Psychology Chapter on Sensation and Perception

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Questions and Answers

What is the absolute threshold for hearing?

Sound of a whisper at 10 meters

Single teaspoon of sugar in 7.5 liters of water

Tick of a clock at approximately 6 meters (correct)

Candle flame seen at approximately 50 kilometers

According to Weber's Law, how does the Just Noticeable Difference (JND) relate to stimulus levels?

JND decreases with the stimulus value.

JND is constant regardless of the stimulus level.

JND increases with the stimulus value. (correct)

JND is lower for auditory stimuli compared to visual stimuli.

What does signal detection theory distinguish between?

Perceptual signals and background noise.

External noise and internal noise in perception.

Physical thresholds and psychological limits.

Sensitivity to perceive a signal and willingness to report it. (correct)

What is the absolute threshold for taste?

Single teaspoon of sugar in approximately 7.5 liters of water Signup and view all the answers

What is indicated by the absolute threshold for vision?

Ability to see a candle flame on a clear, dark night at approximately 50 kilometers. Signup and view all the answers

What role does the basilar membrane play in auditory transduction?

It causes maximum displacement in response to different sound frequencies. Signup and view all the answers

How does sound localization occur using two ears?

It relies on both interaural time and level differences. Signup and view all the answers

What is conduction deafness?

Hearing loss from mechanical issues in the ear. Signup and view all the answers

What is the range of the average cochlea's length?

About 3.5 cm. Signup and view all the answers

Which of the following statements concerning sound amplitude is false?

Amplitude primarily affects the frequency of the sound wave. Signup and view all the answers

What best describes amplitude in relation to sound perception?

It is the amount of compression and expansion of molecules. Signup and view all the answers

Which brain regions are primarily involved in olfaction and emotional memory retrieval?

Hippocampus and Amygdala Signup and view all the answers

What is the primary function of taste buds in the gustatory system?

They contain chemical receptors that respond to taste qualities. Signup and view all the answers

How do 'supertasters' differ from regular tasters?

They have more sensitive taste receptors for bitterness. Signup and view all the answers

What is the difference between taste and flavor?

Taste refers to five basic qualities, while flavor encompasses overall sensory experiences. Signup and view all the answers

What phenomenon describes the diminishing sensitivity to an unchanging stimulus?

Sensory adaptation Signup and view all the answers

What is the approximate range of light waves that humans can perceive?

700 nm to 400 nm Signup and view all the answers

What structures in the human eye are responsible for transducing light into electrical impulses?

Rods and cones Signup and view all the answers

Which cells form the optic nerve from the axons in the retina?

Ganglion cells Signup and view all the answers

Which area of the retina contains only cones and is responsible for excellent visual acuity?

Fovea Signup and view all the answers

How do human visual systems adapt to low light conditions?

Through dark adaptation Signup and view all the answers

What is a significant downside of having only cones in the fovea?

Lower sensitivity in low light Signup and view all the answers

Which characteristic of rods contributes to their effectiveness in low illumination?

Greater sensitivity to light Signup and view all the answers

What is the primary difference between sensation and perception?

Sensation involves detecting stimuli, whereas perception involves giving meaning to those stimuli. Signup and view all the answers

Which of the following best describes sensory transduction?

The conversion of external stimuli into electrical impulses by receptors. Signup and view all the answers

What does the absolute threshold refer to in psychophysics?

The minimum amount of stimulation needed to detect a stimulus 50% of the time. Signup and view all the answers

Which statement about senses is accurate?

Senses are limited to specific energies and respond within a narrow range. Signup and view all the answers

What is the role of context in perception?

Context can alter the meaning assigned to detected sensations. Signup and view all the answers

What combination primarily determines what we commonly refer to as taste?

Taste and retronasal olfaction Signup and view all the answers

What does the gate control theory explain regarding pain perception?

Sensory inputs can influence the perception of pain. Signup and view all the answers

Which of the following senses provides feedback about muscles and joint positions?

Kinesthesis Signup and view all the answers

What term describes the phenomenon where individuals fail to notice unattended stimuli?

Inattentional blindness Signup and view all the answers

Which Gestalt principle explains that we perceive wholes rather than just the sum of parts?

Gestalt principle Signup and view all the answers

What is the term for the psychological readiness to perceive stimuli in a specific way?

Perceptual set Signup and view all the answers

Which factors strongly influence our perceptual hypotheses?

Context in which we perceive stimuli Signup and view all the answers

What defines critical periods in perception?

Times when certain experiences are essential for normal perceptual development Signup and view all the answers

What role does amplification play in attention?

It enhances the perception of specific stimuli. Signup and view all the answers

What is an illusion in the context of perception?

A compelling but incorrect perception of a stimulus. Signup and view all the answers

Study Notes

Sensation and Perception: Introduction and Measurement

Sensation is the ability to detect a stimulus, potentially turning that detection into a conscious experience.
Perception is the act of giving meaning to a detected sensation, allowing us to understand the world around us.
Sensation and perception are vital for gaining knowledge of the environment.

Absolute Thresholds for Humans

Vision: A candle flame seen at approximately 50 kilometers on a clear, dark night.
Hearing: A ticking watch under quiet conditions at approximately 6 meters.
Taste: A single teaspoon of sugar in approximately 7.5 liters of water.
Smell: One drop of perfume diffused into a large apartment.
Touch: A wing of a fly or bee falling on your cheek from a distance of 1 centimeter.

Psychophysics

Psychophysics is the science that defines quantitative relationships between physical and psychological events.
This establishes how physical stimuli relate to perceptual experiences.

Weber's Law

Explains the smallest detectable change in a stimulus.
The smallest noticeable difference (JND) is a constant proportion of the stimulus level.

Signal Detection Theory

Quantifies an observer's response to a signal, considering background noise (both internal and external).
Four possible outcomes in a signal detection scenario are considered: hits, misses, false alarms, and correct rejections.

Sensory Adaptation

Diminishes sensitivity to unchanging stimuli.
This allows perceptual systems to remain sensitive to changes in the environment.

The Human Eye

Light passes through the cornea, pupil, and lens.
The pupil adjusts size to regulate light entering the eye.
Photoreceptors:
- Rods: Function best in dim light, providing sensitivity. Found throughout the retina except the fovea.
- Cones: Function best in brighter light, providing color vision and detail. Concentrated in the fovea at the center of the retina.

The Fovea

Area in the center of the retina with high visual acuity.
Contains only cones.

Perception Processing in Retina

Rods and cones synapse with bipolar cells, which synapse with ganglion cells, creating the optic nerve.
The axons of ganglion cells form the optic nerve.

Dark Adaptation

Becoming sensitive to low illumination takes time.
Progressive improvement in brightness sensitivity in low illumination.

Trichromatic Theory (Young-Helmholtz)

Three types of color receptors (cones) in the retina that respond maximally to different wavelengths of light (blue, green, red).
These signals combine to produce the perception of other colors.

Opponent-Process Theory

Our visual system analyzes color in terms of opposites (red-green, blue-yellow, white-black).

Visual Pathways

Specialized cells in the visual cortex (including feature detectors) analyze the visual stimulus into components.
This happens in hierarchical fashion, building up more complex features from basic ones.

Visual Perception in the Primary Visual Cortex

Visual information from the eye is projected to the lateral geniculate nucleus (LGN) of the thalamus.
Then, this projected information is sent to the primary visual cortex (V1) within the occipital lobe.
The fovea receives a large representation within the cortex, in order to receive and interpret visual information as detailed as possible.

Inferotemporal (IT) Cortex

Important part of the temporal lobe.
Crucial for object recognition.
Lesions of this area cause deficits in object recognition (anosmia).
It has very large receptive fields.
Does not respond to simple stimuli like lines or spots. It responds effectively to complex objects like faces, hands, or objects.

Sound Localization

Using subtle differences in how sounds arrive at both ears (interaural time and level differences).

Hearing Loss

Various kinds of hearing loss: conduction deafness from issues with the outer or middle ear, or nerve deafness from issues in the inner ear (such as the cochlea). Different types of hearing loss respond differently to solutions.

Taste and Smell

Taste (Gustation):
- Chemical receptors on taste buds.
- Four basic tastes: sweet, sour, salty, bitter, umami.
- Individual differences in taste perception.
Smell (Olfaction):
- Chemical receptors in the nasal cavity.
- Direct connection to the limbic system, influencing emotional responses and memory.
- Relatively poor sense for humans.

Body Senses

Kinesthesis: Provides feedback about muscle and joint positions.
Vestibular Sense: Helps with equilibrium and orientation (in inner ear).

Gestalt Principles of Perceptual Organization

Similarity: Items that are similar are perceived as belonging to the same group.
Proximity: Items that are close together are perceived as a group.
Closure: We tend to perceive incomplete figures as complete.
Continuity: We tend to perceive continuous lines and patterns rather than disrupted ones.

Perception and Hypothesis Testing

Perceptual schemas help us to interpret ambiguous stimuli based on our past experiences.
Our perceptual systems seek clear, concise interpretations of ambiguous stimuli.
Knowing that something is an illusion allows the observer to sometimes see through the illusion.

Critical Periods in Perception

Specific periods are crucial for learning some perceptual abilities. Experiences during these periods can have lasting effects, such as the specific pattern perception in kittens.

Key Concepts for modules 1-3 (summarized)

Module 1: Psychology's roots, scientific method, experimental designs.
Module 2: Neuron function, nerve impulses, synaptic transmission, and brain structure.
Module 3: Sensation and perception (from physical aspects of stimuli to how we build a sense of perception), sensory and perception pathways, cortical processing.

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Description

This quiz covers key concepts in sensation and perception, including absolute thresholds for hearing, taste, and vision, as well as Just Noticeable Difference in relation to Weber's Law. It also explores signal detection theory, auditory transduction, and the function of taste buds, among other topics. Test your knowledge on these foundational principles of psychology.