Search results for "semantic memory"
showing 10 items of 54 documents
The influence of rTMS over prefrontal and motor areas in a morphological task: grammatical vs. semantic effects
2008
We investigated the differential role of two frontal regions in the processing of grammatical and semantic knowledge. Given the documented specificity of the prefrontal cortex for the grammatical class of verbs, and of the primary motor cortex for the semantic class of action words, we sought to investigate whether the prefrontal cortex is also sensitive to semantic effects, and whether the motor cortex is also sensitive to grammatical class effects. We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of a portion of left prefontal cortex (first experiment) and of the motor area (second experiment). In the first experiment we found that rTMS applied to t…
Taking both sides: do unilateral anterior temporal lobe lesions disrupt semantic memory?
2010
The most selective disorder of central conceptual knowledge arises in semantic dementia, a degenerative condition associated with bilateral atrophy of the inferior and polar regions of the temporal lobes. Likewise, semantic impairment in both herpes simplex virus encephalitis and Alzheimer's disease is typically associated with bilateral, anterior temporal pathology. These findings suggest that conceptual representations are supported via an interconnected, bilateral, anterior temporal network and that it may take damage to both sides to produce an unequivocal deficit of central semantic memory. We tested and supported this hypothesis by investigating a case series of 20 patients with unila…
Famous face recognition and naming test: a normative study.
2003
Tests of famous face recognition and naming, and tasks assessing semantic knowledge about famous people after presentation either of their faces or their names are often used in the neuropsychological examination of aphasic, amnesic and demented patients. A total of 187 normal subjects took part in this study. The aim was to collect normative data for a newly devised test including five subtests: famous face naming, fame judgement after face presentation and after name presentation, semantic knowledge about famous people after face presentation and after name presentation. Norms were calculated taking into account demographic variables such as age, sex and education and adjusted scores were…
The facilitative effect of gestures on the neural processing of semantic complexity in a continuous narrative
2019
© 2019 Elsevier Inc. Gestures are elemental components of social communication and aid comprehension of verbal messages; however, little is known about the potential role of gestures in facilitating processing of semantic complexity in an ecologically valid setting. The goal of this study was to investigate whether cognitive load, as indexed by semantic complexity, is modulated by the presentation of gestures accompanying speech. Twenty healthy participants watched 16 video clips of a short narrative while instructed to carefully listen to and watch the narrator while functional magnetic resonance imaging (fMRI) data were acquired. The videos contained passages with and without various co-s…
Electrophysiological correlates of cross-linguistic semantic integration in hearing signers : N400 and LPC
2014
We explored semantic integration mechanisms in native and non-native hearing users of sign language and non-signing controls. Event-related brain potentials (ERPs) were recorded while participants performed a semantic decision task for priming lexeme pairs. Pairs were presented either within speech or across speech and sign language. Target-related ERP responses were subjected to principal component analyses (PCA), and neurocognitive basis of semantic integration processes were assessed by analyzing the N400 and the late positive complex (LPC) components in response to spoken (auditory) and signed (visual) antonymic and unrelated targets. Semantically-related effects triggered across modali…
The effect of associative strength on semantic priming in schizophrenia
2017
The present research was designed to investigate the pattern of semantic priming in schizophrenia as a function of strength of association (or semantic distance between concepts in the semantic network). Thirty schizophrenia patients, without formal thought disorder, and twenty-nine healthy controls participated in a lexical decision task in which prime-target associative strength (strong, weak and not related) and stimulus-onset asynchrony (SOA: 250 ms and 750 ms) were manipulated. Patients and controls showed the same associative strength effect on RTs. In the short SOA condition priming effects were obtained for both strong and weak prime-target associative conditions. However in the lon…
Evidence against preserved syntactic comprehension in healthy aging.
2018
We investigated age-related differences in syntactic comprehension in young and older adults. Most previous research found no evidence of age-related decline in syntactic processing. We investigated elementary syntactic comprehension of minimal sentences (e.g., I cook), minimizing the influence of working memory. We also investigated the contribution of semantic processing by comparing sentences containing real verbs (e.g., I cook) versus pseudoverbs (e.g., I spuff). We measured the speed and accuracy of detecting syntactic agreement errors (e.g., I cooks, I spuffs). We found that older adults were slower and less accurate than younger adults in detecting syntactic agreement errors for both…
Associative and semantic priming effects occur at very short stimulus-onset asynchronies in lexical decision and naming
1997
Abstract Prior research has found significant associative/semantic priming effects at very short stimulus-onset asynchronies (SOAs) in experimental tasks such as lexical decision, but not in naming tasks (however, see Lukatela and Turvey, 1994 ). In this paper, the time course of associative priming effects was analyzed at several very short SOAs (33, 50, and 67 ms), using the masked priming paradigm ( Forster and Davis, 1984 ), both in lexical decision (Experiment 1) and naming (Experiment 2). The results show small—but significant—associative priming effects in both tasks. Additionally, using the masked priming procedure at the 67 ms SOA, Experiments 3 and 4, shows facilitatory priming ef…
Reversibility in Chinese word formation influences target identification.
2011
We recorded event-related brain potentials during the processing of visually presented compound words in Mandarin Chinese. We capitalized on a particular characteristic of Chinese word formation, where two constituents can be combined in two different orders (A+B or B+A), yielding distinct meanings-so-called "reversible words". By investigating the impact of structural reversibility on the processing of compounds in Chinese during a lexical decision task, the present study revealed a pronounced difference between reversible and non-reversible words. Analyses revealed a more enhanced negativity (N400) for reversible words, reflecting demands during semantic processing, followed by a P300-lik…
The role of novelty detection in food memory
2010
International audience; Memory plays a central role in food choice. Recent studies focusing on food memory in everyday eating and drinking behaviour used a paradigm based on incidental learning of target foods and unexpected memory testing, demanding recognition of the target among distractors, which deviate slightly from the target. Results question the traditional view of memory as reactivation of previous experiences. Comparison of data from several experiments shows that in incidentally learned memory, distractors are rejected, while original targets are not recognised better than by chance guessing. Food memory is tuned at detecting novelty and change, rather than at recognising a prev…