Attention Flashcards
Learning objectives:
• 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
Inattentional blindness
Anecdote that started the inquiry
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?
Inattentional blindness
Research study (Chabris 2011) –
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
Inattentional blindness
Definition
Inattentional blindness – the failure to see visible and otherwise salient events when paying attention to something else
Inattentional blindness
Everyday examples
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
Attention spotlight
What is this?
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
Attention spotlight
Target detection study (Laberge, 1983)
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
Attention spotlight
Posner (1980) quote
“more attentional resources to the centre and more diffuse attentional processing to the periphery”
Attention spotlight
What might shift our attention spotlight?
Environmental cues
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
Attention spotlight
Exogenous cues
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)
Attention spotlight
Endogenous cues
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)
Attention spotlight
Exogenous and endogenous cues data
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
Attentional spotlight
Key terms with timing
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
Inhibition of return
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
Global/ local processing
Navon task
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.
Individual differences and the attention spotlight
Autism study
“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
Feature integration - motion perception
Global and local motion
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.
Feature integration - motion perception
Global and local motion fMRI study
Zaretskaya, Anstis & Bartels, 2013
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…
Feature integration - motion perception
Global and local motion fMRI study
Zaretskaya, Anstis & Bartels, 2013
Brain activity localization
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.
Stroop Task outline
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.
Stroop Task - fMRI Study
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.
Recap of lecture so far
• 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
Investigating attention using ERPs - how can ERPs help?
Luck et al, 2000
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.
ERPs and the Neural Basis of attention - overview
- 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
