Category Archives: Research

Proper nutrition for brain health

In a 2008 meta study of 160 papers on food’s affect on the brain, researcher Fernando Gómez-Pinilla found some foods that my help with memory and cognition while avoiding depression and Alzheimer’s disease.  Here is a short summary of the paper’s findings.   Below is a list of the foods and behaviors that can affect brain health.

  • Omega-3 fatty acids from fish(Salmon)
  • Folic acid
  • Turmeric
  • Intermittent caloric restriction and meal skipping
  • Exercise
  • A enough sleep

Study: Time may enhance native-like neural responses

Second Language Processing Shows Increased Native-Like Neural Responses after Months of No Exposure

Kara Morgan-Short, Ingrid Finger, Sarah Grey, Michael T. Ullman

Although learning a second language (L2) as an adult is notoriously difficult, research has shown that adults can indeed attain native language-like brain processing and high proficiency levels. However, it is important to then retain what has been attained, even in the absence of continued exposure to the L2—particularly since periods of minimal or no L2 exposure are common. This event-related potential (ERP) study of an artificial language tested performance and neural processing following a substantial period of no exposure. Adults learned to speak and comprehend the artificial language to high proficiency with either explicit, classroom-like, or implicit, immersion-like training, and then underwent several months of no exposure to the language. Surprisingly, proficiency did not decrease during this delay. Instead, it remained unchanged, and there was an increase in native-like neural processing of syntax, as evidenced by several ERP changes—including earlier, more reliable, and more left-lateralized anterior negativities, and more robust P600s, in response to word-order violations. Moreover, both the explicitly and implicitly trained groups showed increased native-like ERP patterns over the delay, indicating that such changes can hold independently of L2 training type. The results demonstrate that substantial periods with no L2 exposure are not necessarily detrimental. Rather, benefits may ensue from such periods of time even when there is no L2 exposure. Interestingly, both before and after the delay the implicitly trained group showed more native-like processing than the explicitly trained group, indicating that type of training also affects the attainment of native-like processing in the brain. Overall, the findings may be largely explained by a combination of forgetting and consolidation in declarative and procedural memory, on which L2 grammar learning appears to depend. The study has a range of implications, and suggests a research program with potentially important consequences for second language acquisition and related fields

Study: Increasing Retention Without Increasing Study Time

Increasing Retention Without Increasing Study Time
Doug Rohrer and Harold Pashler
University of South Florida and
University of California, San Diego


Because people forget much of what they learn, students could benefit from learning strategies that yield long-lasting knowledge. Yet surprisingly little is known about how long-term retention is most efficiently achieved. Here we examine how retention is affected by two variables: the duration of a study session and the temporal distribution of study time across multiple sessions. Our results suggest that a single session devoted to the study of some material should continue long enough to ensure that mastery is achieved but that immediate further study of the same material is an inefficient use of time. Our data also show that the benefit of distributing a fixed amount of study time across two study sessions—the spacing effect —depends jointly on the interval between study sessions and the interval between study and test. We discuss the practical implications of both findings, especially in regard to mathematics learning.

Study: Difficulty in practice retrieval correlates with higher test performance.

Testing the retrieval effort hypothesis: Does greater difficulty correctly recalling information lead to higher levels of memory?

Mary A. Pyc, ,
Katherine A. Rawson


Although substantial research has demonstrated the benefits of retrieval practice for promoting memory, very few studies have tested theoretical accounts of this effect. Across two experiments, we tested a hypothesis that follows from the desirable difficulty framework [Bjork, R. A. (1994). Memory and metamemory considerations in the training of human beings. In J. Metcalfe, A. Shimamura, (Eds.), Metacognition: Knowing about knowing (pp. 185–205). Cambridge, MA: MIT Press], the retrieval effort hypothesis, which states that difficult but successful retrievals are better for memory than easier successful retrievals. To test the hypothesis, we set up conditions under which retrieval during practice was successful but differentially difficult. Interstimulus interval (ISI) and criterion level (number of times items were required to be correctly retrieved) were manipulated to vary the difficulty of retrieval. In support of the retrieval effort hypothesis, results indicated that as the difficulty of retrieval during practice increased, final test performance increased. Longer versus shorter ISIs led to more difficulty retrieving items, but higher levels of final test performance. Additionally, as criterion level increased, retrieval was less difficult, and diminishing returns for final test performance were observed.

Study: Lack of sleep impairs formation of new memories

A deficit in the ability to form new human memories without sleep

Seung-Schik Yoo1, Peter T Hu2, Ninad Gujar2, Ferenc A Jolesz1 & Matthew P Walker2


Evidence indicates that sleep after learning is critical for the subsequent consolidation of human memory. Whether sleep before learning is equally essential for the initial formation of new memories, however, remains an open question. We report that a single night of sleep deprivation produces a significant deficit in hippocampal activity during episodic memory encoding, resulting in worse subsequent retention. Furthermore, these hippocampal impairments instantiate a different pattern of functional connectivity in basic alertness networks of the brainstem and thalamus. We also find that unique prefrontal regions predict the success of encoding for sleep-deprived individuals relative to those who have slept normally. These results demonstrate that an absence of prior sleep substantially compromises the neural and behavioral capacity for committing new experiences to memory. It therefore appears that sleep before learning is critical in preparing the human brain for next-day memory formation—a worrying finding considering society’s increasing erosion of sleep time.

Study: People learn best when they are active participants.

Four Principles of Memory Improvement: A Guide to Improving Learning Efficiency

Bennett L. Schwartz – Florida International University, USA
Lisa K. Son – Barnard College, USA
Nate Kornell – Williams College, USA
Bridgid Finn – Washington University, USA

Recent advances in memory research suggest methods that can be applied toenhance educational practices. We outline four principles of memory improvementthat have emerged from research: 1) process material actively, 2) practice retrieval,3) use distributed practice, and 4) use metamemory. Our discussion of eachprinciple describes current experimental research underlying the principle andexplains how people can take advantage of the principle to improve their learning.The techniques that we suggest are designed to increase efficiency—that is, toallow a person to learn more, in the same unit of study time, than someone usingless efficient memory strategies. A common thread uniting all four principles isthat people learn best when they are active participants in their own learning.

Study: Incremental hints help in retaining information

Scaffolding feedback to maximize long-term error correction.

Bridgid Finn and Janet Metcalfe
Washington University, St. Louis, Missouri

Columbia University, New York, New York Scaffolded feedback was tested against three other feedback presentation methods (standard corrective feed – back, minimal feedback, and answer-until-correct multiple-choice feedback) over both short- and long-term retention intervals in order to assess which method would produce the most robust gains in error correction. Scaffolded feedback was a method designed to take advantage of the benefits of retrieval practice by providing incremental hints until the correct answer could be self-generated. In Experiments 1 and 3, on an immediate test, final memory for the correct answer was lowest for questions given minimal feedback, moderate for the answer-until-correct condition, and equally high in the scaffolded feedback condition and the standard feedback condition. However, tests of the maintenance of the corrections over a 30-min delay (Experiment 2) and over a 1-day delay (Experiment 3) demonstrated that scaffolded feedback gave rise to the best memory for the correct answers at a delay.

Study: A 3 second delay could enhance fact retention.

Delaying feedback by three seconds benefits retention of face – name pairs: the role of active anticipatory processing

Shana K. Carpenter & Edward Vul

In three experiments, we used face – name learning toexamine the puzzling feedback delay benefit — the tendency for feedback to be more effective when it is delayed rather than presented immediately. In Experiment 1 , we found that feedback presented after a 3-s blank screen was more effective than feedback presented immediately, even after controlling for the exposure time to the material. In Experiment 2 , we replicated the benefit of a feedback delay even when participants were given extra time to view the feedback or to try to retrieve the answer, indicating that this benefit is specific to a delay before feedback. Finally, in Experiment 3 , we showed that the 3-s delay is beneficial only if it involves a blank screen, not if the delay is filled with an unrelated distracter task. These results suggest that the feedback delay benefit in this paradigm could arise from an active anticipatory process that occurs during the delay.

Study: Does Incorrect Guessing Impair Fact Learning?

Does Incorrect Guessing Impair Fact Learning?

Sean H. K. Kang and Harold Pashler – University of California, San Diego
Nicholas J. Cepeda – York University
Doug Rohrer – University of South Florida
Shana K. Carpenter – Iowa State University
Michael C. Mozer – University of Colorado, Boulder

Taking a test has been shown to produce enhanced retention of the retrieved information. On tests, however, students often encounter questions the answers for which they are unsure. Should they guess anyway, even if they are likely to answer incorrectly? Or are errors engrained, impairing subsequent learning of the correct answer? We sought to answer this question in 3 experiments. In Experiments 1 and 2, subjects read 80 obscure facts (e.g., “Where is Disko Island? Greenland”) and then took a cued recall test. When a subject reported being unable to answer a question, on a randomly chosen half of those questions the computer program insisted upon a guess. Corrective feedback was provided either immediately (Experiment 1) or after a delay (Experiment 2). Forced guessing did not affect subjects’ performance on a final test given 1 day later. We extended the investigation to more complex material in Experiment 3. Subjects saw a question (e.g., “Why do ice cubes often pop as they melt in your drink?”) and its answer, but for half of the questions, subjects did not see the answer until they first provided a plausible explanation. On a test administered either on the same day or 1 week later, recall performance was again unaffected by a prior wrong guess.

Study: Do Unsuccessful Retrieval Attempts Enhance Learning?

The Pretesting Effect: Do Unsuccessful Retrieval Attempts Enhance Learning?

Lindsey E. Richland – University of California, Irvine
Nate Kornell – Williams College
Liche Sean Kao – University of California, Irvine

Testing previously studied information enhances long-term memory, particularly when the information is successfully retrieved from memory. The authors examined the effect of unsuccessful retrieval attempts on learning. Participants in 5 experiments read an essay about vision. In the test condition, they were asked about embedded concepts before reading the passage; in the extended study condition, they were given a longer time to read the passage. To distinguish the effects of testing from attention direction, the authors emphasized the tested concepts in both conditions, using italics or bolded keywords or, in Experiment 5, by presenting the questions but not asking participants to answer them before reading the passage. Posttest performance was better in the test condition than in the extended study condition in all experiments—a pretesting effect— even though only items that were not successfully retrieved on the pretest were analyzed. The testing effect appears to be attributable, in part, to the role unsuccessful tests play in enhancing future learning.