PSY 214 Lecture # 3 (09/07/2011) - Physiology of Perception Dr. Achtman PSY 214. Lecture 3 Topic: Physiology of Perception Chapter 2, pages 23-31

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1 PSY 214 Corrections: Lecture 3 Topic: Physiology of Perception Chapter 2, pages None needed Lecture Notes: I. Review The Perceptual Process Dillon Foley, Dfoley7@mail.naz.edu Page 1 of 8

2 A: Psychophysics- relationship of physics of stimulus and psychological processing 1) Qualitative Description or recognition 2) Quantitative Detection a. Absolute Threshold (Thh) slightest amount of stimulus to be perceivable i. Method of limits (MoL) ii. Method of Adjustment (MoA) iii. Method of Constant Stimuli (MCS) b. Difference Thh (DL) discrimination between 2 stimuli i. Weber s Law DL/(S)tandard = (K)onstant 1. Each sense has unique Ks B: Physiological Level Ex put electrode in cat-brain to detect which objects it likes to see* C: Experience of world Ex See what individual is thinking with (f)unctional (M)agnetic (R)esonance (I)maging** FOCUS QUESTIONS How are physiological processes involved in perception? How do electrical signal represent objects in environment? *Unethical to use B on humans except in rare circumstances **Animals are not capable of higher level thinking, and we cannot communicate with them Dillon Foley, Dfoley7@mail.naz.edu Page 2 of 8

3 II. Basic brain Structure A: Brain has modular, or a subdivided organization III. Receptors A. Transduction happens at the level of the receptor Dillon Foley, Dfoley7@mail.naz.edu Page 3 of 8

4 IV. Nerves and Neurons: Communication and Processing A: Transmission 1) Picture the below illustration below of a nerve as a banana (Potassium) dipped in salt (Sodium) Dillon Foley, Dfoley7@mail.naz.edu Page 4 of 8

5 2)Selective Permeability: only certain ions may go in or out of atom B: Action Potentials 1) Propagated Response- once a response is triggered, the message is carried all the way through the axon without changing in size a. This allows for messages to be carried extremely long distances 2) Refractory Period- period of time between one axon firing and the recovery to the next one 3) Spontaneous Activity- somewhat random activity in without need for stimulation Dillon Foley, Dfoley7@mail.naz.edu Page 5 of 8

6 V. Neurotransmitters A: These are chemicals released from synaptic vesicles B: Similar to jigsaw pieces, these neurotransmitters can only fit in certain receptor sites 1) When the two make contact, a the chemicals are converted back into electricity and continue its journey through the nerves 2) This voltage can result in one of two forms a. Excitatory Transmitters result in inside of neuron to be more positive AKA depolarization. Think of this as getting more psyched up b. Inhibitory Transmitters- cause inside of neuron to be more negative AKA hyperpolarization. This of this as freezing up Dillon Foley, Dfoley7@mail.naz.edu Page 6 of 8

7 Dillon Foley, Page 7 of 8

8 For more information: This is a well written article about a more in depth look at the earlier part of the lecture, in specific how the brain works and operates. It is worthwhile to glace over it to solidify one s understanding of the material. The second article is about specific types of drugs and how the effect the reuptake of neurotransmitters. This was briefly mentioned in class, and if you are looking to see some of the real life applications of our learning, check out the article. Real-life example: The physiological nature of perception is easy enough to study about in a book; but when you actually take the time to think about how all of these tiny millisecond reactions are occurring at such a rapid pace just to tell your brain that you are receiving a tap on the shoulder is astounding. To think that this vast army of micro processors is there with the sole purpose of alerting us to our surroundings makes me stop and think. The billions of cells all working in perfect coordination (usually) makes me wonder if somehow these same principals of vast and near instant communication and synchronicity can be applied to other areas of human life. Maybe the best model for civilization and culture is one that uses the way the human body itself is rigged. Dillon Foley, Dfoley7@mail.naz.edu Page 8 of 8