Visuospatial integration: Paleoanthropological and archaeological perspectives

The visuospatial system integrates inner and outer functional processes, organizing spatial, temporal, and social interactions between brain, body, and environment. These processes involve sensorimotor networks like the eye–hand circuit, which is especially important to primates, given their reliance on vision and touch as primary sensory modalities and the use of the hands in social and environmental interactions. At the same time, visuospatial cognition is intimately connected with egocentric memory, self-awareness, and simulation capacity. In the present article, we review issues associated with investigating visuospatial integration in extinct human groups through the use of anatomical and behavioral data gleaned from the paleontological and archaeological records. In modern humans, paleoneurological analyses have demonstrated noticeable and unique morphological changes in parietal cortex, an area crucial to visuospatial management. Archaeological data provides information on hand-tool interaction, the spatial behavior of past populations and their interaction with the environment (e.g. in domains like landscape use and navigation, the spatial relations implicit in social networks, etc.). Visuospatial integration may represent a critical bridge between extended cognition, self-awareness, and social perception. As such, visuospatial functions are relevant to the hypothesis that human evolution is characterized by changes in brain–body–environment interactions and relations, which enhance possibilities for integrating inner and outer cognitive components through neural plasticity and a specialized embodiment capacity. We therefore advocate the investigation of visuospatial functions in past populations through the paleoneurological study of anatomical elements and archaeological analysis of visuospatial behaviors.

501 - Prediction of Mild Cognitive Impairment (MCI) progression to Alzheimer Disease (AD) or Dementia with Lewy Bodies (DLB): Is this possible neuropsychologically?

Objective:Aim of the present review study was to describe and compare the neurocognitive features of MCI which could predict its progression to DLB vs AD.Background:Progression of MCI to AD or DLB is a relatively recent field of study with emphasis on the clinical or neuropsychological features of MCI which could potentially predict its progression to specific types of dementia.Methods:A literature review in the Pubmed database has been made, after the year 2005, using the key- words: neuropsychological assessment; MCI; AD; DLB; progression to dementia. Seventeen relevant articles have been found.Results:Data from most studies supports that, in MCI, impairment in executive, attentional and visuospatial functions, as well as letter fluency and fluctuating concentration are mainly related to progression to DLB. In contrast, prominent episodic and recognition memory deficits are mostly found in MCI which progresses in AD. Furthermore, non-amnestic MCI has been related most often to progression in DLB, whereas the amnestic type to AD, although memory loss may not necessarily predict the development of AD. Nevertheless, fewer studies suggest that MCI-DLB is related to cognitive profile similar to that of MCI-AD, while cognitive scoring alone does not accurately predict MCI-DLB vs MCI-AD. Interestingly, quantitative electroencephalogram has been found to help in predicting the progression of MCI to DLB, while preservation of hippocampal volume is associated with increased risk of DLB vs AD, especially in non-amnestic MCI. Moreover, specific patterns on neuroimaging MCI may predict progression to AD in contrast to DLB.Conclusions:Predicting the progression of MCI to AD or DLB based on neuropsychological profiles is challenging and useful for early therapeutic interventions. More studies are needed, since there are some conflicting findings and, at present, the combination of clinical symptoms with neurocognitive assessment and neuroimaging is the ideal method for the prediction of MCI progression to various types of dementia.

Provocation and prediction of visual peripersonal neglect-like symptoms in preoperative planning and during awake brain surgery

Neglect is a severe neuropsychological/neurological deficit that usually develops due to lesions of the posterior inferior parietal area of the right hemisphere and is characterized by a lack of attention to the left side. Our case is a proven right-handed, 30-year-old female patient with a low-grade glioma, which was located in the temporo-opercular region and also in the superior temporal gyrus of the right hemisphere. Upon presurgical planning, the motor, language, and visuospatial functions were mapped. In order to achieve this, the protocol for routine magnetic resonance imaging and navigated transcranial magnetic stimulation has been expanded, accordingly.

Neuropsychologische problemen na focale laesies in het cerebellum: de kleine hersenen worden groot

Neuropsychological problems after focal lesions in the cerebellum: the little brain grows big Initially researchers believed that the cerebellum was only involved in motor and speech functions. During the last few years however, increasing knowledge was gained regarding the neuropsychological functions of the cerebellum. These functions are not exclusively considered as being regulated by cortical brain structures, but rather as functions regulated by a closed cerebro-cerebellar circuit. Studies focused on evaluating neuropsychological functioning in patients with focal lesions in the cerebellum have discovered that cognitive problems with regard to working memory, anterograde memory, visuospatial functions, language and executive functions are frequently documented. Besides cognitive deficits, these patients can also show emotional and/or behavioral changes. Several authors assume that the research findings concerning memory, visuospatial functions and more particularly language can be explained by the concept of crossed cerebellar-cerebral diaschisis.

Prediction of Long-term Cognitive Functions after Minor Stroke, Using Functional Connectivity

Objective.To determine whether functional MRI connectivity can predict the long-term cognitive functions 36 months after minor stroke.Methods.Seventy-two participants with first-ever stroke were included at baseline and followed up for 36 months. A ridge regression machine learning algorithm was developed and used to predict cognitive scores 36 months post-stroke on the basis of the functional networks measured using MRI at 6 months (referred to here as the post-stroke cognitive impairment (PSCI) network). The prediction accuracy was evaluated in four domains (memory, attention/executive, language and visuospatial functions) and compared with clinical data and other functional networks. The models’ statistical significance was probed with permutation tests. The potential involvement of cortical atrophy was assessed 6 months post-stroke. A second, independent dataset (n=40) was used to validate the results and assess their generalizability.Results.Based on the PSCI network, a machine learning model was able to predict memory, attention, visuospatial functions and language functions 36 months post-stroke (r2: 0.67, 0.73, 0.55 and 0.48, respectively). The PSCI-based model was at least as accurate as models based on other functional networks or clinical data. Specific patterns were demonstrated for the four cognitive domains, with involvement of the left superior frontal cortex for memory, attention and visuospatial functions. The cortical thickness 6 months post-stroke was not correlated with cognitive function 36 months post-stroke. The independent validation dataset gave similar results.Conclusions.A machine learning model based on the PSCI network can predict the long-term cognitive outcome after stroke.

Progression of language and cognitive impairment in patients with the logopenic variant of primary progressive aphasia – case series

Aim: The paper presents longitudinal observation of four patients diagnosed with the logopenic variant of primary progressive aphasia (lvPPA). Materials and methods: The results of 3–4 language and cognitive assessments were available for four individuals (three women, one man) with lvPPA. The length of the observation period was 2–4 years. Language evaluation was comprehensive and addressed narrative speech, naming, word and sentence comprehension, repetition, reading and writing. Neuropsychological examination, whenever feasible, assessed visuospatial function, praxis, memory and executive functions. Results: Anomia was not an isolated symptom at the time of lvPPA diagnosis. Rapid deterioration of both spoken and written communication was observed. Reading aloud single words and high-frequency word comprehension were preserved longer than other linguistic competences. The narrative speech was progressively impoverished in terms of idea density, manifested by a reduced use of nouns and verbs in particular and an increased use of pronouns. At the advanced stage of the disease, the idea density was very low. There was marked deterioration of visuospatial functions, praxis and episodic memory in all patients. Progression to full-blown dementia was observed in all patients. Conclusions: The progression of linguistic and cognitive symptoms in lvPPA, albeit slightly heterogeneous, is relatively fast. The patients usually reach dementia stage within 1–2 years of the diagnosis and sometimes even earlier than 2 years of the declared symptom onset. When planning long-term management of lvPPA cases, rapid deterioration and progression to full-blown dementia within a relatively short time should be considered.

Patients with Parkinson’s Disease Show Alteration in their Visuospatial Abilities and in their Egocentric and Allocentric Spatial Orientation Measured by Card Placing Tests

Background: Visuospatial skills are impaired in Parkinson’s disease (PD). Other related skills exist, such as spatial orientation have been poorly studied. The egocentric (based on internal cues) and allocentric frameworks (based on external cues) are used in daily spatial orientation. Depending on PD onset, the allocentric framework may have a higher level of impairment in tremor-dominant and the egocentric one in akinetic-rigid. Objective: To evaluate spatial orientation and visuospatial functions in PD patients and controls, and to assess whether their performance is related to disease duration and the PD subtype (tremor-dominant and akinetic-rigid). Methods: We evaluated egocentric and allocentric spatial orientation (Egocentric and Allocentric Spatial Memory Tasks) and visuospatial abilities, span and working memory in 59 PD patients and 51 healthy controls. Results: Visuospatial skills, visuospatial span, and egocentric and allocentric orientation are affected in PD. Visuospatial skills and allocentric orientation undergo deterioration during the first 5 years of the disease progression, while egocentric orientation and visuospatial span do so at later stages (9–11 years). The akinetic-rigid subtype presents worse results in all the spatial abilities that were measured when compared to controls, and worse scores in visuospatial working memory, visuospatial abilities and allocentric orientation when compared to the tremor-dominant group. The tremor-dominant group performed worse than controls in egocentric and allocentric orientation. Conclusion: PD patients show deficits in their visuospatial abilities and in their egocentric and allocentric spatial orientation compared to controls, specifically in akinetic-rigid PD. Only spatial orientation are affected in tremor-dominant PD patients. Allocentric orientation is affected earlier in the progression of the disease.