As time passes, details in memories degrade. The memory of lunch with a friend is still with you a week later, but do you recall the color of the shirt he wore?

Ask a witness to a crime what they saw immediately following the event and they will recall more detail than they would if you waited several days or a week to ask them to recount their memories. It seems a simple concept, but often witnesses are only interviewed briefly at the crime scene. The full interview may not take place for several days. By this time, many of the important details about people and events have been forgotten. The more time that elapses between the event and being asked to fully recall the details, the less accurate the report is likely to be.

With funding from the British Academy and working with police forces in England and Scotland, Dr Lorraine Hope from the University of Portsmouth and collaborators Dr Fiona Gabbert (University of Abertay) and Professor Ronald Fisher (Florida International University) have developed the Self Administered Interview. Tests conducted using simulated crime scenes, showed that recall concerning the events was 42-44% more accurate when witnesses used the SAI following the event. A second test showed that even a week later, accuracy for details and people involved was 30% higher for those who used the SAI than for witnesses who were simply asked to “tell us all that you can remember”.

Memory decay happens very quickly in the first few days following an event and eventually slows and levels off. This means that over time, witnesses memories of events will include the basic framework of the event but be devoid of details they might have recalled if they had the opportunity to record their memories before the information is forgotten. Going over the details sooner helps strengthen and protect the memory, guarding it from the natural process of forgetting.

Scientists develop new tool to ‘freeze’ crime scene memories

Have you ever felt that your mind gets hemmed in by your congested office? Do you crave some wide-open space in which to let your mind wander? If you’ve ever felt that small spaces cramp your style and your thought processes, there’s evidence you may be right.

Researchers at the University of Minnesota say that ceiling height has an influence on how we act and think and even on what we buy.

Their research shows that consumers are likely to buy more in a retail space that has high ceilings. They contend that high-ceilings and the space they lend lead people to think more freely and abstractly. A high ceiling vs. a low ceiling gives a feeling of freedom rather than confinement. People are able to make more abstract connections. Conversely, in a room with lower ceilings, people are more likely to be detail-oriented and focus on specifics.

Of course, this means you may need to choose your environment to suit the task at hand, decide if you need to concentrate on specifics or need room to allow your mind to explore new possibilities. Finding the right space in which to think may be the key to decision-making and problem-solving.

U of M researchers find ceiling height can affect how a person thinks, feels and acts

Knowledge is gained in pieces, but these individual pieces are not all we know. In order to understand the big picture, we put together these bits of knowledge, like pieces of a jigsaw puzzle. If we learn that A is greater than B, and that B is greater than C, we know a third fact by deduction: that A is greater than C.

Our brains demonstrate their capacity for inference by this kind of linking bits of knowledge. The ability to make logical big picture inferences from disparate pieces of information is called relational memory.

A study led by researchers at Beth Israel Deaconess Medical Center and Brigham & Women’s Hospital in Boston, MA found that this ability to link bits of directly-learned information and to make leaps of inference to construct the big picture is enhanced when we sleep.

The study involved student participants divided into three groups who learned facts about pairs of shapes they were shown. Each group was tested to see how well they were able to infer the relationship between the facts they learned about individual pairs. Group one was tested after 20 minutes, Group Two was tested after 12 hours and Group Three was tested after a full 24-hour period.

Group One, which was tested only 20 minutes after the learning period, scored the worst on understanding the interrelationship between the pairs. Approximately half of the students in Group Two slept during the 12-hour period, while the other half remained awake. All of the students in Group Three had a full night’s sleep.

Groups Two and Three showed a clear understanding of the interrelationships between the pairs of shapes.

According to senior author Matthew Walker, PhD, Director of the Sleep and Neuroimaging Laboratory at BIDMC and Assistant Professor of Psychology at Harvard Medical School (HMS), “These findings point to an important benefit [of sleep] that we had not previously considered. Sleep not only strengthens a person’s individual memories, it appears to actually knit them together and helps realize how they are associated with one another. And this may, in fact, turn out to be the primary goal of sleep: You go to bed with pieces of the memory puzzle, and awaken with the jigsaw completed.”

To Understand The Big Picture, Give It Time - And Sleep

A five-year study of the brains of 136 subjects showed that changes in the brain precede symptoms and diagnosis of cognitive impairment and Alzheimers.

The participants, all over the age of 65, ranked as cognitively normal on tests given at the start of the study. Brain scans of the participants were also taken at the start of the study. The participants were followed with neurological and cognitive testing over the study period.

At the end of the study, 23 participants had developed MCI (mild cognitive impairment) and, of those, 9 went on to be diagnosed with Alzheimers.

Researchers discovered that changes in the brain had taken place as much as four years before the subjects had started to show cognitive impairment. The brain scans showed a decrease in grey matter in those participants who went on to develop memory problems while they still tested normal for cognitive function.

Researchers hope that the results of the study will help in identifying people at risk of developing MCI which leads to Alzheimers.

The study is published in the April 17, 2007, issue of Neurology®, the scientific journal of the American Academy of Neurology.