Search

Aim: The aim of the present study was to investigate topographical working memory in individuals with motor disabilities. Methods: Topographical working memory was investigated using the Walking Corsi Test in 89 participants with motor disability, mean age 11.5 years, of which 40 with cerebral palsy, 31 with spina bifida, and 18 with orthopaedic or peripheral symptoms. The participants were grouped according to everyday mobility, i.e. walking outdoors, walking indoors, and using wheelchair. A control group constituted 120 typically developing participants, mean age 9.9 years. Results: Individuals with spina bifida, orthopaedic or peripheral symptoms as well as typically developing participants performed significantly larger walking spans than the cerebral palsy group. With respect to mobility, those walking outdoors had significantly larger span than those walking indoors and those using wheelchair for mobility. Conclusions: Participants with outdoor walking in the community, apart from type of motor disability, seem to have improved topographic memory compared to individuals who don't walk outside and individuals who are mobile through wheelchair. The results highlight the question of development of spatial cognition to enhance participation in social environments. Future research should focus on prematurity in the cerebral palsy group, and on hydrocephalus in the spina bifida group. [ABSTRACT FROM AUTHOR]

Representational neglect, which is characterized by the failure to report left-sided details of a mental image from memory, can occur after a right hemisphere lesion. In this study, we set out to verify the hypothesis that two distinct forms of representational neglect exist, one involving object representation and the other environmental representation. As representational neglect is considered rare, we also evaluated the prevalence and frequency of its association with perceptual neglect. We submitted a group of 96 unselected, consecutive, chronic, right brain-damaged patients to an extensive neuropsychological evaluation that included two representational neglect tests: the Familiar Square Description Test and the O'Clock Test. Representational neglect, as well as perceptual neglect, was present in about one-third of the sample. Most patients neglected the left side of imagined familiar squares but not the left side of imagined clocks. The present data show that representational neglect is not a rare disorder and also support the hypothesis that two different types of mental representations (i.e. topological and non-topological images) may be selectively damaged in representational neglect. [ABSTRACT FROM AUTHOR]

In this paper, we review several studies that analyze the relationship between lateralized deficits of visuo-spatial processing and deficits in the navigational and topographical domain. In particular, we show that in visuo-spatial or perceptual neglect basic navigational skills are spared. In fact, patients affected by perceptual neglect are able to represent travelled distances and build cognitive maps of real environments despite their difficulty in taking into account left-sided elements. By contrast, although they have no explorative deficits, patients affected by representational neglect show selective impairments in developing, storing and using cognitive maps. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present paper is to review several studies which assessed the validity of a visuo-spatial training for the rehabilitation of neglect patients. In addition two peripheral stimulations (TENS and Optokinetic Stimulation) have been studied to assess the improvements of neglect disorders when used in combination with the visuo-spatial training. Also we analyzed the potential effect of training for attention on neglect and, viceversa, the effect of visuo-spatial training on attentional impairments. Methods: the goals have been investigated by both group studies and descriptions of single cases. Results: The visuo-spatial training produced significant improvements on the performance of neglect patients which generalized to every day living situations: the results showed to be stable over time and had positive effects on a variety of other neurological impairments. It was also shown that the improvements are confined to tasks involving spatial exploration of extrapersonal space, but did not extend to other neglect disorders, such as representational and personal neglect. The use of peripheral stimulations, at variance with other studies in the literature, did not add any advantage as compared to the improvements produced by the visuo-spatial training. No transfer between training for neglect and attention was observed. Conclusions: the present review pointed out that neglect disorders can be improved in a clinically meaningful way: the studies described also showed some limitations and proposed the need of further researches in order to extend the improvements to several other aspects of the neglect syndrome. [ABSTRACT FROM AUTHOR]

Abstract: Topographical orientation relies on several cognitive strategies adopted by humans to move within the environment. In the present study, we investigate whether mental representation disorders affect specific cognitive mechanisms subserving human orientation. In order to differentiate distinct cognitive mechanisms involved in topographical orientation, we created a human version of the well-known “Morris Water Maze” and tested left and right brain damaged patients in a place-learning task. The test required the subjects to explore an experimental room in which no visual cues were present, find a target location, and then reach it in different conditions. The ability to memorise target locations in short- and long-term memory was also assessed. We found that all participants were able to reach the target location by using idiothetic cues (vestibular inputs, motor efferent copy, etc.). On the other hand, when starting position changed and re-orientation was necessary to reach the target location, in order to compute a new trajectory, only patients affected by representational neglect got lost. These results provide the first neuropsychological evidence of involvement of mental representation in a specific cognitive process allowing humans to reach a target place from any location in the environment. [Copyright &y& Elsevier]

Visual hallucinations in Lewy body disease (LBD) can be differentiated based on phenomenology into minor phenomena (MVH) and complex hallucinations (CVH). MVH include a variety of phenomena, such as illusions, presence and passage hallucinations occurring at early stages of LBD. The neural mechanisms of visual hallucinations are largely unknown. The hodotopic model posits that the hallucination state is due to abnormal activity in specialized visual areas, that occurs in the context of wider network connectivity alterations and that phenomenology of VH, including content and temporal characteristics, may help identify brain regions underpinning these phenomena. Here we investigated both the topological and hodological neural basis of visual hallucinations integrating grey and white matter imaging analyses. We studied LBD patients with VH and age matched healthy controls (HC). VH were assessed using a North-East-Visual-Hallucinations-Interview that captures phenomenological detail. Then we applied voxel-based morphometry and tract based spatial statistics approaches to identify grey and white matter changes. First, we compared LBD patients and HC. We found a reduced grey matter volume and a widespread damage of white tracts in LBD compared to HC. Then we tested the association between CVH and MVH and grey and white matter indices. We found that CVH duration was associated with decreased grey matter volume in the fusiform gyrus suggesting that LBD neurodegeneration-related abnormal activity in this area is responsible for CVH. An unexpected finding was that MVH severity was associated with a greater integrity of white matter tracts, specifically those connecting dorsal, ventral attention networks and visual areas. Our results suggest that networks underlying MVH need to be partly intact and functional for MVH experiences to occur, while CVH occur when cortical areas are damaged. The findings support the hodotopic view and the hypothesis that MVH and CVH relate to different neural mechanisms, with wider implications for the treatment of these symptoms in a clinical context. [ABSTRACT FROM AUTHOR]

• We tested whether spatial navigation and autobiographical memory share their neural substrates. • Shared and distinct networks support episodic autobiographic memory and egocentric navigation. • Separate networks support semantic autobiographic memory and allocentric navigation. • Spatial mechanisms could provide a specific contribution to episodic components of memory. It has been proposed that declarative memory evolved from spatial navigation, with episodic memory having its roots in mechanisms of egocentric navigation and semantic memory in those of allocentric navigation; however, whether these brain networks actually overlap is still unclear. Using Activation Likelihood Estimation, we assessed the correspondence between brain correlates of spatial navigation (SN) and autobiographical memory (AM), further testing whether neural substrates of episodic memory (EAM) and egocentric navigation, and those of semantic memory (SAM) and map-like navigation, coincide. SN and AM commonly activated the parahippocampal gyrus and middle hippocampus, posterior cingulate cortex and right angular gyrus, but also involved distinct brain regions. Similarly, EAM and egocentric navigation, besides sharing a network involving the right angular gyrus, bilateral posterior cingulate and parahippocampal gyrus, activated distinct brain regions; no region was commonly activated by SAM and allocentric navigation. We discuss findings in the light of theories on the relation between navigation and memory, and propose a new theoretical perspective, which takes into account the dynamic nature of navigational processes. [ABSTRACT FROM AUTHOR]

Forty children with cerebral palsy (CP) and 120 typical developing children (TD) performed a topographic working memory (WalCT) test requiring to move their body in a walked vista-space and a visuo-spatial test (CBT) requiring just reaching movements. WalCT score was significantly higher in GMFCS II/III than in TD. CBT score was significantly lower in GMFCS I than in III/IV but lower than TD in all CP groups. Similar results in WalCT between GMFCS I and TD and GMFCS II and III/IV respectively indicate that mobility is associated with topographic working memory. Differently in CBT, the absence of bodily movement allows using different cognitive strategies. Children should be provided with opportunities and active participation to enhancing spatial awareness and navigational skills. [ABSTRACT FROM AUTHOR]

Loneliness has been associated to a greater risk of cognitive decline and dementia in older individuals. However, evidence on whether this association also exists for older individuals who complain of cognitive problems is limited. We conducted a survey to examine the association between subjective cognitive decline in the working memory domain, perceived loneliness, depression, anxiety, and stress in older individuals with different profiles. A total of 302 healthy, old individuals completed 3 questionnaires to assess subjective cognitive problems in attention, executive functions, storage, depression, anxiety, stress, and perceived loneliness. We conducted a cluster analysis and 3 clusters of individuals with different profiles emerged. Individuals with greater subjective cognitive problems (cluster 1) in the attention and storage domains, reported higher perceived loneliness and stress but not depression. In contrast, individuals with the least subjective cognitive problems (cluster 3) in the storage domain, reported lower perceived loneliness. Individuals with higher subjective cognitive decline also report higher levels of perceived loneliness but not more depression than their peers. However, this correlation is present only for individuals with mild subjective cognitive decline (cluster 2). The implications for future research and interventions are discussed. [ABSTRACT FROM AUTHOR]

Timing alterations occur in Alzheimer's disease (AD), even in early stages (mild cognitive impairment, MCI). Moreover, a stage named subjective cognitive decline (SCD), in which individuals perceive a change in cognitive performance not revealed by neuropsychological tests, has been identified as a preclinical phase of AD. However, no study to date has investigated different dimensions of time processing along the continuum from physiological to pathological aging, and whether timing alterations occur in SCD. Here a sample of participants with SCD, MCI, AD and healthy controls (HC) performed tasks assessing prospective duration estimation, production, reproduction, implicit temporal learning in conditions dependent from external cues (externally-cued learning, ECL) or independent from external cues (internally-based learning, IBL), retrospective duration estimation, the subjective experience of time and the temporal collocation of events. AD patients performed worse than HC and SCD in prospective timing, and in collocating events in time. The subjective experience of time did not differ between groups. Concerning temporal learning, AD performed worse in ECL than in IBL, whereas SCD performed worse in IBL than in ECL. SCD, MCI and AD patients all showed errors greater than HC in retrospective duration estimation. Results point to implicit temporal learning in externally-cued conditions and retrospective time estimation as possible early markers of cognitive decline. [ABSTRACT FROM AUTHOR]

• Neural substrates of episodic autobiographical memory (EAMs) recall are debated. • ALE meta-analysis shows that different networks process recent and remote EAMs. • Recent EAMs activate angular gyrus, medial temporal lobe and dorsomedial prefrontal cortex. • Remote EAMs activate posterior cingulate cortex (PCC). • PCC is connected with medial temporal lobe during memory recall. Episodic autobiographical memory (EAM) is pivotal for the development and maintenance of personal identity. However, a theoretical debate still exists about where EAMs are stored in our brain and about hippocampal unique contribution to their recollection. Here we disentangled this issue performing an Activation Likelihood Estimation (ALE) meta-analysis on 79 neuroimaging experiments, classified according to the remoteness of EAMs, and meta-analytic connectivity modeling. A wide brain network, spanning from occipital to frontal lobe, was involved in recalling EAMs. However, remote and recent EAMs were processed by different nodes of this network: recent EAMs activated angular gyrus, dorsomedial prefrontal cortex and hippocampus/parahippocampal gyrus, that we found to be connected with its contralateral homologous, bilateral middle cingulate cortex, left inferior frontal gyrus and left superior parietal lobule. Instead, remote EAMs activated posterior cingulate cortex, that we found to be connected with hippocampus/parahippocampal gyrus. These results provide new important evidence for the theoretical discussion about where and how EAMs are stored in the brain and new exciting insights into hippocampal contribution to EAM. [ABSTRACT FROM AUTHOR]

Field dependence-independence (FDI) is a stable dimension of individual functioning, transversal to different cognitive domains. While the role of some individual variables in time perception has received considerable attention, it is not clear whether and how FDI influences timing abilities. In this study, we tested the hypothesis that FDI differently affects timing performance depending on whether the task requires cognitive restructuring. Participants were assessed for FDI using the embedded figures test (EFT). They performed a prospective timing task, reproducing the duration of a flickering stimulus, and a retrospective timing task, estimating the duration of the task. We expected performance of field-dependent (FD) and field-independent (FI) individuals not to differ in the prospective task, since restructuring of task material is not needed to reproduce the stimulus duration. Conversely, we predicted that FI individuals should be more accurate than FD ones in the retrospective condition, involving restructuring skills. Results show that while both FD and FI individuals under-reproduced the stimulus duration in the prospective task, only FD participants significantly underestimated the duration of the timing task in the retrospective condition. These results suggest that differences across FD and FI individuals are apparent in timing only when the task requires high-level cognitive processing; conversely, these differences do not affect basic sensory processing. [ABSTRACT FROM AUTHOR]

Gaucher disease (GD) has been increasingly recognized as a continuum of phenotypes with variable neurological and sensory involvement. No study has yet specifically explored the spectrum of neuropsychiatric and sensory abnormalities in GD patients through a multidisciplinary approach. Abnormalities involving the nervous system, including sensory abnormalities, cognitive disturbances, and psychiatric comorbidities, have been identified in GD1 and GD3 patients. In this prospective study, named SENOPRO, we performed neurological, neuroradiological, neuropsychological, ophthalmological, and hearing assessments in 22 GD patients: 19 GD1 and 3 GD3. First, we highlighted a high rate of parkinsonian motor and non-motor symptoms (including high rates of excessive daytime sleepiness), especially in GD1 patients harboring severe glucocerebrosidase variants. Secondly, neuropsychological evaluations revealed a high prevalence of cognitive impairment and psychiatric disturbances, both in patients initially classified as GD1 and GD3. Thirdly, hippocampal brain volume reduction was associated with impaired short- and long-term performance in an episodic memory test. Fourthly, audiometric assessment showed an impaired speech perception in noise in the majority of patients, indicative of an impaired central processing of hearing, associated with high rates of slight hearing loss both in GD1 and GD3 patients. Finally, relevant structural and functional abnormalities along the visual system were found both in GD1 and GD3 patients by means of visual evoked potentials and optical coherence tomography. Overall, our findings support the concept of GD as a spectrum of disease subtypes, and support the importance of in-depth periodic monitoring of cognitive and motor performances, mood, sleep patterns, and sensory abnormalities in all patients with GD, independently from the patient's initial classification. [ABSTRACT FROM AUTHOR]

Phonological complexity may be central to the nature of human language. It may shape the distribution of phonemes and phoneme sequences within languages, but also determine age of acquisition and susceptibility to loss in aphasia. We evaluated this claim using frequency statistics derived from a corpus of phonologically transcribed Italian words (phonitalia, available at phonitalia,org), rankings of phoneme age of acquisition (AoA) and rate of phoneme errors in patients with apraxia of speech (AoS) as an indication of articulatory complexity. These measures were related to cross-linguistically derived markedness rankings. We found strong correspondences. AoA, however, was predicted by both apraxic errors and frequency, suggesting independent contributions of these variables. Our results support the reality of universal principles of complexity. In addition they suggest that these complexity principles have articulatory underpinnings since they modulate the production of patients with AoS, but not the production of patients with more central phonological difficulties. [ABSTRACT FROM AUTHOR]

Prism adaptation (PA) is a well-known and widely used technique for rehabilitating unilateral spatial neglect and studying sensory–motor plasticity. However, there is conflicting evidence in the literature regarding its effectiveness which may arise from differences in the type of prisms used, clinical characteristics of the patients, and the procedure used in training. Individual differences may play a role in PA effectiveness in rehabilitating neglect, affecting both its development and its effects. Field-dependent/independent cognitive style is a pervasive characteristic of individual functioning, affecting how environmental information is processed. Here, we tested the hypothesis that cognitive style plays a role in PA efficacy by submitting to a protocol of prism adaptation to 38 health participants, who were classified as field-dependent (FD, N = 19) or field-independent (FI, N = 19), by using the Embedded Figure Test. Results show that during the exposure phase, FI individuals needed a lesser number of pointing movements to reduce the deviation error than FD individuals. However, there are no differences in the extinction of sensory–motor and cognitive after-effects. These results suggest that prismatic adaptation is affected by individuals' cognitive style since FI individuals will need fewer trials to reach adaptation and this could explain why using this rehabilitation technique with a unique, standard protocol is not always effective. [ABSTRACT FROM AUTHOR]

The acquisition of information on the timing of events or actions (temporal learning) occurs in both the subsecond and suprasecond range. However, although relevant differences between participants have been reported in temporal learning, the role of dimensions of individual variability in affecting performance in such tasks is still unclear. Here we investigated this issue, assessing the effect of field-dependent/independent cognitive style on temporal learning in the suprasecond range. Since different mechanisms mediate timing when a temporal representation is self-generated, and when it depends on an external referent, temporal learning was assessed in two conditions. Participants observed a stimulus across six repetitions and reproduced it. Unbeknownst to them, in an internally-based learning (IBL) condition, the stimulus duration was fixed within a trial, although the number of events defining it varied; in an externally-cued learning (ECL) condition, the stimulus was defined by the same number of events within each trial, although its duration varied. The effect of the reproduction modality was also assessed (motor vs. perceptual). Error scores were higher in IBL compared to ECL; the reverse was true for variability. Field-independent individuals performed better than field-dependent ones only in IBL, as further confirmed by correlation analyses. Findings provide evidence that differences in dimensions of variability in high-level cognitive functioning, such as field dependence/independence, significantly affect temporal learning in the suprasecond range, and that this effect depends on the type of temporal representation fostered by the specific task demands. [ABSTRACT FROM AUTHOR]

Keeping oriented in the surrounding space requires an accurate representation of one’s spatial position and facing direction. Although previous studies provided evidence of specific spatial codes for position and direction within room-sized and large-scale navigational environments, little is known about the mechanisms by which these spatial quantities are represented in a real small-scale environment. Here, we used two spatial tasks requiring participants to encode their own position and facing direction on a series of pictures taken from a familiar circular square. Crucially, directions and positions were incidentally manipulated, so that when participants were required to encode their current position in the square, the perceived direction across consecutive trials was the same, and vice versa. We found a behavioral advantage (priming effect: reduced reaction times and increased accuracy) for repeated directions and positions, even in the absence of any explicit demand to encode either of them. The advantage was higher for repeated directions, indicating that representation of one’s own direction is more automatic than representation of one’s own location. Furthermore, priming effects were partially mediated by gender: females (but not males) showed a stronger priming effect for repeated directions than for repeated positions. Finally, although priming effects were not linearly related to the physical distances between consecutive positions and directions, they revealed a rough preservation of real-world distance relationships. [ABSTRACT FROM AUTHOR]

A decline in navigational abilities is a consistent feature of aging. Although many studies focused on recall of navigational information, the impact of time and type of learning on recall has received little attention. We submitted older adults and young participants to an extensive training of an ecological environment, from both route and survey perspectives. Then, we tested participants’ learning using from both route and survey perspectives. Although older adults benefit from the extensive training, they did not reach the same performance of the young participants. Despite this main effect of age, the effect of the type of learning was the same in the two groups. Congruence between type of learning and recall led to better performance in both groups. We discuss these findings in the light of cognitive models of human navigation and aging. Useful suggestions about how these findings may inform a specific cognitive intervention in older adults are also provided. [ABSTRACT FROM PUBLISHER]

Background and Purpose: Deficits of self-awareness (SA) are very common after severe acquired brain injury (sABI), especially in traumatic brain injury (TBI), playing an important role in the efficacy of the rehabilitation process. This pilot study provides information regarding two structured group therapies for disorders of SA. Methods: Nine patients with severe TBI were consecutively recruited and randomly assigned to one SA group therapy programme, according either to the model proposed by Ben-Yishay & Lakin (1989) (B&L Group), or by Sohlberg & Mateer (1989) (S&M Group). Neuropsychological tests and self-awareness questionnaires were administered before and after a 10 weeks group therapy. Results: Results showed that both SA and neuropsychological functioning significantly improved in both groups. Conclusion: It is important to investigate and treat self-awareness, also to improve the outcome of neuropsychological disorders. The two group therapies proposed seem to be specific for impulsivity and emotional dyscontrol and for cognitive disorders. [ABSTRACT FROM AUTHOR]

The Developmental Topographical Disorientation (DTD) is a pathological condition that impairs an individual's ability to orient in space, even in the most familiar environments. It is a lifelong selective condition in individuals without brain damage or without impaired general cognitive functions. Here, we aimed at characterizing 54 individuals with DTD identified in a previous study, aged between 18 and 35 years and assessed through a 4-year-long online survey. To this purpose, we compared them with 54 matched healthy participants. We described the demographics, sense of direction, town knowledge, navigational strategies, left-right confusion as well as agnosic disorders (for landmarks, faces and objects). This novel study attempts to characterize the phenotype of DTD, providing an important contribution to the worldwide definition of a condition that was first described only 13 years ago, but which, considering the growing number of cases complaining of the disorder, deserves continuous and increasing attention. [ABSTRACT FROM AUTHOR]

Psychosis is frequent in Alzheimer's disease (AD) and it is associated with a worse disease course. AD psychosis may represent a distinct AD phenotype, though its specific neurobiological underpinnings have yet to be identified. This study investigated neural underpinnings of AD psychosis using surface-based-morphometry.Data from 32 AD patients, 17 with psychosis (AD-P) and 15 without were analyzed. Average cortical complexity (fractal dimension, FD) was estimated for each theoretically motivated ROI and patient. First, we compared regional FD in AD-P and AD patients. Then we calculated the correlation coefficients between FD and the severity of misidentification and paranoid psychotic symptoms. AD-P showed decreased FD in ventral-visual-stream compared to AD, suggesting that perceptual processes might be pivotal in psychosis. A negative correlation was found between misidentification severity and FD in the entorhinal cortex suggesting that misidentification may be specifically associated with alterations in regions involved in high-level perceptual and contextualization processes. [ABSTRACT FROM AUTHOR]

Slowness of information processing (SIP) is frequently reported after traumatic brain injury (TBI). Previous studies point toward a pivotal role of white matter damage on speed of information processing. However, little is known about the more comprehensive and ecological assessment of SIP in TBI. Here, we combined an ecological assessment of SIP with the use of tract-based spatial statistics (TBSS) on individuals' fractional anisotropy (FA) maps. Twenty-six moderate-to-severe patients with TBI (21 males and 5 females) participated in this study: 10 individuals were classified as not having SIP (SIP-) and 16 were classified as having SIP (SIP +). SIP + showed lower FA in bilateral anterior thalamic radiation, corticospinal tract, cingulum, and forceps, as well as in bilateral inferior fronto-occipital, inferior and superior longitudinal fasciculi and uncinate fasciculus. Overall, this result is consistent with and expands previous reports on information processing speed to a more comprehensive and ecological perspective on SIP in TBI. [ABSTRACT FROM AUTHOR]

ABSTRACT Individuals vary widely in their ability to orient and navigate within the environment. Previous neuroimaging research has shown that hippocampus (HC) and scene-responsive regions (retrosplenial complex [RSC] and parahippocampal gyrus/parahippocampal place area [PPA]) were crucial for spatial orienting and navigation. Resting-state functional connectivity and a self-reported questionnaire of navigational ability were used to examine the hypothesis that the pattern of reciprocal connections between these regions reflects individual differences in spatial navigation. It was found that the functional connectivity between the posterior HC and RSC was significantly higher in good than in poor navigators. These results confirmed the crucial role of hippocampal and extra-hippocampal regions in spatial navigation and provided new insight into how spontaneous brain activity may account for individual differences in spatial ability. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

In the last decade, several cases affected by Developmental Topographical Disorientation (DTD) have been described. DTD consists of a neurodevelopmental disorder affecting the ability to orient in the environment despite well-preserved cognitive functions, and in the absence of a brain lesion or other neurological or psychiatric conditions. Described cases showed different impairments in navigational skills ranging from topographic memory deficits to landmark agnosia. All cases lacked a mental representation of the environment that would allow them to use high-order spatial orientation strategies. In addition to the single case studies, a group study performed in Canada showed that the disorder is more widespread than imagined. The present work intends to investigate the occurrence of the disorder in 1,698 young Italian participants. The sample is deliberately composed of individuals aged between 18 and 35 years to exclude people who could manifest the loss of the ability to navigate as a result of an onset of cognitive decline. The sample was collected between 2016 and 2019 using the Qualtrics platform, by which the Familiarity and Spatial Cognitive Style Scale and anamnestic interview were administered. The data showed that the disorder is present in 3% of the sample and that the sense of direction is closely related to town knowledge, navigational strategies adopted, and gender. In general, males use more complex navigational strategies than females, although DTD is more prevalent in males than in females, in line with the already described cases. Finally, the paper discusses which protective factors can reduce DTD onset and which intervention measures should be implemented to prevent the spread of navigational disorders, which severely impact individuals' autonomy and social relationships. [ABSTRACT FROM AUTHOR]

Visual hallucinations (VH) in Lewy body disease (LBD) have a heterogenous phenomenology classified into minor phenomena (MVH) and complex hallucinations (CVH). Mechanisms underpinning VH and their temporal aspects are largely unknown. According to the hodotopic model, we investigated whether changes in distinct cognitive domains and neural networks in the hallucination trait underpin temporal aspects of MVH and CVH in the hallucination state. 35 LBD patients with VH underwent a complete neuropsychological evaluation and resting-state fMRI. North-East-Visual-Hallucinations-Interview was used to assess their typical VH content, duration, and frequency. We found that MVH was not associated with cognitive impairment, while CVH was associated with impairments in visuoperceptual processes, attention and visual abstract reasoning. In seed-to-seed functional connectivity (FC) analysis we identified functional couplings associated with MVH and CVH temporal severity (duration x frequency), duration and frequency. MVH severity was negatively associated with FC between early visual areas (EVA) and ventral-visual-stream regions, and negatively associated with FC between brainstem and EVA, which may be linked to LBD brainstem neuropathology. CVH duration was positively associated with FC between ventral-visual stream and salience network (SN). CVH frequency was negatively associated with FC between DMN and SN. Functional alterations in distinct visual and attentional networks and their dynamic interaction in trait LBD hallucinators are linked to both the phenomenology of state content and its temporal characteristics. Within a network, VH frequency and duration may be linked to different types of functional alterations: increased connectivity leading to sustained activity prolonging VH (duration) and decreased connectivity increasing dysregulated, spontaneous activity (frequency). These findings support the hodotopic hypothesis of VH and may reflect a link between VH phenomenology, LBD neuropathological progression and the involvement of specific neurotransmitter systems. [ABSTRACT FROM AUTHOR]

The cerebellum has a homogeneous structure and performs different computational functions such as modulation/coordination of the communication between cerebral regions, and regulation/integration of sensory information. Albeit cerebellar activity is generally associated with motor functions, several recent studies link it to various cognitive functions, including spatial navigation. In addition, cerebellar activity plays a modulatory role in different cognitive domains and brain processes. Depending on the network involved, cerebellar damage results in specific functional alterations, even when no function loss might be detected. In the present review, we discuss evidence of brainstem degeneration and of a substantial reduction of neurons in nuclei connected to the inferior olivary nucleus in the early stages of Alzheimer's disease. Based on the rich patterns of afferences from the inferior olive nucleus to the cerebellum, we argue that the subtle alterations in spatial navigation described in the early stages of dementia stem from alterations of the neuromodulatory functions of the cerebellum. [ABSTRACT FROM AUTHOR]

Slowness of Information Processing (SIP) is frequently experienced after traumatic brain injury (TBI); however, the impact of SIP on everyday functioning may be underestimated by standard neuropsychological tests. Objective: we aimed to adapt two ecological instruments assessing SIP in Italian patients with moderate-to-severe TBI, as formerly proposed by Winkens and colleagues for persons with stroke, testing also its possible relation with other neuropsychological processes and functional outcomes. Method: we performed an observational study on 37 patients with moderate-to-severe TBI and 35 demographically matched healthy controls, who underwent the Mental Slowness Observation Test (MSOT) and the Mental Slowness Questionnaire (MSQ), which had been adapted through a pilot study on independent sample of participants; extensive neuropsychological and functional evaluations were performed as well. Results: We found good clinical and psychometric properties of the Italian adaptation of the MSOT and MSQ; also, performance on MSOT significantly correlated with executive functions. Moreover, patients with TBI are significantly slower and less accurate than healthy controls on the MSOT, in particular in tasks with time limits. Even if the subjective feeling of SIP does not differ between patients and controls, we found a significant correlation between MSQ and MSOT. Finally, the performances on the MSOT correlated with measures of functional outcome and community integration. Conclusions: the results support the use of the MSOT and the MSQ to measure SIP in an ecological fashion in patients with TBI, so that specific treatments for persons with acquired brain injury can be prescribed. [ABSTRACT FROM AUTHOR]

Global navigation satellite systems (GNSS) can provide better data quality for different purposes; however, some age groups might lie outside its use. Understanding the barriers to its adoption is of interest in different fields. This work aims at developing a measurement instrument of the adoption attitudes towards this technology and examining the relationship of variables such as age and gender. A UTAUT model was tested on 350 participants. The main results can be summarised as follows: (i) the proposed GNSS scale on human spatial navigation attitudes towards geopositioning technology showed optimal psychometric properties; (ii) although statistically significant differences were found in the Wayfinding Questionnaire (WQ) between men and women, these did not reach the level of statistical significance for the scores on attitudes towards GNSS; (iii) by testing a model on human spatial navigation attitudes towards geopositioning technology, it was possible to show a higher relationship with age in women. [ABSTRACT FROM AUTHOR]

Research on aphasia has struggled to identify apraxia of speech (AoS) as an independent deficit affecting a processing level separate from phonological assembly and motor implementation. This is because AoS is characterized by both phonological and phonetic errors and, therefore, can be interpreted as a combination of deficits at the phonological and the motoric level rather than as an independent impairment. We apply novel psycholinguistic analyses to the perceptually phonological errors made by 24 Italian aphasic patients. We show that only patients with relative high rate (>10%) of phonetic errors make sound errors which simplify the phonology of the target. Moreover, simplifications are strongly associated with other variables indicative of articulatory difficulties – such as a predominance of errors on consonants rather than vowels – but not with other measures – such as rate of words reproduced correctly or rates of lexical errors. These results indicate that sound errors cannot arise at a single phonological level because they are different in different patients. Instead, different patterns: (1) provide evidence for separate impairments and the existence of a level of articulatory planning/programming intermediate between phonological selection and motor implementation; (2) validate AoS as an independent impairment at this level, characterized by phonetic errors and phonological simplifications; (3) support the claim that linguistic principles of complexity have an articulatory basis since they only apply in patients with associated articulatory difficulties. [ABSTRACT FROM AUTHOR]

Several studies investigating environmental navigation require participants to navigate in virtual environments, in which the proprioceptive and vestibular components present during real environmental navigation are lost. Here, we aimed to provide a novel computerized ecological navigational battery, investigating whether the absence of proprioceptive and vestibular inputs yields a representation of the navigational space comparable to that acquired ecologically. In Study 1, 38 participants underwent two sets of tasks, one performed in a laboratory-based setting (LBS) and the other in an ecological environment (EE), with both including evaluation of route, landmark, and survey knowledge and a landmark ordering task. All tasks, except the route task, significantly correlated between EE and LBS. In LBS, performance in the landmark ordering task was predicted by that in the survey task, but not by those in the route and landmark tasks. Results of Study 1 were replicated in Study 2, in which 44 participants completed a modified and shorter online version of LBS tests. Reliability of the online LBS tests was also tested and showed a moderate-to-high internal consistency. Overall, results show that the conditions in which tasks are performed affect the acquisition of route knowledge, likely due to the lack of proprioceptive and vestibular information in LBS. However, LBS tasks presented here provide a standard battery of tests that can overcome the replicability problems encountered by ecological navigation tests, while taking into consideration all the complexities of navigational processes in terms of the use of landmark, route, and survey strategies. [ABSTRACT FROM AUTHOR]

Background: Detecting the beginning of cognitive decay is crucial to guarantee good management and the possible prevention of dementia progression. The present study arises from observations collected during an educational event to promote mental and physical health in which incidental neuropsychological data gathered on 290 citizens showed the importance of routine neuropsychological examination in detecting early signs of cognitive decay, since many individuals were unaware of the decrease in their cognitive efficiency. Accordingly, the availability of a screening tool that is computerized, portable, self-administrable, and sensitive to the main neurocognitive changes testifying the progression towards pathological aging is critical.Objective: To this aim, we developed a computerized battery for the early, preclinical Diagnosis of Neurocognitive disease (DiaNe), that can be self-administered and performed autonomously by using a tablet.Methods: DiaNe includes tests expected to evaluate the main cognitive domains involved in neurodegenerative diseases (memory, attention, executive functions) with a detailed assessment of visuospatial memory in particular.Results: DiaNe is not just the translation of standard tests into telematics, rather it is a new tool that provides both accuracy and response time measurements, aimed to screen cognitive profile and monitor it over time, being able to detect changes in still normal performances that may be suggestive of an ongoing onset of neurocognitive disorders.Conclusion: Here we present an investigation of DiaNe concurrent validity showing that its results are comparable to those obtained by existing paper-and-pencil neuropsychological tests, and propose that DiaNe could be a useful, quick, and economical instrument for the monitoring of cognitive aging. [ABSTRACT FROM AUTHOR]

Objective: Systematic studies about the impact of unilateral brain damage on the different body representations (body schema, body structural representation, and body semantics) are still rare. Aim of this study was to evaluate body representation deficits in a relatively large sample of patients with unilateral brain damage and to investigate the impact of right or left brain damage on body representations (BRs), independently from deficits in other cognitive processes. Method: Sixty-four patients with unilateral stroke (22 with left brain damage, LBD; 31 with right brain damage without neglect, RBD-N; 11 with right brain damage with neglect, RBD+N) and 41 healthy individuals underwent a specific battery including BR as well as control tasks. Results: In more than a third of the sample, selective (37.5%) and pure (31%) deficits of BR were presented and equally distributed among the different BRs (˜10% for each representation), with selective (27.2%) and pure (22.7%) body schema deficit mainly presented after left brain damage. As a group, patients with unilateral brain damage, independently of the side of lesion (LBD, RBD-N, RBD+N), had significantly worse performance on body structural representation with respect to healthy individuals, whereas LBD had numerically worse performance on body schema with respect to healthy individuals and RBD-N. No significant differences among groups were found on body semantics. Conclusion: BR deficits are not a rare consequence of unilateral brain damage and are independent of a more general cognitive dysfunction. Accordingly, the need for an accurate assessment and specific neuropsychological training in clinical settings is discussed. [ABSTRACT FROM AUTHOR]

In the past 20 years, many studies in the cognitive neurosciences have analyzed human ability to navigate in recently learned and familiar environments by investigating the cognitive processes involved in successful navigation. In this study, we reviewed the main experimental paradigms and made a cognitive-oriented meta-analysis of fMRI studies of human navigation to underline the importance of the experimental designs and cognitive tasks used to assess navigational skills. We performed a general activation likelihood estimation (ALE) meta-analysis of 66 fMRI experiments to identify the neural substrates underpinning general aspects of human navigation. Four individual ALE analyses were performed to identify the neural substrates of different experimental paradigms (i.e., familiar vs. recently learned environments) and different navigational strategies (allocentric vs. egocentric). Results of the general ALE analysis highlighted a wide network of areas with clusters in the occipital, parietal, frontal and temporal lobes, especially in the parahippocampal cortex. Familiar environments seem to be processed by an extended temporal-frontal network, whereas recently learned environments require activation in the parahippocampal cortex and the parietal and occipital lobes. Allocentric strategy is subtended by the same areas as egocentric strategy, but the latter elicits greater activation in the right precuneus, middle occipital lobe and angular gyrus. Our results suggest that different neural correlates are involved in recalling a well-learned or recently acquired environment and that different networks of areas subtend egocentric and allocentric strategies. [ABSTRACT FROM AUTHOR]

In the past two decades research has highlighted how implicit memory processes are spared in degenerative disorders, such as Alzheimer's disease (AD), which are characterized by the early onset of explicit memory deficits. However, according to recent studies, there may be dissociations among different types of implicit memory. Although several studies have shown selective sparing of lexical priming in AD, it is not completely clear what happens to other types of implicit memory processes, such as visuo-perceptual priming. The present study examines the possibility that the visuo-perceptual priming effect is spared in AD. We tested two groups of participants, i.e., a group of AD patients and a group of healthy age-matched controls, using a visuo-perceptual priming task. The task required the identification of fragmented pictures. Results showed a deficient priming effect in AD patients when it was measured by an Identification of Fragmented Pictures task. We discuss our results in light of the current hypothesis of a functional segregation in priming processes. [ABSTRACT FROM AUTHOR]

Abstract: Several studies provide evidence that mental imagery is critical for human navigation. However, the contribution of different mental imagery abilities to the individuals’ skill of using specific orientation strategies remains unclear. In the present study we assessed a variety of mental imagery skills and investigated their contribution in relationship with the selective individuals’ ability of forming and using a mental representation of the environment, namely a cognitive map. Indeed, despite the use of alternative strategies that individuals may adopt while moving along the same well-known route, cognitive maps are critical for orientation since they allow individuals to reach any target location from any place in the environment. We found that the ability to form a cognitive map was related to the specific ability of performing mental rotations of simple geometrical shapes, and the ability to imaging ourselves moving on a map. Other imagery skills such as the ability to generate mental images from memory or the ability of mentally manipulate objects were not correlated with the individuals’ performance in forming the cognitive map. Moreover, we revealed gender differences in forming a cognitive map, as well as in performing some of the mental imagery tests. We discuss these findings in order to shed more light on the specific role of mental imagery in human topographical orientation. [Copyright &y& Elsevier]

The ability to orientate within familiar environments relies on the formation and use of a mental representation of the environment, namely a cognitive map. Neuropsychological and neuroimaging studies suggest that the retrosplenial and hippocampal brain regions are involved in topographical orientation. We combined functional magnetic resonance imaging with a virtual-reality paradigm to investigate the functional interaction of the hippocampus and retrosplenial cortex during the formation and utilization of cognitive maps by human subjects. We found that the anterior hippocampus is involved during the formation of the cognitive map, while the posterior hippocampus is involved when using it. In conjunction with the hippocampus, the retrosplenial cortex was active during both the formation and the use of the cognitive map. In accordance with earlier studies in non-human animals, these findings suggest that, while navigating within the environment, the retrosplenial cortex complements the hippocampal contribution to topographical orientation by updating the individual's location as the frame of reference changes. [ABSTRACT FROM AUTHOR]

It is commonly acknowledged that visual imagery and perception rely on the same content-dependent brain areas in the high-level visual cortex (HVC). However, the way in which our brain processes and organizes previous acquired knowledge to allow the generation of mental images is still a matter of debate. Here, we performed a representation similarity analysis of three previous fMRI experiments conducted in our laboratory to characterize the neural representation underlying imagery and perception of objects, buildings and faces and to disclose possible dissimilarities in the neural structure of such representations. To this aim, we built representational dissimilarity matrices (RDMs) by computing multivariate distances between the activity patterns associated with each pair of stimuli in the content-dependent areas of the HVC and HC. We found that spatial information is widely coded in the HVC during perception (i.e. RSC, PPA and OPA) and imagery (OPA and PPA). Also, visual information seems to be coded in both preferred and non-preferred regions of the HVC, supporting a distributed view of encoding. Overall, the present results shed light upon the spatial coding of imagined and perceived exemplars in the HVC. [ABSTRACT FROM AUTHOR]

Background: Interoception is the basic process enabling evaluation of one's own internal state of body, but its alteration in brain-damaged patients has not been adequately investigated. Our study aimed to investigate awareness of visceral and somatosensorial sensations in brain-damaged patients with unilateral stroke.Methods: Sixty patients (22 with left brain damage, LP; 25 with right brain damage without neglect, RPN-; and 13 with right brain-damage and extrapersonal and/or personal neglect, RPN+) and 45 healthy controls (HC) completed the Self-Awareness Questionnaire (SAQ), a self-report tool for assessing interoceptive awareness with two domains related to visceral (VD) and somatosensory feelings (SD), respectively.Results: Comparing the SAQ subdomains scores between three groups of patients (LP, RPN-, and RPN+) and HC, we found that RPN+ had significantly lower scores on VD than HC and LP, whereas no significant difference was found on scores of SD between groups.Conclusion: Our results support the hypothesis of a right-hemispheric dominance for "interoceptive neural network" suggesting that processing of visceral sensations would be located mainly in the right hemisphere. Therefore, a careful assessment of interoceptive awareness in clinical practice would be useful to improve rehabilitation and to engage patients with deficit of interoceptive awareness in developing greater accuracy of body signals. [ABSTRACT FROM AUTHOR]

This study investigates prospective memory (PM) deficits as well as the interplay between performance in executive functions (EFs), speed of processing, episodic memory and PM in traumatic brain injury (TBI), differentiating between time based and event based tasks. The Memory for Intentions Screening Test was administrated to a sample of 19 participants with TBI and 50 healthy controls. Tasks probing different EFs (i.e., shifting, updating/working memory, inhibition, and access to long term memory), speed of processing, and episodic memory were also administrated to the TBI group. PM deficits were found in participants with TBI compared to controls. In the role of EFs in PM, only tasks probing updating/working memory and access to the long-term memory showed to play a specific role in PM performance in TBI. However, while updating/working memory was related to both time and event based PM, access to the long term memory was associated to performance on time based PM task only. Speed of processing and retrospective memory abilities do not seem to play a specific role in PM deficit in TBI. Our results provide a better understanding of the PM deficit in TBI, which may contribute to improve existing rehabilitation programs for individuals with TBI. [ABSTRACT FROM AUTHOR]

We investigated whether the gender differences in working memory are linked to the nature of the stimuli (verbal vs. visuo-spatial) or to the type of processing (active vs. passive). With this aim, we administered two well-known tests: Corsi Block-tapping test (CBT) and the Digit span (DS) using two versions: forward (fCBT and fDS) and backward (bCBT and bDS). During the forward processing (fCBT and fDS), subjects being required to repeat stimuli in the same order they are presented, passive working memory is assessed. Otherwise, during the backward processing (bCBT and bDS), subjects being required repeating stimuli in an order opposite to that of presentation, active working memory is assessed. A total of 208 college students (104 women) were assessed. We found a gender effect on fCBT and bCBT, but not on fDS and bDS, with men outperforming women. The results from the present study support previous findings in which the presence of gender differences emerged in visuo-spatial working memory, that is, when verbal encoding is less efficacious with respect to other strategies. Failing in finding the opposite trend in fDS and bDS, that is, women performing better than men on these tasks, previously documented, may be due to the fact that we selected a sample of young subjects with the same educational level. Indeed, gender differences in verbal working memory have been reported especially for low level of education. Furthermore, our results suggest that such differences are more related to the type of material (verbal vs. visuo-spatial) more than to the type of processing (active vs. passive). This last finding supports the idea that when age and educational level are well matched among sexes, differences due to the stimuli processing disappear. [ABSTRACT FROM AUTHOR]

Objectives: Psychosis of Alzheimer's disease (AD) may represent a distinct disease phenotype; however, neuropsychological profile and neural basis linked to this phenotype have not yet been clarified. In this study, we aimed at detecting whether impairment in specific cognitive domains predicts the onset of psychosis in AD patients and what grey matter alterations, their location, and the rate of atrophy are associated with psychosis of AD.Methods: Longitudinal neuropsychological data from AD patients with and without psychosis were analysed to determine whether the neuropsychological profile can predict the onset of psychosis. A voxel-based morphometry (VBM) on longitudinal T1-weighted images was used to explore differences in grey matter volume and in the rate of atrophy between groups.Results: Noncognitive domain predicted the psychosis onset. However, AD patients with psychosis exhibited greater atrophy in the right anterior-inferior temporal lobe, including the fusiform gyrus (cluster-p-family-wise error [pfwe] < 0.05; peak-p uncorrected [pUNC] < 0.001) as well as greater rate of atrophy in the right insula than nonpsychotic patients (cluster-pFWE = 0.075; peak-pUNC < 0.001). The anterior-inferior temporal lobe is part of the ventral visual stream, and the insula plays a key role in the salience network.Conclusions: This finding suggests that damage in these areas underpins an impairment in the visual processing of the objects and an impairment in the attribution of salience to the misperceived stimuli, which in turn leads to the onset of psychosis. These findings tie in well with the neuropsychological model of psychosis, according to which the simultaneous presence of two factors, namely misperception and misattribution, underlies psychosis in dementia. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the characteristics of individuals working in the field of neuropsychology in Italy, as part of a larger study examining the practice of neuropsychology across various countries. They were asked about their background, professional training, current work situation, types of assessment, preferred diagnostic procedures, as well as the rehabilitation techniques, their targeted populations, teaching responsibilities, and research activities. A total of 154 professionals completed an online survey from April 28, 2016 through June 30, 2016. The majority of participants were women, with a mean age of 42.6 years. Participants reported working for the National Health System, in private practice, or in private rehabilitation facilities. Overall, they reported being very satisfied with their work. Those who identified themselves as neuropsychologists primarily assessed individuals with dementia, stroke, movement disorders, and traumatic brain injury. While the majority of participants declared no problems with the instruments they used, others reported complaints, including but not limited to the financial cost of current neuropsychological tests and the lack of psychometric support. The main perceived obstacles were the lack of willingness to collaborate among professionals, the scarcity of academic training programs, and the lack of clinical training opportunities. [ABSTRACT FROM AUTHOR]

Herein, we investigate how the three types of mental spatial representation (landmark, route and survey) are reorganized to perform wayfinding and homing behaviour. We also investigate the contribution of visuo-spatial working memory in reaching and in vista space in performing the retracing of the path. For this purpose, we asked 68 healthy college students to learn and come back along an unknown path in a real environment and to perform two different forward and backward working memory tasks, one in the reaching space (Corsi Block-Tapping Test) and the other in a vista space (Walking Corsi Test). The results show that participants performed better when travelling the route forward (which corresponds to the originally learned direction) than when travelling the route backward (return path) and that working memory in vista space is crucial for both wayfinding and homing behaviour, while the working memory for reaching space contributes only to homing behaviour. Although homing behaviour is an early mechanism in navigation shared among many species, it represents a very complex behaviour that requires both topographic and visuo-spatial memory as well as the first two levels of environmental knowledge. [ABSTRACT FROM AUTHOR]

Mental imagery and visual perception rely on the same content‐dependent brain areas in the high‐level visual cortex (HVC). However, little is known about dynamic mechanisms in these areas during imagery and perception. Here we disentangled local and inter‐regional dynamic mechanisms underlying imagery and perception in the HVC and the hippocampus (HC), a key region for memory retrieval during imagery. Nineteen healthy participants watched or imagined a familiar scene or face during fMRI acquisition. The neural code for familiar landmarks and faces was distributed across the HVC and the HC, although with a different representational structure, and generalized across imagery and perception. However, different regional adaptation effects and inter‐regional functional couplings were detected for faces and landmarks during imagery and perception. The left PPA showed opposite adaptation effects, with activity suppression following repeated observation of landmarks, but enhancement following repeated imagery of landmarks. Also, functional coupling between content‐dependent brain areas of the HVC and HC changed as a function of task and content. These findings provide important information about the dynamic networks underlying imagery and perception in the HVC and shed some light upon the thin line between imagery and perception which has characterized the neuropsychological debates on mental imagery. [ABSTRACT FROM AUTHOR]

Notwithstanding its well-established role on high-demanding spatial navigation tasks during adulthood, the effect of field dependence-independence during the acquisition of spatial navigation skills is almost unknown. This study assessed for the first time the effect of field dependence-independence on topographical learning (TL) across the life span: 195 individuals, including 54 healthy young-adults (age-range = 20-30), 46 teenagers (age-range = 11-14), and 95 children (age-range = 6-9) participated in this study. Field dependence-independence interacted with age in predicting TL. Also during childhood higher field independence was associated with better performances but not later in the life, that is, during adolescence and adulthood. This result suggests that field dependence-independence may have a role in fostering the acquisition of TL. [ABSTRACT FROM AUTHOR]

Spatial navigation tasks reveal small differences between normal and pathological aging and may thus disclose potential neuropsychological predictors of neurodegenerative diseases. The aim of our study was to investigate which navigational skills are compromised in the early phase of pathological aging as well as the extent to which they are compromised. We performed an extensive neuropsychological evaluation based on working memory and learning tasks (i.e., Corsi Block-Tapping Test and Walking Corsi Test) involving both reaching and navigational vista spaces. We also assessed spatial navigation skills in the real world by asking participants to perform route-learning and landmark-recognition tasks. We conducted a cross-sectional study on nineteen patients with a diagnosis of mild cognitive impairment (MCI) who displayed either an isolated memory deficit (single-domain amnestic MCI, MCIsd; N = 3) or a memory deficit associated with deficits in other cognitive functions (multi-domain MCI, MCImd; N = 16) as well as on nineteen healthy control participants. The groups' performances were compared by means of mixed factorial ANOVA and two-sample t-tests. We found that patients with MCI performed worse than controls, especially when they were required to learn spatial positions within the navigational vista space. Route-learning within the real environment was also impaired whereas landmark-recognition was spared. The same pattern of results emerged in the MCImd subgroup. Moreover, single case analyses on MCIsd patients revealed a dissociation between learning of spatial positions within navigational vista space and within reaching space. These results suggest that topographical learning is compromised in the early phase of MCIsd and MCImd and that spatial navigation tasks may be used to better characterize topographical disorientation in MCI patients as well as for the early diagnosis of pathological aging. [ABSTRACT FROM AUTHOR]

Highlights • Interval timing involves both internally-based and externally-cued timing processes. • ALE meta-analysis suggests these processes might be partially dissociated. • Internally-based timing involves areas also involved in externally-cued timing. • SMA, right IFG, left PCG and INS are more activated during externally-cued timing. Abstract A dynamic interplay exists between Internally-Based (IBT) and Externally-Cued (ECT) time processing. While IBT processes support the self-generation of context-independent temporal representations, ECT mechanisms allow constructing temporal representations primarily derived from the structure of the sensory environment. We performed an activation likelihood estimation (ALE) meta-analysis on 177 fMRI experiments, from 79 articles, to identify brain areas involved in timing; two individual ALEs tested the hypothesis of a neural segregation between IBT and ECT. The general ALE highlighted a network involving supplementary motor area (SMA), intraparietal sulcus, inferior frontal gyrus (IFG), insula (INS) and basal ganglia. We found evidence of a partial dissociation between IBT and ECT. IBT relies on a subset of areas also involved in ECT, however ECT tasks activate SMA, right IFG, left precentral gyrus and INS in a significantly stronger way. Present results suggest that ECT involves the detection of environmental temporal regularities and their integration with the output of the IBT processing, to generate a representation of time which reflects the temporal metric of the environment. [ABSTRACT FROM AUTHOR]

Introduction: Developmental topographical disorientation (DTD) is a lifelong condition in which affected individuals are selectively impaired in navigating space. Although it seems that DTD is widespread in the population, only a few cases have been studied from both a behavioral and a neuroimaging point of view. Here, we report a new case of DTD, never described previously, of a young woman (C.F.) showing a specific deficit in translating allocentrically coded information into egocentrically guided navigation, in presence of spared ability of constructing such representations. Method: A series of behavioral experiments was performed together with a resting-state functional magnetic resonance imaging (fMRI). Results: We demonstrated that C.F. was fully effective in learning and following routes and in building up cognitive maps as well as in recognizing landmarks. C.F.’s navigational skills, instead, dropped drastically in the map-following task when she was required to use a map to navigate in a novel environment. The rs-fMRI experiment demonstrated aberrant functional connectivity between regions within the default-mode network (DMN), and in particular between medial prefrontal cortex and posterior cingulate, medial parietal, and temporal cortices. Discussion: Our results would suggest that, at least in C.F., dysfunctional coactivation of core DMN regions would interfere with the ability to exploit cognitive maps for real-life navigation even when these maps can be correctly built. [ABSTRACT FROM AUTHOR]

Objective. Following current model of body representations, we aimed to systematically investigate the association between brain modifications, in terms of grey matter loss, and body representation deficits, in terms of alterations of the body schema (BS) and of non-action oriented body representations (NA), in individuals with lower limb amputation (LLA). Method. BS and NA (both semantic and visuospatial NA) were evaluated in 11 healthy controls and in 14 LLA, considering the impact of clinical variables such as prosthesis use. The association between BS and NA deficits and grey matter loss was also explored in LLA by using Voxel Based Morphometry analysis. Results. LLA's performance was fine in terms of semantic NA, while it showed behavioural impairments both in BS and visuospatial NA as compared to healthy controls. Interestingly the visuospatial NA performance was related to the amount of prosthesis use. NA deficits in terms of visuospatial body map processing were associated with grey matter reduction in left (lobule VIII) and right (crus II) cerebellum, while BS deficits were associated with grey matter reduction in right anterior cingulate cortex and the bilateral cuneus. No significant association was detected for semantic NA. Conclusion. The study of BS and NA representations after limb loss has informed our understanding of the different dynamics (i.e., adjustments to body change) of such representations, supporting current cognitive models of body representation. The clinical relevance of present findings is also discussed. [ABSTRACT FROM AUTHOR]