Psych Chapter 5

A subliminal stimulus is one that is so weak or brief that, although it is received by the senses, it cannot be perceived consciously

the stimulus is well below the absolute threshold. '

Behind of hair cells

Cause a release of neurotransmitter substance into the synaptic space between the hair cells and the neurons of the auditory nerve resulting in never impulses which are sent to the brain.

§ Trichromatic and opponent-process components.

Color Vision Processes

Cones

Color receptors, function best in bright illumination.

Organ of Corti

Contains roughly 16000 hair cells that are the actual sound receptors.

Light enters through the a transparent protective structure at the front of the eye.

Cornea

Visual Association Cortex

Here, more complex features of the visual scene are combined and interpreted in light of our memories and knowledge.

2) Anvil (incus)

Is in the middle of hammer and stirrup

Never Deafness

It is caused by damages receptors within the inner ear or damage to the auditory nerve itself, and it cannot be helped by a hearing aid. Exposure to loud sounds is the leading cause of nerve deafness.

Retina receives information in only two dimensions.

Length and Width

Bottom-up processing

The system takes an individual elements of the stimulus and then combines them into a unified perception. Your visual system operates in a bottom-up fashion.

Hertz

The technical measure of cycles per second. (1 hert = 1 cycle per second)

Menstrual Synchrony

The tendency of women who live together or are close friends to become more similar in their mentsrual cycles.

Olfactory Bulb

a forebrain structure immediately about the nasal cavity.

Perceptual Schema

a mental representation or image to compare it with. Our schemas contain the critical features of objects, events, and other perceptual phenomena.

Dichromat

a person who is color-blind in only one the systems.

Dr. Richard

a prominent psychologist who could not perceive information correctly.

Phantom Limb Phenomenon

happens with amputees, being able to experience "pain" from amputated limbs. This can be quite annoying, having an itch that you can never scratch or an ache you cannot rub.

Bipolar cells

have synaptic connections with the rods and cones.

Gate Control Theory

proposed by Canadian psychologist Ronal Melzack, experience of pain results from the opening and closing of gated mechanisms in the nervous system.

Amplitude

refers to the vertical size of the sound waves.

Perceptual Constancies

that allow us to recognize familiar stimuli under varying conditions.

Sensation

the activites involved by which our sense organs receive and transmit information.

Absolute Threshold

the lowest intensity at which a stimulus can be detected 50 percent of the time. THEREFORE = The lower the absolute threshold the higher the sensitivity.

Ganglion Cells

(are synaptic with bipolar cells as well), axons are collected into a bundle to form the optic nerve.

ERNEST WEBER

- 1830s, he discovered that: there is some of lawfulness in the range of sensitivities within our sensory systems.

1) Light and shadow

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2 Binocular Cues:

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2) Linear perspective

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3) Interposition

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4) Height in the horizontal plane

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5) Texture

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6) Clairty

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7) Relative size

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8 monocular cues (page 171)

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8) Motion paralax

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Brain translates these cues into three-dimensional perceptions. Monocular cues (which only require one eye) and Binocular cues (which require both eyes)

...

Endorphins play a major role in pain reduction.

...

Three key small bones in the ear:

...

§ Trichromatic involved the reactions of cones that are maximally sensitive to red, green, and blue wavelengths. In the second stage, color information from the cones is coded through an opponent-process mechanism further along the visual system.

...

Humans

40million olfactory receptors.

Decision Criteria

A standard of how certain a person must be that a stimulus is present before they say they will detect it. Can change bases on biological factors such as fatigue, expectation, and potential significance of stimulation.

The Trichromatic Theory

Around 1800, it was discovered that any color in the visible spectrum can be produced by some combination of the wave-lengths that correspond to the colors, blue, green, and red in what is known as additive color mixture. This theory was advanced by Thomas Young and Hermann Von Helmholtz. According to Young-Helmholtz trichromatic theory, there are three types of color receptors in the retina. Cones are more sensitive to wavelengths of either blue, green, or red. If all three cones are equally activated, a pure white color is perceived.

The tips of the Haircells

Attach to the tectorial membrane that overhands the basilar membrane along the enire length of the cochlea.

RM Pritchard

Attached a tiny projector to a contact lens worn by the participant. This procedure guaranteed that visual images presented through the projector would maintain a constant position on the retina, even when the eye moved. When the image was projected through the lens onto the retina, the participants reported that the image appeared on its entirety for a time, then began to vanish and reappear as parts of the original stimulus.

Difference Threshold

Defined as the smallest difference between two stimuli that people can perceive 50% of the time.

Transduction

Energy forms are transformed into the common language of nerve impulses.

Opponent-process theory

Ewald Hering in 1870, also assumed three types of cones. Proposed that each of the three cone types responds to two different wave-lengths. One type responds to red or green, another blue or yellow, and a third black or white.

Feature detectors

Groups of neurons within the primary visual cortex are organized to receive and integrate sensory nerve impulses originating in specific regions of the retina. These fire selectively in response to stimuli that have specific characteristics. (Discovered by David Hubel).

Behind the pupil is the , an elastic structure that becomes thinner to focus on distant objects and thicker to focus on nearby objects. The lens of the eye focuses the visual image on the light-sensitive retina (a multi-layered tissue at the rear of the fluid-filled eyeball.

Lens

Interestingly, have suggested that we are all born synesthetic: The neural pathways of infants are fairly undifferentiated and lead to cross-modal perceptions.

Maurer and Mondloch

Myopia

Nearsightedness, focuses the visual image in front of the retina (too near the lens), resulting in a blurred image for faraway objects.

Frequency Theory of Pitch Perception has one problem

Neurons have a rate of firing and cannot keep up with nerve impulses in ear.

Hyperopia (Farsightedness)

Occurs when the lens does not thicken enough and the image is therefore focused on a point behind the retina.

contains the blind spot. Where there are no photoreceptors.

Optic Nerve

Humans four tactile sensations:

Pressure (touch), pain, warmth, and cold.

Sensory prosthetic devices

Provide sensory input that can, to some extent, substitute for what cannot be supplied by a persons sensory receptors. Sonicguide - provides new " eyes" through the ears, capitalizing on principles of auditory localization. The sonicguide allows a blind person to perceive the size, distance, movement, shape, and texture of objects through sound waves that represent visual features.

Behind the cornea is the an adjustable opening that can dilate or constrict to control the amount of light that enters the eye. The pupils size is controlled by the muscles in the colored iris that surrounds the pupil.

Pupil

Inattentional blindness -

Refers to the failure of unattended stimuli to register in consciousness.

Trichromats

Sensitive to all three systems: red-green. Yellow-blue, and black-white

Top-down processing

Sensory information is interpreted in the light of existing knowledge, concepts, ideas, and expectations.

Signal detection theory

Signal detection is concerned with the factors that influence sensory judgments.

Olfaction

Smell

Russian Psych A.R Luria

Studied a highly successful writer and musician who's life was a perpetual stream of mixed-up sensations.

Psychophysics

Studies the relations between the physical characteristics of stimuli and sensory capabilities. This theory is concerned with two kinds of sensitivity. First, is the absolute limits of sensitivity (Softest sound or weakest salt solution that humans can detect, how good is out senses really?). Second is what kind of sensitivity has to do with differences between stimuli, (what is the smallest difference in two stimuli that we can tell apart before they are identical?) eg. A change in brightness, will we be able to detect it?

** No matter the source of energy, it MUST BE CONVERTED into nerve impulses, this is the only way the nervous system will understand. This process is called

TRANSDUCTION

Gustation

Taste

WEBERS LAW

The difference threshold, or ind (just noticeable difference) is directly proportional to the magnitude of the stimulus in which the comparison is being made. He came up with a fraction law of 1/50 (WEBERS FRACTION). This means if you were to lift a weight of 50kg, the noticeable difference in order to distinguish between the two would be to lift 51kg. Or if it was 500g, the ind would be 510g. (1/50 = 1/500, common denominator)

Frequency

The number of sound waves, or cycles, per second.

The skin and body senses include touch, kinesthesis, and equilibrium. The sense organs for equilibrium are in the

Vascular Membrane

Five senses:

Vision, Audition (hearing), Touch, Gustation (Taste), Olfaction (smell)

Or ability to see fine detail is greatest when the visual image projects directly onto the fovea.

Visual acuity

Sensory Adaption

When sensory neurons are engineered to respond to a constant stimulus by decreasing their activity and thus diminishing sensitivity to an unchanging stimulus.

Pheromones

a chemical signals found in natural body scents may affect human behavior in subtle ways.

Inner ear contains the cochlea, which is

a coiled, snail-shaped tube about 3.5cm in length that is filled with fluid and contains the basilar membrane

Synesthesia

a rare, mysterious condition which means mixing of the senses. These patients may experience sounds as colours or tastes as touch sensations that have different shapes. Women are more likely to be synesthetic than men.

Perceptual set

a readiness to perceive stimuli in a particular way. Some times believing is seeing. (Shooting down an innocent airplane with passengers rather than noticing that it is not a threat)

Decision Criterion

a standard of how certain they must be that a stimulus is present before they will say they detect it.

Transduction

a translate of a stimulus whether it is light, sound waves, a chemical molecule, or pressure. Sensory receptors translate it.

Photo pigments

absorption of light by these molecules produces a chemical reaction that changes the rate of neurotransmitter release at the receptors synapse with the bipolar cells.

1) Hammer (malleus)

attached firmly to the eardrum

3) Stirrup (stapes)

attached to the oval window (forms boundary between middle ear and inner ear)

Rods

function best in dim light, are primarily black and white brightness receptors, 500 times more sensitive to light than are the cones. (No rise to color)

Taste Buds

chemical receptors concentrated along the edge and back surface of the tongue.

Duel Processes in Color Transduction

combines the trichromatic and opponent process theories to account for color transduction.

Shadowing experiments

demonstrate that we cannot attend completely to more than one thing at a time. But we can shift our attention rapidly back and fourth between the two messages.

James Vicary

flashed subliminal messages across the screen during a move. These messages were either "drink coca-cola" or "eat popcorn". Vicary claimed that popcorn sales increased by 50% and soft drink sales by 18%. American T.V banned subliminal messages even though. Made up his results!

In humans rods are found throughout the retina except in the .... (a small centre that only contains cones)

fovea

Continuity

holds that people link individual elements together so they form a continuous line or pattern that makes sense.

Gestalt Theorists emphasized the

importance of figure-ground relations. We tend to organize stimuli into a central or foreground figure and a background.

1) Binocular Disparity

in which the eye sees a slightly different image.

Umami

increases the sensitivity of other taste qualities.

Perception

involved the brains processing and interpretation of the information.

Conduction Deafness

is caused by problems involving the mechanical system that transmit sound waves to the cochlea.

Signal Detection Theory

is concerned with the factors that influence sensory judgements.

Subliminal Stimulus

is one that is so weak or brief that, although it is received by the senses, it cannot be perceived consciously, the stimulus is well below the ABSOLUTE THRESHOLD

2) Convergence

is produced by feedback from the muscles that turn your eyes inward to view a near object.

Dark Adaptation

is the progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination

Kenges

living in an environment without open spaces, led him to believe that every animal was an insect and could therefore no longer perceive the size of objects correctly.

Frequency Theory of pitch perception

never impulses send to the brain match the frequency of the sound wave, thus a 30 hertz sound wave from a piano should send 30 volleys of nerve impulses per second to the brain.

We can detect a dim star if we look slightly to one side so that its image falls not on the fovea but on the....., where the rods are packed more densely.

peripheral portion of the retina

Castro Alamancos

reported sensory adaptation was mostly absent in animals while they were alert and engaged in a behavioral learning task. After the task was learned and became a behavior levels of alertness lowered and sensory adaptation returned.

Proximity

says that elements that are near one another are likely to be perceived as part of the same configuration.

Similarity

says that when parts of a configuration are perceived as similar, they will be perceived as belonging together

Monochromat

sensitive to black-white system and is totally color blind.

Jon Krosnick

showed participants nine slides of a particular person and then measure their attitudes towards the target person. Half of the participants each were shown a picture then each photograph was immediately followed by an unpleasant picture and it was presented subliminally. The other half were shown pleasant subliminal stimuli. Participants sown the associated unpleasant subliminal stimuli expressed somewhat negative attitudes towards the person, this means a process of subconscious attitude conditioning.

Researchers have suggested that humans have developed a special visual system that

unconsciously triggers protective responses to stimuli that are interpreted as threatening.

Closure

which sates that people tend to close the open edges of a figure or fill in gaps in an incomplete figure, so that their identification of the form is more complete than what is actually there.