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From creation to consolidation: a novel framework for memory processing.

Robertson EM - PLoS Biol. (2009)

View Article: PubMed Central - PubMed

Affiliation: Berenson-Allen Centerfor Non-Invasive Brain Stimulation, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA. emrobert@bidmc.harvard.edu

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These studies have contrasted the patterns of activation before and after consolidation to reveal how the brain has been changed by consolidation... Yet just because the activation of a brain area is changed by consolidation does not mean that area was responsible for supporting consolidation... Disrupting the function of these activated areas, by using TMS or through lesion studies, would determine which areas are necessary for consolidation... Thus, the challenge for future studies is to identify those circuits activated during consolidation, as opposed to those circuits altered by consolidation, and use this as a foundation to define those circuits making a functional contribution to consolidation... These motor skill components are processed offline over different brain states (i.e., sleep versus wakefulness), and so differences in the relative size of these component may restrict the benefits of consolidation to a specific brain state... Potentially, this leads to motor skill acquisition that is predominately goal-based, and as this component is preferentially processed over sleep, to a task that shows sleep-dependent consolidation (; see also )... These heterogeneous changes in functional connectivity during NREM sleep may support reduced connectivity between memory systems, allowing disengagement, while simultaneously supporting enhanced or maintained connectivity within memory systems, allowing the offline processing necessary for memory consolidation... Alternatively, a decrease in functional connectivity may be associated with a specific sleep stage—such as NREM—while other sleep stages support the offline processing within specific memory systems... This alternative implies that when declarative and procedural memories are acquired simultaneously, consolidation will be dependent upon NREM sleep when memory systems are disengaged... Consistent with this prediction are observations that the consolidation of motor skills, when acquired along with declarative knowledge for the skill, is correlated with NREM sleep, whereas when the same motor skill is acquired in isolation, its subsequent consolidation is correlated with REM sleep... Evidence that the memory processing benefits of sleep can be replicated over wakefulness through the loss of declarative knowledge (, Figure 3) implies that the loss of declarative knowledge may be critical for memory processing during sleep... Yet the sleep-related memory processing benefits can occur without a permanent loss of declarative knowledge... Yet this unique framework extends beyond accounting for observations by also making experimentally testable predictions for future work (Box 6)... Direct evidence for a differential organization supporting the offline processing of declarative memories is awaited, and a greater understanding of the relationship between biological events, such as decreases in functional connectivity and the disengagement between memory systems during sleep, is required.

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Memory System Interactions during Consolidation(A) Our behaviors are frequently supported by a blend of declarative (D) and procedural (P) knowledge. In such behaviors, procedural (ΔP, blue bar) and declarative (ΔD, red bar) knowledge change little over wakefulness. (B) When the declarative component of such behaviors is knocked out—for example, by learning an interfering word list—there is a substantial enhancement in motor performance. This implies that declarative knowledge inhibits motor consolidation over wakefulness [48].
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pbio-1000019-g003: Memory System Interactions during Consolidation(A) Our behaviors are frequently supported by a blend of declarative (D) and procedural (P) knowledge. In such behaviors, procedural (ΔP, blue bar) and declarative (ΔD, red bar) knowledge change little over wakefulness. (B) When the declarative component of such behaviors is knocked out—for example, by learning an interfering word list—there is a substantial enhancement in motor performance. This implies that declarative knowledge inhibits motor consolidation over wakefulness [48].

Mentions: When a motor skill is acquired along with declarative knowledge—as occurs during explicit learning—removing or “knocking out” the declarative memory should induce offline motor memory processing, leading to enhanced performance (Box 3 and Figure 3). Consistent with this prediction, when declarative knowledge for a previously acquired motor skill was knocked out, participants' motor skill was enhanced [48]. Disrupting declarative knowledge for the motor sequence was achieved by having participants learn a list of words. The declarative knowledge for the list of words interfered with and so reduced participants' declarative knowledge for the 12-item sequence from 7.3 ± 0.9 to 4.0 ± 0.8 items. In principle, any intervention that disrupts declarative knowledge should result in the offline enhancement of motor skill. In contrast, when declarative knowledge for the motor skill is not disrupted, there is no enhancement of motor skill. Thus, interactions occurring between memory systems can play an important role in controlling the processing of memories after their acquisition.


From creation to consolidation: a novel framework for memory processing.

Robertson EM - PLoS Biol. (2009)

Memory System Interactions during Consolidation(A) Our behaviors are frequently supported by a blend of declarative (D) and procedural (P) knowledge. In such behaviors, procedural (ΔP, blue bar) and declarative (ΔD, red bar) knowledge change little over wakefulness. (B) When the declarative component of such behaviors is knocked out—for example, by learning an interfering word list—there is a substantial enhancement in motor performance. This implies that declarative knowledge inhibits motor consolidation over wakefulness [48].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2631067&req=5

pbio-1000019-g003: Memory System Interactions during Consolidation(A) Our behaviors are frequently supported by a blend of declarative (D) and procedural (P) knowledge. In such behaviors, procedural (ΔP, blue bar) and declarative (ΔD, red bar) knowledge change little over wakefulness. (B) When the declarative component of such behaviors is knocked out—for example, by learning an interfering word list—there is a substantial enhancement in motor performance. This implies that declarative knowledge inhibits motor consolidation over wakefulness [48].
Mentions: When a motor skill is acquired along with declarative knowledge—as occurs during explicit learning—removing or “knocking out” the declarative memory should induce offline motor memory processing, leading to enhanced performance (Box 3 and Figure 3). Consistent with this prediction, when declarative knowledge for a previously acquired motor skill was knocked out, participants' motor skill was enhanced [48]. Disrupting declarative knowledge for the motor sequence was achieved by having participants learn a list of words. The declarative knowledge for the list of words interfered with and so reduced participants' declarative knowledge for the 12-item sequence from 7.3 ± 0.9 to 4.0 ± 0.8 items. In principle, any intervention that disrupts declarative knowledge should result in the offline enhancement of motor skill. In contrast, when declarative knowledge for the motor skill is not disrupted, there is no enhancement of motor skill. Thus, interactions occurring between memory systems can play an important role in controlling the processing of memories after their acquisition.

View Article: PubMed Central - PubMed

Affiliation: Berenson-Allen Centerfor Non-Invasive Brain Stimulation, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA. emrobert@bidmc.harvard.edu

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Please rate it.

These studies have contrasted the patterns of activation before and after consolidation to reveal how the brain has been changed by consolidation... Yet just because the activation of a brain area is changed by consolidation does not mean that area was responsible for supporting consolidation... Disrupting the function of these activated areas, by using TMS or through lesion studies, would determine which areas are necessary for consolidation... Thus, the challenge for future studies is to identify those circuits activated during consolidation, as opposed to those circuits altered by consolidation, and use this as a foundation to define those circuits making a functional contribution to consolidation... These motor skill components are processed offline over different brain states (i.e., sleep versus wakefulness), and so differences in the relative size of these component may restrict the benefits of consolidation to a specific brain state... Potentially, this leads to motor skill acquisition that is predominately goal-based, and as this component is preferentially processed over sleep, to a task that shows sleep-dependent consolidation (; see also )... These heterogeneous changes in functional connectivity during NREM sleep may support reduced connectivity between memory systems, allowing disengagement, while simultaneously supporting enhanced or maintained connectivity within memory systems, allowing the offline processing necessary for memory consolidation... Alternatively, a decrease in functional connectivity may be associated with a specific sleep stage—such as NREM—while other sleep stages support the offline processing within specific memory systems... This alternative implies that when declarative and procedural memories are acquired simultaneously, consolidation will be dependent upon NREM sleep when memory systems are disengaged... Consistent with this prediction are observations that the consolidation of motor skills, when acquired along with declarative knowledge for the skill, is correlated with NREM sleep, whereas when the same motor skill is acquired in isolation, its subsequent consolidation is correlated with REM sleep... Evidence that the memory processing benefits of sleep can be replicated over wakefulness through the loss of declarative knowledge (, Figure 3) implies that the loss of declarative knowledge may be critical for memory processing during sleep... Yet the sleep-related memory processing benefits can occur without a permanent loss of declarative knowledge... Yet this unique framework extends beyond accounting for observations by also making experimentally testable predictions for future work (Box 6)... Direct evidence for a differential organization supporting the offline processing of declarative memories is awaited, and a greater understanding of the relationship between biological events, such as decreases in functional connectivity and the disengagement between memory systems during sleep, is required.

Show MeSH