The structural basis of semantic control: Evidence from individual differences in cortical thickness

Wang, Xiuyi; Bernhardt, Boris C.; Karapanagiotidis, Theodoros; Caso, Irene de; Alam, Tirso Rene del Jesus Gonzalez; Cotter, Zacharria Peter Alexander; Smallwood, Jonathan; Jefferies, Elizabeth

doi:10.1016/j.neuroimage.2018.07.044

Cited by 33 publications

(25 citation statements)

References 88 publications

(151 reference statements)

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“…Second, pMTG is associated with understanding thematic relations, events and actions (Gennari et al., 2007, Kable et al., 2005, Martin and Chao, 2001, Perani et al., 1999, Shapiro et al., 2005, Tranel et al., 2003, Vigliocco et al., 2011). A third set of studies show that pMTG participates in a left-lateralised network underpinning semantic control, along with anterior IFG (Davey et al., 2016, Hallam et al., 2016, Jefferies, 2013, Noonan et al., 2013, Teige et al., 2018, Wang et al., 2018, Whitney et al., 2011). We observed a greater engagement of pMTG for thematic than taxonomic relationships (irrespective of difficulty), and for weak compared with strong thematic relationships.…”

Section: Discussionmentioning

confidence: 99%

Dissociations in semantic cognition: Oscillatory evidence for opposing effects of semantic control and type of semantic relation in anterior and posterior temporal cortex

Teige

Cornelissen

Mollo

et al. 2019

Cortex

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How does the brain represent and process different types of knowledge? The Dual Hub account postulates that anterior temporal lobes (ATL) support taxonomic relationships based on shared physical features (mole – cat), while temporoparietal regions, including posterior middle temporal gyrus (pMTG), support thematic associations (mole – earth). Conversely, the Controlled Semantic Cognition account proposes that ATL supports both aspects of knowledge, while left pMTG contributes to controlled retrieval. This study used magnetoencephalography to test these contrasting predictions of functional dissociations within the temporal lobe. ATL and pMTG responded more strongly to taxonomic and thematic trials respectively, matched for behavioural performance, in line with predictions of the Dual Hub account. In addition, ATL showed a greater response to strong than weak thematic associations, while pMTG showed the opposite pattern, supporting a key prediction of the Controlled Semantic Cognition account. ATL showed a stronger response for word pairs that were more semantically coherent, either because they shared physical features (in taxonomic trials) or a strong thematic association. These effects largely coincided in time and frequency (although an early oscillatory response in ATL was specific to taxonomic trials). In contrast, pMTG showed non-overlapping effects of semantic control demands and thematic judgements: this site showed a larger oscillatory response to weak associations, when ongoing retrieval needed to be shaped to suit the task demands, and also a larger response to thematic judgements contrasted with taxonomic trials (which was reduced but not eliminated when the thematic trials were easier). Consequently, time-sensitive neuroimaging supports a complex pattern of functional dissociations within the left temporal lobe, which reflects both coherence versus control and distinctive oscillatory responses for taxonomic overlap (in ATL) and thematic relations (in pMTG).

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Section: Discussionmentioning

confidence: 99%

Dissociations in semantic cognition: Oscillatory evidence for opposing effects of semantic control and type of semantic relation in anterior and posterior temporal cortex

Teige

Cornelissen

Mollo

et al. 2019

Cortex

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“…Resting state fMRI Data -under Data preprocessing). As described in the introduction, aspects of the resting state data and their associations to patterns of ongoing thought have been previously published in various papers (Turnbull et al, 2019;Wang et al, 2018c).…”

Section: Participantsmentioning

confidence: 99%

Individual variation in patterns of task focused, and detailed, thought are uniquely associated within the architecture of the medial temporal lobe

Wang

Vatansever

et al. 2019

NeuroImage

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Understanding the neural processes that support different patterns of ongoing thought is an important goal of contemporary cognitive neuroscience. Early accounts assumed the default mode network (DMN) was especially important for conscious attention to taskirrelevant / personally relevant material. However, simple task-negative accounts of the DMN are incompatible with more recent evidence that neural patterns within the system can be related to ongoing processing during active task states. To better characterise the contribution of the DMN to ongoing thought, we conducted a cross-sectional analysis of the relationship between the structural organisation of the brain, as indexed by cortical thickness, and patterns of experience, identified using experience sampling in the cognitive laboratory. In a sample of 181 healthy individuals (mean age 20 years, 117 females) we identified an association between cortical thickness in the anterior parahippocampus and patterns of task focused thought, as well as an adjacent posterior region in which cortical thickness was associated with experiences with higher levels of subjective detail. Both regions fell within regions of medial temporal lobe associated with the DMN, yet varied in their functional connectivity: the time series of signals in the 'on-task' region were more correlated with systems important for external task-relevant processing (as determined by meta-analysis) including the dorsal and ventral attention, and fronto-parietal networks. In contrast, connectivity within the region linked to subjective 'detail' was more correlated with the medial core of the DMN (posterior cingulate and the medial pre-frontal cortex) and regions of primary visual cortex. These results provide cross-sectional evidence that confirms a role of the DMN in how detailed experiences are and so provide further evidence that the role of this system in experience is not simply task-irrelevant. Our results also highlight processes within the medial temporal lobe, and their interactions with other regions of cortex as important in determining multiple aspects of how human cognition unfolds.

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“…Semantic tasks recruit both DMN and MDN regions, yet the peak response during semantic decisions often falls within regions associated with semantic control, such as the left inferior frontal gyrus, posterior middle temporal gyrus and dorsal anterior cingulate cortex (19). These peaks typically fall outside the MDN, and are adjacent to, yet distinct from, the DMN (6,(19)(20)(21). Semantic control regions also show structural and functional connectivity to regions implicated in conceptual representation (anterior temporal lobes) and domain-general executive control (inferior frontal sulcus), suggesting that integration of long-term conceptual knowledge with currently-relevant goals might support flexible patterns of semantic retrieval (5).…”

Section: Introductionmentioning

confidence: 99%

A gradient from long-term memory to novel cognition: transitions through default mode and executive cortex

Wang

Margulies

Smallwood

et al. 2020

Preprint

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Human cognition is flexible, supporting decisions that are novel as well as those that arise from long-term memory. Traditionally, these aspects of cognition are ascribed to dichotomous neural systems supported by default mode (DMN) and multiple-demand (MDN) networks. In reality, however, most situations are neither completely familiar, nor entirely new, highlighting the need to understand how cognition is constrained in a graded fashion. A contemporary account proposes a functional connectivity gradient along the cortical surface that captures the transition from heteromodal DMN, through MDN regions, to unimodal regions. We asked whether brain responses changed systematically along the connectivity gradient as we parametrically varied the global semantic similarity of items within a feature matching task to create a 'task gradient', from conceptual combinations that were highly overlapping in long-term memory to trials that only shared the goal-relevant feature. We found the brain's response to the task gradient varied systematically along the connectivity gradient, with the strongest response in DMN when the probe and target items were highly overlapping conceptually. This graded functional change was seen in multiple brain regions and within individual brains, and was not readily explained by task difficulty. Moreover, the gradient captured the spatial layout of networks involved in semantic processing, providing an organizational principle for controlled semantic cognition across the cortex.How is human cortex organized to produce a spectrum of cognition, from efficient memory-based decisions to more novel patterns of thought? We addressed this question by asking participants to match words on the basis of a specific semantic feature, such as colour, while parametrically varying other features. This created a 'task gradient' from strong to weak overlap in long-term memory. We investigated whether this task gradient co-varied with a previously-described functional connectivity gradient which captures transitions along the cortical surface from perception and action, through executive control areas, to heteromodal regions of default mode network. We found the neural response to the task varied systematically along this connectivity gradient providing an organizational principle for semantic cognition across the cortex.

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The structural basis of semantic control: Evidence from individual differences in cortical thickness

Cited by 33 publications

References 88 publications

Dissociations in semantic cognition: Oscillatory evidence for opposing effects of semantic control and type of semantic relation in anterior and posterior temporal cortex

Dissociations in semantic cognition: Oscillatory evidence for opposing effects of semantic control and type of semantic relation in anterior and posterior temporal cortex

Individual variation in patterns of task focused, and detailed, thought are uniquely associated within the architecture of the medial temporal lobe

A gradient from long-term memory to novel cognition: transitions through default mode and executive cortex

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