Load-Dependent Roles of Frontal Brain Regions in the Maintenance of Working Memory

Tuning down the emotional brain: An fMRI study of the effects of cognitive load on the processing of affective images

“…During the fourth time frame (t = 13-16 s), right dorsolateral frontal cortex (t(16) = 3.43, p = .003), right superior parietal cortex (t(16) = 2.43, p = .027), and left dorsal occipital cortex (t(16) = 2.52, p = .023) showed greater activation to negative pictures followed by a complex task rather than a simple task (see Table 4). These regions are known to be involved in cognitive processing and to respond to increasing task demands (De Fockert et al, 2001;Duncan and Owen, 2000;Prabhakaran et al, 2000;Rypma et al, 1999). Thus, as expected, performing complex arithmetic sums engaged brain regions that support cognitive processes.…”

“…We predicted that, relative to exposure to neutral pictures, exposure to negative pictures would activate both negative feelings and emotional brain circuits such as the amygdalae and the insulae (Phan et al, 2002). In addition, we predicted that task load would increase activation in brain regions implicated in cognitive processing, such as the dorsolateral frontal cortex, the superior parietal cortex, and the dorsal occipital cortex (Duncan and Owen, 2000;Rypma et al, 1999).…”

Processing of temporal duration information in working memory after frontodorsal tumour excisions

“…The importance of the frontal lobes for working memory functions on delay tasks had been demonstrated earlier in lesion-, imaging-and electrophysiological studies on humans and non-human primates (Fuster, 1984;Fuster, 1991;Goldman-Rakic, 1994;Rypma, Prabhakaran, Desmond, Glover, & Gabrieli, 1999;Ve erin et al, 1993;Wilson et al, 1993). The result of a non-specific degradation of working memory functions after frontal lobe lesion is compatible with recent studies indicating poor performance after frontal lobe lesions on temporal as well as on non-temporal tasks (Casini & Ivry, 1999;Mangels et al, 1998), especially when long ISIs were used.…”

Early emergence of deviant frontal fMRI activity for phonological processes in poor beginning readers

“…But semantic operations (Jobard et al, 2003;Poldrack et al, 1999;Vigneau et al, 2006) have often been associated with more ventral and anterior parts of the inferior frontal gyrus (Fiez, 1997;Vigneau et al, 2006). Apart from phonological and semantic processes several studies have also located specific language-related processes of verbal working memory in the inferior frontal gyrus (Cohen et al, 1997;Rypma et al, 1999). Since working memory load was matched across conditions in the present task, it seems unlikely that differences in verbal working memory involvement are responsible for the condition differences in the inferior frontal gyrus.…”