Search results for "Memory"
showing 10 items of 2004 documents
Dissociable contributions of left and right dorsolateral prefrontal cortex in planning.
2010
It is well established that the mid-dorsolateral prefrontal cortex (dlPFC) plays a critical role in planning. Neuroimaging studies have yielded predominantly bilateral dlPFC activations, but the existence and nature of functionally specific contributions of left and right dlPFC have remained elusive. In recent experiments, 2 independent parameters have been identified which substantially determine planning: 1) the degree of interdependence between consecutive steps (search depth) and 2) the degree to which the configuration of the goal state renders the order of single steps either clearly evident or ambiguous (goal hierarchy). Thus, search depth affects the actual mental generation and eva…
The hippocampus is required for short-term topographical memory in humans.
2007
The hippocampus plays a crucial role within the neural systems for long-term memory, but little if any role in the short-term retention of some types of stimuli. Nonetheless, the hippocampus may be specialized for allocentric topographical processing, which impacts on short-term memory or even perception. To investigate this we developed performance-matched tests of perception (match-to-sample) and short-term memory (2 s delayed-match-to-sample) for the topography and for the nonspatial aspects of visual scenes. Four patients with focal hippocampal damage and one with more extensive damage, including right parahippocampal gyrus, were tested. All five patients showed impaired topographical m…
Primary motor area contribution to attentional reorienting after distraction
2008
The anatomical structures involved in distraction-related processing in the auditory domain were investigated using magnetoencephalography. Participants performed a duration-discrimination task on a sequence of 200 and 400 ms long tones. Infrequent (12%) task-irrelevant pitch changes resulted in slower discriminative responses and more errors. Event-related potentials to these changes show an increased N1, a mismatch negativity, a P3a, and a reorienting negativity. The event-related magnetic fields revealed focal activities in superior and medial temporal areas in the N1/mismatch negativity time range. No significant activity was found in the P3a interval. In the reorienting negativity inte…
Pitch accent type affects the N400 during referential processing
2010
Discourse processing depends on semantic memory as well as maintaining and updating of a mental model. Using event-related potentials, we investigated how a referent's information status (new, accessible, given) is processed in combination with three different prosodic realizations (an appropriate accent and two inappropriate accents). The data reveal a biphasic N400-late positivity pattern, indicating that prosodic information affects an early discourse linking stage, during which prominence information reflecting a referent's accessibility is computed (N400), and a later discourse updating stage, during which conflicts between prosodic information and a referent's actual information statu…
Working Memory in Children: A Time-Constrained Functioning Similar to Adults
2009
International audience; Within the Time-Based Resource-Sharing (TBRS) model, we tested a new conception of the relationships between processing and storage in which the core mechanisms of WM are time constrained. However, our previous studies were restricted to adults. The present study aimed at demonstrating that these mechanisms are present and functional before adulthood. For this purpose, we investigated the effect on maintenance of the duration of the attentional capture induced by processing. In two experiments using computer-paced WM span tasks, 10- year-old children were asked to maintain letters while performing spatial location judgments. The duration of this processing was manipu…
Incongruence Between Implicit Attachment Schemes and Unconscious Attachment Representations.
2019
Assessments based on reaction time and language-based interviews postulate that unconscious attachment processes be measured. Nevertheless, a possible empirical equivalence of these two approaches has not yet been investigated. To fill this void, the Adult Attachment Interview and the Implicit Association Test were implemented with a group of patients with panic disorder (n = 157, mean age = 29, SD = 2.47) based on the Structured Clinical Interview for DSM-IV, axis I and II disorders and a group of healthy individuals (n = 138). In total, the securely attached individuals showed significantly more positive attitudes toward their mother than the insecurely attached individuals. In the health…
Neural correlates of working memory dysfunction in first-episode schizophrenia patients: an fMRI multi-center study.
2005
Working memory dysfunction is a prominent impairment in patients with schizophrenia. Our aim was to determine cerebral dysfunctions by means of functional magnetic resonance imaging (fMRI) in a large sample of first-episode schizophrenia patients during a working memory task. 75 first-episode schizophrenia patients and 81 control subjects, recruited within a multi-center study, performed 2- and 0-back tasks while brain activation was measured with fMRI. In order to guarantee comparability between data quality from different scanners, we developed and adopted a standardized, fully automated quality assurance of scanner hard- and software as well as a measure for in vivo data quality. After t…
Altered effective connectivity during working memory performance in schizophrenia: a study with fMRI and structural equation modeling
2003
The present study aimed to explore altered effective connectivity in schizophrenic patients while performing a 2-back working memory task. Twelve right-handed, schizophrenic patients treated with typical or atypical antipsychotics and 6 healthy control subjects were studied with fMRI while performing a "2-back" working memory task. Effective connectivity within a cortical-subcortical-cerebellar network for mnemonic information processing was assessed and compared between both groups. The path model included cortico-cortical connections comprising the parietal association cortex, ventrolateral prefrontal cortex (VLPFC), and the dorsolateral prefrontal cortex (DLPFC) as well as a cortico-cere…
Single dose of l-dopa makes extinction memories context-independent and prevents the return of fear
2013
Traumatic events can engender persistent excessive fear responses to trauma reminders that may return even after successful treatment. Extinction, the laboratory analog of behavior therapy, does not erase conditioned fear memories but generates competing, fear-inhibitory "extinction memories" that, however, are tied to the context in which extinction occurred. Accordingly, a dominance of fear over extinction memory expression--and, thus, return of fear--is often observed if extinguished fear stimuli are encountered outside the extinction (therapy) context. We show that postextinction administration of the dopamine precursor L-dopa makes extinction memories context-independent, thus strongly…
Limitations of concurrently representing objects within view and in visual working memory
2020
AbstractRepresenting visibly present stimuli is as limited in capacity as representing invisible stimuli in visual working memory (WM). In this study, we explored whether concurrently representing stimuli within view affects representing objects in visual WM, and if so, whether this effect is modulated by the storage states (active and silent state) of memory contents? In experiment 1, participants were asked to perform the change-detect task in a simultaneous-representing condition in which WM content and the continuously-visible stimuli in view were simultaneously represented, as well as a baseline condition in which only the representations of visual WM content were maintained. The resul…