Monday, May 6, 2013

Priming and Semantic Networks



The extrastriate cortex (shown in orange and red) is believed to be involved in perceptual priming

From ye wiki:

Priming is an implicit memory effect in which exposure to a stimulus influences a response to a later stimulus. It can occur following perceptual, semantic, or conceptual stimulus repetition. For example, if a person reads a list of words including the word table, and is later asked to complete a word starting with tab, the probability that he or she will answer table is greater than if they are not primed.

Another example is if people see an incomplete sketch that they are unable to identify and they are shown more of the sketch until they recognize the picture, later they will identify the sketch at an earlier stage than was possible for them the first time.

The effects of priming can be very salient and long lasting, even more so than simple recognition memory. Unconscious priming effects can affect word choice on a word-stem completion test long after the words have been consciously forgotten.

Priming works best when the two stimuli are in the same modality. For example visual priming works best with visual cues and verbal priming works best with verbal cues. But priming also occurs between modalities, or between semantically related words such as "doctor" and "nurse".

In daily life

Priming is thought to play a large part in the systems of stereotyping. This is because attention to a response increases the frequency of that response, even if the attended response is undesired. The attention given to these response or behaviours primes them for later activation.

This can occur even if the subject is not conscious of the priming stimulus. An example of this was done by Bargh et al. in 1996. Subjects were implicitly primed with words related to the stereotype of elderly people (example: Florida, forgetful, wrinkle). While the words did not explicitly mention speed or slowness, those who were primed with these words walked more slowly upon exiting the testing booth than those who were primed with neutral stimuli.

Similar effects were found with rude and polite stimuli: those primed with rude words were more likely to interrupt an investigator than those primed with neutral words, and those primed with polite words were the least likely to interrupt. A Yale study showed that something as simple as holding a hot or cold beverage before an interview could result in pleasant or negative opinion of the interviewer.

These findings have been extended to therapeutic interventions. For example, Cox etal (2012) suggest that presented with a depressed patient who "self-stereotypes herself as incompetent, a therapist can find ways to prime her with specific situations in which she had been competent in the past... Making memories of her competence more salient should reduce her self-stereotype of incompetence."

The replicability and interpretation of goal-priming findings has become controversial. Recent studies have failed to replicate finds, including age priming, with additional reports of failure to replicate this and other findings such as social-distance also reported.

Criticism

Many of the priming effects could not be replicated in further studies, casting doubt on their effectiveness or even existence. Nobel Laurate and psychologist Daniel Kahneman has called on social psychologists to check the robustness of priming studies in an open letter to the community, claiming that social psychology has become a "poster child for doubts about the integrity of psychological research." Other critics have asserted that priming studies suffer from major publication bias, experimenter effect and that criticism of the field is not dealt with constructively.

Priming

A technique called priming can demonstrate implicit memory. A person who sees the word yellow will be slightly faster to recognize the word banana as a word. This happens because the words yellow and banana are closely associated in memory.

What is "priming"? What is a "semantic network"?







Researchers sometimes envision a network of word meanings or semantic network somewhat like the diagram. The distance between words indicates the frequency with which the words are associated in everyday life. Because of these associations, activating one node of the network (showing the person one word) warms up or primes nearby words, speeding retrieval. This effect lasts about 30 minutes after exposure to the priming word.

Priming does not require conscious rehearsal of word meanings. The associations between words used in a priming experiment are not consciously memorized for purposes of the experiment; they are naturally occurring associations. (However, they are learned, and they can be culture-specific. Not every society has yellow school busses, for example.) No conscious strategy is required to show priming effects.

Brain-damaged and intoxicated people show the same priming effects as other people. This is another example of implicit memory. Indeed, the example used on the preceding page, about implicit vs. explicit memory, was also a form of priming. It involved degraded words, shown as a cue to recall words a person saw earlier in the experiment. In that case, the experimenters were interested in seeing whether the priming effect (showing the words earlier) would occur equally in drunk and sober subjects, which it did.

How does priming normally help language comprehension?

In normal reading, words seen ahead of the fixation point of the eye (in peripheral vision) are activated in semantic memory ("warmed up") so when the eye fixates upon them, their meanings are available faster. Similarly, in conversation, if you hear somebody say, "I ate a yellow" [followed by a muffled word that sounds like "an-an-an"] you might well hear "I ate a yellow banana" because you have a semantic network like the one in the diagram. The word banana is activated by its association to the word yellow, so you easily retrieve it even if the stimulus is partial or degraded. The memory retrieval is automatic, evoked by the situation, so this is an example of implicit memory.


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