An information-theoretical approach to contextual processing in the human brain: evidence from prefrontal lesions.

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 perspective. 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 electrophysiological 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 subsequent to lateral PFC damage.