Selective Attention

Question 1

VOICE DIVISION

Answer 1

CHERRY (1950s)

• perception of speech sounds -> lexical access -> syntactic parsing/semantic interpretation -> understanding
• we cannot understand/remember contents of 2 concurrent spoken messages
• best we can do = alternate selective attendance

Question 2

SIMULTANEOUS SPEECH MESSAGE DIVISION

Answer 2

• “shadowing” (repeating aloud):
• GOOD messages differ physically (location/voice/amplitude)
• BAD if only differ semantically (ie. novel VS recipe)
• pps notice:
• PHYSICAL changes (ie. English to Czech)
• NOT SEMANTIC changes (ie. meaningful to babble)
• word repeated x35 in unattended not remembered better than word heard once

Question 3

ATTENTION X LEXICAL IDENTIFICATION

Answer 3

• attentional selection precedes lexical identification/access to meaning
• unattended words = filtered out early after physical analysis before identity access
• unattended speech = aware in pitch/loudness/phonetics (background) BUT no identity procession
• if identity/meaning extraction = vital, switch attention filter (slow/effortful)

Question 4

THE FILTER MODEL

Answer 4

BROADBENT (1958)
attended/unattended message -> sensory store -> selective filter (physical properties; unattended message = blocked) -> (bottleneck) higher level processing -> WM
- sensory features of all speech sources processed in parallel; stored briefly in echoic memory
- selective filter directed only to one source at a time
- early filter processing achieves: recognition/activation of meaning/memory rep (LTM/WM)/voluntary action control/conscious awareness access
- assumptions are that filter is all-or-none/obligatory structural bottleneck

Question 5

FILTERING IS NOT ALL-OR-NOTHING

Answer 5

• examples of partial breakthroughs of meaning in unattended speech in shadow studies (ie. own name noticed in unattended speech)
• attended = “they say the port for the first time”; unattended = “they drank until the bottle was empty”

Question 6

LATE SELECTION THEORIES

Answer 6

DEUTSCH (1963)

• both attended/unattended words processed up to/including identification meaning activation
• relevant meanings then picked out on basis of permanent salience/current relevance
• BUT doesn’t say why:
• selection on basis of sensory attributes = > efficient than selection on meaning basis
• GSR to unattended probe words = < than attended

Question 7

FILTER-ATTENUATION THEORY

Answer 7

TREISMAN (1969)

• early filter BUT…
• not all-or-none; attenuates (turns down) input from unattended sources (top-down activation support; unattended words (if salient/contextually relevant) can still activate meanings
• early filtering = optional strategy (non-fixed structural bottleneck)

Question 8

NON-STRUCTURAL BOTTLENECK

Answer 8

MONITORING FOR TARGET WORD
- animal name (ie. 9 = bear; 5 = pig p/ear)
TASK
- press L/R when animal name is heard
- post practice, target detonation = accurate as when word targeted must be detected on either ear unless selective repetition is required

Question 9

THE ATTENTIONAL SPOTLIGHT

Answer 9

POSNER et al (1978/1980)

• endogenous cueing; probable stimulus location indicated via arrow cue (80% valid) or not (neutral)
• pp responds as fast as they can (maintaining central fixation)
• simple RT to onset
• choice spatial RT (above/below centre)
• choice symbolic RT (letter/digit)
• all faster for unexpected location; slower for unexpected

Question 10

ENDOGENOUS VS EXOGENOUS SHIFT

Answer 10

• endogenous (voluntary; top-down)
• exogenous (stimulus-driven; bottom-up)
• RT faster after sudden onset/change at stimulus location though does not predict location
• timing of exogenous cueing = dif from endogenous; exogenous attraction of the spotlight = fast (<200ms); endogenous movement of spotlight = slower (+100ms)

Question 11

VOLUNTARY ATTENTION

Answer 11

MANGUN et al (1993)

- voluntary attention to a spatial locus modulates early components of ERP in extra-striate visual cortex

Question 12

EARLY SELECTION IN PRIMARY VISUAL CORTEX

Answer 12

O’CONNER (2002)

• retina -> lateral geniculate nucleus -> V1
• fixation on central point = digits appear; high/low contrast checkerboards appear left/right periphery
• pp either counts fixation digits/detects random luminance changes in l/r checkerboards
• fMRI in LGN/VI voxels w/checker luminance change > w/attention directed away than fixation
• OVERALL some selection in visual field regions = early processing

Question 13

VISUAL SELECTION FOR AUDITORY ATTENTION

Answer 13

• NOT all-or-none; enhancement/suppression gradient across visual field
• optional; attended area size = under voluntary control (zooming on spotlight)
• EG. most trials = dif subject groups classified = central letter/whole word BUT also responded to occasional probe displays

Question 14

PROCESSING LOAD X EARLY SELECTION EFFICIENCY

Answer 14

LAVIE (1995)

• “flanker” task; left key = x/right = z on midline; ignore caps above/below midline (distracting flanker)
• low processing load = incongruent distractor slows response relative to congruent BUT not if higher load via pp needing to pick target from irrelevancies

Question 15

INATTENTIONAL BLINDNESS IN DYNAMIC SCENES

Answer 15

DANIEL SNOW

• pp attends 1 coherent visual event stream spatially overlapping another (ie. football game)
• unattended stream high saliency events = 50% missed
• unattended events NOT processed to meaning level despite in pp fixated visual field (eye-tracking studies)

Question 16

VISUAL SUMMARY

Answer 16

• info processing in visual field to recognition/meaning level = highly selective/limited:
• visual attention “spotlight” can be moved voluntarily/relatively slowly to potentially interesting locations/objects away from fixation; automatically/quickly attracted to visual field local transients (ie. Posner exps); spotlight size = varied/zoomed (ie. Laberge exps)
• selective filtering = early visual info processing (ie. brain-activation measures)
• outside spotlight processing = shallow; little object recognition/meaning activation evidence (ie. inattentional blindness)