Search results for "Memory"
showing 10 items of 2004 documents
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…
Double-decision lexical tasks in thought-disordered schizophrenic patients: a path towards cognitive remediation?
2005
Abstract It has been shown that schizophrenics have certain difficulties in the processing of semantic context. These difficulties have usually been evaluated using lexical decision tasks with semantic priming. In this study, we chose to examine the idea of an abnormality in the early stages of semantic context processing in thought-disordered schizophrenics using two double lexical decision tasks: one with a high (25%) and one with a low (15%) proportion of related words to assess the participants’ competency in controlled and possibly also more automatic context processing. The results obtained in 40 control participants and 40 schizophrenic patients revealed no significant differences in…
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…
A Comparison of implicit memory tests in schizophrenic patients and normal controls
2007
The objective of the current study was to compare the performance of schizophrenic patients and normal controls on implicit memory tests. Two neuropsychological tasks were administered to 29 patients and normal participant samples. The implicit tests were: Word fragment completion and Word production from semantic categories. The priming score was the variable of interest. Priming effects are obtained in normal subjects and schizophrenia patients, regardless of the implicit test used. However, a dissociation in priming between normal and patient groups was observed, depending on the test used. For word fragment test, priming was identical between... (Ver más) the two groups. However, for wo…
Spatial Inferences in Narrative Comprehension: the Role of Verbal and Spatial Working Memory
2016
During the comprehension of narrative texts, readers keep a mental representation of the location of protagonists and objects; a breach in spatial coherence is detected by longer online reading times (consistency effect). We addressed whether these spatial inferences involve verbal or spatial working memory in two experiments, combining the consistency paradigm with selective verbal and spatial working memory concurrent tasks. The first experiment found longer reading times with a concurrent spatial task under imagery instructions (t33 = 2.87, p =.021). The second experiment, under comprehension reading instructions, found effects of verbal interference on reading times and accuracy. With a…
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…
Age of onset of Cannabis use and cognitive function in first-episode non-affective psychosis patients: Outcome at three-year follow-up
2018
In recent years, the effects of cannabis use on cognitive functions in patients with psychosis have been widely studied. Recently, special emphasis has been placed on the impact of age at the onset of consumption on cognition in these patients.349 patients with a first episode of non-affective psychosis were studied. Patients were classified as cannabis users and non-users. Users were divided, according to their age when they began using cannabis, into: early-onset (age 16) and late-onset (age ≥ 16) users. Differences between groups at baseline were studied based on sociodemographic, clinical, and cognitive variables. The groups were longitudinally (3-year) compared on cognitive variables.…
The formation of structurally relevant units in artificial grammar learning
2002
A total of 78 adult participants were asked to read a sample of strings generated by a finite state grammar and, immediately after reading each string, to mark the natural segmentation positions with a slash bar. They repeated the same task after a phase of familiarization with the material, which consisted, depending on the group involved, of learning items by rote, performing a short term matching task, or searching for the rules of the grammar. Participants formed the same number of cognitive units before and after the training phase, thus indicating that they did not tend to form increasingly large units. However, the number of different units reliably decreased, whatever the task that…
Familiarity-based recognition in the young, healthy elderly, mild cognitive impaired and Alzheimer's patients
2009
This study investigates the possible existence of deficits in familiarity in five samples of participants spanning a broad range of ages and cognitive states. Five groups of 16 participants with a diagnosis of multi-domain cognitive impairment with a slight or no deficit in memory, 16 multi-domain amnestic, and 16 Alzheimer's disease patients were compared in a recognition test with equivalent samples of old and young healthy participants. In one of the tests, participants studied words extracted from a restricted set of letters of the alphabet that were later mixed with new words from a different set. The unconscious use of the fluency produced by the repeated use of the set of letters was…
Integration of cognitive allocentric information in visuospatial short-term memory through the hippocampus
2005
Visuospatial short-term memory relies on a widely distributed neocortical network: some areas support the encoding process of the visually acquired spatial information, whereas other ares are more involved in the active maintenance of the encoded information. Recently, in a pointing to remembered targets task, it has been shown in healthy subjects that, for memory delays of 5 s, spatial errors are affected also by cognitive allocentric information, i.e., covert spatial information derived from a pure mental representation. We tested the effect of a lesion of the hippocampus on the accuracy of pointing movements toward remembered targets, with memory delays falling in the 0.5-30 s range. The…