sight smell taste

Sensory Processes

  • Overview of the sensory systems: Vision, Hearing, Smell, Taste, Touch.

Introduction to Sensory Processes

  • The brain is designed to process complex information.

  • Deliberately confusing information can challenge the sensory systems.

Sensation and Perception

Definitions

  • Sensation: The process of receiving stimuli from the environment.

  • Perception: The process of organizing and interpreting sensory information to give it meaning.

Experiment #1

  • Prepare to measure the time taken to read sentences:

    • Some sentences may require reading backwards.

    • Record your times and check against the provided correct answers.

Importance of the Five Senses

  • The five senses play a crucial role in human experience and understanding of the environment.

Examples of Confusing Sentences

  • Example A: "The cow gave you water and it made you smile."

  • Example B: "I am the real slim shady, I am the very best."

  • Example C: "The five senses are important, didn't you know?"

  • Example D: "The cat was the tar and ran very far away."

Absolute Threshold

  • Definition: Minimum level of sensory stimulation necessary for sensation to occur.

  • Examples:

    • Light: How much can you see in the dark?

    • Sound: Can you hear a whisper?

Adaptation

  • Gradual decrease in response to constant stimuli (e.g., tuning out background noise in a classroom).

Touch Experiment

Procedure

  • Use a toothpick to gently poke a partner in various body areas with consistent pressure.

  • Assess sensitivity in different body parts and record observations.

Human Vision

Functionality

  • Eyes capable of focusing on distant and close objects.

  • Adjustments in response to varying light environments (bright to dim).

How Light Enters the Eye

  • Light enters through the pupil, which appears dark.

Role of the Iris

  • Controls the size of the pupil to adjust light intake:

    • Dilates in dim light.

    • Contracts in bright light.

Internal Eye Structures

  • Cornea: Transparent tissue allowing light entry; plays major role in focusing.

  • Sclera: Opaque tissue covering the eye (whites of the eyes).

  • Lens: Flexible structure that changes shape to fine-tune focus.

Retina Function

  • Acts like a screen at the back of the eye where images are projected.

  • Converts light into electrical signals sent to the brain via the optic nerve.

  • Images are inverted before being interpreted upright by the brain.

Blind Spot

  • Area where the optic nerve connects to the retina lacking light-sensitive cells.

  • Instruction for an activity to demonstrate the blind spot through a card exercise.

Optical Illusions

Explanation

  • Use light, color, and patterns, misleading our perception.

  • Demonstrative activities to show that what the eyes see can differ from reality.

The Sense of Touch

Overview

  • Skin allows for the sense of touch; includes various receptors.

Sensitivity Experiment

  • Uses toothpicks to evaluate sensitivity across body parts.

  • Discuss regions of highest and lowest sensitivity.

Functions of the Skin

  • Protects against infection, injury, and water loss.

  • Regulates temperature and sensations of hot, cold, and pain.

The Touch Pathway

  • Touch information travels through dermis receptors to the brain, recognizing:

    • Pressure

    • Temperature (cold and heat)

    • Body positioning

    • Pain

Olfaction - The Sense of Smell

  • Taste is heavily dependent on smell; about 75% of taste derived from olfactory senses.

  • Unique individual scent profiles; women typically have better olfactory senses.

How Smell Works

  • Molecules stimulate olfactory cilia in the nasal cavity, relaying messages to the olfactory bulb for interpretation.

Pheromones

  • Chemicals communicating messages related to attraction among animals, roles in human communication are still being researched.

Gustation - The Sense of Taste

Connection with Smell

  • Flavor perceived when both taste and smell receptors are engaged.

Structure of Taste Buds

  • Papillae on the tongue contain taste buds, with an average of 200 per papilla.

Five Distinct Tastes

  1. Sweet (energy source)

  2. Sour (potentially toxic)

  3. Bitter (poison indicator)

  4. Salty (necessary sodium)

  5. Umami (savory proteins)

Taste Perception Factors

  • Influenced by odor, temperature, texture, and past experiences with food.

Summary Activities

  • Identifying flavors through smells while blindfolded, noting differences between anticipated and actual tastes.