Featured Research

from universities, journals, and other organizations

Strongest evidence yet of two distinct human cognitive systems

Date:
March 18, 2014
Source:
University at Buffalo
Summary:
Cognitive scientists may have produced the strongest evidence yet that humans have separate and distinct cognitive systems with which they can categorize, classify, and conceptualize their worlds. The systems also may have different courses of decline in cognitive aging, which would have ramifications for remediation and compensation in dementia.

A new study presents the strongest evidence yet that humans have separate and distinct cognitive systems with which they can categorize, classify, and conceptualize their worlds.
Credit: Terence Mendoza / Fotolia

Cognitive scientists may have produced the strongest evidence yet that humans have separate and distinct cognitive systems with which they can categorize, classify, and conceptualize their worlds.

"Our finding that there are distinct, discrete systems has implications for the fields of child development and cognitive aging," says lead researcher, cognitive psychologist J. David Smith, PhD, of the University at Buffalo.

"These distinct systems may have different developmental courses as the cortex matures," he says, "meaning that children may categorize differently than adults, using different systems at different ages. This would have educational and training implications in cases of developmental disability."

He says the systems also may have different courses of decline in cognitive aging, which would have ramifications for remediation and compensation in dementia.

The study "Deferred Feedback Sharply Dissociates Implicit and Explicit Category Learning," was conducted by Smith and colleagues at UB and at the University of California at Santa Barbara. It was published in the Feb. 7 edition of the journal Psychological Science.

The age-old question of whether humans have discrete cognitive systems operating on different levels that are more or less conscious, more or less available to introspection, and so forth, has been debated for years.

"This issue of whether there are separate cognitive systems famously arose regarding humans' declarative and procedural memory and in the field of categorization," Smith says.

"Cognitive neuroscientists have hypothesized that humans have distinguishable systems for categorizing the objects in their world -- one more explicit (i.e., conscious and available to introspection), one less so, or more implicit," says Smith.

To grasp the differences between these two types of learning, Smith recommends that we remember certain distinctions in our performance of the tasks of daily life.

"For instance, when you select a cereal named 'Chocoholic' from the store shelf," he says, "consider why you are doing so. Is it a deliberate, explicit choice, or is it possibly an implicit-procedural chocolate reaction, one triggered by processes, memories and so on, of which you are generally unaware?"

"Because of the considerable controversy surrounding the question of whether we have more than one cognitive system, researchers have continued to seek models that distinguish the processes of explicit and implicit category learning," Smith says, "and this study presents the clearest distinction yet found between these systems.

"To make this discovery," he says, "we borrowed an influential model from our studies of macaque monkeys, which illustrates the valuable synergies that exist between primate and human research."

Their technique was to ask humans to work for blocks of trials without any corrective feedback, and then deliver feedback when they were finished. Smith likens this process to an undergraduate testing situation in which the student taking a test does not get item-by-item feedback, but receives a summary score once the test is completed.

Because this manipulation, he says, prevents the formation of automatic (implicit) stimulus-response associations, Smith and his colleagues hypothesized that it would undermine the processes of conditioning and eliminate the possibility of implicit category learning.

"Implicit category learning," he says, "is a system that depends on trial-by-trial feedback of response correctness and incorrectness to establish the stimulus-response associations that allow implicit learning and responding.

"In fact," Smith says, "the blocked-feedback technique made implicit category learning impossible. We then used extensive trial-strategy analyses and formal-mathematical modeling to demonstrate this conclusively.

"So we were able to selectively unplug one category-learning system -- the implicit system -- but leave the explicit-conscious system functioning and intact," he says.

Smith et al. even found that, facing a task that could only be learned implicitly, participants with blocked feedback turned futilely to conscious strategies that were inadequate, because this was all they could do when implicit category learning was defeated.

"In the area of categorization research," Smith says, "the issue of single vs. multiple systems is nearly closed. The evidence is now very strong that there are multiple category-learning systems -- in particular, the explicit-conscious and the implicit-procedural system."

Smith says it is fascinating to consider where in cognitive evolution the roots of the explicit-declarative categorization system lie. He and his colleagues have found the beginnings of this system in non-human primates like rhesus macaques and capuchin monkeys. Interestingly, though, thus far pigeons have shown no evidence of having distinguishable explicit and implicit systems.

Smith's co-authors were Joseph Boomer and Alexandria C. Zakrzewski, graduate students, andBarbara Church PhD, senior research scientist, all in the UB Department of Psychology, and graduate student Jessica Roeder and F. Gregory Ashby, PhD, both in the Department of Psychological and Brain Sciences, University of California, Santa Barbara.


Story Source:

The above story is based on materials provided by University at Buffalo. The original article was written by Pat Donovan. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. D. Smith, J. Boomer, A. C. Zakrzewski, J. L. Roeder, B. A. Church, F. G. Ashby. Deferred Feedback Sharply Dissociates Implicit and Explicit Category Learning. Psychological Science, 2013; 25 (2): 447 DOI: 10.1177/0956797613509112

Cite This Page:

University at Buffalo. "Strongest evidence yet of two distinct human cognitive systems." ScienceDaily. ScienceDaily, 18 March 2014. <www.sciencedaily.com/releases/2014/03/140318140759.htm>.
University at Buffalo. (2014, March 18). Strongest evidence yet of two distinct human cognitive systems. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/03/140318140759.htm
University at Buffalo. "Strongest evidence yet of two distinct human cognitive systems." ScienceDaily. www.sciencedaily.com/releases/2014/03/140318140759.htm (accessed July 28, 2014).

Share This




More Mind & Brain News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) A new study shows sleep deprivation can make it harder for people to remember specific details of an event. Video provided by Newsy
Powered by NewsLook.com
University Quiz Implies Atheists Are Smarter Than Christians

University Quiz Implies Atheists Are Smarter Than Christians

Newsy (July 25, 2014) An online quiz from a required course at Ohio State is making waves for suggesting atheists are inherently smarter than Christians. Video provided by Newsy
Powered by NewsLook.com
Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

AFP (July 24, 2014) A so-called drugs rehab 'clinic' is closed down in Pakistan after police find scores of ‘patients’ chained up alleging serial abuse. Duration 03:05 Video provided by AFP
Powered by NewsLook.com
New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins