Prosthetic Device Improves Impaired Decision-Making Ability in Animals
Imagine a prosthetic device capable of restoring decision-making in people who have reduced capacity due to brain disease or injury. Researchers at Wake Forest Baptist Medical Center have brought that scenario one step closer to reality now that they have demonstrated for the first time that it is possible in non-human primates.
The scientists used an electronic prosthetic system to tap into existing circuitry in the brain at the cellular level and record the firing patterns of multiple neurons in the prefrontal cortex, the part of the brain involved in decision-making. They then “played” that recording back to the same brain area to electrically stimulate decision-based neural activity. Not only did it restore function, but in some cases, it also improved it.
In the study, the scientists trained five monkeys to match multiple images on a computer screen until they were correct 70 to 75 percent of the time. First, an image appeared on the screen, which the animals were trained to select using a hand-controlled cursor. The screen then went blank for up to two minutes, followed by the reappearance of two to eight images, including the initial one, on the same screen.
When the monkeys correctly chose the image they were shown first, the electronic prosthetic device recorded the pattern of neural pulses associated with their decision by employing a multi-input multi-output nonlinear (MIMO) mathematical model, developed by researchers at the University of Southern California.
In the next phase of the study, a drug known to disrupt cognitive activity, cocaine, was administered to the animals to simulate brain injury. When the animals repeated the image-selection task, their decision-making ability decreased 13 percent from normal. However, during these “drug sessions,” the MIMO prosthesis detected when the animals were likely to choose the wrong image and played back the previously recorded “correct” neural patterns for the task.
According to the study findings, the MIMO device was exceedingly effective in restoring the cocaine-impaired decision-making ability to an improved level of 10 percent above normal, even when the drug was still present and active.
Source: Wake Forest News. The study was published in the Sept. 14, 2012, issue of the Journal of Neural Engineering.
Improving Memory and Thought-Processing Speed Among Breast Cancer Survivors Appears Possible
Breast cancer survivors often report memory problems or feelings of mental slowness, which can lead to depression, anxiety, fatigue, and an overall poorer quality of life. These symptoms can be severe and may persist after cancer treatment ends.
To date, very few treatment options have been available for patients to deal with these problems. Indiana University researchers compared the effects of two different training programs on breast cancer survivors to no treatment.
The study included 82 breast cancer survivors who reported concerns about their cognitive function, such as poor memory and mental slowness. All of the women had undergone chemotherapy. Each woman completed cognitive assessments prior to, immediately after, and two months after training.
The results, published in the journal Breast Cancer Research and Treatment, showed that a memory training program improved memory performance, while a computer program called Insight improved both memory performance and the ability and speed in which the survivors processed information.
Memory training involved, for example, teaching participants strategies for remembering word lists, sequences, and text material. Using Insight, a computer program developed by Posit Science, study participants followed a series of progressively more difficult information tasks.
Researchers plan to confirm their findings in a larger study.
Source: Indiana University School of Nursing news. For brain exercizes provided by Posit Science, a provider of clinically proven brain-fitness programs, visit www.BrainHQ.com.
How Time Perception Is Warped—By Life-Threatening Situations, Tiredness, Age, Emotions, and more ...
PsyBlog explores 10 ways the mind misperceives time. The excerpted list follows; see also the full discussion of the research on each time-bending phenomenon.
- Life-threatening situations: People often report that time seems to slow down in life-threatening situations, like skydiving. … [Researchers found that] we remember the time as longer because we record more of the experience.
- Time doesn’t fly when you’re having fun: The fact that we intuitively believe time flies when we’re having fun may have more to do with how time seems to slow when we’re not having fun. Boredom draws our attention to the passage of time, which gives us the feeling that it’s slowing down. Or … [p]erhaps you’re having fun when time flies. In other words, we assume we’ve been enjoying ourselves when we notice that time has passed quickly. … [Researchers found that] people who believed more strongly in the idea that time flies when you’re having fun were more likely to believe they were having fun when time flew.
- The stopped-clock illusion: It happens when you look at an analog watch, and the second-hand seems to freeze for longer than a second before moving on. I always thought this was because I just happened to look at it right at the start of the second, but this is actually an illusion. What is happening is that when your eyes move from one point to another (a saccade), your perception of time stretches slightly (Yarrow et al., 2001). Weirdly, it stretches backwards. So your brain tells you that you’ve been looking at the watch for slightly longer than you really have.
- Too tired to tell the time: When we’re tired, … our perception of time goes awry and we find it more difficult to distinguish between short spaces of time. This fact can be used to measure whether people are too tired to fly a plane, drive a truck, or be a doctor.
- Self-regulation stretches time: The effort of trying to either suppress or enhance our emotional reactions seems to change our perception of time. Psychologists have found that when people are trying to regulate their emotions, time seems to drag.
- Altered states of consciousness: [Y]ou don’t need drugs to enter an altered state of consciousness; hypnosis will do the trick. People generally seem to underestimate the time that they’ve been under hypnosis. One study found this figure was around 40 percent (Bowers & Brenneman, 1979).
- Does time speed up with age? One study has found that people in their 20s are pretty accurate at guessing an interval of three minutes, but people in their 60s systematically overestimate it, suggesting time is passing about 20 percent more quickly for them (Mangan & Bolinsky, 1997).
- The emotional experience of time: The emotions we feel in the moment directly affect our perception of time. Negative emotions in par-ticular seem to bring time to people’s attention and so make it seem longer.
- It’s getting hot in here: Experiments have found that when body temperature is raised, our perception of time speeds up (Wearden & Pento-Voak, 1995). Conversely when we are cooled down, our sense of time also slows down.
- What’s your tempo? Psychologists have found that people who are impulsive and oriented towards the present tend to find that time moves faster for them than others (from O’Brien et al., 2011).