Lecture 7 - Attention in Space and Time

Question 1

Define Spatial Attention

Question 2

What is one of the common ways our ability to engage in Visual Search is studied?

Question 3

In Visual Search experiments, what effect do pop-out targets have on response times compared to non pop-out targetst?

Answer 3

Pop-out targets show little effect on RTs, even in large set sizes, compared to non pop-out targets, which, with increasing set size RTs increase.
We are very good at recognising pop-out targets.

Question 4

What determines whether a target will be a pop-out target or not?

Answer 4

Unique colours and unique orientations will both pop out.

Question 5

What is parallel search?

Question 6

In conjunction target tasks, what is the difference between RTs for target present and target absent trials?

Answer 6

Target absent trials have RTs that are twice as long as RTs for target-present trials.
This is interpreted as a “serial search” task.

Question 7

What is “serial search” when it comes to target locating tasks?

Question 8

What is meant by “self-terminating serial search”?

Question 9

Feature Integration Theory (Treisman & Gelade, 1980) is a theory of what?

Question 10

In regards to visual search tasks, when are serial-search and parallel-search used?

Question 11

What are some of the problems with FIT that we discussed in lecture?

Question 12

Based on Wolfe’s (1998) meta-analysis of 2,500 experimental sessions, what did he conclude about the usefulness or validity of serial- and parallel-search as terms for types of search we engage in when performing visual target search?

Question 13

What is Guided Search Theory (Wolfe et al,1989)?

Answer 13

This is a theory of how we engage in visual search, that was birthed in response to Triesman’s Feature Integration Theory. This theory has two stages: 1) a candidate list is generated (parallel search), 2) candidates are serially searched for target.

Question 14

What was Guided Search 2.0 (Wolfe, 1994) and why did Wolfe feel the need to revise the first Guided Search Theory?

Question 15

What was The Stroop Effect (Stroop, 1935)? And, why was it a good example of Focused Attention Failure?

Question 16

In the Stroop Effect, is reading a word considered a faster process than naming a colour?

Answer 16

Yes.

Question 17

What makes a process automatic?

Answer 17

Automatic processes require minimal effort and minimal capacity.

Question 18

What were the findings from the Controlled and Automatic Processing experiment done by Shiffrin and Schneider (1977)?

Question 19

What is The Erikson Flanker Task? And, what were the main effects seen in this task?

Question 20

What is the Zoom Lens Model (Eriksen & St James, 1986)?

Question 21

What is the minimum time required for letter recognition? And, what happens when if exposure time is less than this minimum time?

Answer 21

100ms.

Question 22

What is The Attentional Blink?

Answer 22

Similar to what happens to our vision when we blink. The Attentional Blink occurs when we are processing the identification of the first target - hence, identification of subsequent targets is more difficult.

Question 24

What are some of the effects seen with the Attentional Blink?

Question 25

In visual search tasks with pop-out targets are they affected by set size?

Answer 25

No.

Question 26

In visual search tasks is ability to find non-pop out targets affected by set size?

Answer 26

Yes.

Question 27

When we are searching for a pop-out target we engage in what kind of visual search?

Answer 27

Parallel search.

Question 28

When we are searching for non pop-out targets what type of search are we engaging in?

Answer 28

Serial search.

Question 29

Why are target-absent trials for non pop-out targets for more difficult and have longer RTs than target-present trials?

Answer 29

In target-absent trials we need search each item, whereas in the target present trials once we have located the target we can stop the search, i.e. we do not need to look at each item.

Question 30

Who was the author of Feature Integration Theory of Attention and Visual Search?

Answer 30

Treisman (and Gelade) 1980.

Question 31

What is FIT and how does it explain our ability to quickly identify pop out targets, but it takes us much longer for conjunction or non pop-out targets?

Answer 31

Feature Integration Theory is based on this idea that when we perceive visual stimuli we perceive them in distinct feature maps for colour, orientation etc. It is only when we attend to a specific feature that these maps come together/integrate and we can see unique entities. In pop-out target tasks we just need to identify if there is any activity in the feature map that makes the target pop-out, such as colour. But in conjunction targets we need to focus on each stimuli in order to assess their conjunction of features. If we did not focus our attention on unique entities then there would be activation in the different feature maps, but we would not know whether the activation pertained to which entity - i.e. we would be susceptible to ILLUSORY CONJUNCTIONS.

Question 32

What are some criticisms of FIT?

Answer 32

It has been shown that actually it is not just simple feature differences that make targets pop-out or not, but that quite complex processing/perceiving of features is required for certain pop-out features.

Question 33

What is Wolf et al.'s (1989) Guided Search Theory?

Answer 33

This theory is based on this idea that we don't just engage in either parallel or serial search but that we engage in both parallel and serial search. We first use parallel search to determine what entities may be relevant and then we use serial search to work through these entities to find the target.

Question 34

How many versions of Guided Search have their been?

Answer 34

As of 2021, Wolfe has proposed 6 versions of Guided Search.

Question 35

Wolfe collated the data present at the time on visual search in 1998 and proposed that there did not appear to be this dichotomous differentiation between serial and parallel search as proposed by Treismann's FIT theory. What was his response to this?

Answer 35

Wolfe proposed the idea of Guided Search Theory, which understood attention as involving parallel search that allowed relevant stimuli to be narrowed down into a candidate list and then serial search was used to identify the target. Difficulty of visual search was based on the similarity between distractors and target. Later versions of Guided search took into account the idea the features of the stimuli have different priorities and this is taken into account when doing visual search.

Question 36

What is the STROOP EFFECT?

Answer 36

Stroop Effect describes what happens when asked to name the colour the ink of a word is written in if the word is incompatible with the colour, such as yellow written in blue ink, then our ability to name the colour or RT is compromised.

Question 37

Was the Stroop effect seen as being a failure of the idea of focused attention?

Answer 37

Yes.

Question 38

How did Posner explain what was happening in the Stroop Effect?

Answer 38

Posner suggested that what was happening was that there were two processes occuring: naming the colour and reading the word. Reading in a native language is fast and automatic whereas naming a colour is slower and intentional. There is interference occuring between what was read and naming the colour. This does not occur when the ask to read words that have incompatible colours, which Posner suggested as further evidence as there was no interference from the naming of the colour because it did not need to be intentionally engage in.

Question 39

In Shiffrin and Schneider's 1977 experiment looking at Automaticity, where participants had identify either letter or number targets amidts letter or number distractors, what did they find about learned automaticity and CONSISTENT MAPPING CONDITIONS (where participants only ever had letters/numbers as a target) and VARIED MAPPING conditions (where participants had targets vary between letters or numbers)?

Answer 39

Automaticity was achieved after just over 1000 trials for CM conditions, but was NEVER achieved for VM conditions.

Question 40

In the Eriksen Flanker Tasks where participants are required to indicate whether an arrow is pointing one way or the other and are adjoined by distractors that are neutral, compatible, or incompatible, what do we see regarding RTs for the three conditions?

Answer 40

Neutral flankers - do not affect RTs Compatible flankers - reduce RTs Incompatible flankers - increase RTs This was more evidence for the failure of focused attention, because participants were told the flankers do not matter and so they do not need to attend to them, however, the flankers nonetheless had an impact on performance.

Question 41

What is the ATTENTIONAL BLINK?

Answer 41

The ATTENTIONAL BLINK refers to the phenomenon where in a stream of stimuli, such as letters, known as a RAPID SERIAL VISUAL PRESENTATION once we have identified a target we struggle to identify another target that is presented close in time to the first target. This is thought to occur because whatever cognitive processes we engage in when we identify a target, causes us to mentally "blink" and not be able to identify the other target.

Question 42

In an RSVP where stimuli are abuot 100ms apart, within how many presentations of first target to second target does the attentional blink occur?

Answer 42

When there are around 2-5 intervening stimuli or 200ms-600ms then the attentional blink is worst.

Question 43

What is Lag 1 sparing?

Answer 43

Lag 1 sparing refers to the fact that the attentional blink does not seem to come into affect until around 200ms or after 1 intervening distractor stimuli. If the next target is presented straight after the first stimuli then it is recognised.

Question 44

If target 1 is not identified then do we still see an ATTENTIONAL BLINK?

Answer 44

No. The AB occurs as a results of the cogntiive processes involved IN identifying the first target.