Stimulus to Perception

Flashcards reviewing key concepts related to sensation, perception, and the visual system.

What is the difference between sensation and perception?

Sensation is the raw data received by sensory organs, while perception is the brain’s interpretation of that data.

What is transduction in the context of perception?

Transduction is the conversion of physical stimuli (like light or sound) into neural signals that the brain can process.

How does the brain process sensory information?

Sensory information is transmitted to the brain through neural pathways, where it is interpreted to create perceptual experiences.

What are the major types of sensory receptors?

Photoreceptors (for vision), mechanoreceptors (for touch), chemoreceptors (for taste and smell), and thermoreceptors (for temperature).

How does sensory input lead to perception?

Sensory receptors detect stimuli (e.g., light or sound), convert them into neural signals through transduction, and transmit these signals to the brain, where they are interpreted as meaningful experiences.

What is the role of attention in perception?

Attention allows us to focus on specific sensory inputs, enhancing our perception of relevant stimuli and filtering out distractions.

What is the role of the retina in vision?

The retina contains photoreceptors (rods and cones) that detect light and initiate the process of visual perception.

What is the difference between rods and cones?

Rods are responsible for vision in low-light conditions and detect light intensity, while cones are responsible for color vision and detail in bright light.

What is the fovea?

The fovea is the central part of the retina, where vision is sharpest due to a high concentration of cones.

What is the optic nerve's role in vision?

The optic nerve transmits visual information from the retina to the brain for further processing.

Describe the pathway that visual information takes from the eye to the brain.

Light enters the eye through the cornea, passes through the lens, and hits the retina, where photoreceptors convert it into neural signals. These signals travel via the optic nerve to the brain's visual cortex for processing.

How do the fovea and peripheral retina contribute to visual perception?

The fovea provides sharp, detailed vision due to its high concentration of cones, while the peripheral retina is more sensitive to light and motion but less detailed.

What is bottom-up processing?

Bottom-up processing is perception driven by sensory input, where the brain starts with raw data and builds up a perception from it.

What is top-down processing?

Top-down processing is perception shaped by prior knowledge, experiences, and expectations.

What is the Gestalt principle of proximity?

The Gestalt principle of proximity states that objects that are close together are perceived as part of the same group.

What is perceptual constancy?

Perceptual constancy is the ability to perceive an object as constant despite changes in its appearance due to lighting, distance, or angle.

How do top-down and bottom-up processing work together in perception?

Bottom-up processing builds perception from sensory input, while top-down processing uses prior knowledge to interpret and make sense of that input, guiding perception.

Why is perceptual constancy important for everyday functioning?

It allows us to recognize objects as the same, even when they appear different under various conditions (e.g., a white shirt looks white regardless of lighting).

What is unconscious inference in perception?

Unconscious inference refers to the brain's automatic process of filling in missing information based on experience and context.

What does it mean that perception is inferential?

Perception is inferential because the brain makes educated guesses about sensory data based on prior knowledge and expectations.

How does the brain use context to influence perception?

The brain uses the surrounding context to interpret ambiguous sensory data and make sense of incomplete information.

What is a perceptual set?

A perceptual set is a tendency to perceive things in a certain way based on prior experiences or expectations.

How do illusions illustrate the concept of perception as inference?

Illusions occur when the brain misinterprets sensory data, often due to context, prior knowledge, or expectations, showing that perception is not always a direct reflection of reality.

Give an example of how context can alter perception.

In the “Müller-Lyer” illusion, two lines of equal length appear different due to the context of arrowheads at the ends, demonstrating how context influences perception.

What is the dorsal stream in the visual system responsible for?

The dorsal stream processes spatial information and guides actions, such as determining where objects are located ("where/how" pathway).

What is the ventral stream in the visual system responsible for?

The ventral stream is involved in object recognition and identification ("what" pathway).

What is an affordance?

An affordance is an object's properties that suggest how it can be used (e.g., a doorknob affords turning).

How does perception influence action?

Perception provides the sensory input needed to guide actions, such as reaching for an object or navigating through space.

How do the dorsal and ventral streams work together?

The dorsal stream helps determine how to act based on spatial information, while the ventral stream helps identify what objects are, guiding appropriate responses.

Describe how vision influences motor action in a real-world situation.

When catching a ball, vision processes its trajectory and speed, allowing the brain to adjust motor actions (e.g., moving hands to catch it).