07 Lecture attention

Psy 1: 

Psy 1 Today: Attention Learning & conditioning

Psy 102: 

Psy 102 Today: Attention Visual Search Change Blindness

Limited capacity processor: 

Limited capacity processor

One way to study attention is to measureREACTION TIMES: 

One way to study attention is to measure REACTION TIMES

Stroop Effect: 

Stroop Effect Fig. 8.29

Stroop Spy Test: 

Stroop Spy Test ROUGE VERT NOIR JAUNE VERT BLANC ROUGE VERT NOIR JAUNE ROUGE BLEIKT GULT SVART GULT BLEIKT HVITT SVART BLEIKT SVART GULT HVITT

What causes the Stroop effect?: 

What causes the Stroop effect? Response competition. Overlearned “name that word” reading response competes with unfamiliar “name that ink” task

Attention andVisual Search: 

Attention and Visual Search

Finding Laura Bush at a Jesse Jackson rally is hard: 

Finding Laura Bush at a Jesse Jackson rally is hard

But your friend with the green scarf at Pamplona jumps out at you: 

But your friend with the green scarf at Pamplona jumps out at you

Visual Search: 

Visual Search Looking for a target in a display containing distracting elements Target: the goal of visual search Distractor: any stimulus other than the target Set Size: the number of items in a visual display

Reaction times in visual search: 

Reaction times in visual search Fast, easy, parallel, pre-attentive search Slow, hard, serial, post-attentive search (must inspect each item in turn)

Selection based on color is easy: 

Selection based on color is easy

Selection based on upright vs upside down is not easy : 

Selection based on upright vs upside down is not easy

Slide16: 

One target present on half the trials Vary the number of items in display Subject reports whether target is present or absent Measure the time from the appearance of the display to the response Visual search experiments

Slide17: 

If reaction time is unaffected by number of distractors (slope=0) Then target identity was available preattentively and “drew attention” to itself Visual search experiments

Slide18: 

If reaction time increases with number of distractors Then identity not available preattentively, had to be determined by selecting each item in turn and analyzing it for match to target Visual search experiments

Visual Search (cont’d): 

Visual Search (cont’d)

Slide20: 

But high-level properties may also be easy to find, scene properties like surface curvature from shading Preattentive identification not not limited to properties extracted by cells in striate cortex

Slide21: 

It is not just the features, the same pattern with accentuated features is hard to find here At either orientation. It is the shaded depth that was the easily found surface, or scene property.

Preattentive to Attentive Stages: 

Preattentive to Attentive Stages

How long does it take you to react when driving? Reaction time: 

How long does it take you to react when driving? Reaction time Chronometry (Measuring reaction times) can tell us about brain processes Typical reaction times: .01 sec to 1 sec [$ & Broomstick demonstration]

Reaction time: 

Reaction time Nerve conduction time Muscle movement time CHOICE DECISION TIME in brain

To measure short reaction time: 

To measure short reaction time Get an accurate timer OR: Measure a series of reaction times and take the average [Class demonstration] Ankle vs. Shoulder: measure neural conduction velocity!

Slide26: 

How many can you track? Tracking, individuation Once captured, attention tracks moving and/or changing targets Why should attention move independently of eyes? Useful for multiple targets, covert surveillance

Slide27: 

Pylyshyn & Storm, 1988; Yantis, 1992; Intriligator & Cavanagh, 2001.

Slide28: 

You can shrink the area of selection to be small But not as small as the smallest detail you can see Spatial resolution of attention While looking in the center, you can see the bars but you cannot attend to individual bars — try counting them without moving your eyes

Slide29: 

Region of selection can zoom in or out but has a minimum size that is surprisingly coarse

Slide30: 

Region of selection can zoom in or out but has a minimum size that is surprisingly coarse

5. Temporal Attention: 

5. Temporal Attention individuate events at slow speed vs a rush of undifferentiable flicker Focused attention improves representation in time as well

Deficits in attention: 

Deficits in attention

Right parietal damage leads to inattention to objects on the left (Spatial Neglect): 

Right parietal damage leads to inattention to objects on the left (Spatial Neglect) Clothes Medawar: slides Dinner plate Draw a clock

Artist’s self portraits as he recovers from neglect: 

Artist’s self portraits as he recovers from neglect

Right-parietal patient shows spatial neglect of left side: 

Right-parietal patient shows spatial neglect of left side

Imagery and neglect: 

Imagery and neglect

Slide38: 

LEFT hemisphere sees the TREE RIGHT hemisphere sees the FOREST

Balint’s syndrome: 

Balint’s syndrome Bilateral parietal damage Can only attend to one thing at a time

Slide40: 

Problems with attention span, concentration, distractibility, impulsivity, and hyperactivity Difficulty remaining seated, easily distracted, fidgets, often interrupts, can't play quietly, loses things, talks impulsively or excessively, doesn't seem listen. Affects about 3 to 5 percent of all children, can continue to adulthood. Different attentional style Moderated by stimulants Attentional Deficit Hyperactivity Disorder

Change Blindness: 

Change Blindness [demonstrations:] Helicopter Boats

“Real-life” change blindness: 

“Real-life” change blindness Dan Simon’s DOOR experiment Cav 21.rm

Change blindness & attention: 

Change blindness & attention We don’t see changes until we ATTEND to specific part of field where change is Suggests we do NOT see the detailed picture of the world that we think we do.

Thank you.: 

Thank you.