Sensation and Perception

What part of the brain is responsible for face recognition?

A specialized sector of the temporal lobe is responsible for facial recognition.

What is the difference between bottom-down and top-down processing?

Bottom-up processing is the analysis that begins at the sensory receptors and works up to the brain. Conversely, top-down processing is the analysis guided by higher level mental processes as the brain perceives based on expectation and experience.

Name the special sensitivity of rods and cones respectively.

Cones are sensitive to detail and color, whereas rods are sensitive to dim light.

What are the three opponent retinal processes.

The three opponent retinal processes are red-green, blue-yellow, and black-white.

What are feature detectors and what are their function?

Feature detectors are specialized neurons in the visual cortex of the occipital lobe that are responsible for receiving info from ganglion cells and responding to specific features of a scene-edges, lines, angles, and movements.

What two physical characteristics of light help determine our sensory experience of them?

Light's wavelength determines the hue we see and light's amplitude determines the intensity of the color we see.

What psychological phenomena do magicians employ and how?

Magicians rely upon inattentional blindness, failing to see objects when one's mind is directed elsewhere, and change blindness, failing to notice changes in the environment. Magicians selectively rivet the audience's attention on one object, and through these phenomena the audience won't notice changes that take place.

What is the difference between sensation and perception?

Sensation is the process by which our sensory receptors and nervous system receive stimulus energies, whereas perception is the process by which the brain organizes and interprets these stimulus energies.

Why do the eyes not experience sensory adaptation?

Sensory adaptation, the process by which sensitivity is diminished in the presence of a constant stimulus, is not experienced with vision because the eyes are constantly moving, and therefore no stimulus is viewed the same way continuously.

Describe sensory interaction in the context of discerning a flavor.

Sensory interaction is the principle that one sense may influence another. When smell influences taste and texture (touch of the tongue), we sense flavor. IN short: smell+taste+texture=flavor

How are sounds measured?

Sounds are measured in decibals, with zero decibal corresponding to the absolute threshold. Every 10 decibals signifies a tenfold increase in sound intensity.

What is the term for stimuli that we do not consciously notice but can still prime our response later?

Subliminal stimuli are stimuli that we are not consciously aware of, but can still influence our responses to certain events.

Summarize the Young-Helmholtz trichomatic theory.

The Young-Helmholtz trichomatic theory holds that the retina contains three different types of color receptors: red, green, and blue, which, simulated in combination, can lead to the perception of any color.

What are the four different sensory receptors composing touch?

The four different sensory receptors that make up touch are pain, pressure, warmth, and cold.

How many different color variations can be sensed by the average human?

The average human can detect one million different variations in color.

What is the benefit of sensory adaptation?

The benefit of sensory adaptation is that it allows us on informative changes in the environment without being distracted by background noise.

Give an example of how the brain works backwards in the process of perception.

The brain can work backward in time to allow a later stimulus to determine how an earlier one is perceived. For example, most people, when being told to "eel the orange," would begin peeling the orange because the later stimulus of the orange gives context for the word "peel" to be perceived.

Explain parallel processing in the context of seeing a bird flying in the air.

The brain delegates the task of interpreting and perceiving the bird's motion, form, depth, and color to different parts of the brain. We then integrate these interpretations in order to understand that we're seeing a bird.

Name and describe the type of energy conversion utilized by the brain during sensation and perception.

The brain uses transduction to transform the stimuli energy detected by senses into neural impulses that can be decoded.

What is the cocktail party effect and what psychological phenomenon does it illustrate?

The cocktail party effect is the human ability to attend to only one voice among many and to detect one's own name in an unattended voice. The cocktail party effect is an illustration of selective attention, the focusing of conscious awareness on just one stimulus.

What part of the eye is the first to receive light and bends it to provide focus?

The cornea--outside covering of the eye--is the first part to receive light energy and bends the light waves to provide focus.

What type of cells make up the optic nerve?

The optic nerve is made up of the axons of ganglion nerve cells. They are activated by bipolar cells, which are activated by neural signals of light energy.

What type of vision receptor cells predominate the outer region of the retina and aid in peripheral vision?

The rode receptor cells are clustered primarily in the outer region of the retina and aid in peripheral vision.

Where and why is there a blind spot on the retina?

There is a blind spot on the retina where the optic nerve leaves the eye. However, this does not prevent vision and we see despite the blind spot.

From a scientific perspective, what is color blindness?

Those who are color blind aren't actually blind to colors: the just lack red sensitive receptors, green sensitive receptors, or both.

What is Weber's law? Give an example.

Weber's law is the principle that for the average person to notice a difference, two stimuli must differ by a constant percentage, not a certain amount. For example, I would notice a one pound increase to a 3 lb weight but not to a 100 pound weight because the different threshold is a percentage, not a certain amount.

What is the effect of focusing on blinking?

When people are focused on one task, they blink significantly less than when their mind is wandering.

Can experiences influence interpretation of data?

Yes. According to signal detection theory, one's experience, expectations, emotions, and motivation influence how he or she interprets data. For example, I am more likely to notice sounds similar to a phone ringing if I am expecting a phone call.