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Differential effects of dopamine-directed treatments on cognition.

Ashby FG, Valentin VV, von Meer SS - Neuropsychiatr Dis Treat (2015)

Bottom Line: It has wide-ranging effects on both cortical and subcortical brain regions and on many types of cognitive tasks that rely on a variety of different learning and memory systems.As a result, dopamine-directed treatments will have different effects on different types of cognitive behaviors.To predict what these effects will be, it is critical to understand: which memory system is mediating the behavior; the neural basis of the mediating memory system; the nature of the dopamine projections into that system; and the time course of dopamine after its release into the relevant brain regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, USA.

ABSTRACT
Dopamine, a prominent neuromodulator, is implicated in many neuropsychiatric disorders. It has wide-ranging effects on both cortical and subcortical brain regions and on many types of cognitive tasks that rely on a variety of different learning and memory systems. As neuroscience and behavioral evidence for the existence of multiple memory systems and their corresponding neural networks accumulated, so did the notion that dopamine's role is markedly different depending on which memory system is engaged. As a result, dopamine-directed treatments will have different effects on different types of cognitive behaviors. To predict what these effects will be, it is critical to understand: which memory system is mediating the behavior; the neural basis of the mediating memory system; the nature of the dopamine projections into that system; and the time course of dopamine after its release into the relevant brain regions. Consideration of these questions leads to different predictions for how changes in brain dopamine levels will affect automatic behaviors and behaviors mediated by declarative, procedural, and perceptual representation memory systems.

No MeSH data available.


Related in: MedlinePlus

Examples of rule-based and information-integration category structures.Notes: Each stimulus is a sine wave disk that varies across trials in the number of bars per disk (or bar narrowness) and bar orientation. For each task, three illustrative category A and category B stimuli are shown. The plus signs and open circles denote the specific values of all stimuli used in each task. In the rule-based task, only the number of bars per disk carries diagnostic category information, so the optimal strategy is to respond with a one-dimensional bar narrowness rule (thin vs thick). In the information-integration task, both the number of bars per disk and bar orientation carry useful but insufficient category information. The optimal strategy requires integrating information from both dimensions in a way that is impossible to describe verbally.
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f1-ndt-11-1859: Examples of rule-based and information-integration category structures.Notes: Each stimulus is a sine wave disk that varies across trials in the number of bars per disk (or bar narrowness) and bar orientation. For each task, three illustrative category A and category B stimuli are shown. The plus signs and open circles denote the specific values of all stimuli used in each task. In the rule-based task, only the number of bars per disk carries diagnostic category information, so the optimal strategy is to respond with a one-dimensional bar narrowness rule (thin vs thick). In the information-integration task, both the number of bars per disk and bar orientation carry useful but insufficient category information. The optimal strategy requires integrating information from both dimensions in a way that is impossible to describe verbally.

Mentions: More recently, however, it has been discovered that many more purely cognitive behaviors also recruit procedural learning and memory systems. The best evidence for this comes from information-integration category learning tasks. In category learning tasks, two or more categories of unfamiliar visual images are presented to the subject one at a time and the subject’s task is to use trial-by-trial feedback about response accuracy to learn to assign each image to its correct category. Information-integration category learning tasks are those in which accuracy is maximized only if information from two or more non-commensurable stimulus dimensions is integrated at some predecisional stage.41 Typically, the optimal strategy in information-integration tasks is difficult or impossible to describe verbally, so it is unlikely to be discovered via logical reasoning or by a process of explicit hypothesis generation and testing. Tasks in which these latter explicit strategies succeed are called rule-based category learning tasks. Figure 1 shows examples of rule-based and information-integration tasks that are frequently used in laboratory studies. A real life example of an information-integration task might be learning to discriminate between German shepherds and wolves. Much evidence suggests that success in information-integration tasks depends on procedural learning. For example, switching the locations of the response keys interferes with information-integration categorization, but not with rule-based categorization.39,42


Differential effects of dopamine-directed treatments on cognition.

Ashby FG, Valentin VV, von Meer SS - Neuropsychiatr Dis Treat (2015)

Examples of rule-based and information-integration category structures.Notes: Each stimulus is a sine wave disk that varies across trials in the number of bars per disk (or bar narrowness) and bar orientation. For each task, three illustrative category A and category B stimuli are shown. The plus signs and open circles denote the specific values of all stimuli used in each task. In the rule-based task, only the number of bars per disk carries diagnostic category information, so the optimal strategy is to respond with a one-dimensional bar narrowness rule (thin vs thick). In the information-integration task, both the number of bars per disk and bar orientation carry useful but insufficient category information. The optimal strategy requires integrating information from both dimensions in a way that is impossible to describe verbally.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4524582&req=5

f1-ndt-11-1859: Examples of rule-based and information-integration category structures.Notes: Each stimulus is a sine wave disk that varies across trials in the number of bars per disk (or bar narrowness) and bar orientation. For each task, three illustrative category A and category B stimuli are shown. The plus signs and open circles denote the specific values of all stimuli used in each task. In the rule-based task, only the number of bars per disk carries diagnostic category information, so the optimal strategy is to respond with a one-dimensional bar narrowness rule (thin vs thick). In the information-integration task, both the number of bars per disk and bar orientation carry useful but insufficient category information. The optimal strategy requires integrating information from both dimensions in a way that is impossible to describe verbally.
Mentions: More recently, however, it has been discovered that many more purely cognitive behaviors also recruit procedural learning and memory systems. The best evidence for this comes from information-integration category learning tasks. In category learning tasks, two or more categories of unfamiliar visual images are presented to the subject one at a time and the subject’s task is to use trial-by-trial feedback about response accuracy to learn to assign each image to its correct category. Information-integration category learning tasks are those in which accuracy is maximized only if information from two or more non-commensurable stimulus dimensions is integrated at some predecisional stage.41 Typically, the optimal strategy in information-integration tasks is difficult or impossible to describe verbally, so it is unlikely to be discovered via logical reasoning or by a process of explicit hypothesis generation and testing. Tasks in which these latter explicit strategies succeed are called rule-based category learning tasks. Figure 1 shows examples of rule-based and information-integration tasks that are frequently used in laboratory studies. A real life example of an information-integration task might be learning to discriminate between German shepherds and wolves. Much evidence suggests that success in information-integration tasks depends on procedural learning. For example, switching the locations of the response keys interferes with information-integration categorization, but not with rule-based categorization.39,42

Bottom Line: It has wide-ranging effects on both cortical and subcortical brain regions and on many types of cognitive tasks that rely on a variety of different learning and memory systems.As a result, dopamine-directed treatments will have different effects on different types of cognitive behaviors.To predict what these effects will be, it is critical to understand: which memory system is mediating the behavior; the neural basis of the mediating memory system; the nature of the dopamine projections into that system; and the time course of dopamine after its release into the relevant brain regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, USA.

ABSTRACT
Dopamine, a prominent neuromodulator, is implicated in many neuropsychiatric disorders. It has wide-ranging effects on both cortical and subcortical brain regions and on many types of cognitive tasks that rely on a variety of different learning and memory systems. As neuroscience and behavioral evidence for the existence of multiple memory systems and their corresponding neural networks accumulated, so did the notion that dopamine's role is markedly different depending on which memory system is engaged. As a result, dopamine-directed treatments will have different effects on different types of cognitive behaviors. To predict what these effects will be, it is critical to understand: which memory system is mediating the behavior; the neural basis of the mediating memory system; the nature of the dopamine projections into that system; and the time course of dopamine after its release into the relevant brain regions. Consideration of these questions leads to different predictions for how changes in brain dopamine levels will affect automatic behaviors and behaviors mediated by declarative, procedural, and perceptual representation memory systems.

No MeSH data available.


Related in: MedlinePlus