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An Information-Theoretical Approach to Contextual Processing in the Human Brain: Evidence from Prefrontal Lesions

An Information-Theoretical Approach to Contextual Processing in the Human Brain: Evidence from Prefrontal Lesions,10.1093/cercor/bhm111,Cerebral Corte

An Information-Theoretical Approach to Contextual Processing in the Human Brain: Evidence from Prefrontal Lesions   (Citations: 16)
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Context shapes perception, thought, and action, but little is known about the neural mechanisms supporting these modulations. Here, we addressed the role of lateral prefrontal cortex (PFC) in context updating and maintenance from an information-theoretic perspec- tive. Ten patients with PFC lesions and 10 age-matched controls responded to bilaterally displayed visual targets intermixed with repetitive and novel distracters in 2 different task contexts. In a predictable context, targets were always preceded by a novel event, whereas this temporal contingency was removed in an unpredictable context condition. We applied information theory to the analysis and interpretation of behavioral and electrophysiolog- ical data. The results revealed deficits in both the selection and the suppression of familiar versus novel information mainly observed at the visual hemifield contralateral to PFC damage due to disrupted frontocortical and frontosubcortical connectivity. The findings support a deficit in the representation of the temporal contingency between contextually related novel and familiar stimulation sub- sequent to lateral PFC damage.
Journal: Cerebral Cortex - CEREB CORTEX , vol. 17, no. Supplement, pp. i51-i60, 2007
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    • ...Although in the current sample of CUD these two findings were not statistically related, these results are generally in line with lesion studies, where, compared with controls, patients with frontal lesions manifest deficits in P300 (P3b) amplitudes in response to predictive contextual processing cues (Fogelson, Shah, Scabini, & Knight, 2009; Barcelo & Knight, 2007; although see Knight, 1984, an earlier study that showed null effects of lateral PFC lesions on the P300 [P3b]; here, effects were in the expected direction [smaller P3b amplitudes compared with controls] but significant differences were primarily confined to the P3a, which peaks earlier than the P3b [described in this study] and primarily reflects an orienting response to unexpected, novel, or infrequent stimuli)...

    Muhammad A. Parvazet al. Structural Integrity of the Prefrontal Cortex Modulates Electrocortica...

    • ...In particular, studies with lesion patients (eg, Barcelo & Knight, 2007) may elucidate the necessary contribution of the regions activated during the distinct trial types (as revealed by previous fMRI work with the paradigm; Cools et al, 2002) both to FRN and P3 generation and to behavior...

    Henry W. Chaseet al. Feedback-related Negativity Codes Prediction Error but Not Behavioral ...

    • ...This set-shifting mechanism is fast and short-lived and depends on an intact lateral prefrontal cortex (Miller, 2000; Milner, 1963; Shallice et al., 2008), but also on a distributed network of cortical and subcortical structures necessary for processing novelty at the highest level of neural representation (Barceló & Knight, 2007; Ranganath & Rainer, 2003)...
    • ...Moreover, even if this set-shifting mechanism develops within a few milliseconds, it is most likely accompanied by parallel accessory processes, as revealed by lesion studies (Barceló & Knight, 2007; Shallice et al., 2008) and as indexed by overlapping slow ERP negativities (Barceló et al., 2006; Nicholson et al., 2005)...

    Erika Nyhuset al. The Wisconsin Card Sorting Test and the cognitive assessment of prefro...

    • ...Such sequential changes in event expectancy may be formally expressed as changes in the amount of novelty or surprise (Baldi, 2005), or as the mutual information between sensory and task representations estimated over the course of an experiment (Koechlin & Summerfield, 2007), a notion recently adopted to quantify the information processing resources associated with task-switching operations and concurrent brain activations (Barceló ...
    • ...However, most past ERP studies used single task settings like oddball tasks, and could not decide whether the sequential effects of novelty P3 (P300) reflect the updating of only sensory, or also task representations (Barceló & Knight, 2007; Barceló et al., 2008; cf., Donchin, 1981)...

    José A. Periáñezet al. Updating sensory versus task representations during task-switching: In...

    • ...ERP and neurophysiological data from neurological patients with LFPC damage also support a role of this brain region in contextual processing (Barcelo & Knight, 2007)...

    Noa Fogelsonet al. Multimodal Effects of Local Context on Target Detection: Evidence from...

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