Matching to sample

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Cognitive Psychology: Attention · Decision making · Learning · Judgement · Memory · Motivation · Perception · Reasoning · Thinking  - Cognitive processes Cognition - Outline Index

---

This article is in need of attention from a psychologist/academic expert on the subject.
Please help recruit one, or improve this page yourself if you are qualified.
This banner appears on articles that are weak and whose contents should be approached with academic caution.

Matching to sample is a form of conditional discrimination. In this form of conditional discrimination procedure, only one of two or more stimuli presented on other comparison keys from the sample, shares some property (e.g., shape). Responses to the similar stimulus are reinforced. In oddity matching, a form of matching-to-sample, responses to the comparison stimulus that does not match the sample are reinforced.

Match-to-Sample Task

Short-term memory for learned associations has been studied using the Match-to-Sample Task (and the related Delayed Match-To-Sample Task, and Non-match to sample task). The general versions of the task ask a participant to first encode a stimulus (often a light of a particular color, or a visual pattern), and later make a forced-choice response among options where one corresponds to that stimulus. The stimulus that is encoded is commonly referred to as the sample stimulus, while the stimuli that the participant must choose from are referred to as the comparison stimuli The correct response options typically, but not always, corresponds directly in some way to the stimulus (i.e., its color is the same).

File:Matchtosample.png

Screen shot of the PEBL computerized Match-to-sample task. The participant originally saw one of the two patterns, and after a delay was asked to choose which of the two was originally shown.

Historical Background

Match to Sample tasks were developed in the during the era of Behaviorism, and were described by, among others, B.F. Skinner In its early form A pigeon would be presented with a colored light stimulus sample. It would then proceed to peck the sample and then be presented with two comparison stimuli. One comparison stimulus matches the sample (either because it is an identical color, or because the animal has learned an association such as green means left) and the other does not match. If it chooses (pecks) the matching comparison, then it is rewarded.

A more complex version of the task has formed the basis for human-centered cognitive test batteries since the 1980s This version of the task involves a 4X4 matrix pattern that is filled with yellow and red squares. Participants are alloted a specific amount of time to study the first pattern that appears on the screen. After the first pattern disappears, it is then replaced by a pair of matrices. One of these is the same as the previously viewed stimulus and one differs by one or more cells of the matrix. The participant then indicates which of the two was the presented stimulus. One trial of this tasks takes approximately 5–10 seconds.

Strengths and Weaknesses

The strengths of this study are that participants have a limited time to think, so if they are more aware/alert, they should receive a higher score. It has also been hypothesized to be impacted by Alertness but resilient to Practice. A Weakness of this study is that participants all have differing times that they are alert throughout the day (old people vs. young people).

Match-to-sample tasks and Sleep Deprivation

The match-to-sample task has been shown to be an effective tool to understand the impact of sleep deprivation on short-term memory.One research study compared performance on a traditional sequential test battery with that on a synthetic work task requiring subjects to work concurrently on several tasks, testing subjects every three hours during 64 hrs of Sleep deprivation. Similarly, another study used an event-related Functional magnetic resonance imaging of the Neural networks underlying the encoding, maintenance, and retrieval phase in the task. This test was used to discover the reduction in pattern expressions with sleep deprivation for each subject and how it related to the change in performance on the delayed-match-to-sample task. It also expanded the prefrontal areas regarding Working memory and revealed substantial individual differences in performance. The test also reproduced findings of other working memory studies which demonstrated interactions between PFC and other parts of the brain.

Delayed Match-to-sample tasks and Working Memory

Delayed match-to-sample tasks, or DMTS, are very similar to match-to-sample tasks except before choosing the correct response, there is a short delay. This delay can vary in length in order to determine how long the subject can retain information in their memory. If the subject responds correctly over fifty percent of the time, it shows that the subject has held that information (sample stimulus - see above) in memory. The amount of information that subjects can retain differs with species. For instance, a study by Grant in 1975, found that pigeons' ability to correctly choose the comparison stimuli (see above) declined as the delay between stimuli presentations increased. On average, a ten-second delay resulted in a correct response choice of around sixty-six percent. In a much more developed species, capuchin monkeys, D'Amato found (in 1973) that monkeys are able to choose the correct stimuli with a sixty-six percent rate, but with a much longer delay.

See also

• Discrimination learning
• Memory
• Recognition (learning)