Untitled Document
Not a member yet? Register for full benefits!

 Subconscious mental categories help brain sort through everyday experiences

This story is from the category The Brain
Printer Friendly Version
Email to a Friend (currently Down)



Date posted: 12/04/2013

Your brain knows it's time to cook when the stove is on, and the food and pots are out. When you rush away to calm a crying child, though, cooking is over and it's time to be a parent. Your brain processes and responds to these occurrences as distinct, unrelated events.

But it remains unclear exactly how the brain breaks such experiences into "events," or the related groups that help us mentally organize the day's many situations. A dominant concept of event-perception known as prediction error says that our brain draws a line between the end of one event and the start of another when things take an unexpected turn (such as a suddenly distraught child).

Challenging that idea, Princeton University researchers suggest that the brain may actually work from subconscious mental categories it creates based on how it considers people, objects and actions are related. Specifically, these details are sorted by temporal relationship, which means that the brain recognizes that they tend to or tend not to pop up near one another at specific times, the researchers report in the journal Nature Neuroscience.

So, a series of experiences that usually occur together (temporally related) form an event until a non-temporally related experience occurs and marks the start of a new event. In the example above, pots and food usually make an appearance during cooking; a crying child does not. Therein lies the partition between two events, so says the brain.

This dynamic, which the researchers call "shared temporal context," works very much like the object categories our minds use to organize objects, explained lead author Anna Schapiro, a doctoral student in Princeton's Department of Psychology.

"We're providing an account of how you come to treat a sequence of experiences as a coherent, meaningful event," Schapiro said. "Events are like object categories. We associate robins and canaries because they share many attributes: They can fly, have feathers, and so on. These associations help us build a 'bird' category in our minds. Events are the same, except the attributes that help us form associations are temporal relationships."

Supporting this idea is brain activity the researchers captured showing that abstract symbols and patterns with no obvious similarity nonetheless excited overlapping groups of neurons when presented to study participants as a related group. From this, the researchers constructed a computer model that can predict and outline the neural pathways through which people process situations, and can reveal if those situations are considered part of the same event.

The parallels drawn between event details are based on personal experience, Schapiro said. People need to have an existing understanding of the various factors that, when combined, correlate with a single experience.

"Everyone agrees that 'having a meeting' or 'chopping vegetables' is a coherent chunk of temporal structure, but it's actually not so obvious why that is if you've never had a meeting or chopped vegetables before," Schapiro said.

"You have to have experience with the shared temporal structure of the components of the events in order for the event to hold together in your mind," she said. "And the way the brain implements this is to learn to use overlapping neural populations to represent components of the same event."

See the full Story via external site: www.princeton.edu

Most recent stories in this category (The Brain):

04/02/2017: HKU scientists utilise innovative neuroimaging approach to unravel complex brain networks

26/01/2017: Personality linked to 'differences in brain structure'

12/01/2017: Donkey Kong used to Help Guide New Approaches in Neuroscience

10/12/2016: Doctors use deep-brain ultrasound therapy to treat tremors

17/02/2015: Hearing experts break sound barrier for children born without hearing nerve

17/02/2015: Smoking thins vital part of brain

05/02/2015: Intracranial Stimulation Proved Efficient in the Recovery of Learning and Memory in Rats

05/02/2015: Repeated head blows linked to smaller brain volume and slower processing speeds