He basal ganglia are ML240 chemical information involved in the heightened risk for substance abuse. More recently, temperament differences in basal ganglia function have been observed during cognitive control tasks that traditionally engage the PFC. First, in their emotional conflict task, Jarcho and colleagues (2013) found that inhibited individuals had increased activationProg Neurobiol. Author manuscript; available in PMC 2016 April 01.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptClauss et al.Pagein the putamen during emotional conflict adaptation. Second, in their attentional control task, Jarcho and colleagues (2014) found that inhibited individuals had increased activation during attentional control to fear stimuli in the caudate and ventral striatum, and decreased activation during attention control in the happy condition in the putamen. While the basal ganglia have traditionally been ascribed a role in motor control and reward processing, these subcortical brain Procyanidin B1MedChemExpress Procyanidin B1 regions are strongly connected to multiple PFC regions (Di Martino et al., 2008; Haber, 2003; Leh icy et al., 2004), forming fronto-striatal loops that subserve attention, learning, executive control and cognition (Leisman et al., 2014). Thus, increased activation of basal ganglia regions during both reward anticipation and cognitive control tasks may reflect inhibitory control functions of both the basal ganglia and PFC. 2.1.4. Cerebellum–Emerging evidence suggests that alterations in cerebellar activity may also contribute to inhibited temperament. Blackford et al. (2009) first reported cerebellar hyperactivity in inhibited young adults during face viewing. This finding has been replicated and extended by another group who found that highly inhibited adults had heightened cerebellar activation to both novel faces and novel scenes (Caulfield and Servatius, 2013). Finally, in an independent sample we have replicated our original finding, showing sustained activation to familiar faces in the cerebellum, similar to the pattern observed in the amygdala (Blackford et al., 2011). These findings may be driven by structural and functional connectivity with the amygdala (Clauss et al., 2014b; Roy et al., 2009); however, the cerebellum may also make a distinct contribution to inhibited temperament through its role in learning and attention. The cerebellum, Latin for “little brain”, has received the most attention for its role in motor function. However, similar to emerging understanding of the basal ganglia, it is now recognized that the cerebellum contributes broadly to cognition and emotion including learning, attention, emotion processing, and emotion control. A recent review provides intriguing evidence that the alterations in cerebellar function confers risk for anxiety disorders through enhanced avoidance learning (Caulfield and Servatius, 2013). Thus, alterations in cerebellar function observed in inhibited temperament may be one neurobiological path towards heightened risk for anxiety. 2.1.5. Functional Connectivity–To date, neuroimaging studies of inhibited temperament have clearly demonstrated differences in brain function in specific regions. However, connections between these regions have remained largely unstudied. In order to fully understand the inhibited brain, it is critical to investigate neural circuits because activity in one brain region influences activity in many other regions. Functional MRI can be used to assess functional connectivity, a measure of the.He basal ganglia are involved in the heightened risk for substance abuse. More recently, temperament differences in basal ganglia function have been observed during cognitive control tasks that traditionally engage the PFC. First, in their emotional conflict task, Jarcho and colleagues (2013) found that inhibited individuals had increased activationProg Neurobiol. Author manuscript; available in PMC 2016 April 01.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptClauss et al.Pagein the putamen during emotional conflict adaptation. Second, in their attentional control task, Jarcho and colleagues (2014) found that inhibited individuals had increased activation during attentional control to fear stimuli in the caudate and ventral striatum, and decreased activation during attention control in the happy condition in the putamen. While the basal ganglia have traditionally been ascribed a role in motor control and reward processing, these subcortical brain regions are strongly connected to multiple PFC regions (Di Martino et al., 2008; Haber, 2003; Leh icy et al., 2004), forming fronto-striatal loops that subserve attention, learning, executive control and cognition (Leisman et al., 2014). Thus, increased activation of basal ganglia regions during both reward anticipation and cognitive control tasks may reflect inhibitory control functions of both the basal ganglia and PFC. 2.1.4. Cerebellum–Emerging evidence suggests that alterations in cerebellar activity may also contribute to inhibited temperament. Blackford et al. (2009) first reported cerebellar hyperactivity in inhibited young adults during face viewing. This finding has been replicated and extended by another group who found that highly inhibited adults had heightened cerebellar activation to both novel faces and novel scenes (Caulfield and Servatius, 2013). Finally, in an independent sample we have replicated our original finding, showing sustained activation to familiar faces in the cerebellum, similar to the pattern observed in the amygdala (Blackford et al., 2011). These findings may be driven by structural and functional connectivity with the amygdala (Clauss et al., 2014b; Roy et al., 2009); however, the cerebellum may also make a distinct contribution to inhibited temperament through its role in learning and attention. The cerebellum, Latin for “little brain”, has received the most attention for its role in motor function. However, similar to emerging understanding of the basal ganglia, it is now recognized that the cerebellum contributes broadly to cognition and emotion including learning, attention, emotion processing, and emotion control. A recent review provides intriguing evidence that the alterations in cerebellar function confers risk for anxiety disorders through enhanced avoidance learning (Caulfield and Servatius, 2013). Thus, alterations in cerebellar function observed in inhibited temperament may be one neurobiological path towards heightened risk for anxiety. 2.1.5. Functional Connectivity–To date, neuroimaging studies of inhibited temperament have clearly demonstrated differences in brain function in specific regions. However, connections between these regions have remained largely unstudied. In order to fully understand the inhibited brain, it is critical to investigate neural circuits because activity in one brain region influences activity in many other regions. Functional MRI can be used to assess functional connectivity, a measure of the.