Objectives
Within the large topic of naming disorders, an important and separated chapter belongs to proper names. Defects of proper naming could be a selective linguistic problem. Sometimes, it ...includes names belonging to various kinds of semantically unique entities, but other times, it has been observed for famous people proper names only. According to Bruce and Young’s model, different stages allow to recognize, identify, and name famous people from their faces and voices, subsuming different anatomical pathways, both in right temporal lobe, and their different efficiency in this task. The present study aimed to report the normative data concerning the naming of the same famous people from voice and face.
Subjects and methods
One hundred fifty-three normal subjects underwent a test in which they were requested to name famous people from their face and from their voice. The stimuli belonged to the previously published Famous People Recognition Battery.
Results
The mean percentage score on naming from face was 84.42 ± 12.03% (range 55.26–100%) and the mean percentage score on naming from voice was 66.04 ± 16.81% (range 28.13–100%). The difference observed in performance by face and by voice resulted significant (t|
153
= 15.973;
p
< 0.001). Regression analyses showed that the percentage score obtained on naming from faces was predicted by education, whereas naming from voice was predicted by education and gender.
Discussion
Naming from voice is more difficult than from face, confirming a different difficulty of the two tasks. Education showed high predicting value for faces and less for voices, whereas gender contributed to predict results only for voices.
The target article carefully describes the memory system, centered on the temporal lobe that builds specific memory traces. It does not, however, mention the laterality effects that exist within this ...system. This commentary briefly surveys evidence showing that clear asymmetries exist within the temporal lobe structures subserving the core system and that the right temporal structures mainly underpin face familiarity feelings.
•Steps of description, conceptualization and naming led to the anosognosia construct.•Patients can be selectively unaware of some disabilities but fully aware of others.•Cognitive and motivational ...factors can be involved in disease unawareness.•The right hemisphere could play a leading role in removed and non-removed unconscious.•Anosognosia could be a multifaceted phenomenon subtended by different mechanisms.
Poor disease awareness (‘anosognosia’) is often observed in patients with various disabilities caused by brain damage. The lack of disease awareness can be due to the disruption of specific cognitive mechanisms and the development of psychodynamic mechanisms of denial. The aim of this paper is to review how these phenomena were discovered and evolved over time and to consider the relationships between them and the right hemisphere dominance for emotions. It is not clear whether the term ‘anosognosia’ refers to a basic mechanism that can explain similar awareness defects in different behavioural domains or whether it must be viewed as a multifaceted phenomenon in which both the disruption of cognitive or sensorimotor mechanisms and the emergence of motivational factors can play different roles in various forms of disease unawareness and in different kinds of ‘anosognosic’ patients.
Background: The role of the right hemisphere (RH) in the recovery of language is quite controversial.
Aims: The aim of the present survey consisted in taking into account three main models advanced ...to explain the reconstitution of language systems: (1) the "perilesional hypothesis," which maintains that language recovery is mainly subsumed by left hemisphere (LH) tissue adjacent to the lesion; (2) the "right hemisphere hypothesis," which assumes that restitution of language entails an increased participation of the RH; and (3) the "disinhibition hypothesis," which maintains that recovery is facilitated by disruption of inhibitions exerted by RH regions over LH language areas.
Methods & Procedures: The prognostic factors in poststroke aphasia are discussed first, focusing attention on factors that could subsume an increased participation of the RH to the recovery of language. Then results obtained with techniques of noninvasive brain stimulations of the RH are taken critically into account.
Outcomes & Results: As for the prognostic factors, the following points are stressed: (1) the anatomical extension of the LH lesion plays an important role both on the degree and on the path of recovery; (2) the RH structures involved in the recovery of language are generally mirror structures of the damaged LH areas; and (3) the time elapsed since the onset of aphasia influences the contribution that contralateral and ipsilesional areas give to the recovery of language. As for results obtained with techniques of noninvasive brain stimulations of the RH, this point remains controversial, because most authors support the "disinhibition hypothesis," but theoretical and factual reasons suggest caution in the interpretation of these results.
Conclusions: Since the meaning of the RH activations and of results obtained with techniques of noninvasive brain stimulations remain controversial, some tentative recommendations to clarify these issues are advanced.
The aim of this study was to shed light on the neural substrate of conceptual representations starting from the construct of higher-order convergence zones and trying to evaluate the unitary or ...non-unitary nature of this construct. We used the 'Thematic and Taxonomic Semantic (TTS) task' to investigate (a) the neural substrate of stimuli belonging to biological and artifact categories, (b) the format of stimuli presentation, i.e., verbal or pictorial, and (c) the relation between stimuli, i.e., categorial or contextual. We administered anodal transcranial direct current stimulation (tDCS) to different brain structures during the execution of the TTS task. Twenty healthy participants were enrolled and divided into two groups, one investigating the role of the anterior temporal lobes (ATL) and the other the temporo-parietal junctions (TPJ). Each participant underwent three sessions of stimulation to facilitate a control condition and to investigate the role of both hemispheres. Results showed that ATL stimulation influenced all conceptual representations in relation to the format of presentation (i.e., left-verbal and right-pictorial). Moreover, ATL stimulation modulated living categories and taxonomic relations specifically, whereas TPJ stimulation did not influence semantic task performances.
A very challenging problem in the domain of the cognitive neurosciences is to explain why herpes simplex encephalitis and semantic dementia show, respectively, a category-specific semantic disorder ...for biological entities and an across-categories semantic disruption, despite highly overlapping areas of anterior temporal lobe damage. The aim of the present review consisted in trying to make a separate survey of anatomo-clinical investigations (single-case studies and group studies) and of activation studies, in order to analyse the factors that could explain these different patterns of semantic disruption. Factors taken into account in this review were laterality of lesions, disease aetiology, kind of brain pathology and locus of damage within the temporal lobes. Locus of damage within the temporal lobes and kind of brain pathology seemed to play the most important role, because in patients with herpes simplex encephalitis and category-specific semantic disorder for biological entities the lesions prevailed in the anteromedial temporal lobes. Furthermore, the neuropathology concerned both the anterior temporal cortices and the white matter pathways connecting these areas with the posterior visual areas, whereas in semantic dementia the inferior longitudinal fasciculus involvement was restricted to the rostral temporal lobe and did not extend into the cortically uninvolved occipital lobe.
In recent years, the anatomical and functional bases of conceptual activity have attracted a growing interest. In particular, Patterson and Lambon-Ralph have proposed the existence, in the anterior ...parts of the temporal lobes, of a mechanism (the ‘amodal semantic hub’) supporting the interactive activation of semantic representations in all modalities and for all semantic categories.
The aim of then present paper is to discuss this model, arguing against the notion of an ‘amodal’ semantic hub, because we maintain, in agreement with the Damasio’s construct of ‘higher-order convergence zone’, that a continuum exists between perceptual information and conceptual representations, whereas the ‘amodal’ account views perceptual informations only as a channel through which abstract semantic knowledge can be activated. According to our model, semantic organization can be better explained by two orthogonal higher-order convergence systems, concerning, on one hand, the right vs. left hemisphere and, on the other hand, the ventral vs. dorsal processing pathways. This model posits that conceptual representations may be mainly based upon perceptual activities in the right hemisphere and upon verbal mediation in the left side of the brain. It also assumes that conceptual knowledge based on the convergence of highly processed visual information with other perceptual data (and mainly concerning living categories) may be bilaterally represented in the anterior parts of the temporal lobes, whereas knowledge based on the integration of visual data with action schemata (namely knowledge of actions, body parts and artefacts) may be more represented in the left fronto-temporo-parietal areas.
Drawing is a multicomponential process that can be impaired by many kinds of brain lesions. Drawing disorders are very common in Alzheimer's disease and other forms of dementia, and can provide ...clinical information for the distinction of the different dementing diseases. In our review we started from an overview of the neural and cognitive bases of drawing, and from a recollection of the drawing tasks more frequently used for assessing individuals with dementia. Then, we analyzed drawing disorders in dementia, paying special attention to those observed in Alzheimer's disease, from the prodromal stages of the amnesic mild cognitive impairment to the stages of full-blown dementia, both in the sporadic forms with late onset in the entorhino-hippocampal structures and in those with early onset in the posterior neocortical structures. We reviewed the drawing features that could differentiate Alzheimer's disease from vascular dementia and from the most frequent forms of degenerative dementia, namely frontotemporal dementia and Lewy body disease. Finally, we examined some peculiar aspects of drawing disorders in dementia, such as perseverations, rotations, and closing-in. We argue that a careful analysis of drawing errors helps to differentiate the different forms of dementia more than overall accuracy in drawing.
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