Masking

Question 1

Masking

Answer 1

Making stimulus invisible by preceding/following it with another stimulus

Forward masking:
- Preceding stimulus w distractor (500ms), than 20ms target stimulus

Backward masking; (most used)
- Following stimulus (20ms) w distractor (500ms)

Question 2

Matacontrast masking

Answer 2

Stimulus is followed by a coinciding contrast to the stimulus.

Contour masks the stimulus, optimally after 50ms.

Target-mask stimulus onset asynchrony curve (SOA) shows curve with strong drop at 50ms

Question 3

Prime experiment

Answer 3

Priming effect of metamasked stimulus. Congruent has lot faster RT, incongruent slower RT.

All the while, prime is not seen (FC = 50% d’ =0)

Question 4

Continuous flas suppression (CFS)

Answer 4

Strong masking by flashing stimuli in one eye, making other stimulus in other eye unseen.

1. Visual adaptation
   - Face shown, after it’s turned off, have to say if they saw male/female. The unconscious stimuli (male face) still causes neutral face to be seen as woman due to adaptation
2. Visual priming
   Tool or animal, congruent is faster than incongruent
3. Breaking suppression (bCFS)
   Increasing contrast of stimulus makes it break through. Upright are faster than upside down. Complex analysis is done before (pre-consciously)

Question 5

Bistable stimuli

Answer 5

Same stimuli, but you contrast due to different percept (vase/face picture).

Seen in binocular rivalry. Dominance lasts several seconds but may vary in length from switch to switch

graph similar in monkey/human

Sharper one will dominate longer,, and high contrast too (compared to blurry/lowcontrast)

Question 6

neural response binocular rivalry

Answer 6

Face selective cells in IT respond stronger *or only ) when the face is dominating.

Transition between seeing face/house si accompanied by activation of PPA going down and FFA up w face and vice versa

You can predict it by looking at V1 activity rather than from higher visual areas.

Question 7

Yellow target illusion

Answer 7

Responses to yellow target are reduced when it’s not seen

(Motion induced Blindness)

When it’s realy gone, it’s also reduced

The response to the moving background is simultaneously increased.

Whey it re-appears, the activation is increased again, whereas the movement is decreased.

Strongest at that time wil by conscious