Towards a unified, computationally-implemented neural network for understanding semantic cognition and its disorders.
Lead Research Organisation:
University of Manchester
Department Name: School of Biological Sciences
Abstract
Semantic memory refers to the rich database of knowledge we have about the meanings of words, objects, people and all the stimuli present in our environment. We activate this information when we comprehend a word or recognise an object. We use the same knowledge to initiate speech or non-verbal activities such as object use. The aim of communication, itself, is for meaning to be conveyed between people. It is evident, therefore, that semantic knowledge is crucial for many everyday activities both at work and at home. When this type of knowledge disintegrates or becomes inaccessible after brain damage, patients become significantly disabled in many aspects of their lives. Imagine, for example, being able to comprehend only a small proportion of the words in everyday conversation, a letter or newspaper; being stuck with significant word-finding problems; or being unable to understand everyday symbols or road signs.
Sadly, these kinds of problems are a common feature of many types of brain disease. Semantic impairment is a characteristic of certain types of dementia, brain infections and after stroke. In a past study of patients with language problems after stroke, we found measurable problems with semantic processing in around 1/3 of them. The core aims of our continuing research programme, therefore, are (a) to build up a formal, working model of how the brain supports semantic processing; (b) to catalogue and investigate all types of patient with semantic impairment; and (c) to use our "brain model" of semantic processing to understand the causes of the patients' different impairments. These steps will be used to improve: detection of semantic deficits; differential diagnosis; clinical management; and evidence-based interventions.
In our last research programme we discovered important qualitative variations in the nature of semantic impairment in different patient groups. In addition to these clinical investigations, we developed and applied new basic science methods to probe the functioning of various specific brain regions. This allowed us to check the patient results in normally-functioning brains and then to use the methods to extend our understanding of semantic processes and which specific brain subregions are involved.
In the next phase of our research, we will use these important findings and methods as a foundation for a new series of studies. Our ultimate aim is to build up a complete picture and model of the network of brain regions that support semantic processing. We will use this model to reproduce each patient group's pattern of performance, which will be catalogued with high precision. This will be achieved by adopting a variety of clinical and basic science methods. These will include: (a) further clinical investigations of existing and new patient groups - leading to a complete catalogue of the semantic processing problems in all types of relevant patient groups (covering dementia, stroke and other forms of brain damage); (b) brain stimulation studies to mimic patient-like deficits and to test key ideas about semantic functioning; (c) functional brain imaging in order to map out the semantic processing, in both healthy participants and various patient groups; (d) to amalgamate the information from all these lines of enquiry through a new form of mathematical modelling which incorporates information about brain regions and their 'wiring' into the model - such that we can simulate not only the patients' behaviour but also the underlying pattern of brain damage. We will then be able to use this model not only to understand the nature of semantic problems across all these different patient groups but also to use the model to gain new insights about minimising these problems and for generating new interventions that could be used by speech therapists with these patient groups.
Sadly, these kinds of problems are a common feature of many types of brain disease. Semantic impairment is a characteristic of certain types of dementia, brain infections and after stroke. In a past study of patients with language problems after stroke, we found measurable problems with semantic processing in around 1/3 of them. The core aims of our continuing research programme, therefore, are (a) to build up a formal, working model of how the brain supports semantic processing; (b) to catalogue and investigate all types of patient with semantic impairment; and (c) to use our "brain model" of semantic processing to understand the causes of the patients' different impairments. These steps will be used to improve: detection of semantic deficits; differential diagnosis; clinical management; and evidence-based interventions.
In our last research programme we discovered important qualitative variations in the nature of semantic impairment in different patient groups. In addition to these clinical investigations, we developed and applied new basic science methods to probe the functioning of various specific brain regions. This allowed us to check the patient results in normally-functioning brains and then to use the methods to extend our understanding of semantic processes and which specific brain subregions are involved.
In the next phase of our research, we will use these important findings and methods as a foundation for a new series of studies. Our ultimate aim is to build up a complete picture and model of the network of brain regions that support semantic processing. We will use this model to reproduce each patient group's pattern of performance, which will be catalogued with high precision. This will be achieved by adopting a variety of clinical and basic science methods. These will include: (a) further clinical investigations of existing and new patient groups - leading to a complete catalogue of the semantic processing problems in all types of relevant patient groups (covering dementia, stroke and other forms of brain damage); (b) brain stimulation studies to mimic patient-like deficits and to test key ideas about semantic functioning; (c) functional brain imaging in order to map out the semantic processing, in both healthy participants and various patient groups; (d) to amalgamate the information from all these lines of enquiry through a new form of mathematical modelling which incorporates information about brain regions and their 'wiring' into the model - such that we can simulate not only the patients' behaviour but also the underlying pattern of brain damage. We will then be able to use this model not only to understand the nature of semantic problems across all these different patient groups but also to use the model to gain new insights about minimising these problems and for generating new interventions that could be used by speech therapists with these patient groups.
Technical Summary
Semantic memory refers to the rich database of knowledge we have about the meanings of words, objects, people and all the stimuli present in our environment. This information is crucial for both verbal and nonverbal activities, and so when it disintegrates or becomes inaccessible, patients become significantly disabled. Semantic impairment is a feature in many different types of neurodegenerative and chronic brain disease including semantic dementia, Alzheimer's disease, stroke and herpes simplex encephalitis. For some of these, semantic impairment is central to diagnosis (e.g., semantic dementia) whilst for others it can be a common feature (e.g., we found that around 1/3 stroke aphasic patients have measurable semantic impairment when assessed with suitable materials).
The core aims of our continuing research programme, therefore, are (a) to implement a neuroanatomically-constrained, computational model of semantic processing; (b) to catalogue and investigate all types of patient with semantic impairment; (c) to mimic and test key hypotheses about the nature and neural basis of semantic processing via transcranial magnetic stimulation studies; (d) to use functional MRI and MR tractography to map the core semantic regions and their connectivity (both structural and functional); and (e) to amalgamate this rich empirical database through the new 'neurocomputational' model in order to understand the causes of the patients' different impairments. These steps will be used to improve: detection of semantic deficits; differential diagnosis; clinical management; and evidence-based interventions.
The core aims of our continuing research programme, therefore, are (a) to implement a neuroanatomically-constrained, computational model of semantic processing; (b) to catalogue and investigate all types of patient with semantic impairment; (c) to mimic and test key hypotheses about the nature and neural basis of semantic processing via transcranial magnetic stimulation studies; (d) to use functional MRI and MR tractography to map the core semantic regions and their connectivity (both structural and functional); and (e) to amalgamate this rich empirical database through the new 'neurocomputational' model in order to understand the causes of the patients' different impairments. These steps will be used to improve: detection of semantic deficits; differential diagnosis; clinical management; and evidence-based interventions.
Planned Impact
Our specific plans for academic, clinical and other types of impact are summarised in the 'Case for Support' and 'Pathways to Impact'. A brief summary is provided here.
The most important beneficiaries of our research are the patients and carers, who are the core groups in our research programme. Improved diagnosis, assessment, clinical management and interventions will follow from a clearer understanding of the cognitive and neural processes that underpin semantic processing. If our methods can be extended and replicated to other aspects of higher cognitive function and its disorders (see 'academic beneficiaries' section) then our multidisciplinary, multi-method approach might also benefit other patient groups in the longer-term.
This patient-related benefit can be delivered directly (a significant proportion of our broader research group is dedicated to the translation of basic sciences through to new speech and language interventions) and indirectly through the patients' clinicians (who can also be considered to be beneficiaries of the research). Our research is intended to improve diagnosis, understanding of patients' disorders as well as preserved function, clinical management and interventions. This will be achieved through our 'communication plan' (see previous section) - not only in terms of disseminating information to clinician and patient groups but also in a more interactive fashion through workshops and seminars. These types of event, combined with our own clinical activities, provide a crucial opportunity to discuss and shape the clinical applicability of our research. As noted throughout this application and in the 'Pathways to Impact' - we will also continue to make all of our clinical materials and assessments openly available. Numerous clinical departments in the UK and abroad now use our semantic battery for improved assessment and identification of semantic impairments, for example.
Our imaging related activities and methods development may also have wider impact both clinically and commercially. For example, white-matter in vivo tractography is becoming more common as a research tool. With appropriate development, it might also prove to be a clinically useful additional form of imaging to inform clinicians about patterns of disconnection as well as the location of damage (as highlighted by standard structural scans). Parker will lead on this aspect of our research impact though commercial links and a local spin-out company (see 'Pathways to Impact' for more detail).
The most important beneficiaries of our research are the patients and carers, who are the core groups in our research programme. Improved diagnosis, assessment, clinical management and interventions will follow from a clearer understanding of the cognitive and neural processes that underpin semantic processing. If our methods can be extended and replicated to other aspects of higher cognitive function and its disorders (see 'academic beneficiaries' section) then our multidisciplinary, multi-method approach might also benefit other patient groups in the longer-term.
This patient-related benefit can be delivered directly (a significant proportion of our broader research group is dedicated to the translation of basic sciences through to new speech and language interventions) and indirectly through the patients' clinicians (who can also be considered to be beneficiaries of the research). Our research is intended to improve diagnosis, understanding of patients' disorders as well as preserved function, clinical management and interventions. This will be achieved through our 'communication plan' (see previous section) - not only in terms of disseminating information to clinician and patient groups but also in a more interactive fashion through workshops and seminars. These types of event, combined with our own clinical activities, provide a crucial opportunity to discuss and shape the clinical applicability of our research. As noted throughout this application and in the 'Pathways to Impact' - we will also continue to make all of our clinical materials and assessments openly available. Numerous clinical departments in the UK and abroad now use our semantic battery for improved assessment and identification of semantic impairments, for example.
Our imaging related activities and methods development may also have wider impact both clinically and commercially. For example, white-matter in vivo tractography is becoming more common as a research tool. With appropriate development, it might also prove to be a clinically useful additional form of imaging to inform clinicians about patterns of disconnection as well as the location of damage (as highlighted by standard structural scans). Parker will lead on this aspect of our research impact though commercial links and a local spin-out company (see 'Pathways to Impact' for more detail).
Organisations
Publications
Hoffman P
(2013)
Semantic diversity: a measure of semantic ambiguity based on variability in the contextual usage of words.
in Behavior research methods
Hoffman P
(2012)
Posterior middle temporal gyrus is involved in verbal and non-verbal semantic cognition: Evidence from rTMS
in Aphasiology
Hoffman P
(2018)
From percept to concept in the ventral temporal lobes: Graded hemispheric specialisation based on stimulus and task.
in Cortex; a journal devoted to the study of the nervous system and behavior
Hoffman P
(2014)
The anterior temporal lobes are critically involved in acquiring new conceptual knowledge: evidence for impaired feature integration in semantic dementia.
in Cortex; a journal devoted to the study of the nervous system and behavior
Hoffman P
(2013)
Be concrete to be comprehended: consistent imageability effects in semantic dementia for nouns, verbs, synonyms and associates.
in Cortex; a journal devoted to the study of the nervous system and behavior
Humphreys GF
(2017)
Mapping Domain-Selective and Counterpointed Domain-General Higher Cognitive Functions in the Lateral Parietal Cortex: Evidence from fMRI Comparisons of Difficulty-Varying Semantic Versus Visuo-Spatial Tasks, and Functional Connectivity Analyses.
in Cerebral cortex (New York, N.Y. : 1991)
Humphreys GF
(2015)
Fusion and Fission of Cognitive Functions in the Human Parietal Cortex.
in Cerebral cortex (New York, N.Y. : 1991)
Humphreys GF
(2015)
Establishing task- and modality-dependent dissociations between the semantic and default mode networks.
in Proceedings of the National Academy of Sciences of the United States of America
Ishibashi R
(2016)
The neural network for tool-related cognition: An activation likelihood estimation meta-analysis of 70 neuroimaging contrasts.
in Cognitive neuropsychology
Jackson R
(2018)
An emergent functional parcellation of the temporal cortex
in NeuroImage
Jackson RL
(2015)
The Nature and Neural Correlates of Semantic Association versus Conceptual Similarity.
in Cerebral cortex (New York, N.Y. : 1991)
Jackson RL
(2015)
The timing of anterior temporal lobe involvement in semantic processing.
in Journal of cognitive neuroscience
Jackson RL
(2020)
The Graded Change in Connectivity across the Ventromedial Prefrontal Cortex Reveals Distinct Subregions.
in Cerebral cortex (New York, N.Y. : 1991)
Jackson RL
(2019)
Exploring distinct default mode and semantic networks using a systematic ICA approach.
in Cortex; a journal devoted to the study of the nervous system and behavior
Jackson RL
(2016)
The Semantic Network at Work and Rest: Differential Connectivity of Anterior Temporal Lobe Subregions.
in The Journal of neuroscience : the official journal of the Society for Neuroscience
Jung J
(2016)
Mapping the Dynamic Network Interactions Underpinning Cognition: A cTBS-fMRI Study of the Flexible Adaptive Neural System for Semantics.
in Cerebral cortex (New York, N.Y. : 1991)
Jung J
(2017)
GABA concentrations in the anterior temporal lobe predict human semantic processing.
in Scientific reports
Jung J
(2018)
Establishing the cognitive signature of human brain networks derived from structural and functional connectivity.
in Brain structure & function
Jung J
(2017)
The structural connectivity of higher order association cortices reflects human functional brain networks.
in Cortex; a journal devoted to the study of the nervous system and behavior
Lambon Ralph MA
(2012)
Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.
in Brain : a journal of neurology
Lambon Ralph MA
(2014)
Neurocognitive insights on conceptual knowledge and its breakdown.
in Philosophical transactions of the Royal Society of London. Series B, Biological sciences
Noonan KA
(2013)
Demonstrating the qualitative differences between semantic aphasia and semantic dementia: a novel exploration of nonverbal semantic processing.
in Behavioural neurology
Noonan KA
(2013)
Going beyond inferior prefrontal involvement in semantic control: evidence for the additional contribution of dorsal angular gyrus and posterior middle temporal cortex.
in Journal of cognitive neuroscience
Pobric G
(2016)
Hemispheric Specialization within the Superior Anterior Temporal Cortex for Social and Nonsocial Concepts.
in Journal of cognitive neuroscience
Rice GE
(2018)
The Roles of Left Versus Right Anterior Temporal Lobes in Semantic Memory: A Neuropsychological Comparison of Postsurgical Temporal Lobe Epilepsy Patients.
in Cerebral cortex (New York, N.Y. : 1991)
Rice GE
(2018)
Concrete versus abstract forms of social concept: an fMRI comparison of knowledge about people versus social terms.
in Philosophical transactions of the Royal Society of London. Series B, Biological sciences
Rice GE
(2015)
The Roles of Left Versus Right Anterior Temporal Lobes in Conceptual Knowledge: An ALE Meta-analysis of 97 Functional Neuroimaging Studies.
in Cerebral cortex (New York, N.Y. : 1991)
Rice GE
(2015)
Graded specialization within and between the anterior temporal lobes.
in Annals of the New York Academy of Sciences
Rice GE
(2018)
Revealing the Dynamic Modulations That Underpin a Resilient Neural Network for Semantic Cognition: An fMRI Investigation in Patients With Anterior Temporal Lobe Resection.
in Cerebral cortex (New York, N.Y. : 1991)
Roberts DJ
(2015)
Processing deficits for familiar and novel faces in patients with left posterior fusiform lesions.
in Cortex; a journal devoted to the study of the nervous system and behavior
Robson H
(2012)
Revealing and quantifying the impaired phonological analysis underpinning impaired comprehension in Wernicke's aphasia.
in Neuropsychologia
Robson H
(2014)
The anterior temporal lobes support residual comprehension in Wernicke's aphasia.
in Brain : a journal of neurology
Robson H
(2017)
Arterial spin labelling shows functional depression of non-lesion tissue in chronic Wernicke's aphasia.
in Cortex; a journal devoted to the study of the nervous system and behavior
Robson H
(2013)
Fundamental deficits of auditory perception in Wernicke's aphasia.
in Cortex; a journal devoted to the study of the nervous system and behavior
Rogers T
(2015)
Disorders of representation and control in semantic cognition: Effects of familiarity, typicality, and specificity
in Neuropsychologia
Rogers TT
(2021)
Evidence for a deep, distributed and dynamic code for animacy in human ventral anterior temporal cortex.
in eLife
Sanaei Nezhad F
(2017)
Quantification of GABA, glutamate and glutamine in a single measurement at 3 T using GABA-edited MEGA-PRESS
in NMR in Biomedicine
Sanaei Nezhad F
(2020)
Number of subjects required in common study designs for functional GABA magnetic resonance spectroscopy in the human brain at 3 Tesla.
in The European journal of neuroscience
Schapiro AC
(2013)
Why bilateral damage is worse than unilateral damage to the brain.
in Journal of cognitive neuroscience
Shimotake A
(2015)
Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes.
in Cerebral cortex (New York, N.Y. : 1991)
Stampacchia S
(2018)
Shared processes resolve competition within and between episodic and semantic memory: Evidence from patients with LIFG lesions.
in Cortex; a journal devoted to the study of the nervous system and behavior
Thompson HE
(2018)
The contribution of executive control to semantic cognition: Convergent evidence from semantic aphasia and executive dysfunction.
in Journal of neuropsychology
Thompson HE
(2015)
Varieties of semantic 'access' deficit in Wernicke's aphasia and semantic aphasia.
in Brain : a journal of neurology
Tochadse M
(2018)
Unification of behavioural, computational and neural accounts of word production errors in post-stroke aphasia.
in NeuroImage. Clinical
Ueno T
(2014)
Not lost in translation: generalization of the primary systems hypothesis to Japanese-specific language processes.
in Journal of cognitive neuroscience
Description | ERC |
Amount | € 2,300,000 (EUR) |
Funding ID | GAP: 670428 - BRAIN2MIND_NEUROCOMP |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 01/2016 |
End | 12/2020 |
Description | The flexible and interactive neural, computational and neurobiological mechanisms underpinning semantic cognition and its disorders. |
Amount | £1,503,850 (GBP) |
Funding ID | MR/R023883/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2018 |
End | 08/2025 |
Title | New neuropsychological assessments and neuroimaging analyses for patient lesion-symptom mapping |
Description | New aphasiological assessments New analysis approach to symptom-lesion mapping (cf. Halai et al. Cotex 2017). |
Type Of Material | Model of mechanisms or symptoms - human |
Year Produced | 2016 |
Provided To Others? | Yes |
Impact | Multiple international research groups use this method |
Description | Clinical dissemination events, various |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Dissemination to clinical groups (speech therapy, neuropsychology, neurology) . |
Year(s) Of Engagement Activity | Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 |