Foundations of Attention
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Lecturer in Computational Psychophysiology
School of Sport Science, Bangor University, UK
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William James
Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrain state.
point 1: We can choose the focus of attention. Attention can be voluntary.
point 2: Inability to attend to many things at once
point 3: Limited capacity to process information. Attention is a selective process
These videos are meant to demonstrate we don’t notice obvious changes when we don’t pay attention to them.
The Monkey Business Illusion: https://www.youtube.com/watch?v=IGQmdoK_ZfY
The demonstration was designed for observers already familiar with the previous one. Knowing that an unexpected event may occur does not ensure that other unexpected events are noticed.
There are several theoretical models of visuospatial attention (but we will not go through each of them)
It is useful to think of attention as a spotlight moving in space

Selecting a certain location or object in space, so that processing of those stimuli is facilitated.
Events occurring in that location (vs those occuring in another location):
Orienting of visuospatial attention = aligning of attention with a source of sensory input or with an internal representation (memory)
Keep your gaze on the center while reading the letters appearing on screen.
+ C O V E R T
Important distinction in the manner visuospatial attention can be oriented.
covert orienting: attention is directed in space independently of the sensorial organs (e.g., direction of eyes or head)
overt orienting: Directing the sensorial organs towards the region of space of interest.
Overt orienting
Introductory video (scene from the movie “Back to the Future”)

Michael Posner
The spatial cueing task is a experiment used to study how attention is directed in space. It helps us understand how cues can guide our focus, even without moving our eyes or head. How does the task work?
There is a catch: the cue does not always tell the truth.
Valid cue
Invalid cue
Neutral cue
Auditory version
Cue: a brief tone presented to either the left, right, of both ears
Target: another brief tone presented to either left or right ear
Task: Press a button as quickly as possible when you hear the target
Tactile version
Cue: a brief vibration presented to either the left, right, or both hands
Target: another brief vibration presented to either the left or right hand
Task: respond with your voice as soon quickly as possible when you feel the vibration
Exogenous orienting: Associated with signals that capture attention automatically and involuntarily (like a sudden flash or sound). It is fast and reflexive.
Endogenous orienting: Associated with symbolic signals (like an arrow or instruction) that provide information about a location. Attention is then oriented voluntarily (intentionally).
In other words, there are two ways that attention can be shifted:
Endogenous shift = “from inside”, goal-directed, top-down (you control it)
Exogenous shift = “from outside”, stimulus driven, bottom-up (the environment controls it). Sometimes associated with a distracting stimulus.
| Exogenous cue | Endogenous cue | |
|---|---|---|
| Visual modality | a flash in a location | an arrow pointing at a location |
| Auditory modality | a tone in a location | a tone pointing at a direction (e.g., a voice saying “right”) |
The two distinctions combine: endogenous and exogenous orienting can each occur overtly or covertly.
| Overt (with eye or head movement) | Covert (without eye or head movement) | |
|---|---|---|
| Endogenous (goal-directed) | A player deliberately turns the head to watch the area into which a team-mate will pass | A dribbling player looks to the right while tracking a team-mate running on the left |
| Exogenous (stimulus-driven) | A tennis player’s gaze is drawn to a spectator who shouts the player’s name | A motorcyclist keeps the eyes on a difficult bend while attention is captured by a crash in peripheral vision |
The previous demonstration included only endogenous cues was
Valid cue The cue is a flash on the left. A short while after, the target appears also on the left. In this trial, the cue was valid.Michael Posner used a spatial cueing task to investigate how attention is directed in space. Participants were asked to fixate on a central point while cues indicated where a target might appear.
The cues could be valid, invalid, or neutral. After a brief delay, the target appeared, and participants responded as quickly as possible. The study measured response times to the onset of the target.
The classic Posner study focused on endogenous (central, symbolic) cues such as arrows presented at the center. Exogenous cues (such as peripheral flashes) were introduced in later studies.
Participants were required to keep their eyes on the fixation cross the whole time.
The classic design typically used 80% valid, 20% invalid, and 50% neutral trials as a separate baseline.
Note
The percentages refer to the distribution of trial types within the experiment, not to a single set of trials. Typically, the experiment is structured so that, for example, 80% of the cued trials are valid and 20% are invalid, while neutral trials are presented as a separate baseline (often making up 50% of the total trials, or sometimes 1/3 if all three types are equally represented). The numbers in the example above are illustrative and not meant to sum to 100% in a single block—they describe the proportions within each trial type.
| trial type | function |
|---|---|
| neutral | serve as a control condition for the other two |
| valid | study the benefits of attending to the correct location |
| invalid | study the costs of attending to the wrong location |
Questions:
Why did Posner decide to make the cue 80% of the times valid? Why not 100%?
If it were 100%, then the cue would never be invalid, and Posner could not study the cost of attending to an incorrect location
Why then 80-20% and not 50-50%?
To build trustworthiness in the cue: the participant oriented their attention to the cued direction because most of the times the cue pointed in the correct direction. If the participant learned over time that the cue was uninformative, they would stop using
Were participants supposed to orient their attention overtly or covertly?
Covertly. In fact, they were required to keep their eyes on the central fixation cross.
Values are illustrative
Key result:
Key interpretation:
Valid cue pre-activates a an attentional path which is the same as that activated by the target
Invalid cue pre-activates a an attentional path which is different from that activated by the target
Invalid trials are, on average, slower than valid trials.
In any sample, two condition means will differ to some extent through random error alone.
Question: how large must a difference be before it is attributed to the cue rather than to chance?
The following slides use simulated data from 45 participants.
The means differ by about 11 ms, but the two distributions overlap almost completely, because participants differ from one another by much more than that.
Each participant is compared with themselves. Differences between participants no longer contribute.
\[ t = \frac{\text{mean difference}}{\text{SD of differences} \,/\, \sqrt{n}} \]
For the simulated sample:
t increases when the difference is larger, when participants are more consistent, and when there are more participants.
Blue: t values from 10000 simulated samples in which there is no true difference between conditions. Grey band: approximately −2 to +2. Red line: the t value of the sample on the previous slides.
With no true difference, t varies by chance around zero, and lies within approximately ±2 in 95% of samples. The observed t is compared with this distribution.
If the observed t lies outside the range expected by chance (p < .05; for samples of this size, approximately beyond ±2), the difference is described as statistically significant.
p is the probability of obtaining a t at least this extreme if there were no true difference.
Statistically significant does not mean large or important. With many participants, a very small difference can be significant.
Results sections report this as, for example, “responses were significantly slower on invalid than on valid trials”. The same wording appears in many articles, including the one(s) to read in this module.
Most later studies are more complex than this.
One (of many) idea: a valid cue does not always cause facilitation…
How can it be? Any ideas?
If the cue is exogenous and the cue-target delay is longer than expected, the target is detected more slowly
This phenomenon is known as inhibition of return (however, this is not topic for this module)
The task is completed in the practical that follows this lecture.
Each participant’s cueing effect (invalid − valid) is pooled, and the class t value is computed.
Try the task yourself at: PsyToolkit spatial cueing task
Can expert athletes detect deceptive movements better than novices?
Overarching aim: determine whether expert basketball players are better than novices in distinguishing true from fake passes
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Participants
Task
Main measure
Both experts and novices performed above chance level, for both movies and pictures: they could distinguish fakes from passes
Experts outperformed novices (i.e., they gave more correct responses) when movies were presented
“Above chance” means that the proportion of correct classifications was significantly greater than the 50% expected from guessing.
Participants
Task
Main measure
Novices performed at the chance level
Experts performed above chance: they could distinguish fakes from passes
Experts performed better when watching from the front than from half-profile
“Above chance” means that the proportion of correct classifications was significantly greater than the 50% expected from guessing.
Interpretation:
visual expertise
motor expertise
How would you follow-up this study?
example: track gaze position to identify which information experts and novices use
Define attention, with reference to its selective and limited-capacity nature.
Distinguish overt from covert, and endogenous from exogenous, orienting. Give a sporting example of each combination.
In the spatial cueing task, why are some cues invalid?
Explain why a difference between two condition means is not, on its own, evidence of a real effect.
overt orienting
covert orienting
exogenous orienting only
inattentional blindness
correct answer: B
an endogenous cue
an exogenous cue
a neutral cue
an invalid cue
correct answer: B
valid trials
neutral trials
invalid trials
trials without a cue
correct answer: C
the mean difference decreases
participants differ more in their difference scores
the number of participants increases
the standard deviation increases
correct answer: C
it is larger than 100 ms
the observed t lies outside the range expected by chance if there were no true difference
every participant shows the difference
the difference is important for performance
correct answer: B
100%
significantly greater than the 50% expected from guessing
greater than that of every novice
equal to 50%
correct answer: B
Please read the article during Reading Week:
Navarro, M., van der Kamp, J., Ranvaud, R., & Savelsbergh, G. J. P. (2013). The mere presence of a goalkeeper affects the accuracy of penalty kicks. Journal of Sports Sciences, 31(9), 921–929.
Social spatial cueing
Directional changes in posture (e.g., eye movements) of a person can influence somebody else’s direction of attetnion.
Sport fakes?