Selective Attention Flashcards
VOICE DIVISION
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
SIMULTANEOUS SPEECH MESSAGE DIVISION
- “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
ATTENTION X LEXICAL IDENTIFICATION
- 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)
THE FILTER MODEL
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
FILTERING IS NOT ALL-OR-NOTHING
- 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”
LATE SELECTION THEORIES
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
FILTER-ATTENUATION THEORY
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)
NON-STRUCTURAL BOTTLENECK
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
THE ATTENTIONAL SPOTLIGHT
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
ENDOGENOUS VS EXOGENOUS SHIFT
- 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)
VOLUNTARY ATTENTION
MANGUN et al (1993)
- voluntary attention to a spatial locus modulates early components of ERP in extra-striate visual cortex
EARLY SELECTION IN PRIMARY VISUAL CORTEX
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
VISUAL SELECTION FOR AUDITORY ATTENTION
- 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
PROCESSING LOAD X EARLY SELECTION EFFICIENCY
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
INATTENTIONAL BLINDNESS IN DYNAMIC SCENES
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)
