Los límites de la percepción humana
Explora cómo la atención, la adaptación sensorial y el contexto influyen en lo que notamos y en lo que pasamos por alto.
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Questions with solutions-
1. Elige la respuesta correcta.
¿Qué tarea se beneficiaría más de mirar directamente el objeto?
Peripheral vision is useful for noticing movement, but fine detail is much clearer near the center of your gaze.
- Noticing someone walking past you.
- Reading the small print on a bottle.
- Detecting a large flash off to one side.
- Noticing a broad area fall into shadow.
Piensa en la diferencia entre notar algo y examinar sus detalles.
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- Reading the small print on a bottle.
La región central de la retina permite una visión especialmente nítida. Movemos los ojos para que los detalles importantes queden en esa región.
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2. Elige la respuesta correcta.
¿Qué revela esto sobre la atención?
While counting passes in a basketball video, some viewers fail to notice an unexpected person walking through the scene.
- Unexpected events automatically receive priority over an assigned task.
- Missing a visible event necessarily indicates poor eyesight.
- People remain aware of every visible event, even if they cannot recall it.
- Focusing on one task can leave a clearly visible event unnoticed.
Considera lo que los espectadores ya estaban intentando hacer.
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- Focusing on one task can leave a clearly visible event unnoticed.
Esto se llama ceguera por falta de atención. Que algo esté dentro de tu campo de visión no garantiza que lo notes conscientemente.
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3. Completa el espacio en blanco.
An odor stays at the same concentration during uninterrupted exposure, but it gradually becomes less noticeable. This fading sensitivity reflects adaptation to ___.
- continuous stimulation
- weaker stimulation
- interrupted stimulation
- a change in odor concentration
El olor sigue presente con la misma intensidad.
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An odor stays at the same concentration during uninterrupted exposure, but it gradually becomes less noticeable. This fading sensitivity reflects adaptation to continuous stimulation.
La menor sensibilidad a un olor persistente puede ayudar a que los olores nuevos destaquen. Que la sensación se desvanezca no significa necesariamente que el olor haya desaparecido.
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4. Elige la respuesta correcta.
¿Qué expectativa es razonable?
You leave a brightly lit lobby and enter a dim theater. At first, the seats are difficult to make out, although the room's lighting remains steady.
- Colors will generally become more vivid than they were in the lobby.
- Checking a bright phone screen will speed up adjustment to the darkness.
- More details may become visible if you remain in the dim room.
- Fine print will eventually become as easy to read as it was in bright light.
Tu sensibilidad a la luz no es fija.
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- More details may become visible if you remain in the dim room.
La adaptación a la oscuridad lleva tiempo. La visión con poca luz depende en gran medida de los bastones, que son sensibles a la luz, pero no permiten ver los colores.
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5. Elige la respuesta correcta.
¿Por qué el punto que falta no deja un hueco evidente en la escena?
With one eye covered, you look at a mark on a page. A nearby dot disappears at a particular viewing distance, yet the page still appears continuous.
- The eye's lens enlarges the surrounding image to close the gap.
- The brain uses surrounding visual information to complete the missing region.
- The covered eye continues to supply the missing part of the image.
- The blind spot has receptors that detect backgrounds but not small objects.
Considera cómo el cerebro procesa la información visual incompleta.
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- The brain uses surrounding visual information to complete the missing region.
El punto ciego es el lugar por donde el nervio óptico sale de la retina; no tiene células sensibles a la luz. Por lo general, percibimos una escena completa en lugar de este vacío.
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6. Elige la respuesta correcta.
Why might seeing a speaker's face matter even when the audio is clear?
When a recorded syllable is paired with a video of a mouth forming a different syllable, some listeners report hearing a third sound.
- Visual information can change which speech sound a listener perceives.
- Lip movements affect speech perception only when the audio is unclear.
- Visual cues influence judgments about speakers but cannot affect perceived sounds.
- Conflicting visual information makes every listener hear the same third sound.
Are hearing and vision always processed independently?
Show solution
- Visual information can change which speech sound a listener perceives.
This audiovisual effect varies across listeners and sound combinations. It shows that our senses can interact, not that vision always overrides hearing.
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7. Elige la respuesta correcta.
¿Qué explica mejor la diferencia de apariencia?
Two identical gray patches are lit equally. One is surrounded by a dark background and the other by a light background, making them appear different in brightness.
- The visual system judges each patch independently of its surroundings.
- Changing the backgrounds changes the patches' physical reflectance.
- The effect requires different amounts of light to fall on the patches.
- Apparent brightness depends partly on contrast with nearby areas.
Los parches en sí no han cambiado.
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- Apparent brightness depends partly on contrast with nearby areas.
La percepción del brillo es relacional: el mismo gris puede verse más claro sobre un fondo oscuro que sobre uno claro.
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8. Elige la respuesta correcta.
Which change would most directly reduce this interference?
In a rapid stream of letters, identifying one target can briefly make a second target harder to notice when it appears a few tenths of a second later.
- Making the second target resemble the irrelevant letters more closely.
- Requiring an additional judgment about the first target.
- Leaving a longer interval between the two targets.
- Reducing the time each target remains visible.
Consider whether attention has enough time to recover between targets.
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- Leaving a longer interval between the two targets.
This pattern is called the attentional blink. Closely spaced events may compete for limited processing, even when both are clearly displayed.
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9. Elige la respuesta correcta.
What trade-off is likely?
A lifeguard begins treating even faint, uncertain movements as possible signs of distress. Visibility and the lifeguard's sensory ability have not improved.
- Fewer false alarms, but more missed emergencies.
- Fewer missed emergencies, but more false alarms.
- Fewer missed emergencies and fewer false alarms.
- More missed emergencies and more false alarms.
The lifeguard has changed the threshold for responding, not the quality of the evidence.
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- Fewer missed emergencies, but more false alarms.
A lower decision threshold makes someone more willing to report a signal. It does not make the underlying sensory information clearer.
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10. Elige la respuesta correcta.
What is the main trade-off in relying on context this way?
The same ambiguous symbol appears to be a letter when surrounded by letters and a number when surrounded by numbers.
- Context can help resolve unclear input, but it can also favor an incorrect interpretation.
- Context improves perception by preventing ambiguous input from reaching awareness.
- Context makes perception more objective by removing the influence of prior experience.
- Context influences only later memory, leaving the initial perception unchanged.
An expectation can be useful without being reliable in every situation.
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- Context can help resolve unclear input, but it can also favor an incorrect interpretation.
Perception combines sensory information with expectations. These expectations are useful shortcuts, but clearer evidence can overturn the initial interpretation.