Lecture 9 - Attention

Question 1

Span of apprehension

Answer 1

asking how do we (or do we) filter info as it comes in?

we have this great big world of sensory data: where does the filtering take place?

one of the first ways we have of probing and testing those questions

Question 2

Selecting channels

Answer 2

what it means for a channel (sensory or information) to exists

Question 3

William James

Answer 3

father of american psychology

helped develop pragmatism in philosophy

wanted to know how people made decisions: what factored into it? what was important to them?

Question 4

how can we quantify information? (airplane pilots, driving)

How much can a person track and make sense of?

cause there’s a lot there

how do you make your experience the most important thing going on?

Answer 4

attention limits what’s coming in

Question 5

Your attention system(s) help bias/constrain what

you process at any one time.

Answer 5

• This helps overcome the problem of computational
complexity (too much happening in our environment to process at any one time: we can’t attend to it all, we can’t remember it all, we can’t learn it all) in the environment.

• Processing and resource limitations
• Action limitations

• Attention is not a single attribute, but rather the result of
many abilities.

Question 6

Processing and resource limitations:

Answer 6

You can only take
in and process so much information at one time.

only so much of the world comes into your field of view (fovea - high detailed vision)

we have to have some means of limiting what’s coming so that we know exactly where to focus to get the most info and what we don’t want to pay attention to (take up finite resources)

Question 7

Action (motor) limitations:

Answer 7

You are spatially and temporally
limited in what you can physically do - how you can interact with your environment

limitations on where I am and what I can do

Question 8

Attention is not a single attribute,

Answer 8

but rather the result (effect) of many abilities (processes).

it’s not a single capacity or attribute, not just one place in the brain where attention lives, it’s the effect of a lot of different processes

we’re trying to modulate the degree to which we process different things

Question 9

attention as the modulation of some kind of information:

Answer 9

focus attention and increase processing “over there” or you ignore something, decrease the processing “over there”

Question 10

Attention can be divided into (many) categories.

how we direct attention, where it is going

Answer 10

Exogenous orienting of attention

Endogenous orienting of attention

Question 11

Exogenous orienting of attention:

Answer 11

exo: outside, external: something grabs your attention

The degree to which outside
stimuli (take control) make you shift you sensory systems toward them.

• Example: A loud sound or flashing light may capture your
attention - novel and extreme [FIRE!] [Automatic, bottom-up: we don’t have control over it, we can’ help but notice it.]

Question 12

Endogenous orienting of attention

Answer 12

how you choose to focus your processing power

The degree to which internal goals and desires direct your attention toward the
environment.

• Example: Searching for a person you know or trying to
hear someone in a crowded room. [Intentional, top-down]

Question 13

Earlier in the course we talked about stimulus salience. By
its nature, a highly salient stimulus is more likely to
engage which kind of attention?

Answer 13

Exogenous attention or Endogenous attention

it depends!

a really strong stimulus can pierce through whatever you’re doing (exo) but in most cases that’s not the world we live in

endo: you’re so focused on something that you don’t notice what’s going on around you - concentration can block out environment

Question 14

Attention can be divided into many functions.

Answer 14

• Focusing
• Perceptual enhancement
• Binding
• Sustaining behavior
• Action selection (central executive)

Question 15

salience

Answer 15

can be something important only to you or can be something about a stimulus that grabs you

Question 16

Focusing

Answer 16

Limiting the number of items being processed and increasing the amount of processing dedicated to that thing

Question 17

Perceptual enhancement

Answer 17

when you’re really starting to get more information out of a stimulus or object

(greater feature resolution)

Question 18

When we “focus” on something in the environment, how much of
the outside (exogenous) world actually gets shut out?

how good are we at this?

Recall Broadbent’s (1958) early filter model

Answer 18

input (sensory data) -> filter -> detector -> to memory

Question 19

Do our sensory systems filter out information as it comes in? ( I can only see so many things or hear so many things)

Early psychological experiments with attention

Answer 19

asked subjects to view an array of letters. Subjects would then
report the letters seen (asked: what were the letters?).

• The number of items subjects could report was called the span
of apprehension (or span of perception - what you can perceive from one brief exposure).

•When using full reports, people will identify 4-5 of the letters.

Question 20

The hypothesis was that the visual system didn’t allow more than 5 letters to be
perceived at any one time.

Answer 20

An early sensory “bottleneck” (funnel) would select a few items to be processed at a time.

eyes as a bottleneck or ears (only see so much or ear so much at one time and only so much info gets through to the brain to be processes further)

Question 21

A competing hypothesis suggested that

more than 5 letters are processed.

Answer 21

the letters don’t get transferred to short-term memory if they aren’t used quickly

maybe you do hear or see more but that info doesn’t get transferred (you don’t do anything with it) to short-term/working memory

Question 22

George Sperling (1960) tested these competing hypothesis:

Answer 22

• Subjects would be shown an array of letter as before.
• One group would be asked to use full report (as before).
• Another group would use partial report: After the letters are flashed, a tone (high, medium, or low) would indicate which row to report.

• When people use partial report, they seem to have access
to more of the visual display.
- probes or cues the different parts of the memory system to show that we have more access than we originally thought

• Full report yielded 4-5 total letters (as before).
• Partial report yielded (on average) > 3 letters per row
  * This suggests that subjects actually had access to at least 9 of the 12 letters.

Sperling concluded that people have a high-capacity iconic
(sensory) memory, it just needs to be transferred to short-term
memory before it decays.

Question 23

iconic (sensory- visual) memory

Answer 23

ex: looking around a room for a second you have this stimuli burned into the retina

if you probe it correctly then you can pull the info out of there and move it to short term memory BUT if you don’t it goes away

Question 24

the important limiter doesn’t seem to be on

where isn’t the bottleneck?

Answer 24

the important limiter doesn’t seem to be on what’s actually sensorially available to us (because that’s more available than what we’re able to process in real time)

so the bottleneck isn’t at the initial sensor filter

Question 25

It appears we can use attention to focus on (transfer) some

information from

Answer 25

sensory memory for additional processing.

Question 26

If there is a bottleneck on sensory processing, it must be after

Answer 26

sensory (iconic) memory

Question 27

How do we focus on (pay attention to) specific elements?

Answer 27

The tone in Sperling’s experiment told us what was important.

the tone was the cue that told us what we need to process out of sensory memory

Question 28

We use our attention to

Answer 28

endogenously orient to what is most
important to us in the immediate environment. Those are the
things that need to be fully processed

Question 29

We focus our attention on the

Answer 29

relevant channel…

we seem to have different pathways for dealing with sensory information

Question 30

What is a channel?

Answer 30

• The concept comes from information processing and started with air traffic
monitoring.

• Channels can be divided by sensory modality (e.g. auditory channel, visual channel, tactile channel, etc.).
- any way that info comes to you that constitutes a distinct channel

• Within a modality, you can also have multiple channels (e.g. two speakers, two screens, etc.).
- different ways in which the info is coming to you

• A channel is any coherent sensory stream, object, location, etc. that demands or uses attention.

slippery!!

Question 31

interface between exogenous memory and endogenous memory

Answer 31

tone was an exogenous cue (salient, relevant but only because endogenously we were listening to it and we knew what to do with it)

tone can from outside (exogenous) and was salient only insofar as we said it was (endogenously it was part of the task, part of the goal )

it was a goal, but the cue was distinctive and exogenous

Question 32

why are channels slippery?

Answer 32

what constitutes a channel?

sensory channels (vision vs. audition) but within those modalities you can have several channels (things you are paying attention to) but more broadly a channel is any coherent sensory stream so that you can have an object as it’s own channel or a location in space as it’s own channel (if a lot of things are happening there)

a channel becomes a general thing that engages your attention: it’s what your attention can focus on for some period of time
- hard to draw that line

Question 33

how do we switch back and forth between channels?

Answer 33

We tend to select the sensory
channel that is most relevant at
any one time.

Question 34

selective attention

Answer 34

We tend to select the sensory
channel that is most relevant at
any one time.

• This is a dynamic process. You
focus on some items, but a
strong exogenous cue (e.g.
someone yells “Fire!”) will
capture our attention.

• Some stimuli (e.g. your name)
appear to be inherently
relevant.

Question 35

Dichotic listening tasks

Answer 35

are used to test how well we attend to specific channels.

• Subjects are presented with two
auditory channels (one in each ear).

• They are instructed to attend to one channel and shadow the content (repeat it out loud).

• Afterwards, the participants are
tested to see what they recall from both the attended and unattended channels.

Question 36

Based on the Sperling ‘span of apprehension’ test, what

do you expect the results would be of the dichotic listening task?

Answer 36

they should recall the attended content only

if you had full report (reporting everything) then not everything could get through (only the things you’re actively attending to could make it)

the listening task is full report (only report things from the attended channel)

Question 37

Your attention system(s) help

Answer 37

constrain complexity to manage

processing, resource and action limitations.

Question 38

Endogenous attention is directed by

Answer 38

you

Question 39

exogenous

attention is captured by

Answer 39

salient stimuli

Question 40

The ‘span of apprehension’ experiments showed that

Answer 40

the
processing bottleneck seem to occur after iconic and echoic
memory.

Question 41

We use selective attention to

Answer 41

process information in one

channel and ignore other channels.

Question 42

Dichotic listening experiments show that

Answer 42

we can reliably do this, but that highly salient information still captures attention.

Question 43

Note that dichotic listening (in this case) is a full report paradigm.

Answer 43

Subjects should lose what was unattended in

echoic memory.

Question 44

the cocktail party effect

Dichotic listening experiments

Answer 44

Dichotic listening experiments typically show that people can easily shadow the attended channel (ear) without interference
from the other channel.

two physical stimuli coming in but you’re able to exclude part of it because you’re not attending (focusing) on it

Question 45

Dichotic listening experiments

Colin Cherry (1953)

Answer 45

• found that people could not report content

from the unattended channel.

Question 46

Dichotic listening experiments

Neville Moray (1959)

Answer 46

found that subjects couldn’t recognize a word repeated 35 times in the unattended channel.

Question 47

selective attention

Answer 47

can be really affective!

Question 48

Unattended items usually

Answer 48

decayed from echoic memory

they don’t get used so they’re filtered out - buff gone.

Question 49

Dichotic listening experiments

If not shadowing, subjects tend to

Answer 49

report items from different channels separately (grouped by channel).

Question 50

Some things do ‘break through’ from the selection filter of the unattended channel:

Answer 50

• Cherry (1953) found that people could report gender, pitch changes, or abrupt tones in the unattended channel. ((but not content)
• Moray (1959) reported that names and other ‘important information’ could get through (~30% of the time).
• In each case, highly salient information seems to capture attention (however briefly). These items were processed before they decayed from sensory memory.

Question 51

Given that some salient, exogenous cues capture attention, this was a problem for Broadbent’s early selection model:

Answer 51

messages –> sensory memory –> fliter (attended or unattended channel –(attended message)–> detector –> to memory

How do unattended (but salient) stimuli get through the filter?
Perhaps some meaning is being processed?

Question 52

Suppose you are attending to one auditory channel and ignoring the other. If you habituate to the stimuli in the unattended channel and then it suddenly changes in pitch,
this would cause:

Answer 52

Dishabituation