Retrieval pathways for common and proper names

Paradigmatic cases of proper name anomia and proper name selective sparing are reviewed from relevant neuropsychological literature. Available evidence supports the existence of functionally and anatomically distinct retrieval pathways for the categories of proper and common names. An information processing model whose main feature lies in the relative independence within the semantic-conceptual system of information concerning individual entities may account for most of the observed phenomena. Localization studies seem to indicate that a complex neural network sustains various tasks implied in proper name processing. A dedicated module dealing with proper name retrieval is probably there, but its location within the left hemisphere is not at present fully understood. The proper name specific retrieval process is shown, in keeping with current philosophical and linguistic theories, to be intrinsically fragile and source-consuming.     

Verbal free recall in high altitude: proper names vs common names

Exposure to extreme altitude is known to cause a general impairment of cognitive functions. In this study we investigated the effect of high altitude on the recall of supraspan lists of proper and common names. High altitude seems to have a dramatic effect on the recall of proper names, while common names are more resistant to hypoxia. This effect, however, seems to selectively concern the early items of the lists. This damage to the primacy effect in proper name recall seems permanent over time. The absence of damage in recalling names from the last serial position clearly shows how STM functions are relatively more resistant to the lack of cognitive sources caused by hypoxia.     

The nature of the disorder underlying the inability to retrieve proper names

Two patients with the syndrome of proper name anomia were investigated. Both patients were only able to produce around 50% of the names of contemporary celebrities, but performed significantly better on a task calling for naming of historical figures. The names of relatives and friends were spared in one patient, while the other retrieved names of people known since childhood much better than those of people familiar to him since the age of 25. Geographical names, names of monuments and masterpieces were preserved. The above dissociations are taken to imply that in moderately impaired patients, a temporal gradient effect concurs to modulate the severity of the naming block.

A similar impairment was found in both patients when they attempted to retrieve or relearn familiar telephone numbers. This finding suggests that the core of the disorder resides in the inability to gain access to words used to identify a single entity, regardless of whether they belong to the class of proper or common names.     

Brain activation when hearing one's own and others' names

Using functional magnetic resonance imaging, brain activation patterns were examined in response to hearing one's own first name in contrast to hearing the names of others. There are several regions in the left hemisphere that show greater activation to one's own name, including middle frontal cortex, middle and superior temporal cortex, and cuneus. These findings provide evidence that hearing one's own name has unique brain functioning activation specific to one's own name in relation to the names of others.     

The semantic organisation of proper nouns: the case of people and brand names

We describe the performance of a patient (AZ) with a semantic refractory access disorder on a series of experiments probing comprehension of two broad proper noun categories, namely person names and brand names. By inducing and manipulating the semantic relatedness effects which are commonly observed in semantic refractory access patients, we demonstrate that famous person knowledge is primarily organised by occupation, whilst knowledge of brands is organised by product type. For instance, we show that AZ has significantly greater difficulty identifying a famous person from among distractor personalities who have the same occupation (e.g. composers: Beethoven, Mozart, Handel, and Bach) than those who have different occupations (e.g. Beethoven, Picasso, Shakespeare, and Jefferson). We also show that such semantic relatedness effects do not occur when stimuli are grouped by another variable such as nationality. We argue that these semantic distance effects reflect the greater build-up of refractoriness among concepts which are supported by shared neural circuitry. In psychological space, it seems natural that these individuals should be classified in this way. The strength of our findings lie in the fact that this organisation of psychological space is mirrored by neural organisation. Thus, we report a previously undocumented degree of fine-grain organisation within conceptual knowledge of these classes of proper nouns. We also interpret our data as providing the strongest empirical support to date for the semantic module of cognitive models of person recognition.     

ERP indexes of functional differences in brain activation during proper and common names retrieval

Functional neuroimaging and neuropsychological findings suggest that memory retrieval of common and proper names is subserved by different neuro-functional systems but little is known about the topographic localization of neural generators. In the present study brain electrical activity was recorded with a high density electrode montage in healthy young volunteers during lexical retrieval upon written definition. ERPs spatio-temporal mapping showed on one side a strong activation of left anterior temporal and left central-frontal areas for proper names, and on the other side a greater involvement of occipital areas for common names retrieval. The specific pattern of bio-electrical activity recorded during proper names retrieval might index the activation of neural circuits for recalling names of high contextual complexity, poor of sensory-motor associations and dependent on precise spatio-temporal coordinates.     

Brain mechanisms for processing affective touch

Despite the crucial role of touch in social development, there is very little functional magnetic resonance imaging (fMRI) research on brain mechanisms underlying social touch processing. The “skin as a social organ” hypothesis is supported by the discovery of C‐tactile (CT) nerves that are present in hairy skin and project to the insular cortex. CT‐fibers respond specifically well to slow, gentle touch such as that which occurs during close social interactions. Given the social significance of such touch researchers have proposed that the CT‐system represents an evolutionarily conserved mechanism important for normative social development. However, it is currently unknown whether brain regions other than the insula are involved in processing CT‐targeted touch. In the current fMRI study, we sought to characterize the brain regions involved in the perception of CT‐supported affective touch. Twenty‐two healthy adults received manual brush strokes to either the arm or palm. A direct contrast of the blood‐oxygenation‐level‐dependent (BOLD) response to gentle brushing of the arm and palm revealed the involvement of a network of brain regions, in addition to the posterior insula, during CT‐targeted affective touch to the arm. This network included areas known to be involved in social perception and social cognition, including the right posterior superior temporal sulcus and the medial prefrontal cortex (mPFC)/dorso anterior cingulate cortex (dACC). Connectivity analyses with an mPFC/dACC seed revealed coactivation with the left insula and amygdala during arm touch. These findings characterize a network of brain regions beyond the insula involved in coding CT‐targeted affective touch. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.     

Brain oscillations during spoken sentence processing

Spoken sentence comprehension relies on rapid and effortless temporal integration of speech units displayed at different rates. Temporal integration refers to how chunks of information perceived at different time scales are linked together by the listener in mapping speech sounds onto meaning. The neural implementation of this integration remains unclear. This study explores the role of short and long windows of integration in accessing meaning from long samples of speech. In a cross-linguistic study, we explore the time course of oscillatory brain activity between 1 and 100 Hz, recorded using EEG, during the processing of native and foreign languages. We compare oscillatory responses in a group of Italian and Spanish native speakers while they attentively listen to Italian, Japanese, and Spanish utterances, played either forward or backward. The results show that both groups of participants display a significant increase in gamma band power (55-75 Hz) only when they listen to their native language played forward. The increase in gamma power starts around 1000 msec after the onset of the utterance and decreases by its end, resembling the time course of access to meaning during speech perception. In contrast, changes in low-frequency power show similar patterns for both native and foreign languages. We propose that gamma band power reflects a temporal binding phenomenon concerning the coordination of neural assemblies involved in accessing meaning of long samples of speech.     

The anatomical basis of proper name processing. A critical review

Abstract

A specific role has recently been proposed in proper name processing for, respectively, the right hemisphere, the anterior temporal lobe and the thalamus. None of these claims seems to be fully justified with regard to a review of known relevant single case reports.     

Reduced verbal fluency for proper names in nondemented patients with Parkinson's disease: a quantitative and qualitative analysis

There has been an increasing interest within neuropsychology in comparing verbal fluency for different grammatical classes (e.g., verb generation vs. noun generation) in neurological populations, including Parkinson's disease (PD). However, to our knowledge, few studies have compared verbal fluency for common nouns and proper names in PD. Common nouns and proper names differ in terms of their semantic characteristics, as categories of common nouns are organized hierarchically based on semantics, while categories of proper nouns lack a well-defined semantic organization. In addition, there is accumulating evidence that the retrieval of these distinct grammatical classes are subserved by somewhat distinct neural systems. Given that verbal fluency deficits are among the first impairments to emerge in PD, and that such deficits are predictors of future cognitive decline, it is important to examine all aspects of verbal fluency in this population. For the current study, we compared the performance of a group of 32 nondemented PD patients with 32 healthy participants (HP) on verbal fluency tasks for common nouns (animals) and proper names (boys' first names). A significant interaction between verbal fluency task and diagnostic status emerged, as the PD group performed significantly worse on only the proper name fluency task. This finding may reflect the absence of well-defined semantic organization that structures the verbal search for first names, thus placing a greater onus on strategic or "executive" verbal retrieval processes.     

Brain activity during face processing in infants

It has been shown that infants prefer looking at faces to looking at equally complex, non-facial visual stimuli. Many behavioral studies have illustrated that infants process faces differently from other objects. In agreement with these findings, recent neuropsychological studies provide evidence indicating face-specific brain activity in infants. The present paper reviews the psychological studies investigating the infant's brain activity for faces, using brain-imaging techniques, such as near-infrared spectroscopy (NIRS). Near-infrared spectroscopy (NIRS) is a new and increasingly used brain imaging technique, which is particularly suitable for use with young infants. Studies using NIRS have reported face-specific brain activation in the temporal area. When 5- to 8-month-old infants view upright faces, a significant increase in oxy-hemoglobin (oxy-Hb) was observed in the right temporal area. Such face-specific brain activity in infants becomes view-invariant at the age of 8 months, but not at 5 months. More recently, an NIRS study employing the adaptation paradigm revealed that the identity of faces was processed in the bilateral temporal area. Additionally, face-specific brain activity was observed for not only static face images, but also for dynamic facial point-light displays. We found that concentrations of oxy-Hb increased in the right temporal area during the presentation of an upright facial point-light display compared to that during the baseline period. Finally, we discuss the possibility of developmental changes in brain activity from infancy to childhood and adolescence as well as in atypical development.     

Brain bases of morphological processing in young children

How does the developing brain support the transition from spoken language to print? Two spoken language abilities form the initial base of child literacy across languages: knowledge of language sounds (phonology) and knowledge of the smallest units that carry meaning (morphology). While phonology has received much attention from the field, the brain mechanisms that support morphological competence for learning to read remain largely unknown. In the present study, young English‐speaking children completed an auditory morphological awareness task behaviorally (n = 69, ages 6–12) and in fMRI (n = 16). The data revealed two findings: First, children with better morphological abilities showed greater activation in left temporoparietal regions previously thought to be important for supporting phonological reading skills, suggesting that this region supports multiple language abilities for successful reading acquisition. Second, children showed activation in left frontal regions previously found active in young Chinese readers, suggesting morphological processes for reading acquisition might be similar across languages. These findings offer new insights for developing a comprehensive model of how spoken language abilities support children's reading acquisition across languages. Hum Brain Mapp 36:2890–2900, 2015. © 2015 Wiley Periodicals, Inc.     

Brain mapping biomarkers of socio-emotional processing in schizophrenia

The Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative has formed with the expressed intent of identifying constructs and paradigms that would identify biomarkers of psychosis. The manipulation of these biomarkers would serve as targets for treatment interventions. The second phase of CNTRICS consisted of critical discussions evaluating brain mapping (functional neuroimaging and brain electrical activity) paradigms as biomarkers to measure specific constructs. Among the constructs identified in, CNTRICS I was socio-emotional processing, specifically focused on affect recognition. Here, we provide a critical appraisal of the ability of candidate socio-emotional tasks to identify putative biomarkers and recommendations for future directions in this rapidly moving research domain.     

Brain processing of duodenal and portal glucose sensing

Peripheral and central glucose sensing play a major role in the regulation of food intake. Peripheral sensing occurs at duodenal and portal levels, although the importance of these sensing sites is still controversial. The present study aimed to compare the respective influence of these sensing pathways on the eating patterns; plasma concentrations of glucose, insulin and glucagon‐like peptide‐1 (GLP‐1); and brain activity in juvenile pigs. In Experiment 1, we characterised the changes in the microstructure as a result of a 30‐min meal in eight conscious animals after duodenal or portal glucose infusion in comparison with saline infusion. In Experiment 2, glucose, insulin and GLP‐1 plasma concentrations were measured during 2 h after duodenal or portal glucose infusions in four anaesthetised animals. In Experiment 3, single photon emission computed tomography brain imaging was performed in five anaesthetised animals receiving duodenal or portal glucose or saline infusions. Both duodenal and portal glucose decreased the amount of food consumed, as well as the ingestion speed, although this effect appeared earlier with the portal infusion. Significant differences of glucose and GLP‐1 plasma concentrations between treatments were found at the moment of brain imaging. Both duodenal and portal glucose infusions activated the dorsolateral prefrontal cortex and primary somatosensory cortex. Only duodenal glucose infusion was able to induce activation of the prepyriform area, orbitofrontal cortex, caudate and putamen, as well as deactivation of the anterior prefrontal cortex and anterior entorhinal cortex, whereas only portal glucose infusion induced a significant activation of the insular cortex. We demonstrated that duodenal and portal glucose infusions led to the modulation of brain areas that are known to regulate eating behaviour, which probably explains the decrease of food intake after both stimulations. These stimulation pathways induced specific systemic and central responses, suggesting that different brain processing matrices are involved.     

Brain processing of the mammary pheromone in newborn rabbits

Chemosignals strongly contribute to social interactions in mammals, including mother-young relationships. In the European rabbit, a volatile compound emitted by lactating females in milk, the 2-methylbut-2-enal, has been isolated. Carrying the properties of a pheromone, in particular the spontaneous ability to release critical sucking-related movements in newborns, it has been called the mammary pheromone (MP). Lesion of the vomeronasal organ and preliminary 2-deoxyglucose data suggested that the MP could be processed by the main olfactory system. However, the neuronal substrate that sustains the MP-induced response of neonates remained unknown. Here, we evaluated Fos expression in 4-day-old-rabbits exposed to the MP (in comparison with control neonates exposed to non-relevant odorant, no odorant or unmanipulated pups) both at the level of the olfactory bulb and central brain regions. Evidence of high and widespread Fos immunoreactivity in the main olfactory bulb appear in MP pups while the accessory olfactory bulb exhibits a negligible staining. However, no obvious bulbar pattern of Fos expression is observed, when in contrast a certain pattern emerges with the neutral odorant. Compared to this latter, the MP exposure increases Fos expression in the anterior piriform cortex, the organum vasculosum of the lamina terminalis and the habenula, with a tendency in the lateral preoptic region. For the first time, a pheromone essential for mother-young interaction is thus highlighted for its processing by the main olfactory system, the whole olfactory bulb, and by brain regions involved in osmoregulation, thirst and motivation-guided motor responses.     

Brain processing of visual sexual stimuli in human males

Despite its critical sociobiological importance, the brain processing of visual sexual stimuli has not been characterized precisely in human beings. We used Positron Emission Tomography (PET) to investigate responses of regional cerebral blood flow (rCBF) in nine healthy males presented with visual sexual stimuli of graded intensity. Statistical Parametric Mapping was used to locate brain regions whose activation was associated with the presentation of the sexual stimuli and was correlated with markers of sexual arousal. The claustrum, a region whose function had been unclear, displayed one of the highest activations. Additionally, activations were recorded in paralimbic areas (anterior cingulate gyrus, orbito-frontal cortex), in the striatum (head of caudate nucleus, putamen), and in the posterior hypothalamus. By contrast, decreased rCBF was observed in several temporal areas. Based on these results, we propose a model of the brain processes mediating the cognitive, emotional, motivational, and autonomic components of human male sexual arousal.     

Brain systems mediating voice identity processing in blind humans

Blind people rely more on vocal cues when they recognize a person's identity than sighted people. Indeed, a number of studies have reported better voice recognition skills in blind than in sighted adults. The present functional magnetic resonance imaging study investigated changes in the functional organization of neural systems involved in voice identity processing following congenital blindness. A group of congenitally blind individuals and matched sighted control participants were tested in a priming paradigm, in which two voice stimuli (S1, S2) were subsequently presented. The prime (S1) and the target (S2) were either from the same speaker (person‐congruent voices) or from two different speakers (person‐incongruent voices). Participants had to classify the S2 as either a old or a young person. Person‐incongruent voices (S2) compared with person‐congruent voices elicited an increased activation in the right anterior fusiform gyrus in congenitally blind individuals but not in matched sighted control participants. In contrast, only matched sighted controls showed a higher activation in response to person‐incongruent compared with person‐congruent voices (S2) in the right posterior superior temporal sulcus. These results provide evidence for crossmodal plastic changes of the person identification system in the brain after visual deprivation. Hum Brain Mapp 35:4607–4619, 2014. © 2014 Wiley Periodicals, Inc .