As we go through the world, we take in a very large amount of information through our senses.
 
 
 
 

Attention is the mechanism by which we limit the amount of this information that we process.

Some information is processed even though we are not consciously aware of this processing, or potentially even of the information itself.

Examples:

1. Blindsight — People with blind spots as a result of lesions in the cortex can still identify the location, orientation, and patterns of movement of spots of light projected in these blind spots.

 

 
 
 

2. Tip-of-the-tongue — "Man, I know who that guy is, I just can’t remember his name. I can picture his face … he was in that movie … the one with the lizard."

Priming is a phenomenon by which the presence of one stimulus either facilitates (positive priming) or inhibits (negative priming) the processing of another stimulus.

Different types of priming:

1. Attentional — Drawing a person’s attention to a particular location will facilitate processing of stimuli at that location, and inhibit processing of stimuli at other locations.

Example: cue-target task; cocktail party effect

2. Associational — Associating a new stimulus with a well-known stimulus will cause processing of the new stimulus to be facilitated.

Example: Reder’s famous people

3. Semantic — When two words are semantically related, such as "tiger" and "stripes," the processing of one can facilitate the processing of another.

Example: Lexical decision task; picture/word categorization

Spreading activation

There seems to be evidence that we have a non-conscious mechanism for learning.

The participant interacts with the computer by entering in numbers that represent "emotions" ranging from 1 (very depressed) to 12 (ecstatic). The computer responds to the subject based on these criteria:

Explicit condition —

R_t = I_t — 2 + [-1, 0, 1]

Implicit condition —

R_t = I_t-1 — 2 + [-1, 0, 1]

First, they measured how many trials it took for subjects to learn how to get the computer to respond with 8 (happy) ± 1 consistently.(In other words, the subject is learning to enter 10 all the time.)

After reaching criterion, subjects in the explicit condition were also able to report what the rule was that determined the computer’s response with reasonable accuracy.

Subjects in the implicit condition were not able to report the rule, even though their interaction with the computer was exactly the same and they were just as good at the task as subjects in the explicit condition!
 

In another experiment, Broadbent & Berry ran subjects in both conditions until they had achieved criterion. Then, without telling the subjects, they changed the task by reversing the sign on the 2, so that the computer’s response was determined by:

Explicit: R_t = I_t+ 2 + [-1, 0, 1]

Implicit: R_t = I_t-1+ 2 + [-1, 0, 1]

Subjects were still supposed to try and get the computer to respond at level 8, but now they need to be entering 6 instead of 10.

Subjects in the explicit condition were able easily (within 20 trials) shift their inputs. Subjects in the implicit condition took significantly longer, if they switched at all.

Controlled processing — processing that you have a conscious sensation of explicitly controlling

Example: playing chess; writing a term paper

Automatic processing — processing that seems to happen without any conscious intervention on your part.

Example: riding a bicycle

Most processes that we would consider automatic started out as controlled processes, and only became automatic after a lot of practice. Automatization is the process by which this happens.

Steps for riding a bike (age 4):

1. Sit on bike seat
2. Put feet on pedals
3. Push on pedals
4. Hold handlebars steady
5. Pray

1. Get on bike
2. Push pedals and go

Habituation is how we reach the point of being able to not pay attention to a stimulus.

Example: Trains going by your apartment; crying children (once you become a parent)