It’s not the noise in the brain; it’s the noise in the input

05/2013

A new study has found that errors in perceptual decisions occurred only when there was confused sensory input, not because of any ‘noise’ or randomness in the cognitive processing. The finding, if replicated across broader contexts, will change some of our fundamental assumptions about how the brain works.

The study unusually involved both humans and rats — four young adults and 19 rats — who listened to streams of randomly timed clicks coming into both the left ear and the right ear. After listening to a stream, the subjects had to choose the side from which more clicks originated.

The errors made, by both humans and rats, were invariably when two clicks overlapped. In other words, and against previous assumptions, the errors did not occur because of any ‘noise’ in the brain processing, but only when noise occurred in the sensory input.

The researchers supposedly ruled out alternative sources of confusion, such as “noise associated with holding the stimulus in mind, or memory noise, and noise associated with a bias toward one alternative or the other.”

However, before concluding that the noise which is the major source of variability and errors in more conceptual decision-making likewise stems only from noise in the incoming input (in this case external information), I would like to see the research replicated in a broader range of scenarios. Nevertheless, it’s an intriguing finding, and if indeed, as the researchers say, “the internal mental process was perfectly noiseless. All of the imperfections came from noise in the sensory processes”, then the ramifications are quite extensive.

The findings do add weight to recent evidence that a significant cause of age-related cognitive decline is sensory loss.

http://www.futurity.org/science-technology/dont-blame-your-brain-for-that-bad-decision/

[3376] Brunton, B. W., Botvinick M. M., & Brody C. D.
(2013).  Rats and Humans Can Optimally Accumulate Evidence for Decision-Making.
Science. 340(6128), 95 - 98.

Related News

Following on from earlier studies that found individual neurons were associated with very specific memories (such as a particular person), new research has shown that we can actually regulate the activity of specific neurons, increasing the firing rate of some while decreasing the rate of others

A study involving 110 toddlers (aged 14-42 months), of whom 37 were diagnosed with an autism spectrum disorder and 22 with a developmental delay, has compared their behavior when watching a 1-minute movie depicting moving geometric patterns (a standard screen saver) on 1 side of a video monitor

Children with autism often focus intently on a single activity or feature of their environment.

A couple of years ago I reported on a finding that walking in the park, and (most surprisingly) simply looking at photos of natural scenes, could improve memory and concentration (see below). Now a new study helps explain why.

Because male superiority in mental rotation appears to be evident at a very young age, it has been suggested that testosterone may be a factor.

Following a monkey study that found training in spatial memory could raise females to the level of males, and human studies suggesting the video games might help reduce gender differences in spatial processing (see below for these), a new study shows that training in spatial skills can eliminate

I’ve talked about the importance of labels for memory, so I was interested to see that a recent series of experiments has found that hearing the name of an object improved people’s ability to see it, even when the object was flashed onscreen in conditions and speeds (50 milliseconds) that would

While brain training programs can certainly improve your ability to do the task you’re practicing, there has been little evidence that this transfers to other tasks.

A rat study demonstrates how specialized brain training can reverse many aspects of normal age-related cognitive decline in targeted areas. The month-long study involved daily hour-long sessions of intense auditory training targeted at the primary auditory cortex.

Because Nicaraguan Sign Language is only about 35 years old, and still evolving rapidly, the language used by the younger generation is more complex than that used by the older generation. This enables researchers to compare the effects of language ability on other abilities.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news
Error | About memory

Error

The website encountered an unexpected error. Please try again later.