Attention

Question 1

Learning objectives:

Answer 1

• Use the following terms:

• Inattentional blindness
• Attention spotlight
• Endogenous/Exogenous
• Inhibition of Return
• Explain the mechanisms of the attention spotlight, attention cueing and feature integration
• Explain how fMRI can be used to establish which brain areas are involved in attention processes
• Explain how to assess the neural basis of attention using ERPs

Question 2

Inattentional blindness

Anecdote that started the inquiry

Answer 2

Police officer in Boston ran past a brutal assault while pursuing a criminal (different crime), didn’t see the assault at all. Prosecuted for perjury. Is it possible to run past something and not see it?

Question 3

Inattentional blindness

Research study (Chabris 2011) –

Answer 3

Research study (Chabris 2011) –

Task: “Follow the runner maintaining a distance of 30ft”… had to follow a runner around a specific course (picture 1). At the end of the route the researchers asked the ppts did they see anything unusual/ did you see anyone fighting? There were people fighting next to the running route.

**2 conditions:
Day time vs Night time

Results:

• In daytime 72% saw the fight
• Night time 35% saw the fight

**Another 2 conditions:
Asked ppts to count how many times the runner tapped their head as they were running, ppt had to count while maintaining distance.
- Had to count either how many times they tapped with their left hand
- or how many times they tapped with both left and right hands.

Results:

• When ppts asked to count just left hand, 56% able to spot the fight
• When ppts asked to count both left- and right-hand taps, 42% able to spot the fight
• **What this means:
• Probably very harsh to prosecute the police officer, completing a cognitively challenging task, plausible that he did not see the fight. Phenomenon is called inattentional blindness

Question 4

Inattentional blindness

Definition

Answer 4

Inattentional blindness – the failure to see visible and otherwise salient events when paying attention to something else

Question 5

Inattentional blindness

Everyday examples

Answer 5

Can you think of an everyday example of inattentional blindness?
- Driving on the road and missing a cyclist

Would inattentional blindness be more likely to affect an expert or a novice? Why?
- Novice, it takes a lot more cognitive resources to concentrate on driving, for example, for an inexperienced driver compared to an experienced driver

Question 6

Attention spotlight

What is this?

Answer 6

We aren’t able to attend to all stimuli in our environment at once. The attention spotlight theory/ attention as a limited resource theory views attention as…

…the spotlight of our consciousness that is focused on some aspect of our environment that we are currently attending to.

This spotlight can be moved around our environment intentionally or automatically as our attention shifts.

Think “where’s wally” - shifting of spotlight around the page

Question 7

Attention spotlight

Target detection study (Laberge, 1983)

Answer 7

Target detection study (Laberge, 1983)

Showed some strings to ppts, timed how long people took to notice a target item to appear at one of these 5 locations

Found that when a target appeared in the centre of the screen, people were faster to spot the target

Question 8

Attention spotlight

Posner (1980) quote

Answer 8

“more attentional resources to the centre and more diffuse attentional processing to the periphery”

Question 9

Attention spotlight

What might shift our attention spotlight?

Environmental cues

Answer 9

Environmental cues

Something happening in the environment causing us to shift our attentional spotlight around

There are two types of environmental cues:

• Exogenous cues
• Endogenous cues

Question 10

Attention spotlight

Exogenous cues

Answer 10

Cue that happens in a location we are not currently attending to, causes us to shift our attention to that particular location

Valid = cue appears in same place as stimulus (helpful)

Invalid = cue appears in a different location 
to stimulus (unhelpful)

Question 11

Attention spotlight

Endogenous cues

Answer 11

Symbolic cue e.g. an arrow directing our attention left or right but not to a specific location

Valid = cues our attention in the right direction
(helpful)

Invalid = cues our attention
in the wrong direction
(unhelpful)

Question 12

Attention spotlight

Exogenous and endogenous cues data

Answer 12

When delay between cue and target is short:

• If cue is valid to target, quick to identify target
• If cue is invalid to target, takes longer to identify target

If there’s a delay between cue and target:
- if the cue was valid, inhibition of return occurs –> slower to detect targets even when validly cued

Question 13

Attentional spotlight

Key terms with timing

Answer 13

Stimulus onset asynchrony - time between onset of first stimulus and onset of second stimulus

Inter-stimulus interval - time between offset of first stimulus and onset of second stimulus

Question 14

Inhibition of return

Answer 14

Definition: people respond ore slowly to target stimuli in locations where they previously viewed a distractor or irrelevant stimuli.

IOR allows us to not just focus on one thing in the visual field, helps us to search multiple locations. If we didn’t have IOR we might just become fixated on one aspect of a picture, without taking in the whole scene

If monkeys had no IOR… In terms of their foraging activity, they would become less efficient searchers as they wouldn’t be able to search multiple locations at once, would become fixated on one location

Question 15

Global/ local processing

Navon task

Answer 15

The navon task assesses whether global information (larger scale) interferes with local information processing

[Image] Letters S and H made up of smaller letters, either S or H respectively, some conflict and some don’t

Task: Clap when you see a small S (e.g. image 1 or 3)

Easier to distinguish when the smaller letters were S as well as the larger letter, there was conflict when small Hs appeared, making the task significantly harder.

In this task we are required to shift our attention between very narrow point and a broader point, difficult, creates lots of conflict.

Individual differences affect this, some people quicker than others when clapping.
Order effects also affect it, you get better with practice.

Question 16

Individual differences and the attention spotlight

Autism study

Answer 16

“Autism and a deficit in broadening the spread of visual attention”

Study:
Took a group of ppts who had a diagnosis of autism and a group who were classified as neurotypical. Showed two images of lines crossing, asked to say which line was longer.
So first one vertical line is longer, then break, then the horizontal line is longer

Data:
Autistic participants had difficulty broadening their attentional spotlight

Findings:
Task was to change your attention spotlight from a narrow field to a broader field. Ppts with autism had difficulty doing these trials – broadening their spotlight of attention, number of responses was lower and they were slower at completing the task

Question 17

Feature integration - motion perception

Global and local motion

Answer 17

Square visual field with dots rotating, 8 dots. Can either be viewed as 4 pairs rotating in small circles (local motion) or 2 sets of 4 rotating in larger square motions (global motions). You can’t see both global and local motion at once.

Question 18

Feature integration - motion perception

Global and local motion fMRI study

Zaretskaya, Anstis & Bartels, 2013

Answer 18

Zaretskaya, Anstis & Bartels, 2013 - Study:

Asked people to lay in an fMRI scanner and asked to watch stimulus video of global/local motion, asked to report what they saw

Findings:
Ppts tended to report different perceptions over time, would see one type of motion at one speed, 15 second break, motion in different direction at different speed, 15 second break, different colour/speed/direction etc…ppts would report seeing global/ local motion at different points throughout the trial

Overall, when they compared the scan with when the participants weren’t completing the tasks, there was increased activity in certain areas…

Question 19

Feature integration - motion perception

Global and local motion fMRI study

Zaretskaya, Anstis & Bartels, 2013

Brain activity localization

Answer 19

Overall, when they compared the scan with when the participants weren’t completing the tasks, there was increased activity in certain areas…

The right posterior parietal cortex plays an important role in directing attention between local and global information.

This study suggests that spatial and feature-based attention are closely related, and these functions are processed in the anterior intraparietal sulcus.

Global vs local trials – in blue we can see the areas that are more active when ppts are perceiving local motion over global motion, in the orange we can see the areas that are more active when people say that they’re perceiving the global motion over the local motion

In particular, the only area that has really lit up in orange, is the area that’s more active in global over local motion, so this is the area that is processing global motion - anterior intraparietal sulcus.

This is data that is averaged over lots of participants

For each of the participants, the areas of activity that are more active for global (rather than local) are pretty similar. So not only can we see this when averaged over lots are participants, we can also see this on an individual level.

***Overall Conclusion:
The right posterior parietal cortex plays a very important role in directing attention between local and global motion. Suggests that spatial and feature based attention are closely related, and the functions are processed in the intraparietal sulcus.

Question 20

Stroop Task outline

Answer 20

Task:
Identify the colour of the text you see, don’t read the word just perceive the colour of the word

It’s difficult for us to inhibit/supress our natural tendency to read words, even when trying not to, as adults who speak English we tend to do this automatically. This is learnt over time, changing throughout development. This task is much easier for a non-native English speaker as there is less conflict between reading the word and identifying the colour.

Question 21

Stroop Task - fMRI Study

Answer 21

Study:
Researchers tested people at different ages in an fMRI scanner whilst completing a Stroop task. They were trying to find out which areas in the brain are associated with this conflict processing, and do they change as we age.

On the trials where there was a conflict vs where there was no conflict, where there was conflict there was more activity in the brain overall, but it was also located in specific regions –
areas that was more active during conflict (when trying to attend to one aspect of the stimulus);
- left lateral prefrontal cortex
- left parietal and parieto-occipital regions
- anterior cingulate

This was the first study to show the relationship between Stroop task-related brain activity and age

They found a positive correlation between age and stroop related activation in the areas previously mentioned, but the development in the different areas happened at different points.

The left parietal and parieto-occipital cortexes, the process seemed to be fully developed by adolescence.
The left lateral prefrontal cortex, the activity seemed to be developed by adulthood.

The anterior cingulate – general progression.

Question 22

Recap of lecture so far

Answer 22

• Attention is necessary for perception

It’s not just necessary to have things in the visual field, we need to attend to them in order to perceive that they exist

• Attention can be cued from object to object/ location to location/feature to feature
• Attention can be narrow/ broad

Depending on the top-down processes or how we are trying to direct our attention

• Parietal/parieto-occipital regions are heavily involved in attention processin

Question 23

Investigating attention using ERPs - how can ERPs help?

Luck et al, 2000

Answer 23

Basis:
Asking participants to attend to the same visual stimulus in two different ways and then comparing the responses between the two different conditions can tell us about the attention process.

Study:

• In this example participants were shown the same stimulus multiple times but asked to attend to it differently. Their neural activity was recorded and compared.
• Had to fix their eyes on the fixation cross, their eyes stayed in the same place but their attention spotlight changed.
• When participants looked at the stimulus shown and attended to the left, where there was a large black block to process, the neural response was as shown on the black trace.
• When participants looked at the stimulus shown and attended to the right, where there was no visual stimulus to process, the neural response was as shown on the dashed trace.
• We can see that the neural response was stronger when the participant viewed the stimulus shown and attended to the left than when the participant viewed the stimulus shown and attended to the right.

It makes sense that this visual evoked response would be stronger when attending to something visually striking (i.e. black against white) compared to something non-visually striking (i.e. nothing).

But critically, what we can see here is the timing of the difference. The onset of our attention is happening very quickly after the stimulus appears, within 100ms.

Question 24

ERPs and the Neural Basis of attention - overview

Answer 24

• ERPs demonstrate the neural response under different task conditions
• ERPs can tell us about the timing of attention processes
• ERP components can show between-group differences in attention mechanisms