PSYC20007 Lecture Notes - Lecture 6: Sensory Analysis, Echoic Memory, Headphones
10 May 2018
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Lecture 6
- Meaig of attetio: ai’s ailit to self-regulate input from the environment [in pursuit of
particular goals or purposes]; pervasive and goal-directed; used in two senses in psychology:
- Sustained attention (alertness): related to psychological arousal (continuum from
drowsy, inattentive to alert, attentive); problem of vigilance → performance declines over
a long watch (radar operators, quality control inspectors etc); sense of attention being
related to alertness, concentration; the ability to focus in a sustained way on a task, the
ability to focus on one task with the exclusion of others
- Selective attention: limited in the number of stimuli we can process; attend to one stimulus at
the expense of others; people as limited capacit sstes: do’t teat all stiuli euall;
processing stimuli, understanding stimuli in the world involves mental, neural, metabolic work
[limited in ability to do this]
- The Cocktail Party Problem: Cherry (1953); How do we follow a conversation in a
crowded environment?; Can pick out one conversation from background [and follow
that conversation]; Picking out: processes take sound energy at ear [raw acoustic
energy that vibrates the eardrum → speech sounds → extract meaning], translate to
understanding; translation is selective (stimuli not all treated equally); How to study this
process?; Cherry: what happens to unattended messages?
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- Dichotic listening and shadowing
- Dichotic → presenting passages of sound to two different ears
find more resources at oneclass.com
find more resources at oneclass.com
- Task: playing people two passages of continuous speech over stereo headphones to
different ears → got people to repeat the contents of one of these speeches out loud
[shadowing]
- Task could be made easier or harder by varying the speed of speech → what happens to
contents of passage of speech that youre not attending to?
- Information [at that time] refers to any sensory modalities that could independently receive
information as a channel [right and left ears are both channels]
- Attended channel receive one message and unattended channel receives another message
- Task: repeat message 1 out loud [shadow message 1]
- Cherrys Finding: Shadow Message 1, then ask about contents of Message 2;
Unattended channel → no memory for unattended message, switch from English to
German - not noticed [acoustically similar], switch from male to female - noticed,
reversed speech - something queer, switch from voice to 400 cps pure tone - noticed
- Fate of the unattended message: conclusions - only superficial (physical) features perceived
(things distinguishing voice, non-voice, or male, female), semantic content not analysed
(language, meaning); preattentive processes vs focal attention (Neisser, 1967) - sensory
(physical) features processed preattentively, meaning requires focal attention; plausible - aware
of unattended stimuli only superficially
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- How do we select the attended message?
- Binaural presentation (Cherry): both ears receive both messages [left ear gets message 1 and 2,
right ear also gets message 1 and 2], same voice, differ only in content
- Get people to attempt to shadow the same passage over and over again until they
achieve some level of proficiency → typically took around 10-20 presentations of
messages → until they could began to shadow coherently
- Very difficult, no sound localisation [people’s pefoae ollapses]
find more resources at oneclass.com
find more resources at oneclass.com
- Source localisation in space is an important cue (phase differences [slight delay, enables
us to localise sound in space] in arrival times at ear) → because of finite speed of sound,
sound from a particular source in space arrives at left ear and right ear at slightly
different times [very slight delay, 1-3 ms]
- A itiis of Che: iteested i hat’s peeied, Che looked at hat’s eeeed;
confounds perception and memory; may be perceived then forgotten
-
- Filter Theory (Broadbent, 1958): Attention acts as a filter to select stimuli for further processing;
we are limited in our capacity to process all stimuli potentially available in environment
- Limited capacity channel - translating sound into understanding, recognising stimuli in
environment and deciding what to do with them
- Series of cognitive actions which are limited in their ability to process all of the stimuli in
environment
- If limited capacity channel would not protect it, it would be overloaded/overwhelmed by
all the stimuli out there → only able to deal with a limited number [possibly one thing at
once]
- Selective filter [attention] - protective role, sits in front of and stops limited capacity channel
from being overloaded
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Mea(cid:374)i(cid:374)g of (cid:862)atte(cid:374)tio(cid:374)(cid:863): (cid:271)(cid:396)ai(cid:374)"s a(cid:271)ilit(cid:455) to self-regulate input from the environment [in pursuit of particular goals or purposes]; pervasive and goal-directed; used in two senses in psychology: Dichotic presenting passages of sound to two different ears. Task: playing people two passages of continuous speech over stereo headphones to different ears got people to repeat the contents of one of these speeches out loud. Information [at that time] refers to any sensory modalities that could independently receive information as a channel [right and left ears are both channels] Attended channel receive one message and unattended channel receives another message. Task: repeat message 1 out loud [shadow message 1] Cherry(cid:3244)s finding: shadow message 1, then ask about contents of message 2; Unattended channel no memory for unattended message, switch from english to. German - not noticed [acoustically similar], switch from male to female - noticed, reversed speech - (cid:3247)something queer(cid:3248), switch from voice to 400 cps pure tone - noticed.
