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Spaced learning produces better learning performance than extended learning periods without or with little interruptions. This "spacing effect" exists on different time scales, ranging from seconds to months. We recently found large spacing effects with a hitherto rarely investigated 12-hours spacing interval. The present study tested for potentially larger learning effects in the temporal vicinity of 12 h and analyzed spacing effects separately for learning and forgetting. 102 participants learned 40 German-Japanese vocabulary pairs in separate conditions with 7.5 min and 4-, 8-, 12-, and 24-hours spacing intervals. Two final tests were executed after retention intervals of 24 h and 7 days. The 7.5-min spacing interval produced a steeper initial learning curve than all other spacing intervals. 24 h after the last learning unit, we found almost no forgetting in the 4-, 8- and 12-hours spacing conditions, but about 9.3% and 3.6% forgetting in the 7.5 min and 24 h spacing conditions. After 7 days, forgetting was in the range of 13% for all conditions between 4 and 24 h. The 7.5 min condition produced 34% forgetting. Our results indicate that spacing intervals in the range of 8 h ± 4 h provide high learning performance and can be easily integrated in our daily schedules.
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Cocaine-dependent individuals show altered brain activation during decision making. It is unclear, however, whether these activation differences are related to relapse vulnerability. This study tested the hypothesis that brain-activation patterns during reinforcement learning are linked to relapse 1 year later in individuals entering treatment for cocaine dependence. Subjects performed a Paper-Scissors-Rock task during functional magnetic resonance imaging (fMRI). A year later, we examined whether subjects had remained abstinent (n=15) or relapsed (n=15). Although the groups did not differ on demographic characteristics, behavioral performance, or lifetime substance use, abstinent patients reported greater motivation to win than relapsed patients. The fMRI results indicated that compared with abstinent individuals, relapsed users exhibited lower activation in (1) bilateral inferior frontal gyrus and striatum during decision making more generally; and (2) bilateral middle frontal gyrus and anterior insula during reward contingency learning in particular. Moreover, whereas abstinent patients exhibited greater left middle frontal and striatal activation to wins than losses, relapsed users did not demonstrate modulation in these regions as a function of outcome valence. Thus, individuals at high risk for relapse relative to those who are able to abstain allocate fewer neural resources to action-outcome contingency formation and decision making, as well as having less motivation to win on a laboratory-based task.
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- *Learning
- Abstinence (1)
- Adult (1)
- Brain/physiopathology (1)
- Cerebral Cortex/physiopathology (1)
- Cocaine dependence (1)
- Cocaine-Related Disorders/*physiopathology (1)
- Corpus Striatum/*physiopathology (1)
- Decision Making (1)
- Distributed-practice effect (1)
- Female (1)
- Forgetting (1)
- Frontal Lobe/physiopathology (1)
- Functional magnetic resonance imaging (1)
- Humans (2)
- Lag effect (1)
- Learning (1)
- Magnetic Resonance Imaging (1)
- Male (1)
- Middle Aged (1)
- Motivation (1)
- Recurrence (1)
- *Reinforcement, Psychology (1)
- Relapse (1)
- *Retention, Psychology (1)
- Reward (1)
- Spacing effect (1)
- Substance-Related Disorders/physiopathology (1)
- Testing effect (1)
- Vocabulary (1)