Monday, October 18th, 2010Objective: Develop an understanding of our senses

review of where we are going this unit What is Sensation and Perception View a movie to review where we are going

Do Now: Write down our senses and each one’s purpose What do you think sensation and perception mean? Hand in your Project!

Sensation – what occurs when a stimulus activates a receptor

Perception – the organization of sensory information into meaningful experiences

Sensation and Perception Sensation and Perception

• Sensory processing and adaptation• Vision• The Other Senses:

Hearing Touch Taste Smell

• Perception• Subliminal Messages• What is real?

Tuesday, October 19th

Today’s Goals discussion of our senses discuss terms used in discussing our sensations Experiment to understand absolute threshold

Do Now•What are our 6 senses?

Homework•Evaluating our senses

How many senses do we have?

The five we always remember, but we really do have a 6th sense….not seeing dead people, but our sense of balance.

What is the difference?

Sensation Perception

Absolute Threshold The weakest amount of a stimulus necessary to

produce a sensation 50% of the time.

sight Candle flame 30 miles away

hearing Ticking 20 feet away

taste Tsp sugar in 2 gallons water

smell 1 drop of perfume in a house

touch Bees wing falling a distance of one centimeter

Difference Threshold

The smallest change in a physical stimulus that can be noticed half the time.

Do you notice another book in your bag if you already have 5 in it?

Signal detection theory

Study of people’s tendencies to make correct judgments in detecting the presence of stimuli. Combines concept of ability to detect with one’s own judgments.

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EXAMPLES OF THE SIGNAL DETECTION THEORYThe Classic Radar Operator Example

The Shower/Phone Example The Eye Exam

 

Signal: Are there actually enemy aircraft indicated on the radar screen?

Yes No

Decision: are they enemy Aircraft?

Yes Hit False Alarm

No Miss Correct Rejection

Weber’s Law

The larger or stronger a stimulus, the larger the change required for a person to notice that anything has happened to it.

This increase in a stimulus need to produce a just-noticable difference is constant:

dR = C * R "equal relative increments of stimuli are

proportional to equal increments of sensation."

Is the Room too Dark? Well, to see the SAME level of improvement…

1 candle x 10 = 10 candles 10 candles x 10 = 100 candles And for the same improvement again, 100 candles x 10 = 1000 candles!

EXPERIMENT TIME!Also, handout homework – rank your senses

Why are we doing this?

Rationale – Psychology is often considered a “hard” (versus “easy” science) because of the complexity of measuring concept of interest. Although one would think that physical stimuli would be easily measured, psychological reaction to a stimuli is not so easily measured. Today, we will evaluate the concept of absolute threshold in order to understand why this is so hard to precisely determine, as well as to further understand how one studies sensation and perception.

To determine absolute threshold of the sugar water using two different methods

Method of limits – using ascending on descending order Method of Constant Stimuli – using

Procedure Break into groups of four

subject (blindfolded) Experimenter (hands water to subject) Recorder (Puts results on the worksheet) Math wiz (averages a chart)

Supplies blindfold 10 small cups (labeled 1-10) Fill each small cup with samples from the larger cups. calculator

Procedure 1 (method of limits) – give subject sips in ascending and descending 4 times; average and report mean. Record response of subject.

Procedure 2 – Give sips according to preset random order. Record responses

Finish any final calculations and report results

Period 1Group 1 Group 2 Group 3 Group 4 Group 5

Limits threshold (mean)Constant Stimuli threshold

Period 9Group 1 Group 2 Group 3 Group 4 Group 5

Limits threshold (mean)Constant Stimuli threshold