Role of medial cortical, hippocampal and striatal interactions during cognitive set-shifting

The past tense debate: Is phonological complexity the key to the puzzle?

“…We note that one of the reported regions (right IPL, BA40) in this contrast has previously been implicated in response inhibition (e.g. Garavan et al, 1999Garavan et al, , 2002Graham et al, 2009).…”

Prefrontal cortex and hippocampus in behavioural flexibility and posttraumatic functional recovery: Reversal learning and set-shifting in rats

“…Regarding the basal ganglia, especially the core of nucleus accumbens (as opposed to the shell) has been demonstrated to be implicated in this type of behavioural flexibility as its inactivation disrupts shifting from an egocentric response strategy to a visual-cue discrimination strategy (corresponding to our set-shift) and vice versa [Block et al, 2007;Floresco et al, 2006a]. The caudate nucleus of the striatum also appears to be implicated in strategy shifting as its activation peaks when the first negative feedback signalling the need for a strategy shift is given -while it is lowest once the rule has been identified [Graham et al, 2009]. It is also claimed that the caudate nucleus is involved during the planning of a set-shift, while the putamen participates during the execution of a set-shift [Monchi et al, 2006;Simard et al, 2011].…”

“…The increased perseveration often reported after hippocampal injury -regardless M a n u s c r i p t of whether the study designs dealt with reversal learning or set-shifting [Brady, 2009;Jarrard et al, 2012;Kosaki andWatanabe, 2012, Mogensen et al, 2007] -favours the hypothesis by Davidson and Jarrard [Davidson and Jarrard, 2004] suggesting that the hippocampal impairment seen in shifting tasks stems from an inability to suppress the previously learned strategy (due to deficient formation of inhibitory associations) [Chan et al, 2001]. This hypothesis is also strengthened by the neuroimaging data reported by Graham et al [Graham et al, 2009] who studied the activation pattern during cognitive set-shifting in the medial cortex, hippocampus and striatum and proposed that the hippocampus helps consolidate knowledge about the correct stimulus-stimulus associations, associations that become inappropriate once the shift is to take place.…”

A study of problems encountered in Granger causality analysis from a neuroscience perspective

“…Neuroscientists have applied Granger causality methods to diverse sources of data, including electroencephalography (EEG), magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI), and local field potentials (LFP). These studies have investigated functional neural systems at scales of organization from the cellular level (1-3) to whole-brain network activity (4), under a range of conditions, including sensory stimuli (5-7), varying levels of consciousness (8)(9)(10), cognitive tasks (11), and pathological states (12,13). In such analyses, the time series data are interpreted to reflect neural activity from a particular source, and Granger causality is used to characterize the directionality, directness, and dynamics of influence between sources.…”