Attention & Awareness
Why can something reach the senses without reaching conscious awareness?
Seen but not noticed
Describe a situation in which a person could look directly at a scene yet fail to notice an unexpected detail. What might attention be doing?
What does attention select?
By the end of today
- Define selective and divided attention.
- Explain inattentional blindness and change blindness.
- Use reaction time and accuracy to study attention.
- Explain why “humans cannot multitask” is too absolute.
- Design a fair test of a multitasking claim.
inattentional blindness
Formal definition
Failure to notice a visible and unexpected stimulus when attention is engaged elsewhere.
Student-friendly definition
Something can be right in front of you and still go unnoticed because your attention is committed to another task.
Related: selective attention · awareness · unexpected stimulus · task demand
Attention as limited selection
Selective attention
Prioritizing some information for processing while other information receives less attention.
Divided attention
Attempting to allocate attention across more than one task or information stream.
Change blindness
Failure to notice a change in a visual scene, especially when the change is interrupted or attention is elsewhere.
Reaction time
Time between a defined stimulus and a defined response.
Accuracy
Proportion or number of responses that meet the scoring rule.
Visual search
A task requiring detection of a target among other items.
Attention is selection under limited processing conditions
The senses continuously deliver more information than can be fully processed at once. Selective attention helps prioritize information that is relevant to current goals. This is useful: without selection, every sound, color, movement, memory, and bodily sensation would compete equally for processing.
Selective attention also creates limits. Inattentional blindness occurs when people fail to notice an unexpected but visible event while focused on another task. The stimulus may reach the eyes, but awareness depends on attention. Change blindness similarly shows that people can miss substantial changes when attention is interrupted or not directed to the changing feature.
Divided attention examines performance when people attempt more than one task. Some combinations can be performed together relatively well, especially when one task is highly practiced or relies on different resources. Other combinations interfere strongly. Rapidly switching between demanding tasks often produces costs in time, accuracy, or memory. Therefore, “humans cannot multitask” is too absolute, but “performing two demanding tasks at once can produce measurable interference” is well supported.
Psychologists study attention using reaction time, accuracy, eye movements, brain measures, and carefully controlled task conditions. A visual-search task can vary the number of distractors and examine how search time changes. If reaction time rises sharply as more distractors are added, the task may require more serial attention. If reaction time stays nearly constant, the target may “pop out” because a feature is easy to detect in parallel.
Attention is not simply eyesight. A person can have normal visual input and still fail to notice an object because of task demands. Conversely, noticing something does not mean it received deep processing or will be remembered accurately.
Task switching
Students complete two simple tasks separately in 40 seconds each. When required to switch between them every few seconds, total completion time rises to 104 seconds with more errors.
The extra time is evidence of switching cost under those conditions. It does not prove that every form of doing two things together is impossible.
Claim audit
- Define what counts as multitasking.
- Specify whether tasks are simultaneous or rapidly switched.
- Measure reaction time, accuracy, and memory.
- Compare easy/practiced versus demanding task combinations.
- State a conclusion proportional to the conditions tested.
Visual Search Lab
| Distractors | Target present: mean RT | Accuracy |
|---|---|---|
| 4 | 410 ms | 98% |
| 8 | 475 ms | 97% |
| 16 | 590 ms | 94% |
| 24 | 690 ms | 92% |
Reaction time increases as the display becomes more crowded, while accuracy declines slightly. This suggests greater search demand in this fictional task.
“If you looked at it, you must have seen it.”
Verdict
Unsupported. Eye direction and sensory exposure do not guarantee attention or conscious awareness.
Better statement
Looking can make visual information available, but noticing depends on attention, expectation, task demand, and other factors.
Design a fair multitasking test
| Design component | Your plan |
|---|---|
| Task A | |
| Task B | |
| Single-task baseline | |
| Dual-task condition | |
| Measures | |
| Potential confound |
Multitasking Claim Test
Write a 500–700 word research design testing a specific multitasking claim. Include operational definitions, single-task baselines, dual-task condition, reaction-time and accuracy measures, one alternative explanation, and a conclusion statement that avoids an absolute “can/cannot multitask” claim.