesion studies have demonstrated that frequency memory, or memory for the frequency of occurrence, is associated with prefrontal and not temporal lobe lesions. This study examined neural activation during performance on a frequency-memory-judgment task and a recognition-memory task, both using words. Relative to a control task, the authors observed peaks of activation during frequency-memory performance in the left ventrolateral prefrontal cortex (BA 45) and other areas typically associated with working memory (dorsolateral prefrontal cortex, posterior parietal cortex). Recognition performance was associated with activation in the same left ventrolateral prefrontal location as was observed with frequency memory. When comparing activation during frequency memory with activation during recognition memory, the authors found a suppression of activation in the hippocampus bilaterally during frequency memory. This study supports a neuroanatomical distinction between frequency and recognition memory.
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Haut MW, Muehleman T. Informed consent: the effects of clarity and specificity on disclosure in a clinical interview. Psychotherapy (Chic) 2001; 23:93-101. [PMID: 11653806 DOI: 10.1037/h0085598] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Haut MW, Arias RG, Moran MT, Leach S, Parsons MW, Kuwabara H. Neural activation during frequency-memory performance. Neuropsychology 2001; 15:568-75. [PMID: 11761046 DOI: 10.1037/0894-4105.15.4.568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Lesion studies have demonstrated that frequency memory, or memory for the frequency of occurrence, is associated with prefrontal and not temporal lobe lesions. This study examined neural activation during performance on a frequency-memory-judgment task and a recognition-memory task, both using words. Relative to a control task, the authors observed peaks of activation during frequency-memory performance in the left ventrolateral prefrontal cortex (BA 45) and other areas typically associated with working memory (dorsolateral prefrontal cortex, posterior parietal cortex). Recognition performance was associated with activation in the same left ventrolateral prefrontal location as was observed with frequency memory. When comparing activation during frequency memory with activation during recognition memory, the authors found a suppression of activation in the hippocampus bilaterally during frequency memory. This study supports a neuroanatomical distinction between frequency and recognition memory.
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Haut MW, Kuwabara H, Leach S, Arias RG. Neural activation during performance of number-letter sequencing. APPLIED NEUROPSYCHOLOGY 2001; 7:237-42. [PMID: 11296686 DOI: 10.1207/s15324826an0704_5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Recent advances in neuroimaging have enabled researchers to establish relatively specific areas of the brain that are involved in working memory. In this positron emission tomography study we examined the pattern of neural activation associated with performance on number-letter sequencing, a purported measure of working memory included in the new Wechsler scales for memory and intelligence. After controlling for basic audition, verbalization, and attention, areas of activation were observed in the orbital frontal lobe, dorsolateral prefrontal cortex, and posterior parietal cortex. This is highly consistent with reports from the literature on activation patterns associated with working memory. More activation peaks were observed in the right hemisphere, suggesting the participants utilized visualization of the verbal information. Consistent with task conceptualization, this study provides support for number-letter sequencing as a task involving working memory.
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