Science posts

See science posts on page 43 below.

    • 2013
    • Benjamin Baird et al
    • Medial and Lateral Networks in Anterior Prefrontal Cortex Support Metacognitive Ability for Memory and Perception
    • Convergent evidence indicates that frontopolar Brodmann area 10, and more generally the anterior prefrontal cortex (aPFC), supports the human capacity to monitor and reflect on cognition and experience. An important unanswered question, however, is whether aPFC is a homogeneous region that supports a general-purpose metacognitive ability or whether there could be regional specialization within aPFC with respect to specific types of metacognitive processes. Previous studies suggest that the lateral and medial subdivisions within aPFC may support metacognitive judgments of moment-to-moment perceptual processes and assessments of information from memory stored over longer time scales, respectively. Here we directly compared intraindividual variability in metacognitive capacity for perceptual decisions and memorial judgments and used resting-state functional connectivity (rs-fcMRI) to relate this variability to the connectivity of the medial and lateral regions of aPFC. We found a behavi..
    • 2007
    • Jean Decety et al
    • The Role of the Right Temporoparietal Junction in Social Interaction: How Low-Level Computational Processes Contribute to Meta-Cognition
    • Accumulating evidence from cognitive neuroscience indicates that the right inferior parietal cortex, at the junction with the posterior temporal cortex, plays a critical role in various aspects of social cognition such as theory of mind and empathy. With a quantitative meta-analysis of 70 functional neuroimaging studies, the authors demonstrate that this area is also engaged in lower-level (bottom-up) computational processes associated with the sense of agency and reorienting attention to salient stimuli. It is argued that this domain-general computational mechanism is crucial for higher level social cognitive processing.
    • 2014
    • Adrian W. Gilmore et al
    • The Contextual Association Network Activates More for Remembered than for Imagined Events
    • The human capacities to remember events from the past and imagine events in the future rely on highly overlapping neural substrates. Neuroimaging studies have revealed brain regions that are more active for imagined events than remembered events, but the reverse pattern has not been shown consistently. Given that remembered events tend to be associated with more contextual information ( Johnson et al. 1988), one might expect a set of regions to demonstrate greater activity for remembered events. Specifically, regions sensitive to the strength of contextual associations might be hypothesized to show greater activity for remembered events. The present experiment tests this hypothesis. fMRI was used to identify brain regions within the contextual association network ( Bar and Aminoff 2003); regions within this network were then examined to see whether they showed differential activity during remembering and imagining. Bilateral regions within the parahippocampal cortex and retrosplenial..
    • 2010
    • Charan Ranganath
    • Binding Items and Contexts
    • In order to remember a past event, the brain must not only encode the specific aspects of an event but also bind them in a manner that can later specify the spatiotemporal context in which event occurred. Here, I describe recent research aimed at characterizing the functional organization of two brain regions—the medial temporal lobes and the prefrontal cortex—that allow us to accomplish this task. Converging evidence indicates that different regions of the medial temporal lobes may form representations of items, contexts, and item-context bindings and that areas in the prefrontal cortex may implement working-memory control processes that allow us to build meaningful relationships between items that are encountered over time. The results are compatible with an emerging model that generates novel predictions at both the behavioral and neural levels.
    • 2010
    • Kestutis Kveragaa et al
    • Early onset of neural synchronization in the contextual associations network
    • Objects are more easily recognized in their typical context. However, is contextual information activated early enough to facilitate the perception of individual objects, or is contextual facilitation caused by postperceptual mechanisms? To elucidate this issue, we first need to study the temporal dynamics and neural interactions associated with contextual processing. Studies have shown that the contextual network consists of the parahippocampal, retrosplenial, and medial prefrontal cortices. We used functional MRI, magnetoencephalography, and phase synchrony analyses to compare the neural response to stimuli with strong or weak contextual associations. The context network was activated in functional MRI and preferentially synchronized in magnetoencephalography (MEG) for stimuli with strong contextual associations. Phase synchrony increased early (150–250 ms) only when it involved the parahippocampal cortex, whereas retrosplenial–medial prefrontal cortices synchrony was enhanced late..
    • 2007
    • Anthony J. Greene et al
    • Hippocampal differentiation without recognition: An fMRI analysis of the contextual cueing task
    • A central role of the hippocampus is to consolidate conscious forms of learning and memory, while performance on implicit tasks appears to depend upon other structures. Recently, considerable debate has emerged about whether hippocampal-dependent tasks necessarily entail task awareness. In the contextual cueing task, repetition facilitation is implicit, but impaired in patients with amnesia. Whether the hippocampus alone or other MTL structures are required is unclear. Event-related functional magnetic resonance imaging revealed hippocampal activity that differentiates novel from repeated arrays. This pattern of results was observed without recognition of the repeating arrays. This finding provides support for the claim that the hippocampus is involved in processes outside the domain of conscious learning and memory.
    • 2009
    • Sebastian J. Crutch et al
    • The different representational frameworks underpinning abstract and concrete knowledge: Evidence from odd-one-out judgements
    • Recent evidence from neuropsychological investigations of individuals with global aphasia and deep or deep-phonological dyslexia suggests that abstract and concrete concepts are underpinned by qualitat- ively different representational frameworks. Abstract words are represented primarily by their associ- ation to other words, whilst concrete words are represented primarily by their taxonomic similarity to one another. In the current study, we present the first evidence for this association/similarity distinc- tion to be gathered from healthy research participants. Using a semantic odd-one-out task, it is shown that normal participants identify associative connections more quickly than similarity-based connec- tions when processing abstract words, but that the pattern is reversed for concrete words. It is also demonstrated that the typical concrete-word advantage observed in many cognitive tasks is abolished and even reversed when participants have to comprehend the semantic associati..
    • 2014
    • Anna Mestres-Misse et al
    • Functional Neuroanatomy of Contextual Acquisition of Concrete and Abstract Words
    • The meaning of a novel word can be acquired by extract- ing it from linguistic context. Here we simulated word learn- ing of new words associated to concrete and abstract concepts in a variant of the human simulation paradigm that provided linguistic context information in order to characterize the brain systems involved. Native speakers of Spanish read pairs of sentences in order to derive the meaning of a new word that appeared in the terminal position of the sentences. fMRI revealed that learning the meaning associated to concrete and abstract new words was qualitatively different and re- cruited similar brain regions as the processing of real concrete and abstract words. In particular, learning of new concrete words selectively boosted the activation of the ventral ante- rior fusiform gyrus, a region driven by imageability, which has previously been implicated in the processing of concrete words.
    • 2014
    • Kris Baetens et al
    • Involvement of the mentalizing network in social and non-social high construal
    • The dorsomedial prefrontal cortex (dmPFC) is consistently involved in tasks requiring the processing of mental states, and much rarer so by tasks that do not involve mental state inferences. We hypothesized that the dmPFC might be more generally involved in high construal of stimuli, defined as the formation of concepts or ideas by omitting non-essential features of stimuli, irrespective of their social or non-social nature. In an fMRI study, we presented pictures of a person engaged in everyday activities (social stimuli) or of objects (non-social stimuli) and induced a higher level of construal by instructing participants to generate personality traits of the person or categories to which the objects belonged. This was contrasted against a lower level task where participants had to describe these same pictures visually. As predicted, we found strong involvement of the dmPFC in high construal, with substantial overlap across social and non-social stimuli, including shared activation..
    • 2013
    • Arnaud D’Argembeau et al
    • Brains creating stories of selves: the neural basis of autobiographical reasoning
    • Personal identity critically depends on the creation of stories about the self and one’s life. The present study investigates the neural substrates of autobiographical reasoning, a process central to the construction of such narratives. During functional magnetic resonance imaging scanning, participants approached a set of personally significant memories in two different ways: in some trials, they remembered the concrete content of the events (autobiographical remembering), whereas in other trials they reflected on the broader meaning and implications of their memories (autobiographical reasoning). Relative to remembering, autobiographical reasoning recruited a left-lateralized network involved in conceptual processing [including the dorsal medial prefrontal cortex (MPFC), inferior frontal gyrus, middle temporal gyrus and angular gyrus]. The ventral MPFC—an area that may function to generate personal/affective meaning—was not consistently engaged during autobiographical reasoning acr..

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