Editing Putamen (section)

==Role in learning==
In many studies, it has become apparent that the putamen plays a role in many types of learning. Some examples are listed below:

===Reinforcement and implicit learning===
Along with various types of movement, the putamen also affects reinforcement learning and [[implicit learning]].<ref name="Mark">{{cite journal | journal = Annu Rev Neurosci | year = 2002| volume = 25 | issue =  1| pages = 563–93 | title = Learning and memory functions of the Basal Ganglia | author = Packard MG |author2=Knowlton BJ  | pmid = 12052921 | doi =10.1146/annurev.neuro.25.112701.142937 }}</ref>

[[Reinforcement learning]] is interacting with the environment and catering actions to maximize the outcome. Implicit learning is a passive process where people are exposed to information and acquire knowledge through exposure. Although the exact mechanisms are not known, it is clear that dopamine and tonically active neurons play a key role here. Tonically active neurons are [[cholinergic]] [[interneurons]] that fire during the entire duration of the stimulus and fire at about 0.5–3 impulses per second. Phasic neurons are the opposite and only fire an action potential when movement occurs.<ref name="Yamada">{{cite journal | journal = Journal of Neuroscience | date = April 7, 2004 | volume = 24 | issue = 14 | pages = 3500–10 | title = Tonically active neurons in the primate caudate nucleus and putamen differentially encode instructed motivational outcomes of action | author = Yamada H |author2=Matsumoto N |author3=Kimura M  | pmid = 15071097 | doi =10.1523/JNEUROSCI.0068-04.2004 | pmc = 6729748 | doi-access = free }}</ref>

===Category learning===
One particular study used patients with focal lesions on the basal ganglia (specifically the putamen) due to [[stroke]] in order to study [[category learning]]. The advantage to using these types of patients is that dopaminergic projections to the [[prefrontal cortex]] are more likely to be intact. Also, in these patients, it is easier to relate specific brain structures to function because the lesion only occurs in a specific place. The goal of this study was to determine whether or not these lesions affect rule-based and information-integration task learning. Rule-based tasks are learned via hypothesis-testing dependent on working memory. Information-integration tasks are ones wherein the accuracy is maximized when information from two sources are integrated at a pre-decisional stage, which follows a procedural-based system.

Seven participants with basal ganglia [[lesion]]s were used in the experiment, along with nine control participants. It is important to note that the caudate was not affected. The participants were tested for each type of learning during separate sessions, so the information processes would not interfere with each other. During each session, participants sat in front of a computer screen and various lines were displayed. These lines were created by using a randomization technique where random samples were taken from one of four categories. For ruled-based testing, these samples were used to construct lines of various length and orientation that fell into these four separate categories. After the stimulus was displayed, the subjects were asked to press 1 of 4 buttons to indicate which category the line fell into. The same process was repeated for information-integration tasks, and the same stimuli were used, except that the category boundaries were rotated 45°. This rotation causes the subject to integrate the quantitative information about the line before determining what category it is in.

It was found that subjects in the experimental group were impaired while performing rule-based tasks, but not information-integration ones. After statistical testing, it was also hypothesized that the brain began using information-integration techniques to solve the rule-based learning tasks. Since rule-based tasks use the hypothesis-testing system of the brain, it can be concluded that the hypothesis-testing system of the brain was damaged/weakened. It is known that the caudate and working memories are part of this system. Therefore, it was confirmed that the putamen is involved in category learning, competition between the systems, feed-back processing in rule-based tasks, and is involved in the processing of pre-frontal regions (which relate to working memory and executive functioning). Now it is known that not only the basal ganglia and caudate affect category learning.<ref name="Ell">{{cite journal | journal = Neuropsychologia | year = 2006 | volume = 44 | issue = 10 | pages = 1737–51 | title = Focal putamen lesions impair learning in rule-based, but not information-integration categorization tasks | author = Ell SW |author2=Marchant NL |author3=Ivry RB  | pmid = 16635498 | doi =10.1016/j.neuropsychologia.2006.03.018 | s2cid = 16312162 | url = https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1028&context=psy_facpub }}</ref>