Psyc Final

Sensation

• the process that occurs when special neuron receptor sites in the sense organs are activated, allowing various forms of outside stimuli to become neural signals in the brain

Perception

•  the methods by which the sensations experienced at any given moment are interpreted and organized in some meaningful fashion 

Just a noticeable difference (jnd)

• Difference threshold.

• The smallest difference between two stimuli is detectable 50 percent of the time. 

who came up with just noticable difference?

ernest webber

• Absolute Threshold

• The lowest level of stimulation that a person can consciously detect is 50 percent of the time the stimulation is present.

who came up with absolute threshold?

• Gustav Fechner (expanded on Weber’s work)

Absolute Threshold for Humans

50% of the time with Vision, hearing, smell, taste, and touch.

• Subliminal Stimulation 

• Receiving messages below your absolute threshold for conscious awareness.

Cornea

the clear outer covering of the eye, behind which is a fluid

Aqueous humor

the fluid that nourishes the eye

Pupil

the black circle in the middle of the eye that changes size as the iris muscles contract and expand to cover and uncover the lens

Iris

the colored circular muscle that opens and closes, which controls the amount of light getting into the eye

Lens

the transparent structure of the eye that focuses light on the retina (back of the eye), where there are receptors 

Vitreous humor

the liquid that nourishes and gives shape to the eye

Retina

the back of the eye, which contains millions of receptors for light 

Fovea

the central area of the retina; greatest density of photoreceptors

Blind spot

portion of the retina through which the optic nerve exits and where there are no receptors for light waves

Optic nerve

where the nerve cells leave the eye and send info to the brain

Color (hue)

length of wave (long waves - red range) (short waves - blue range)

how is color seen?

“Color” is seen after the waves of light hit objects and bounce back to us at different frequencies

why is color seen?

“Color” is seen because the eyes have different receptors for different wavelengths

2 parts of the retina

rods and cones

rods

visual receptors most sensitive to the violet-purple wavelengths; very sensitive for night vision, used for night vision because they respond well to low levels of light

describe rods

• “Sees” only in black and white 

• Packed on the sides of the retina

• Packed on the sides of the retina

• There are about 125 million rods in the retina

Cones

visual receptors that respond during daylight

describe cones

• See color

• Respond best to wavelengths in the red range

• Shut off with little or no light

• There are about 6 million cones in the retina

• Located in the center of the retina 

• Provide sharpness of vision

Trichromatic theory

• theory of color vision that proposes three types of cones: red, blue, and green

Opponent-process theory

• The theory of color vision proposes that visual neurons are stimulated by the light of one color and inhibited by the light of another color

Visual accommodation

• As a monocular cue of depth perception, the brain’s use of information about the changing thickness of the lens of the eye in response to looking at objects that are close or far away

Visual acuity

• Keenness or sharpness of vision

• Measured by the Snellen chart 

The outer ear (pinna)

catches the sound waves and funnels them down the auditory canal to the eardrum

eardrum

• a piece of skin stretched over the entrance to the ear. It vibrates to the sound waves, which causes the three bones (hammer, anvil, and stirrup) to vibrate in succession

cochlea

• a snail-shaped unit filled with fluid

basilar membrane

contains hair cells- receptor cells for hearing. These 20,000 cells are the key to hearing. They are tuned to different frequencies. The vibration is then sent to the Auditory Nerve

Auditory Nerve

• the cranial nerve that carries sound from the cochlea of the inner ear to the brain for sound to be interpreted

Conductive Hearing Impairment (Conductive hearing loss)

• Hearing loss is caused by damage to the middle ear, thus interfering with the transmission of sound waves to the cochlea. 

• Can’t hear sounds that are not loud enough.

• Hearing aids can help with the amplification of sound.

Nerve Hearing Impairment (Sensorineural hearing loss)

• Deafness that results from damage to the inner ear (cannot perceive sounds of certain frequencies).

• Can have a cochlear implant if the cochlea is damaged

• Cannot fix auditory nerve damage (from disease or prolonged exposure to loud noises).

Place Theory

 theory of pitch that states that different pitches are experienced by the stimulation of hair cells in different locations on the organ of Corti (Works for moderate to high pitches.)

Frequency theory

 - theory of pitch that states that pitch is related to the speed of vibrations in the basilar membrane 

• The faster the membrane vibrates, the higher the pitch.

• Works for low pitches.

Volley Principle

1. groups of auditory neurons take turns sending the message to the brain

• Accounts for pitches from 400Hz to 4000Hz

Mechanism of smell

• There are cilia in the nasal cavity that collect molecules of odor 

• The odor molecules attach themselves to the cilia and send a signal to the olfactory bulbs 

Smell Communication

• Smell is important to eating because it gives out information about food 

• Smell is important to eating because it gives out information about food

• Animals use smell to communicate sexual interest by sending out pheromones

Olfactory bulbs

• receive the odor molecules and communicate to the brain, where it is interpreted 

Kinesthetic sense

Location of body parts in relation to each other

Vestibular Sense (Balance)

• Having to do with movement and body position.

• Structures for this are located in the inner ear. 

Proximity

• Perceive objects that are close to one another as part of the same grouping

Law of proximity

objects near each other tend to be grouped together

Similarity

perceive things that look similar as being part of the same group

Law of similarity

items that are similar tend to be grouped together

Closure

•  the tendency to complete figures that are incomplete

Law of closure

objects grouped together are seen as a whole

Continuity

perceive things as simple as possible with a continuous pattern rather than with a complex, broken-up pattern

Law of continuity

lines are seen as following the smoothest path

Monocular cues

cues for perceiving depth based on one eye only

• Linear perspective

Parallel lines seem to converge on each other in the distance

• Texture gradient

•  noticing a certain amount of detail depending on how close something is, giving a sense of depth perception

Binocular cues

cues for perceiving depth based on both eyes

Convergence

• rotation of the two eyes in their sockets to focus on a single object

Binocular Disparity

•  Each eye sees a slightly different image 

• Focus on an object- close one eye, open it, and close the other

Perceptual set

• perceive things a certain way because of previous experiences or expectations influence them

Inattentional blindness

an individual fails to perceive an unexpected stimulus in plain sight, purely as a result of a lack of attention rather than any vision

Top-down processing

• use of pre-existing knowledge to organize individual features 

Bottom-up processing

• analysis of the smaller features to build up to a complete perception 

Classical Conditioning

learning to elicit an involuntary response to a stimulus other than the original, natural stimulus that normally produces the response

Operant Conditioning

the learning of voluntary behavior through the effects of pleasant and unpleasant consequences

Ivan Pavlov

Russian psychologist who discovered classical conditioning through his work on digestion in dogs

describe Pavlov’s famous experiment

• Pavlov presented a stimulus (e.g., the sound of a metronome) and then gave the dog food; after a few repetitions, the dog started to salivate in response to the stimulus.  

explain what the visual cliff experiment was about and how it worked

• Visual Cliff experiment was performed using babys and they were placed on a table with half of the side having a pattern while the other half was glass that had a drop underneath the experiment measured if babies depth perception

Reflex

• unlearned, involuntary response

  • Ex: Flinching before someone hits you 

Stimulus

• any object, event, or experience that causes a response 

  • Ex: Music 

Response

•  reaction of an organism 

Ex:  Dancing to music.

UCS (US): unconditioned stimulus

• a naturally occurring stimulus that leads to an involuntary response  

UCR (UR): unconditional response

 an involuntary response to a naturally occurring or unconditioned stimulus

NS: neutral stimulus

an agent that initially causes no response

CS: conditioned stimulus

• stimulus that becomes able to produce a learned response by being paired with an unconditioned stimulus 

CR: conditioned response

learned response to a conditioned stimulus

Mary Cover Jones

studied counterconditioning

Counterconditioning

• is when a pleasant stimulus is paired repeatedly with a fearful stimulus to counteract the fear. 

John B. Watson

performed the Little Albert experiment

Vicarious conditioning

• seeing someone else go through something and live through them 

Stimulus generalization

•  the tendency to respond to a stimulus similar to the original conditioned stimulus with the conditioned response 

  • Ex: Pavlov’s dogs salivating to any bell

Stimulus discrimination

•  a distinction is made between the conditioned stimulus and a similar stimulus, and an unconditioned response is not elicited  

  • Ex: Pavlov’s dogs salivating to a specific bell 

Extinction

• the disappearance or weakening of a learned response following the removal or absence of the unconditioned stimulus 

  • Ex:  If Palvov stopped presenting the food with the bell, then, slowly, over time, when the dogs hear the bell, they will stop salivating

 Spontaneous recovery

• the reappearance of a learned response after extinction has occurred 

  • Ex: If one of Palvov’s dogs here the original bel, then they might salivate to it randomly 

B.F. Skinner

• followed in the steps of John Watson, emphasizing the study of only observable, measurable behavior (behaviorism) 

  • Skinner Box

Reinforcement

anything that, when following a response, causes that response to be more likely to happen again

Elements of observational learning

1. Attention

2. Memory (retention

3. Imitation (without reinforcement)

4. Desire (motivation) 

• Albert Bandura

• Known for observational learning

• BoboDoll experiment

• John Garcia

• He makes rats sick and researches what drugs people associate things with 

• Taste Aversion- a special kind of classical conditioning involving the learned association between a particular taste and nausea (can happen with only one pairing) 

Mark Seligman

• Performed an experiment with dogs where one would push a button to shock another dog, while the other dog would cry 

• Learned helplessness-the tendency to fail to act to escape from a situation because of a history of repeated failures in the past

• E. C. Tolman 

• Would experiment with rats and mazes to see if they would recall the rats

• Would experiment with chimps and cognitive maps 

• Wolfgang Kohler 

• Known for two big things:

1. The Box problems 

•  would hang a banana out of reach from chimps and wanted them to stack the boxes to get one 

2. Stick problem 

• Would hang a banana out of reach from a chimp and the chimps would put the sticks together to reach the banana

Insight

• the sudden perception of relationships among various parts of a problem, allowing the solution to the problem to come quickly 

• Aha! moment 

Edward Thorndike

discovered the Law of effect

Law of effect

•  a law stating that if an action is followed by a pleasurable effect consequence, it will tend to be repeated, and if followed by an unpleasant consequence, it will tend not to be repeated

Continuous reinforcement

• very time a behavior is done, the reward is given

  • Ex: Every time Skinner’s rat clicked the button, they were rewarded with food 

Partial Reinforcement

• a response that is reinforced after some, but not all

  • Correct responses will be more resistant to extinction.

Fixed Interval

• the interval of time that must pass before reinforcement becomes possible is always the same. 

  • Ex: Paycheck every 2 weeks, a 15-minute break after working for 3 hours, rat presses lever for 2 minutes and gets a pellet of food, April 15th, studying night before test, flossing right before a dentist appointment.

Variable interval

•  the interval of time that must pass before reinforcement becomes possible is different for each trial or event. 

  • Ex: Random uniform check, every so often your friend calls, fishing, pop quizzes

Fixed Ratio

• the number of responses required for reinforcement is always the same. 

  • Ex: Punch cards, rat presses 5 times, and gets a pellet of food.