Eleonora Catricalà

Computerized Neuropsychological Assessment in Aging: Testing Efficacy and Clinical Ecology of Different Interfaces

Digital technologies have opened new opportunities for psychological testing, allowing new computerized testing tools to be developed and/or paper and pencil testing tools to be translated to new computerized devices. The question that rises is whether these implementations may introduce some technology-specific effects to be considered in neuropsychological evaluations. Two core aspects have been investigated in this work: the efficacy of tests and the clinical ecology of their administration (the ability to measure real-world test performance), specifically (1) the testing efficacy of a computerized test when response to stimuli is measured using a touch-screen compared to a conventional mouse-control response device; (2) the testing efficacy of a computerized test with respect to different input modalities (visual versus verbal); and (3) the ecology of two computerized assessment modalities (touch-screen and mouse-control), including preference measurements of participants. Our results suggest that (1) touch-screen devices are suitable for administering experimental tasks requiring precise timings for detection, (2) intrinsic nature of neuropsychological tests should always be respected in terms of stimuli presentation when translated to new digitalized environment, and (3) touch-screen devices result in ecological instruments being proposed for the computerized administration of neuropsychological tests with a high level of preference from elderly people.

Beyond the abstract—concrete dichotomy: Mode of acquisition, concreteness, imageability, familiarity, age of acquisition, context availability, and abstractness norms for a set of 417 Italian words

The main objective of this study is to investigate the abstract-concrete dichotomy by introducing a new variable: the mode of acquisition (MoA) of a concept. MoA refers to the way in which concepts are acquired: through experience, through language, or through both. We asked 250 participants to rate 417 words on seven dimensions: age of acquisition, concreteness, familiarity, context availability, imageability, abstractness, and MoA. The data were analyzed by considering MoA ratings and their relationship with the other psycholinguistic variables. Distributions for concreteness, abstractness, and MoA ratings indicate that they are qualitatively different. A partial correlation analysis revealed that MoA is an independent predictor of concreteness or abstractness, and a hierarchical multiple regression analysis confirmed MoA as being a valid predictor of abstractness. Strong correlations with measures for the English translation equivalents in the MRC database confirmed the reliability of our norms. The full database of MoA ratings and other psycholinguistic variables may be downloaded from http:// brm.psychonomic-journals.org/content/supplemental or www.abstract-project.eu.

The lexical processing of abstract and concrete nouns

Recent activation studies have suggested different neural correlates for processing concrete and abstract words. However, the precise localization is far from being defined. One reason for the heterogeneity of these results could lie in the extreme variability of experimental paradigms, ranging from explicit semantic judgments to lexical decision tasks (auditory and/or visual). The present study explored the processing of abstract/concrete nouns by using repetitive Transcranial Magnetic Stimulation (rTMS) and a lexical decision paradigm in neurologically-unimpaired subjects. Four sites were investigated: left inferior frontal, bilaterally posterior-superior temporal and left posterior-inferior parietal. An interference on accuracy was found for abstract words when rTMS was applied over the left temporal site, while for concrete words accuracy decreased when rTMS was applied over the right temporal site. Accuracy for abstract words, but not for concrete words, decreased after frontal stimulation as compared to the sham condition. These results suggest that abstract lexical entries are stored in the posterior part of the left temporal superior gyrus and possibly in the left frontal inferior gyrus, while the regions involved in storing concrete items include the right temporal cortex. It cannot be excluded, however, that additional areas, not tested in this experiment, are involved in processing both, concrete and abstract nouns.

Free and cued selective reminding test: an Italian normative study

The presence of episodic memory impairment is required for the diagnosis of Alzheimer’s dementia by all current diagnostic criteria. The new research criteria proposed by Dubois et al. (Lancet Neurol 6:734–746, 2007) require that the impairment should not improve significantly with cueing, recognition testing nor after the control of effective encoding. This is considered to be the core deficit of “prodromal Alzheimer’s disease”. The Free and Cued Selective Reminding Test (FCSRT) is a memory test that allows in assessing these specific features of memory impairment. Here, we report normative data for an Italian version of the FCSRT. The test is based on the 12 pictorial stimuli, 6 belonging to the living domain, and 6 to the non-living domain. Six scores were derived from the performance of 227 healthy Italian adults, with age, sex and education homogenously distributed across subgroups: immediate free recall (IFR), immediate total recall (ITR), delayed-free recall (DFR), delayed total recall (DTR), Index of Sensitivity of Cueing (ISC), number of intrusions. In multiple regression analyses, age emerged as an influencing factor for both IFR and DFR, with older people obtaining lower scores. Education and gender appear to influence only IFR, with better performance by more educated subjects and females. Adjusted scores were used to determine inferential cutoff scores and to compute equivalent scores.

An Italian battery for the assessment of semantic memory disorders

We report the construction and standardization of a new comprehensive battery of tests for the assessment of semantic memory disorders. The battery is constructed on a common set of 48 stimuli, belonging to both living and non-living categories, rigidly controlled for several confounding variables, and is based on an empirically derived corpus of semantic features. It includes six tasks, in order to assess semantic memory through different modalities of input and output: two naming tasks, one with colored pictures and the other in response to an oral description, a word-picture matching task, a picture sorting task, a free generation of features task and a sentence verification task. Normative data on 106 Italian subjects pooled across homogenous subgroups for age, sex and education are reported. The new battery allows an in-depth investigation of category-specific disorders and of progressive semantic memory deficits at features level, overcoming some of the limitations of existing tests.

Conceptual knowledge in the brain: fMRI evidence for a featural organization

The organization and representation of conceptual knowledge in the brain remains a controversial issue in terms of both neuropsychological and imaging evidence. We report the results of a functional magnetic resonance study in which the role of the most debated dimensions (domain and feature type) was evaluated through a concept-feature verification task. The scope of the task was to eliminate serious methodological concerns that weighed down previous imaging research in this area, and to allow more definitive conclusions regarding the specific contribution of these dimensions. The results show differential patterns of brain activity according to feature type (both motion and visual form/surface features) but not according to concept domain (living vs. nonliving things). These findings are in accord with a modality-specific account of conceptual knowledge organization in the brain, in which specific kinds of features (e.g. form, color, motion, etc) have differential importance for representing different concepts.

Beyond the consensus criteria: multiple cognitive profiles in amyotrophic lateral sclerosis?

The Strong consensus recommendations (2009) propose behavioural (ALSbi) and/or dysexecutive (ALSci) impairment as the two main clinical profiles of non-motor manifestations in non-demented amyotrophic lateral sclerosis (ALS) patients. We aimed at assessing whether clustering pattern of neuropsychological performance of ALS patients suggest the existence of additional clinical syndromes beyond the currently recognized phenotypes. We applied principal component analysis (PCA) to a comprehensive neuropsychological evaluation of 71 non-demented ALS patients in order to identify clusters of variables correlating highly with each other, with the aim of detecting distinct patterns of neuropsychological test performance. The outcome of PCA demonstrated the existence of three main test clusters. Two, accounting for 27% of the patients, were compatible with the recognised ALSbi and ALSci profiles. An additional third cluster loaded on social cognition, language and memory tests and accounted for 24% of the patients. Of these, 15% had defective performance on at least two tests belonging to the latter non-executive cluster, and were thus unclassifiable according to current criteria. Our data-driven approach indicated a third dimension of cognitive impairment, including language, social cognition and episodic memory, as a distinct pattern of non-motor manifestations in ALS patients, in addition to the recognized ALSci and ALSbi profiles.

The semantic variant of primary progressive aphasia: clinical and neuroimaging evidence in single subjects.

Background/Aim We present a clinical-neuroimaging study in a series of patients with a clinical diagnosis of semantic variant of primary progressive aphasia (svPPA), with the aim to provide clinical-functional correlations of the cognitive and behavioral manifestations at the single-subject level. Methods We performed neuropsychological investigations, 18F-FDG-PET single-subject and group analysis, with an optimized SPM voxel-based approach, and correlation analyses. A measurement of white matter integrity by means of diffusion tensor imaging (DTI) was also available for a subgroup of patients. Results Cognitive assessment confirmed the presence of typical semantic memory deficits in all patients, with a relative sparing of executive, attentional, visuo-constructional, and episodic memory domains. 18F-FDG-PET showed a consistent pattern of cerebral hypometabolism across all patients, which correlated with performance in semantic memory tasks. In addition, a majority of patients also presented with behavioral disturbances associated with metabolic dysfunction in limbic structures. In a subgroup of cases the DTI analysis showed FA abnormalities in the inferior longitudinal and uncinate fasciculi. Discussion Each svPPA individual had functional derangement involving an extended, connected system within the left temporal lobe, a crucial part of the verbal semantic network, as well as an involvement of limbic structures. The latter was associated with behavioral manifestations and extended beyond the area of atrophy shown by CT scan. Conclusion Single-subject 18F-FDG-PET analysis can account for both cognitive and behavioral alterations in svPPA. This provides useful support to the clinical diagnosis.

Connected speech in neurodegenerative language disorders: A review

Language assessment has a crucial role in the clinical diagnosis of several neurodegenerative diseases. The analysis of extended speech production is a precious source of information encompassing the phonetic, phonological, lexico-semantic, morpho-syntactic, and pragmatic levels of language organization. The knowledge about the distinctive linguistic variables identifying language deficits associated to different neurodegenerative diseases has progressively improved in the last years. However, the heterogeneity of such variables and of the way they are measured and classified limits any generalization and makes the comparison among studies difficult. Here we present an exhaustive review of the studies focusing on the linguistic variables derived from the analysis of connected speech samples, with the aim of characterizing the language disorders of the most prevalent neurodegenerative diseases, including primary progressive aphasia, Alzheimers disease, movement disorders, and amyotrophic lateral sclerosis. A total of 61 studies have been included, considering only those reporting group analysis and comparisons with a group of healthy persons. This review first analyzes the differences in the tasks used to elicit connected speech, namely picture description, story narration, and interview, considering the possible different contributions to the assessment of different linguistic domains. This is followed by an analysis of the terminologies and of the methods of measurements of the variables, indicating the need for harmonization and standardization. The final section reviews the linguistic domains affected by each different neurodegenerative disease, indicating the variables most consistently impaired at each level and suggesting the key variables helping in the differential diagnosis among diseases. While a large amount of valuable information is already available, the review highlights the need of further work, including the development of automated methods, to take advantage of the richness of connected speech analysis for both research and clinical purposes.

Abstract and concrete categories? Evidences from neurodegenerative diseases.

We assessed the performance of patients with a diagnosis of Alzheimer׳s disease (AD) and of the semantic variant of primary progressive aphasia (sv-PPA) in a series of tasks involving both abstract and concrete stimuli, which were controlled for most of the variables that have been shown to affect performance on lexical-semantic tasks. Our aims were to compare the patients׳ performance on abstract and concrete stimuli and to assess category-effects within the abstract and concrete domains. The results showed: (i) a better performance on abstract than concrete concepts in sv-PPA patients. (ii) Category-related effects in the abstract domain, with emotion concepts being preserved in AD and social relations being selectively impaired in sv-PPA. In addition, a living-non living dissociation may be (infrequently) observed in individual AD patients after controlling for an extensive set of potential confounds. Thus, differences between and within the concrete or abstract domain may be present in patients with semantic memory disorders, mirroring the different brain regions involved by the different pathologies.