Question #8 PSY 361 Exam

Attention has what effect on synchrony?

Increases the process.

What are the two stages of the feature integration theory?

- Initial Stage (pre-attentive stage) - Focused Attention Stage

Explain the methods of their experiment.

- Used a stimulus display of four objects. - Each left/right end of the total stimulus was flanked by a black number. - Display was flashed onto a screen for 1/5th of a second, followed by a dot-masking field (to make sure no residual perception would remain after presentation). - Subjects were asked to report the black numbers first, then the 4 shapes.

What were the results?

18% of trials showed illusory conjunctions. (18% of stimuli were reported wrong)

The synchrony hypothesis attempts to explain.. what?

Binding.

Neurons associated with color may be organized into?

Columns (like orientation neurons). Multiple color columns are activated on common objects.

What was wrong with Patient R.M.? What were his symptoms?

Experienced damage to the parietal lobe (damage was the result of a condition called Balint's syndrome): resulted in an inability to focus attention of individual objects.

This means that if a neuron is firing three times in response to a red triangle, corresponding neural tissue will respond by firing a neuron how many times in response to a green circle?

Three times.

When looking at a jersey of team A with color white, there are various columns of color neurons that will be stimulated and firing in response to that specific pattern of white. When looking at the jersey of team B with the color white, a different column of color specific neurons will be activated (a different firing pattern than in team A). HOWEVER - these neurons for both A and B will fire in synchrony.

When looking at a jersey of team A with color white, there are various columns of color neurons that will be stimulated and firing in response to that specific pattern of white. When looking at the jersey of team B with the color white, a different column of color specific neurons will be activated (a different firing pattern than in team A). HOWEVER - these neurons for both A and B will fire in synchrony.

What is the synchrony hypothesis?

When neurons in differing locations are firing in response to the same object, the pattern of nerve impulses in those neurons will be synchronized to each other.

What is the feature integration theory?

assigns a central role to attention in the solution of the binding problem

What happens in the initial stage?

color, orientation, location and movements are processed independently.

What happens in the focused attention stage?

combines (binds) all of an object's features into a clear perception of that object.

What was the study by Treisman and Schmidt (1982)

examined illusory conjunctions (when some conditions of features are associated incorrectly with another object).

These observations of R.M. showed what?

parts of patient R.M.'s brain (attention areas) were necessary for the binding of multiple stimuli. Further supported the idea that illusory conjunctions are caused by a failure of attention.

It was found that when presented with a pair of stimuli with varying letter/color patterns, he was ???

unable to make distinctions between them 23% of the time (in spite of the fact he could observe the stimuli for up to 10 seconds).