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Ulep MG, Liénard P. Free-listing and Semantic Knowledge: A Tool for Detecting Alzheimer Disease? Cogn Behav Neurol 2024; 37:117-143. [PMID: 38899852 PMCID: PMC11356687 DOI: 10.1097/wnn.0000000000000370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 02/05/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND Impairment in semantic knowledge contributes to Alzheimer disease (AD)-related decline. However, the particulars of the impact AD has on specific domains of knowledge remain debatable. OBJECTIVE To investigate the impact of AD on specific semantic categories that are integral to daily functions-living things and man-made objects. METHOD We administered a free-listing task (written version) to 19 individuals with AD and 15 cognitively normal older adults and assessed the task's relationship with other cognitive and functional tests in clinical use. We compared the contents of the lists of salient concepts generated by the AD and control groups. RESULTS Group membership (AD or control), after controlling for age, sex, formal education, and an estimate of premorbid intellectual ability, predicted the groups' performance on the free-listing task across two categories. Functional status was inversely related to performance on the free-listing task, holding demographic variables constant. Based on a comparison of the contents of the free lists that were generated by the two groups, it was possible to conclude that, in individuals with AD, conceptual knowledge central to the respective categories was well preserved, whereas the peripheral conceptual material showed evidence of degradation. CONCLUSION The free-listing task, which is an easy-to-administer and cost-effective tool, could aid in the preliminary detection of semantic knowledge dysfunction, revealing concepts that are better preserved and, possibly, the characterization of AD. Cognitive assessment tools that can be applied across cultures are needed, and the free-listing task has the potential to address this gap.
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Affiliation(s)
- Maileen G. Ulep
- Cognitive Disorders Clinic, Cleveland Clinic Nevada, Lou Ruvo Center for Brain Health, Las Vegas, Nevada
- Department of Anthropology, University of Nevada Las Vegas, Las Vegas, Nevada
| | - Pierre Liénard
- Department of Anthropology, University of Nevada Las Vegas, Las Vegas, Nevada
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2
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Salillas E, De Pellegrin S, Semenza C. Awake brain surgery: toward optimal cognitive explorations. Front Hum Neurosci 2024; 18:1369462. [PMID: 38601802 PMCID: PMC11004270 DOI: 10.3389/fnhum.2024.1369462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/18/2024] [Indexed: 04/12/2024] Open
Affiliation(s)
- Elena Salillas
- Department of Psychology and Sociology, Universidad de Zaragoza, Zaragoza, Spain
| | - Serena De Pellegrin
- Neurology Clinic, Department of Neuroscience, Padua University Hospital, Padova, Italy
| | - Carlo Semenza
- Padova Neuroscience Center, University of Padova, Padova, Italy
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3
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Thompson HE, Noonan KA, Halai AD, Hoffman P, Stampacchia S, Hallam G, Rice GE, De Dios Perez B, Lambon Ralph MA, Jefferies E. Damage to temporoparietal cortex is sufficient for impaired semantic control. Cortex 2022; 156:71-85. [PMID: 36183573 DOI: 10.1016/j.cortex.2022.05.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 01/26/2023]
Abstract
Semantic control allows us to focus semantic activation on currently relevant aspects of knowledge, even in the face of competition or when the required information is weakly encoded. Diverse cortical regions, including left prefrontal and posterior temporal cortex, are implicated in semantic control, however; the relative contribution of these regions is unclear. For the first time, we compared semantic aphasia (SA) patients with damage restricted to temporoparietal cortex (TPC; N = 8) to patients with infarcts encompassing prefrontal cortex (PF+; N = 22), to determine if prefrontal lesions are necessary for semantic control deficits. These SA groups were also compared with semantic dementia (SD; N = 10), characterised by degraded semantic representations. We asked whether TPC cases with semantic impairment show controlled retrieval deficits equivalent to PF+ cases or conceptual degradation similar to patients with SD. Independent of lesion location, the SA subgroups showed similarities, whereas SD patients showed a qualitatively distinct semantic impairment. Relative to SD, both TPC and PF+ SA subgroups: (1) showed few correlations in performance across tasks with differing control demands, but a strong relationship between tasks of similar difficulty; (2) exhibited attenuated effects of lexical frequency and concept familiarity, (3) showed evidence of poor semantic regulation in their verbal output - performance on picture naming was substantially improved when provided with a phonological cue, and (4) showed effects of control demands, such as retrieval difficulty, which were equivalent in severity across TPC and PF+ groups. These findings show that semantic impairment in SA is underpinned by damage to a distributed semantic control network, instantiated across anterior and posterior cortical areas.
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Affiliation(s)
- Hannah E Thompson
- School of Psychology and Counselling, The Open University, Milton Keynes, UK.
| | - Krist A Noonan
- School of Social and Community Medicine, University of Bristol, UK
| | - Ajay D Halai
- MRC Cognition & Brain Sciences Unit, University of Cambridge, UK
| | - Paul Hoffman
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, UK
| | - Sara Stampacchia
- Laboratory of Neuroimaging and Innovative Molecular Tracers (NIMTlab), Geneva University Neurocenter and Faculty of Medicine, University of Geneva, Geneva, Switzerland; Department of Psychology and York Neuroimaging Centre, University of York, UK
| | - Glyn Hallam
- School of Human and Health Sciences, University of Huddersfield, UK
| | - Grace E Rice
- MRC Cognition & Brain Sciences Unit, University of Cambridge, UK
| | - Blanca De Dios Perez
- Division of Psychiatry and Applied Psychology, School of Medicine, University of Nottingham, UK
| | | | - Elizabeth Jefferies
- Department of Psychology and York Neuroimaging Centre, University of York, UK
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4
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Bruera A, Poesio M. Exploring the Representations of Individual Entities in the Brain Combining EEG and Distributional Semantics. Front Artif Intell 2022; 5:796793. [PMID: 35280237 PMCID: PMC8905499 DOI: 10.3389/frai.2022.796793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 01/25/2022] [Indexed: 11/23/2022] Open
Abstract
Semantic knowledge about individual entities (i.e., the referents of proper names such as Jacinta Ardern) is fine-grained, episodic, and strongly social in nature, when compared with knowledge about generic entities (the referents of common nouns such as politician). We investigate the semantic representations of individual entities in the brain; and for the first time we approach this question using both neural data, in the form of newly-acquired EEG data, and distributional models of word meaning, employing them to isolate semantic information regarding individual entities in the brain. We ran two sets of analyses. The first set of analyses is only concerned with the evoked responses to individual entities and their categories. We find that it is possible to classify them according to both their coarse and their fine-grained category at appropriate timepoints, but that it is hard to map representational information learned from individuals to their categories. In the second set of analyses, we learn to decode from evoked responses to distributional word vectors. These results indicate that such a mapping can be learnt successfully: this counts not only as a demonstration that representations of individuals can be discriminated in EEG responses, but also as a first brain-based validation of distributional semantic models as representations of individual entities. Finally, in-depth analyses of the decoder performance provide additional evidence that the referents of proper names and categories have little in common when it comes to their representation in the brain.
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Affiliation(s)
- Andrea Bruera
- Cognitive Science Research Group, School of Electronic Engineering and Computer Science, Queen Mary University of London, London, United Kingdom
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5
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Flurie M, Ungrady M, Reilly J. Evaluating a Maintenance-Based Treatment Approach to Preventing Lexical Dropout in Progressive Anomia. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:4082-4095. [PMID: 33181044 PMCID: PMC8608146 DOI: 10.1044/2020_jslhr-20-00059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/26/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Purpose Primary progressive aphasia (PPA) and the amnestic variant of Alzheimer's disease (AD) are neurodegenerative conditions characterized by a profound loss of functional communication abilities. Communicative impairment in AD and PPA is especially apparent in the domain of naming common objects and familiar faces. We evaluated the effectiveness of a language intervention targeting maintenance of an individualized core vocabulary in a longitudinal cohort of older adults experiencing either PPA or AD. Method PPA (n = 9) and AD (n = 1) patients were administered a semantically based language treatment for up to 2 years. Patients repeatedly named and generated semantic features for a personalized lexicon consisting of 100 words. We evaluated naming accuracy and off-line neuropsychological measures at four successive timepoints. Naming accuracy was assessed in patients (n = 7) who completed at least three recurrent evaluations. Off-line neuropsychological performance was assessed across timepoints in all patients. Results Patients demonstrated relative preservation of naming trained words relative to a steep decline for untrained (control) words. The greatest decrements were observed for naming people relative to objects. Conclusion These results suggest that consistent training of a finite set of words can protect a core lexicon composed of crucial target concepts (e.g., a spouse's name). We discuss potential benefits and clinical implications of maintenance-based approaches to promoting language functioning in the context of neurodegeneration.
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Affiliation(s)
- Maurice Flurie
- Eleanor M. Saffran Center for Cognitive Neuroscience, Temple University, Philadelphia, PA
- Department of Communication Sciences and Disorders, Temple University, Philadelphia, PA
| | - Molly Ungrady
- Department of Psychology, Temple University, Philadelphia, PA
| | - Jamie Reilly
- Eleanor M. Saffran Center for Cognitive Neuroscience, Temple University, Philadelphia, PA
- Department of Communication Sciences and Disorders, Temple University, Philadelphia, PA
- Department of Psychology, Temple University, Philadelphia, PA
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6
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Borghesani V, Battistella G, Mandelli ML, Welch A, Weis E, Younes K, Neuhaus J, Grinberg LT, Seeley WM, Spina S, Miller B, Miller Z, Gorno-Tempini ML. Regional and hemispheric susceptibility of the temporal lobe to FTLD-TDP type C pathology. Neuroimage Clin 2020; 28:102369. [PMID: 32798912 PMCID: PMC7426562 DOI: 10.1016/j.nicl.2020.102369] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 07/23/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Post-mortem studies show that focal anterior temporal lobe (ATL) neurodegeneration is most often caused by frontotemporal lobar degeneration TDP-43 type C pathology. Clinically, these patients are described with different terms, such as semantic variant primary progressive aphasia (svPPA), semantic dementia (SD), or right temporal variant frontotemporal dementia (FTD) depending on whether the predominant symptoms affect language, semantic knowledge for object or people, or socio-emotional behaviors. ATL atrophy presents with various degrees of lateralization, with right-sided cases considered rarer even though estimation of their prevalence is hampered by the paucity of studies on well-characterized, pathology-proven cohorts. Moreover, it is not clear whether left and right variants show a similar distribution of atrophy within the ATL cross-sectionally and longitudinally. Here we study the largest cohort to-date of pathology-proven TDP-43-C cases diagnosed during life as svPPA, SD or right temporal variant FTD. We analyzed clinical, cognitive, and neuroimaging data from 30 cases, a subset of which was followed longitudinally. Guided by recent structural and functional parcellation studies, we constructed four bilateral ATL regions of interest (ROIs). The computation of an atrophy lateralization index allowed the comparison of atrophy patterns between the two hemispheres. This led to an automatic, imaging-based classification of the cases as left-predominant or right-predominant. We then compared the two groups in terms of regional atrophy patterns within the ATL ROIs (cross-sectionally) and atrophy progression (longitudinally). Results showed that 40% of pathology proven cases of TDP-43-C diagnosed with a temporal variant presented with right-lateralized atrophy. Moreover, the findings of our ATL ROI analysis indicated that, irrespective of atrophy lateralization, atrophy distribution within both ATLs follows a medial-to-lateral gradient. Finally, in both left and right cases, atrophy appeared to progress to the contralateral ATL, and from the anterior temporal pole to posterior temporal and orbitofrontal regions. Taken together, our findings indicate that incipient right predominant ATL atrophy is common in TDP-43-C pathology, and that distribution of damage within the ATLs appears to be the same in left- and right- sided variants. Thus, regardless of differences in clinical phenotype and atrophy lateralization, both temporal variants of FTD should be viewed as a spectrum presentation of the same disease.
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Affiliation(s)
- V Borghesani
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States.
| | - G Battistella
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - M L Mandelli
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - A Welch
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - E Weis
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - K Younes
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - J Neuhaus
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - L T Grinberg
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - W M Seeley
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - S Spina
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - B Miller
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - Z Miller
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States
| | - M L Gorno-Tempini
- Memory and Aging Center, Department of Neurology, University
of California San Francisco, United States; Department of Neurology, Dyslexia Center, University of California, San Francisco, CA, United States
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7
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DeDe G, Salis C. Temporal and Episodic Analyses of the Story of Cinderella in Latent Aphasia. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2020; 29:449-462. [PMID: 31419160 DOI: 10.1044/2019_ajslp-cac48-18-0210] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Purpose The purpose of this study was to improve our understanding of the language characteristics of people with latent aphasia using measures that examined temporal (i.e., real-time) and episodic organization of discourse production. Method Thirty AphasiaBank participants were included (10 people with latent aphasia, 10 people with anomic aphasia, and 10 neurotypical control participants). Speech material of Cinderella narratives was analyzed with Praat software. We devised a protocol that coded the presence and duration of all speech segments, dysfluencies such as silent and filled pauses, and other speech behaviors. Using these durations, we generated a range of temporal measures such as speech, articulation, and pure word rates. Narratives were also coded into episodes, which provided information about the discourse macrostructure abilities of the participants. Results The latent aphasia group differed from controls in number of words produced, silent pause duration, and speech rate, but not articulation rate or pure word rate. Episodic organization of the narratives was similar in these 2 groups. The latent and anomic aphasia groups were similar in most measures, apart from articulation rate, which was lower in the anomic group. The anomic aphasia group also omitted more episodes than the latent aphasia group. Conclusions The differences between latent aphasia and neurotypical controls can be attributed to a processing speed deficit. We propose that this deficit results in an impaired ability to process information from multiple cognitive domains simultaneously.
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Affiliation(s)
- Gayle DeDe
- Department of Communication Sciences and Disorders, Temple University, Philadelphia, PA
| | - Christos Salis
- Department of Speech & Language Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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8
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Salvari V, Paraskevopoulos E, Chalas N, Müller K, Wollbrink A, Dobel C, Korth D, Pantev C. Auditory Categorization of Man-Made Sounds Versus Natural Sounds by Means of MEG Functional Brain Connectivity. Front Neurosci 2019; 13:1052. [PMID: 31636532 PMCID: PMC6787283 DOI: 10.3389/fnins.2019.01052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/19/2019] [Indexed: 01/27/2023] Open
Abstract
Previous neuroimaging studies have shown that sounds can be discriminated due to living-related or man-made-related characteristics and involve different brain regions. However, these studies have mainly provided source space analyses, which offer simple maps of activated brain regions but do not explain how regions of a distributed system are functionally organized under a specific task. In the present study, we aimed to further examine the functional connectivity of the auditory processing pathway across different categories of non-speech sounds in healthy adults, by means of MEG. Our analyses demonstrated significant activation and interconnection differences between living and man-made object sounds, in the prefrontal areas, anterior-superior temporal gyrus (aSTG), posterior cingulate cortex (PCC), and supramarginal gyrus (SMG), occurring within 80–120 ms post-stimulus interval. Current findings replicated previous ones, in that other regions beyond the auditory cortex are involved during auditory processing. According to the functional connectivity analysis, differential brain networks across the categories exist, which proposes that sound category discrimination processing relies on distinct cortical networks, a notion that has been strongly argued in the literature also in relation to the visual system.
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Affiliation(s)
- Vasiliki Salvari
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany
| | - Evangelos Paraskevopoulos
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany.,School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikolas Chalas
- School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Kilian Müller
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany
| | - Andreas Wollbrink
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany
| | - Christian Dobel
- Department of Otorhinolaryngology, Friedrich-Schiller University of Jena, Jena, Germany
| | - Daniela Korth
- Department of Otorhinolaryngology, Friedrich-Schiller University of Jena, Jena, Germany
| | - Christo Pantev
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany
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9
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Abstract
The perirhinal cortex (PRC) serves as the gateway to the hippocampus for episodic memory formation and plays a part in retrieval through its backward connectivity to various neocortical areas. First, I present the evidence suggesting that PRC neurons encode both experientially acquired object features and their associative relations. Recent studies have revealed circuit mechanisms in the PRC for the retrieval of cue-associated information, and have demonstrated that, in monkeys, PRC neuron-encoded information can be behaviourally read out. These studies, among others, support the theory that the PRC converts visual representations of an object into those of its associated features and initiates backward-propagating, interareal signalling for retrieval of nested associations of object features that, combined, extensionally represent the object meaning. I propose that the PRC works as the ventromedial hub of a 'two-hub model' at an apex of the hierarchy of a distributed memory network and integrates signals encoded in other downstream cortical areas that support diverse aspects of knowledge about an object.
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10
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Meier EL, Johnson JP, Kiran S. Left frontotemporal effective connectivity during semantic feature judgments in patients with chronic aphasia and age-matched healthy controls. Cortex 2018; 108:173-192. [PMID: 30243049 PMCID: PMC6234086 DOI: 10.1016/j.cortex.2018.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/01/2018] [Accepted: 08/08/2018] [Indexed: 12/15/2022]
Abstract
Traditional models of neural reorganization of language skills in patients with chronic stroke-induced aphasia (PWA) propose activation of reperfused or spared left hemisphere tissue results in the most favorable language outcomes. However, these models do not fully explain variable behavioral recovery patterns observed in chronic patients. Instead, investigation of connectivity patterns of critical network nodes may elucidate better-informed recovery models. In the present study, we combined fMRI and dynamic causal modeling (DCM) to examine effective connectivity of a simple three-node left hemisphere network during a semantic feature decision task in 25 PWA and 18 age-matched neurologically intact healthy controls. The DCM model space utilized in Meier, Kapse, & Kiran (2016), which was organized according to exogenous input to one of three regions (i.e., left inferior frontal gyrus, pars triangularis [LIFGtri], left posterior middle temporal gyrus [LpMTG], or left middle frontal gyrus [LMFG]) implicated in various levels of lexical-semantic processing, was interrogated. This model space included all possible combinations of uni- and bidirectional task-modulated connections between LIFGtri, LMFG and LpMTG, resulting in 72 individual models that were partitioned into three separate families (i.e., Family #1: Input to LIFGtri, Family #2: Input to LMFG, Family #3: Input to LpMTG). Family-wise Bayesian model selection revealed Family #2: Input to LMFG best fit both patient and control data at a group level. Both groups relied heavily on LMFG's modulation of the other two model regions. By contrast, between-group differences in task-modulated coupling of LIFGtri and LpMTG were observed. Within the patient group, the strength of activity in LIFGtri and connectivity of LpMTG → LIFGtri were positively associated with lexical-semantic abilities inside and outside of the scanner, whereas greater recruitment of LpMTG was associated with poorer lexical-semantic skills.
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Affiliation(s)
- Erin L Meier
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States.
| | - Jeffrey P Johnson
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
| | - Swathi Kiran
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
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11
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Muhammed L, Hardy CJD, Russell LL, Marshall CR, Clark CN, Bond RL, Warrington EK, Warren JD. Agnosia for bird calls. Neuropsychologia 2018; 113:61-67. [PMID: 29572063 PMCID: PMC5946901 DOI: 10.1016/j.neuropsychologia.2018.03.024] [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] [Received: 10/29/2017] [Revised: 01/18/2018] [Accepted: 03/19/2018] [Indexed: 12/02/2022]
Abstract
The cognitive organisation of nonverbal auditory knowledge remains poorly defined. Deficits of environmental sound as well as word and visual object knowledge are well-recognised in semantic dementia. However, it is unclear how auditory cognition breaks down in this disorder and how this relates to deficits in other knowledge modalities. We had the opportunity to study a patient with a typical syndrome of semantic dementia who had extensive premorbid knowledge of birds, allowing us to assess the impact of the disease on the processing of auditory in relation to visual and verbal attributes of this specific knowledge category. We designed a novel neuropsychological test to probe knowledge of particular avian characteristics (size, behaviour [migratory or nonmigratory], habitat [whether or not primarily water-dwelling]) in the nonverbal auditory, visual and verbal modalities, based on a uniform two-alternative-forced-choice procedure. The patient's performance was compared to healthy older individuals of similar birding experience. We further compared his performance on this test of bird knowledge with his knowledge of familiar human voices and faces. Relative to healthy birder controls, the patient showed marked deficits of bird call and bird name knowledge but relatively preserved knowledge of avian visual attributes and retained knowledge of human voices and faces. In both the auditory and visual modalities, his knowledge of the avian characteristics of size and behaviour was intact whereas his knowledge of the associated characteristic of habitat was deficient. This case provides further evidence that nonverbal auditory knowledge has a fractionated organisation that can be differentially targeted in semantic dementia. The cognitive organisation of auditory semantics is poorly understood. We assessed multimodal avian knowledge in a birder with semantic dementia. The patient had auditory (but not visual) agnosia for birds versus healthy birders. Auditory knowledge of avian attributes and human voices were differentially affected. This case illuminates the fractionated organisation of nonverbal auditory knowledge.
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Affiliation(s)
- Louwai Muhammed
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Chris J D Hardy
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Lucy L Russell
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Charles R Marshall
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Camilla N Clark
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Rebecca L Bond
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Elizabeth K Warrington
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom
| | - Jason D Warren
- Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
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12
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Woollams AM, Patterson K. Cognitive consequences of the left-right asymmetry of atrophy in semantic dementia. Cortex 2017; 107:64-77. [PMID: 29289335 DOI: 10.1016/j.cortex.2017.11.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/22/2017] [Accepted: 11/24/2017] [Indexed: 11/17/2022]
Abstract
Semantic dementia (SD) is a condition in which atrophy to the anterior temporal lobes (ATL) produces a selective deterioration of conceptual knowledge. As this atrophy is always bilateral but usually asymmetrical, differences in performance of the two SD subgroups-with left > right (L > R) versus right > left (R > L) atrophy-constitute a major source of evidence regarding the roles of the left and right sides of this region. We explored this issue using large scale case-series methodology, with a pool of 216 observations of neuropsychological data from 72 patients with SD. Anomia was significantly more severe in the L > R subgroup, even when cases from the two subgroups were matched on severity of comprehension deficits. For subgroups matched on the degree of anomia, we show that asymmetry of atrophy also affected both the nature of the naming errors produced, and the degree of a semantic category effect (living things vs artefacts). A comparison across tasks varying in their loading on verbal and visual processing revealed a greater deficit in object naming for L > R cases and in a picture-based semantic association test for R > L cases; this held true whether severity across subgroups was controlled using pairwise matching or statistically via principal components analysis. Importantly, the size of our sample allowed us to demonstrate considerable individual variation within each of the L > R and R > L subgroups, with consequent overlap between them. Our results paint a clear picture of how asymmetry of atrophy affects cognitive performance in SD, and we discuss the results in terms of two mechanisms that could contribute to these differences: variation in the information involved in semantic representations in the left and right ATL, and preferential connectivity between each ATL and other more modality specific intra-hemispheric regions.
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Affiliation(s)
- Anna M Woollams
- Neuroscience and Aphasia Research Unit, School of Biological Sciences, University of Manchester, Manchester, UK.
| | - Karalyn Patterson
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; MRC Cognition & Brain Sciences Unit, Cambridge, UK
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13
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Gainotti G. The Differential Contributions of Conceptual Representation Format and Language Structure to Levels of Semantic Abstraction Capacity. Neuropsychol Rev 2017; 27:134-145. [DOI: 10.1007/s11065-016-9339-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 12/21/2016] [Indexed: 11/24/2022]
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14
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Abstract
PURPOSE OF REVIEW This article reviews the common behavioral and cognitive features of frontotemporal dementia (FTD) and related disorders as well as the distinguishing clinical, genetic, and pathologic features of the most common subtypes. RECENT FINDINGS Advances in clinical phenotyping, genetics, and biomarkers have enabled improved predictions of the specific underlying molecular pathology associated with different presentations of FTD. Evaluation of large international cohorts has led to recent refinements in diagnostic criteria for several of the FTD subtypes. SUMMARY The FTDs are a group of neurodegenerative disorders featuring progressive deterioration of behavior or language and associated pathology in the frontal or temporal lobes. Based on anatomic, genetic, and neuropathologic categorizations, the six clinical subtypes of FTD or related disorders are: (1) behavioral variant of FTD, (2) semantic variant primary progressive aphasia, (3) nonfluent agrammatic variant primary progressive aphasia, (4) corticobasal syndrome, (5) progressive supranuclear palsy, and (6) FTD associated with motor neuron disease. Recognition and accurate diagnoses of FTD subtypes will aid the neurologist in the management of patients with FTD.
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Thompson HE, Henshall L, Jefferies E. The role of the right hemisphere in semantic control: A case-series comparison of right and left hemisphere stroke. Neuropsychologia 2016; 85:44-61. [PMID: 26945505 PMCID: PMC4863527 DOI: 10.1016/j.neuropsychologia.2016.02.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 02/28/2016] [Accepted: 02/29/2016] [Indexed: 11/30/2022]
Abstract
Semantic control processes guide conceptual retrieval so that we are able to focus on non-dominant associations and features when these are required for the task or context, yet the neural basis of semantic control is not fully understood. Neuroimaging studies have emphasised the role of left inferior frontal gyrus (IFG) in controlled retrieval, while neuropsychological investigations of semantic control deficits have almost exclusively focussed on patients with left-sided damage (e.g., patients with semantic aphasia, SA). Nevertheless, activation in fMRI during demanding semantic tasks typically extends to right IFG. To investigate the role of the right hemisphere (RH) in semantic control, we compared nine RH stroke patients with 21 left-hemisphere SA patients, 11 mild SA cases and 12 healthy, aged-matched controls on semantic and executive tasks, plus experimental tasks that manipulated semantic control in paradigms particularly sensitive to RH damage. RH patients had executive deficits to parallel SA patients but they performed well on standard semantic tests. Nevertheless, multimodal semantic control deficits were found in experimental tasks involving facial emotions and the 'summation' of meaning across multiple items. On these tasks, RH patients showed effects similar to those in SA cases - multimodal deficits that were sensitive to distractor strength and cues and miscues, plus increasingly poor performance in cyclical matching tasks which repeatedly probed the same set of concepts. Thus, despite striking differences in single-item comprehension, evidence presented here suggests semantic control is bilateral, and disruption of this component of semantic cognition can be seen following damage to either hemisphere.
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Affiliation(s)
- Hannah E Thompson
- Department of Psychology and York Neuroimaging Centre, University of York, UK.
| | - Lauren Henshall
- Department of Psychology and York Neuroimaging Centre, University of York, UK
| | - Elizabeth Jefferies
- Department of Psychology and York Neuroimaging Centre, University of York, UK
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Clarke A, Tyler LK. Understanding What We See: How We Derive Meaning From Vision. Trends Cogn Sci 2015; 19:677-687. [PMID: 26440124 PMCID: PMC4636429 DOI: 10.1016/j.tics.2015.08.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/07/2015] [Accepted: 08/12/2015] [Indexed: 11/19/2022]
Abstract
Recognising objects goes beyond vision, and requires models that incorporate different aspects of meaning. Most models focus on superordinate categories (e.g., animals, tools) which do not capture the richness of conceptual knowledge. We argue that object recognition must be seen as a dynamic process of transformation from low-level visual input through categorical organisation to specific conceptual representations. Cognitive models based on large normative datasets are well-suited to capture statistical regularities within and between concepts, providing both category structure and basic-level individuation. We highlight recent research showing how such models capture important properties of the ventral visual pathway. This research demonstrates that significant advances in understanding conceptual representations can be made by shifting the focus from studying superordinate categories to basic-level concepts.
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Affiliation(s)
- Alex Clarke
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Lorraine K Tyler
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK.
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