inf1:introtocognive&science&& introduc-onto aen-on · february 8, 2012! intro to...

February 8, 2012 Intro to Cognitive Science 1

Inf1: Intro to Cogni-ve Science Introduc-on to A5en-on

Helen Pain, Alyssa Alcorn and Henry Thompson

1. What is a5en-on? What is a(en+on? What does it mean to a(end or pay a(en+on

to something?

Defini+ons of a"en%on used in psychology and cogni+ve science are usually not the same as how we commonly use the word.

Common-‐usage defini+on from the Oxford English Dic+onary:

*To a(end (v): to direct the mind or observant facul+es, to listen, apply oneself; to watch over, minister to, wait upon, follow, frequent; to wait for, await, expect.

*a(en+on (n): The ac+on, fact, or state of a(ending or giving heed; earnest direc+on of the mind, considera+on, or regard....The mental power or faculty of a(ending.

Even in everyday speech, we treat a(en+on as something that can be directed, applied, or used to follow something. What does that actually mean in terms of cogni+on?


2. Scien-fic defini-ons of a5en-on

Two “textbook” defini+ons of a(en+on suggest more of what the process of a(ending actually does:

*A(en+on means devo+ng cogni+ve resources

“to specific features of the environment in such a way that causes those features to become more deeply processed” (Goldstein book, Chapter 6)

*A(en+on is “The process by which organisms select a subset of available informa+on upon which to focus for advanced processing...and integra+on.” (Ward, 2008).


2. Scien-fic defini-ons of a5en-on, contd Both of these highlight several crucial concepts that inform our

study of a(en+on

-‐ A(en+on is selec%ve *Out of many available items or features, we process only a

few at any given +me because we CANNOT process all of them.

*The selec+on process is influenced by both bo(om-‐up (s+mulus) and top-‐down (cogni+ve) factors.

-‐ A(ending to items or features has a cogni%ve cost in terms of processing.

*We process a(ended items more deeply and in greater detail than non-‐a(ended items

-‐ A(en+on plays a role in integra%ng informa+on


3. Introduc-on to selec-vity, a5en-on and the central execu-ve

Lecture material on the Baddeley-‐Hitch model of working memory (a later unit in this class) describes a modular model of memory which includes an “a(en+onal controller” module that directs

*Selec+on: Which informa+on should be manipulated and stored in memory

*How informa+on should move between modules (more on different modules in the memory unit).


3. Introduc-on to selec-vity, ... The central execu%ve directs other modules’ ac+vi+es rather than storing informa+on, and appears to operate in many other areas of cogni+on with many of the same func+ons

*Direc+ng a(en+on to items or tasks (selec+ng the focus of a(en+on)

*Switching a(en+on between tasks *Dividing a(en+on among mul+ple tasks Other closely related func+ons of the central execu+ve include planning/sequencing of ac+ons, and self-‐monitoring speech and behaviour

Damage to the prefrontal cortex (frontal lobes) can severely disrupt most or all of these func+ons.


4. What does it mean to say that a5en-on is selec-ve?

Again, we cannot process everything in our immediate environments all the +me. There is too much of it, and it is not all equally important!

Selec+vity example from hearing: *You are at a crowded party and run into your friend. The two of you stand and talk.

*Even though there is music playing and other conversa+ons around you, you have no trouble following what your friend is saying.


4. What does it mean to say that a5en-on is selec-ve? (contd) The ability to easily follow this one auditory “thread” while ignoring others is known as the cocktail party effect (Cherry, 1958).

*A(en+on makes the effect possible by allowing you to selec%vely a"end to only some auditory s+muli in the environment (your friend’s voice) while ignoring others

*This can also be conceptualised as filtering out the irrelevant s+muli.

Note: Selec+vity is most easily demonstrated with visual and auditory s+muli and examples, but applies to all of our sensory modali+es!


5. Another example of selec-ve a5en-on Example from vision: Our overall visual percep+on of the world tends to appear complete, coherent, and sharply detailed

*Like the apparent directness of vision, this is also an illusion!

*We have a very +ny area of high visual acuity, the fovea, which we must direct to an item to see its detail. Peripheral vision has very poor acuity and is actually blurry.

This suggests that our percep+on of the world as sharply detailed cannot be correct, simply due to the physiology of our eyes!


5. Another example of selec-ve a5en-on, contd

*We move our eyes to (and focus our a(en+on on) small areas at a +me, processing them in detail

*The rest of a scene is “filled in” by a combina+on of vision, memory, and schemas (defined on next slide)

By extension, this suggests that our mental representa%on of the content and organisa+on of scenes is also very uneven

*Most of it minimally detailed *Only a few areas more deeply processed and encoded as a result of a(en+on


6. What are schemas? Schemas (singular: schema) are integrated pieces of knowledge about the world

*Structure and organise our knowledge about environments, events, and phenomena

*Allow us to form expecta+ons about the world and help us to predict what to do

For this reason, events and items which violate a schema tend to be salient and well-‐remembered


6. What are schemas? contd Examples:

*Your script for what happens when you go to a restaurant

*Knowing what sort of things are usually found in hospitals rather than office buildings

In reading or listening to spoken language, schemas allow us to fill in pieces that are literally missing.

*More importantly, they allow us to draw inferences about content and mo+va+ons

See Baddeley chapter 6 for more on schemas.


7. Top-‐down versus bo5om-‐up a5en-on: determining which s-muli are relevant

At any given +me, there are two concurrent mechanisms at work determining what we a(end to

Top-‐down a"en%on (endogenous a(en+on) involves a conscious decision to focus on some items and not others

*Listening to only your friend’s voice out of all the conversa+ons at the cocktail party

*Scanning a library bookshelf looking for the specific +tle you want

*Usually depends on a current goal or task


7. Top-‐down versus bo5om-‐up a5en-on: determining which s-muli are relevant

Bo"om-‐up a"en%on (exogenous a(en+on) is when the features of something in the environment ac+vely captures our a(en+on

*Moving or flashing objects, bright colours, loud sounds

*Objects such as a human figure or face (for neurotypical people)

It appears possible to develop a"en%onal biases, or predisposi+ons to preferen+ally a(end to some s+muli over others, that are unrelated to a specific task and persist over long period of +me.

We will discuss this more in a subsequent lecture.


8. A5en-on and visual search In the following display, there is a bar which is the “odd one out,” ....

Put up your hand when you spot it....


8. A5en-on and visual search


8. A5en-on and visual search In the display, there is a bar which is the “odd one out,” due to its conjunc%on of features (both red and ver+cal)

In order to find the target, it is necessary to scan the display almost item-‐by-‐item, a(ending to each in turn

*This is known as a serial search *Examples: Finding your friend’s face in a crowd, finding the right jam on a crowded store shelf, looking for the right item in the table of contents


8. A5en-on and visual search contd. In these line displays, the target s+mulus “pops out” because it differed from all other items in its colour or orienta+on


8. A5en-on and visual search contd. *For those displays, we looked instantly at the target item because it was the “odd one out”

*It would s+ll a(ract our a(en+on whether there were five items, or 105 items.

*This is known as a parallel search, in which all items are essen+ally “searched” at the same +me.


9. Visual salience and a5en-onal capture Objects with high visual salience tend to be those capable of

bo(om-‐up a"en%onal capture. Salience is a “perceptual quality which makes some items in

the world stand out from their neighbors” (Ij, 2002) *Conspicuous due to bright colour or mo+on, etc. Important! Note that top-‐down goals and demands will

almost always modulate pure bo(om-‐up salience *Salience is not an intrinsic physical or sta+s+cal quality!

Context is important! *The most salient object in one scene might not be salient

in another, when your top-‐down goals are different.


10. Saliency mapping Saliency mapping is a technique for crea+ng representa+ons of

a scene that mark which areas a human observer is likely to perceive as having high or low salience.

*By extension, it is a map of where a person is likely to a(end first in a scene.

February 8, 2012/www.scholarpedia.org/article/Image:Beach.gif Intro to Cognitive Science 21

10. Saliency mapping contd.

Saliency maps can be computed by a variety of algorithms, and may consider some combina+on of contrast, line orienta+on, colour, and texture.

*The output of saliency-‐compu+ng algorithms may then be assessed by comparison with hand-‐tagged images or eye-‐tracking data

Saliency maps are a useful tool, but may oken disagree with human behavioural data because they can only consider bo(om-‐up elements (e.g. contrast) and not top-‐down demands (“I need to find a specific thing in this picture”)


11. Eye tracking in a5en-on research Eye tracking is currently the best way to study how humans view images and scenes, and to infer what things we a(end to, for how long

Most eye-‐trackers are camera-‐based, and the most accurate oken require holding the head in place

Viewing pa(erns can be represented graphically *The lines indicate eye movements, or saccades *Dots indicate fixa%ons where the eye comes to rest. These indicate where a person is a(ending.


11. Eye tracking in a5en-on research


11. Eye tracking in a5en-on research contd.

Informa+on about gaze can be applied to designing more usable web page layouts or other visible materials (and, of course, to sell things more effec+vely!)


http://www.google.com/imgres?imgurl=http://www.assertivemagazine.com/wp-content/uploads/30-usability-issues-to-be-aware-of/tracking .jpg&imgrefurl=http://www.assertivemagazine.com/tag/usability/page/6/&usg=__KhUQYpAwzGzPxZk6ysECrT3xg4k=&h=382&w=478&sz=166& hl=en&start=7&zoom=1&itbs=1&tbnid=0HknLOudbhNz2M:&tbnh=103&tbnw=129&prev=/images%3Fq%3Deye%2Btracking%26hl%3Den%26sa% 3DX%26rlz%3D1T4DKUS_enUS256US259%26tbs%3Disch:1%26prmd%3Divbl

12. Focus areas within the rest of this unit Func+ons of a(en+on *Deeper processing of s+muli *Orien+ng *Filtering or selec+on *Searching *Integra+on A(en+on research in and out of the lab *Feature integra+on and illusory conjunc+ons *Change blindness *Eyewitness misiden+fica+on *Image salience and eye-‐tracking


References Sensa+on and Percep+on (Goldstein 2007 or 2010) Chapter

6 Scholarpedia ar+cles for ... *“A(en+on” (Ward, 2008) h(p://www.scholarpedia.org/

ar+cle/A(en+on *“Visual salience” (Ij, 2007) h(p://

www.scholarpedia.org/ar+cle/Visual_salience *“Saliency Map” (Niebur, 2007) h(p://

www.scholarpedia.org/ar+cle/Saliency_map For more on the cocktail party effect... *Cherry, E. C. (1953)

Some experiments on the recogni+on of speech, with one and with two ears.

See A"en%on reading list for readings... (to be updated)


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