| 1. |
- Kompus, Kristiina, 1983-, et al.
(författare)
-
Distinct control networks for cognition and emotion in the prefrontal cortex
- 2009
-
Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 467:2, s. 76-80
-
Tidskriftsartikel (refereegranskat)abstract
- The activation of dorsolateral prefrontal cortex (dlPFC) has been suggested to reflect the engagement of a control mechanism for top-down biasing of context processing in resource-demanding memory tasks. Here we tested the hypothesis that the dlPFC subserves a similar function also in attention and emotion tasks. 18 healthy young adults were tested in a functional magnetic resonance imaging (fMRI) study where the demands for context processing were manipulated in three different cognitive domains: auditory attention, episodic retrieval, and emotion regulation. We found that the right dlPFC was jointly sensitive to increased cognitive demands in the attention and memory tasks. By contrast, increased demands in the emotion task (reappraisal) were associated with increased activity in ventromedial PFC along with decreased amygdala activity. Our findings of divergent prefrontal control networks for cognitive and emotional control extend previous separations of cognition and emotion in the anterior cingulate cortex.
|
|
| 2. |
- Kompus, Kristiina, 1983-, et al.
(författare)
-
Dynamic switching between semantic and episodic memory systems
- 2009
-
Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 47:11, s. 2252-2260
-
Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that episodic and semantic long-term memory systems interact during retrieval. Here we examined the flexibility of memory retrieval in an associative task taxing memories of different strength, assumed to differentially engage episodic and semantic memory. Healthy volunteers were pre-trained on a set of 36 face-name pairs over a 6-week period. Another set of 36 items was shown only once during the same time period. About 3 months after the training period all items were presented in a randomly intermixed order in an event-related fMRI study of face-name memory. Once presented items differentially activated anterior cingulate cortex and a right prefrontal region that previously have been associated with episodic retrieval mode. High-familiar items were associated with stronger activation of posterior cortices and a left frontal region. These findings fit a model of memory retrieval by which early processes determine, on a trial-by-trial basis, if the task can be solved by the default semantic system. If not, there is a dynamic shift to cognitive control processes that guide retrieval from episodic memory.
|
|
