Functional Significance of Striatal Responses during Episodic Decisions: Recovery or Goal Attainment?

Abstract

Memory retrieval is typically a goal-directed behavior, and as such, potentially influenced by reinforcement and motivation processes. Although striatal activation is often evident during memory retrieval, its functional significance remains unclear because typical memory paradigms do not control the motivational significance of memory decisions. We used event-related functional magnetic resonance imaging (fMRI) to investigate striatal activation during recognition with and without performance-linked monetary incentives. During initial performance in the absence of incentives, dorsal striatal activation for “Old” memory conclusions nonetheless exceeded that for “New” conclusions irrespective of the accuracy of these conclusions. In contrast, subsequent scans paired incentives with either “Old” or “New” conclusions and demonstrated greater activation for whichever judgment was potentially rewarded, both with and without performance feedback. The data demonstrate that striatal activation during recognition judgments does not signal monetary reward receipt, cognitive feedback, or successful episodic retrieval. Instead, it is heavily dependent upon satisfaction of the subjective goals of the observer.

Antiretroviral Adherence and the Nature of HIV-Associated Verbal Memory Impairment

“…Such an effect could account for our results, as the striatum has been shown to play a unique, although not completely direct, role in memory retrieval. 42,43 That said, our data cannot address the possible causal relationship between HAART adherence and HIV-associated memory impairment. The potential neural mechanism(s) by which HAART might improve or protect memory is currently unknown and remains a topic for future research.…”

Modeling Causal Relationship Between Brain Regions Within the Drug-Cue Processing Network in Chronic Cocaine Smokers

“…In controls, dorsal striatum served as an information hub and was driving the activation of hippocampus. Perhaps the activation of the dorsal striatum and its causal influence on hippocampus, and the subsequent activation of parahippocampal gyrus and amygdala, in controls may indicate their conscious effort to learn (ie, encode) the cocaine cues that were novel to them, as well as to retrieve any information relating to these cues from their long-term memory (Cohn et al, 2010;Han et al, 2010;Scimeca and Badre, 2012). Although speculative, we propose that the common causal pathway activated in both cocaine users and controls (ie, hippocampus → parahippocampal gyrus → orbital frontal cortex → ventral striatum) may indicate two different types of cognitive processing.…”

Novel Developments in Cognitive fMRI

“…Dissatisfaction with the limitations (and sterility) of this approach eventually resulted in its downfall, as researchers began to study internal states through sets of experiments that all converged on a common inference (Garner et al 1956). Recent examples of model-based approaches can be seen, albeit with a variety of labels, in many areas of recent cognitive neuroscience research: neuroeconomics (Kable and Glimcher 2007), memory retrieval (Han et al 2010), and even social cognition (Behrens et al 2009). …”