Social and emotion dimensional organizations in the abstract semantic space: the neuropsychological evidence

An essential aspect of human cognition is supported by a rich reservoir of abstract concepts without tangible external referents (e.g., “honor”, “relationship”, “direction”). While decades of research showed that the neural organization of conceptual knowledge referring to concrete words respects domains of evolutionary salience and sensorimotor attributes, the organization principles of abstract word meanings are poorly understood. Here, we provide neuropsychological evidence for a domain (sociality) and attribute (emotion) structure in abstract word processing. Testing 34 brain-damaged patients on a word-semantic judgment task, we observed double dissociations between social and nonsocial words and a single dissociation of sparing of emotional (relative to non-emotional) words. The lesion profiles of patients with specific dissociations suggest potential neural correlates positively or negatively associated with each dimension. These results unravel a general domain-attribute architecture of word meanings and highlight the roles of the social domain and the emotional attribute in the non-object semantic space.

Association of subcortical gray-matter volumes with life-course-persistent antisocial behavior in a population-representative longitudinal birth cohort

Neuropsychological evidence supports the developmental taxonomy theory of antisocial behavior, suggesting that abnormal brain development distinguishes life-course-persistent from adolescence-limited antisocial behavior. Recent neuroimaging work confirmed that prospectively-measured life-course-persistent antisocial behavior is associated with differences in cortical brain structure. Whether this extends to subcortical brain structures remains uninvestigated. This study compared subcortical gray-matter volumes between 672 members of the Dunedin Study previously defined as exhibiting life-course-persistent, adolescence-limited or low-level antisocial behavior based on repeated assessments at ages 7–26 years. Gray-matter volumes of 10 subcortical structures were compared across groups. The life-course-persistent group had lower volumes of amygdala, brain stem, cerebellum, hippocampus, pallidum, thalamus, and ventral diencephalon compared to the low-antisocial group. Differences between life-course-persistent and adolescence-limited individuals were comparable in effect size to differences between life-course-persistent and low-antisocial individuals, but were not statistically significant due to less statistical power. Gray-matter volumes in adolescence-limited individuals were near the norm in this population-representative cohort and similar to volumes in low-antisocial individuals. Although this study could not establish causal links between brain volume and antisocial behavior, it constitutes new biological evidence that all people with antisocial behavior are not the same, supporting a need for greater developmental and diagnostic precision in clinical, forensic, and policy-based interventions.

Neuropsychological evidence of multi-domain network hubs in the human thalamus

Hubs in the human brain support behaviors that arise from brain network interactions. Previous studies have identified hub regions in the human thalamus that are connected with multiple functional networks. However, the behavioral significance of thalamic hubs has yet to be established. Our framework predicts that thalamic subregions with strong hub properties are broadly involved in functions across multiple cognitive domains. To test this prediction, we studied human patients with focal thalamic lesions in conjunction with network analyses of the human thalamocortical functional connectome. In support of our prediction, lesions to thalamic subregions with stronger hub properties were associated with widespread deficits in executive, language, and memory functions, whereas lesions to thalamic subregions with weaker hub properties were associated with more limited deficits. These results highlight how a large-scale network model can broaden our understanding of thalamic function for human cognition.

The Cerebellum Plays a Role in Cognitive, but Not Affective, Theory of Mind: A Voxel-Based Lesion Mapping Study

Introduction: Theory of Mind (ToM) is a social-cognitive skill that allows the understanding of the intentions, beliefs, and desires of others. There is a distinction between affective and cognitive ToM, with evidence showing that these processes rely on partially distinct neural networks. The role of the cerebellum in social cognition has only been rarely explored. In this study, we tested whether the cerebellum is necessary for cognitive and affective ToM performance. Material and methods: We investigated adults with traumatic brain injury (n=193) and healthy controls (n=52) using voxel-based lesion-symptom mapping (VLSM) and by measuring the impact on functional connectivity. Results: First, we observed that damage to the cerebellum affected Cognitive but not Affective ToM processing. Further, we found a lateralization effect for the role of the cerebellum in cognitive ToM with participants with left cerebellar injury performing worse than those with right cerebellar injury. Both VLSM and standard statistical analysis provided evidence that left cerebellar Crus I and lobule VI contributed to ToM processing. Lastly, we found that disconnection of the left thalamic projection and the left fronto-striatal fasciculus was associated with poor cognitive ToM performance. Conclusions: Our study is the first to reveal direct causal neuropsychological evidence for a role of the cerebellum in cognitive, but not in affective, ToM, processing. It reinforces the idea that social cognition relies on a complex network functionally connected through white matter pathways that include the cerebellum. It supports evidence that the neural networks underpinning cognitive and affective ToM can be differentiated.

Visual Neuropsychology in Development: Anatomo-Functional Brain Mechanisms of Action/Perception Binding in Health and Disease

Vision is the main entrance for environmental input to the human brain. Even if vision is our most used sensory modality, its importance is not limited to environmental exploration. Rather it has strong links to motor competences, further extending to cognitive and social aspects of human life. These multifaceted relationships are particularly important in developmental age and become dramatically evident in presence of complex deficits originating from visual aberrancies. The present review summarizes the available neuropsychological evidence on the development of visual competences, with a particular focus on the associated visuo-motor integration skills in health and disease. With the aim of supporting future research and interventional settings, the goal of the present review is to constitute a solid base to help the translation of neuropsychological hypotheses into straightforward empirical investigations and rehabilitation/training protocols. This approach will further increase the impact, ameliorate the acceptance, and ease the use and implementation of lab-derived intervention protocols in real-life situations.

Neuropsychological evidence of multi-domain network hubs in the human thalamus

Hubs in the human brain support behaviors that arise from brain network interactions. Previous studies have identified hub regions in the human thalamus that are connected with multiple functional networks. However, the behavioral significance of thalamic hubs has yet to be established. Our framework predicts that thalamic subregions with strong hub properties are broadly involved in functions across multiple cognitive domains. To test this prediction, we studied human patients with focal thalamic lesions in conjunction with network analyses of the human thalamocortical functional connectome. In support of our prediction, lesions to thalamic subregions with stronger hub properties were associated with widespread deficits in executive, language, and memory functions, whereas lesions to thalamic subregions with weaker hub properties were associated with more limited deficits. These results highlight how a large-scale network model can broaden our understanding of thalamic function for human cognition.

A Multicomponent Model of Working Memory

The multicomponent model aims to provide a broad theoretical framework enabling both more detailed fractionation and analysis of its components, and a capacity for it be used fruitfully beyond the laboratory. In its current form it comprises four interacting components. Two of these are modality-specific memory storage systems, one verbal-acoustic, the phonological loop, and one visuospatial, the sketchpad. Information in both these stores can be temporarily maintained via focused attention termed ‘refreshing’, while the phonological loop can also maintain familiar verbalizable material by subvocal or overt rehearsal. Both subsystems are controlled by a third component, the central executive, a supervisory system with limited resources. The central executive is principally concerned with internally directed attentional control processes but also has a role in the attentional selection of perceptual information. Information from these three components is coordinated with information from perception and long-term memory through the fourth component, a multidimensional, multimodal episodic buffer. This component is capable of holding up to around four episodic chunks, and is a valuable but essentially passive storage system, controlled by the central executive and accessible to conscious awareness. The multicomponent model has been systematically developed using a number of experimental tools. These include, principally, similarity effects to identify the type of coding involved, concurrent task methods to assess the contributions of the various subsystems to complex tasks, and neuropsychological evidence, in particular from the study of single cases with very specific deficits. The model continues to evolve and has proved successful both in accounting for a broad range of data on memory and related cognitive areas and in its application to the understanding of a wide range of cognitive activities and populations.

Co-speech gestures are a window into the effects of Parkinson’s disease on action representations

Parkinson’s disease impairs motor function and cognition, which together affect language and communication. Co-speech gestures are a form of language-related actions that provide imagistic depictions of the speech content they accompany. Gestures rely on visual and motor imagery, but it is unknown whether gesture representations require the involvement of intact neural sensory and motor systems. We tested this hypothesis with a fine-grained analysis of co-speech action gestures in Parkinson’s disease. 37 people with Parkinson’s disease and 33 controls described two scenes featuring actions which varied in their inherent degree of bodily motion. In addition to the perspective of action gestures (gestural viewpoint/first- vs. third-person perspective), we analysed how Parkinson’s patients represent manner (how something/someone moves) and path information (where something/someone moves to) in gesture, depending on the degree of bodily motion involved in the action depicted. We replicated an earlier finding that people with Parkinson’s disease are less likely to gesture about actions from a first-person perspective – preferring instead to depict actions gesturally from a third-person perspective – and show that this effect is modulated by the degree of bodily motion in the actions being depicted. When describing high motion actions, the Parkinson’s group were specifically impaired in depicting manner information in gesture and their use of third-person path-only gestures was significantly increased. Gestures about low motion actions were relatively spared. These results inform our understanding of the neural and cognitive basis of gesture production by providing neuropsychological evidence that action gesture production relies on intact motor network function.

Callosal anisotropy predicts attentional network changes after parietal inhibitory stimulation

Hemispatial neglect is thought to result from disruption of interhemispheric equilibrium. Right hemisphere lesions deactivate the right frontoparietal network and hyperactivate the left via release from interhemispheric inhibition. Support for this theory comes from neuropsychological evidence as well as transcranial magnetic stimulation (TMS) studies in healthy subjects, in whom right posterior parietal cortex (PPC) inhibition causes neglect-like, rightward, visuospatial bias. Concurrent TMS and fMRI after right PPC TMS show task-dependent changes but may fail to identify effects of stimulation in areas not directly activated by the specific task, complicating interpretations. We used resting-state functional connectivity (RSFC) after inhibitory TMS over the right PPC to examine changes in the networks underlying visuospatial attention.In a crossover experiment in healthy individuals, we delivered continuous theta burst TMS to the right PPC and vertex as control condition. We hypothesized that PPC inhibitory stimulation would cause a rightward visuospatial bias, decrease PPC connectivity with frontal areas, and increase PPC connectivity with the attentional network in the left hemisphere. We also expected that individual differences in fractional anisotropy (FA) in white matter connections between the PPCs would account for variability in TMS-induced RSFC changes.As expected, TMS over the right PPC caused a rightward shift in line bisection judgment and increased RSFC between the right PPC and the left superior temporal gyrus. This effect was inversely related to FA in the posterior corpus callosum. Local inhibition of the right PPC reshapes connectivity in the attentional network and depends on interhemispheric connections.