Presentation on theme: "ATTENTION: SELECTIVITY AND RESOURCE ALLOCATION SELECTIVITY –what events “capture” attention? –how complete is selectivity? AROUSAL AND ALERTNESS –does."— Presentation transcript:
ATTENTION: SELECTIVITY AND RESOURCE ALLOCATION SELECTIVITY –what events “capture” attention? –how complete is selectivity? AROUSAL AND ALERTNESS –does capacity change over time? –how is it affected by arousal,task demands or intention? DIVIDED ATTENTION –how well can we do two things at once? –can we improve our skill in dividing attention?
MEASURING WHERE ATTENTION IS FOCUSSED tracking eye fixations tracking ear fixations (“shadowing”) this is the first day of the rest of your life in the. “when in the course of …..” “and another score for the Gators ……” “.. another score, uh …”
Seven records of eye movements by the same subject. Each record lasted 3 minutes. 1) Free examination. Before subsequent recordings, the subject was asked to: 2) estimate the material circumstances of the family; 3) give the ages of the people; 4) surmise what the family had been doing before the arrival of the "unexpected visitor;" 5) remember the clothes worn by the people; 6) remember the position of the people and objects in the room; 7) estimate how long the "unexpected visitor" had been away from the family (from Yarbus (1967).
“COVERT” SHIFTS OF SPATIAL ATTENTION (Posner & Cohen, 1984) fixate center throughout trial: @ respond to target figure: X @ cue for likely side of test: (p. =.8) 100 to 1000 msec
Fig. 4-22, p. 126 ATTENTION TO OBJECTS vs. LOCATIONS (Egly 1994)
UNILATERAL NEGLECT: Impaired shifting of spatial attention Left hemisphere:focus on right side of space Right Hemisphere: focus on left and right side Damage to Right Hemisphere:
Evidence for “early” selection: –poor detection and memory for unattended input channel(s) –tendency to report concurrent inputs “by channel” SELECTIVE ATTENTION AS A SENSORY FILTER (Broadbent, 1958) input “channels” sensory analysis pattern recogn “early” filter left ear: 2..4..9 right ear: 6..1..8 report: 2,4,9..6, 1 Evidence against “early” selection: –shadowing disrupted by S’s name –context can force switch to ignored ear –meaning of “ignored” words can affect behavior
EFFECTS OF AN “UNATTENDED” WORD (MacKay, 1972) “.. the boy threw a rock at the bank and..” “..scissor.. ladder.. money.. finger..” “Ignored” words not remembered, but still bias interpretation of sentence Evidence for “activation without awareness” Such “automatic” effects are small, and depend on special conditions
ATTENTION AS ALLOCATION OF LIMITED CAPACITY (Kahneman, 1972)
AROUSAL, ATTENTION AND PERFORMANCE For many tasks, performance suffers if arousal is too low or too high (Yerkes & Dodson, 1903) + - Arousal lowhigh Performance capacity too low focus too narrow Easterbrook, ‘59: Cue Utilization Theory
task: decide if two successive letters are the same or different +RJ ? press key MEASURING ATTENTIONAL ALLOCATION (Posner & Boies, 1971) decision and response selection as attentional “bottlenecks”
THE ATTENTIONAL DEMANDS OF SHADOWING (Johnston & Heinz, 1978) Shadowed List: desk couch chair sofa etc... ignored List: NONE voiceclassDIFF SAMEDIFF DIFFSAME or RT to TONE RT to tone alone: 320 msec
PRACTICE AND EXPERTISE Staszewski, 1988 task: mental multiplication 300 hours (!) of practice on simple (1 by 1) and complex (2 by 5) problems using left- to-right procedures e.g. 267 x 97: “.. nine times two is eighteen hundred; nine time six is 540, that’s 2340..”
PRACTICE AND DIVIDED ATTENTION Practice in shadowing (Underwood, 1976) –Task: shadow prose in left ear –and detect occasional digits in right ear Oxford Undergrads: 13% hits Neville Moray: 71% hits Practice in dictation (Spelke, Hirst & Neisser, 1976) –Task: read text for meaning, and write down spoken words –after months of practice, no “cost” of dictation on reading speed or comprehension Is attention skill domain-specific?
ATTENTION AND CELL PHONES Strayer, Drew & Johnston, 2003 About 150 million cell phones 85% use them while driving Inattention a leading cause of crashes So: simulated driving task (track pace car), with/out hands-free chat Drive Drive & Chat Accidents 03 Brake onset 933 ms 1112 ms Following distance25.8 ft29.3 ft Billboard recognition6.93.9 Billboard fixation0.660.62
Date: 2003-03-27 New Study Shows Drivers Using Cell Phones Twice As Likely To Cause Rear-end Collisions CHAPEL HILL -- Drivers talking on cell phones are nearly twice as likely as other drivers involved in crashes to have rear-end collisions, according to a new University of North Carolina at Chapel Hill study. Crashes involving cell phone use, however, are less likely to result in fatalities or serious injuries than crashes not involving the devices.
LAPSES OF ATTENTION: THE “COGNITIVE FAILURES QUESTIONNAIRE (CFQ) How often do you... –read something and realize you haven’t been thinking about it? –forget why you went from one room to another? –bump into people? –forget if you’ve locked the door? –forget to keep appointments? –drop things? –fail to hear people speaking when you’re doing something else? Ratings correlate with performance in tasks of selective and divided attention (e.g., stroop interference; Tipper & Baylis, 1987)