Archive for the ‘Memory’ Category
Memories of visual images are stored in what is called visual memory. Our minds use visual memory to perform even the simplest of computations; from remembering the face of someone we’ve just met, to remembering what time it was last we checked. Without visual memory, we wouldn’t be able to store—and later retrieve—anything we see. Just as a computer’s memory capacity constrains its abilities, visual memory capacity has been correlated with a number of higher cognitive abilities, including academic success, fluid intelligence (the ability to solve novel problems), and general comprehension.
For many reasons, then, it would be very useful to understand how visual memory facilitates these mental operations, as well as constrains our ability to perform them. Yet although these big questions have long been debated, we are only now beginning to answer them.
Nobel Prize-winning psychologist Daniel Kahneman discusses the innate weakness of human thought, deceptive memories and the misleading power of intuition.
Psychologists distinguish between a “System 1″ and a “System 2,” which control our actions. System 1 represents what we may call intuition. It tirelessly provides us with quick impressions, intentions and feelings. System 2, on the other hand, represents reason, self-control and intelligence.
Every experience is given a score in your memory: good, bad, worse. And that’s completely independent of its duration. Only two things matter here: the peaks — that is, the worst or best moments — and the outcome. How did it end up?
While it’s generally accepted that memories are stored somewhere, somehow in our brains, the exact process has never been entirely understood. Strengthened synaptic connections between neurons definitely have something to do with it, although the synaptic membranes involved are constantly degrading and being replaced – this seems to be somewhat at odds with the fact that some memories can last for a person’s lifetime. Now, a team of scientists believe that they may have figured out what’s going on.
Memory is understood as strengthened synaptic connections among neurons. Paradoxically components of synaptic membranes are relatively short-lived and frequently re-cycled while memories can last a lifetime. This suggests synaptic information is encoded at a deeper, finer-grained scale of molecular information within post-synaptic neurons. Long-term memory requires genetic expression, protein synthesis, and delivery of new synaptic components. How are these changes guided on the molecular level?
Princeton University researchers have used a novel virtual reality and brain imaging system to detect a form of neural activity underlying how the brain forms short-term memories that are used in making decisions.
By following the brain activity of mice as they navigated a virtual reality maze, the researchers found that populations of neurons fire in distinctive sequences when the brain is holding a memory. Previous research centered on the idea that populations of neurons fire together with similar patterns to each other during the memory period.
Eric R. Kandel, Howard Hughes Medical Institute investigator, probes into the mind to demonstrate how it is much more complex than just a series of processes carried out by the brain. The brain produces our every emotional, intellectual and athletic act. It allows us to acquire new facts and skills, and to remember them for as long as a lifetime. Memory exists in two major forms, each located in different brain regions. Explicit memory is for people, places, and objects. In contrast, implicit memory serves perceptual and motor skills. In concert, these two memory systems help make us who we are.
Humans move between ‘patches’ in their memory using the same strategy as bees flitting between flowers for pollen or birds searching among bushes for berries.
Researchers at the University of Warwick and Indiana University have identified parallels between animals looking for food in the wild and humans searching for items within their memory – suggesting that people with the best ‘memory foraging’ strategies are better at recalling items.
People who suffer a traumatic experience often don’t talk about it, and many forget it over time. But not talking about something doesn’t always mean you’ll forget it; if you try to force yourself not to think about white bears, soon you’ll be imagining polar bears doing the polka. A group of psychological scientists explore the relationship between silence and memories in a new paper published in Perspectives on Psychological Science, a journal of the Association for Psychological Science.
What does a normally aging brain look like? Are diseases of aging such as Alzheimer’s inevitable?
Only 40 years ago it was widely believed that if you lived long enough, you would eventually experience serious cognitive decline, particularly with respect to memory. The implication was that achieving an advanced age was effectively equivalent to becoming senile—a word that implies mental defects or illness. As a graduate student back then, I was curious why such conclusions were being drawn about the elderly. I had only to look as far as my own great-grandmother and great-aunt to begin questioning the generalization. They lived to 102 and 93, respectively, and were exceptionally active and quick-witted enough to keep us twenty somethings on our toes. A closer look at the literature didn’t give me any confidence that either the biological basis of memory or how it might change with age was well understood. Many discoveries made in the years since have given us better tools to study memory storage, resulting in a major shift away from the view of “aging as a disease” and towards the view of “aging as a risk factor” for neurological diseases. So why do some people age gracefully, exhibiting relatively minor—and at worst annoying—cognitive changes, while others manifest significant and disabling memory decline? Answers to these questions are fundamental for understanding both how to prevent disease and how to promote quality of life.