Section 1.6 a, b, c, d

1.6-1 Explain the three steps that are basic to all of our sensory systems.
1.6-2 Explain the difference between absolute thresholds and difference thresholds.
1.6-3 Explain the function of sensory adaptation.

Background: Indiana Adams, a woman with perfect vision but prosopagnosia (face blindness), illustrated the difference between sensation and perception.
Story: On New Year’s Day 2020, while shopping for a used psychology textbook, Adams recognized clothing in the book that reminded her of her modeling days, but could not recognize herself on the cover due to her face blindness.
Examples of Face Blindness:
- Complimenting a reflection instead of recognizing herself in the mirror.
- Social challenges faced by people with face blindness, such as confusing strangers with loved ones.
- Techniques used by individuals with face blindness to create social connections.

Sensation: The process by which our sensory receptors and nervous systems receive and represent stimulus energies from our environment.
Perception: The process by which our brain organizes and interprets sensory information, enabling us to recognize meaningful objects and events.
Examples: Adams could detect visual information through her sensory receptors but struggles to interpret people's faces correctly.

Three Steps of Sensory Systems (1.6-1)
1. Receive sensory stimulation (using specialized receptor cells).
2. Transform that stimulation into neural impulses (transduction).
3. Deliver the neural information to our brain.
Transduction: The conversion of one form of energy into another, specifically physical energy (sights, sounds, smells) into neural impulses.

Examples of sensory adaptations among animals:
- Human ears are sensitive to sounds pertinent for communication (e.g., baby cries).
- Frogs have specialized vision for detecting small, moving objects critical for their feeding behavior.
- Male silkworm moths can detect chemical scents from females over a mile away.

Sensation relies on physical energy.
Perception relies on neural processing.
The brain constructs an experience from various sensory stimuli through integrated neural connections.
Conscious Experience: For example, the sensory information from a campfire's visual, auditory, and olfactory elements results in a coherent experience of warmth, light, and smell.

Absolute Threshold: The minimum stimulus energy needed to detect a stimulus 50% of the time.
Example: A candle flame visible from 30 miles under ideal conditions.
Difference Threshold (Just Noticeable Difference - jnd): The minimum difference between two stimuli required for detection 50% of the time. It is proportionally dependent on the stimulus's strength.
Example: The volume increase detection differs at low versus high base volumes (Weber's Law).

Definition: For a person to perceive a difference between two stimuli, they must differ by a constant minimum percentage (not a strict amount).
Application: Two objects must differ in weight by about 2%, and two light sources must differ in intensity by roughly 8% to perceive the difference.

Definition: Diminished sensitivity as a consequence of constant stimulation, allowing focus on informative changes in the environment.
Experience: Adapting to a constant stimulus (like the noise of a fan or odor of a seatmate’s perfume) causes gradual imperception over time.

Vision: Constant stimulation leads to constant movement of eyes, thus avoiding visual fading through micro-movements. Studies show this phenomenon prevents sights from leaving awareness and promotes attention to new stimuli.

Three Steps of Sensory Processing:
1. Receive sensory stimulation.
2. Transform that sensation into neural impulses (transduction).
3. Deliver those impulses to the brain for interpretation.
Absolute Threshold: The minimum stimulus energy necessary to detect it 50% of the time.
Difference Threshold: The minimum difference needed to distinguish between two stimuli 50% of the time, generally increasing with the size of the stimulus.
Sensory Adaptation: The psychological process of becoming less sensitive to constant stimuli over time.

After exposure to a loud environment, sensory adaptation allows individuals to feel less sensitive to that stimulus over repeated exposure.
The interactions between sexual pheromones and human responses highlight complex systems that inform behavior and connection.
The field of psychology studies individual variation in sensory experience, suggesting that perception can differ based on several biological, psychological, and environmental factors.