1. Brain Cells ● Difference: Sensation is the detection of stimuli, while perception is the brain’s
● Neurons: Specialized cells for communication via electrical and chemical signals. interpretation of those stimuli.
○ ~100 billion neurons in the brain, ~160 trillion connections. 2. Visual Processing
○ Neuroplasticity: Ability to change size, shape, and connections in response ● Light:
to environmental input. ○ Stimulus for visual sensation.
● Parts of a Neuron: ○ Travels in waves as photons.
○ Soma (Cell Body): Contains nucleus and organelles. ○ Visible light ranges from 400nm (purple) to 700nm (red).
○ Axon: Sends signals away from the cell body. ● Eye Structure:
○ Dendrites: Receive signals from other neurons. ○ Light enters through the pupil, is focused by the cornea and lens, and la
○ Synapse: Space between neurons where communication occurs. on the retina.
○ Neurotransmitters: Chemical messengers released at synapses. ○ Retina: Contains photoreceptors (rods and cones) that detect light and
● Types of Neurons: convert it into electrical signals.
○ Sensory (Afferent): Carry information to the spinal cord. ● Visual Pathways:
○ Motor (Efferent): Send information to muscles/glands. ○ Optic Nerve: Transmits information from the retina to the brain.
○ Interneurons: Connect sensory and motor neurons. ○ Optic Chiasm: Point where optic nerves from both eyes cross, sending
information to the opposite hemisphere of the brain.
●
Glial Cells: Support neurons by providing nutrients, insulation (myelin), and removing ○ Left visual field → Right hemisphere; Right visual field → Left hemisp
waste. 3. Theories of Color Vision
● Types of Glial Cells: ● Trichromatic Theory:
○ Astrocytes: Support and synchronize neuron activity. ○ Suggests humans have three types of receptors sensitive to red, blue, an
○ Microglia: Remove waste and damaged neurons. green.
○ Oligodendrocytes & Schwann Cells: Produce myelin. ○ These colors combine to create all visible colors.
○ Radial Glia: Guide neuron migration during development. ● Opponent Process Theory:
2. Neuronal Communication ○ Receptors respond to color pairs (red vs. green, yellow vs. blue, black v
● Action Potential: Electrical signal that travels down the axon. white).
● Steps: ○ One color suppresses the other in each pair.
○ Resting potential (-70mV). ● Both Theories:
○ Depolarization (Na+ enters, making the cell more positive). ○ Trichromatic theory explains the first stage of processing (cones in the
○ Repolarization (K+ leaves, restoring negative charge). retina).
○ Hyperpolarization (temporary increase in polarity). ○ Opponent process theory explains later stages (ganglion cells, thalamus
● All-or-Nothing Law: Action potentials either fire fully or not at all. visual cortex).
○ Synapse: Junction where neurons communicate. 4. Visual Perception:
● Chemical Synapse: Neurotransmitters released into the synaptic cleft. ● Outcome: Seeing color, edges, texture, and parts of a whole.
● Electrical Synapse: Direct flow of ions through gap junctions. ● Afterimages: Visual images that persist after the stimulus is removed, explained by
○ Neurotransmitters: opponent process theory.
● Excitatory: Increase likelihood of action potential (e.g., Glutamate, ● Parallel Processing: The brain processes multiple aspects of a visual scene simultane
Acetylcholine). (e.g., color, motion, depth).
● Inhibitory: Decrease likelihood of action potential (e.g., GABA). 5. Perceptual Set & Illusions
● Examples: ● Perceptual Set: A bias toward interpreting sensory information based on expectation
○ Dopamine: Motivation, addiction, motor control. ● Illusions:
○ Serotonin: Mood, sleep, hunger. ○ McGurk Effect: Demonstrates how visual information can influence aud
○ Norepinephrine/Epinephrine: Arousal, fight-or-flight response. perception.
○ Endorphins: Pain relief, pleasure. ○ Rubber Hand Illusion: Shows how tactile and visual information can cr
3. The Nervous System false sense of body ownership.
● Central Nervous System (CNS): Brain and spinal cord. ● Cross-Modal Effects: Interaction between different senses (e.g., synesthesia, where o
● Peripheral Nervous System (PNS): Nerves outside the CNS. sense triggers another, like hearing colors).
● Brain Structures: 6. Attention:
○ Cerebral Cortex: Responsible for higher-order functions (e.g., planning, ● Plays a crucial role in perception by filtering and prioritizing sensory information.
speech). Key Concepts:
○ Limbic System: Emotion, motivation, memory (includes amygdala, ● Sensation: Detection of stimuli by sense organs.
hippocampus, thalamus, hypothalamus). ● Perception: Brain’s interpretation of sensory input.
○ Brainstem: Controls survival functions (e.g., breathing, heart rate). ● Transduction: Conversion of sensory stimuli into neural signals.
○ Cerebellum: Coordination and balance. ● Visual Pathways: Light → Retina → Optic Nerve → Optic Chiasm → Brain.
4. Brain Mapping ● Color Vision: Explained by both trichromatic and opponent process theories.
● Neuroimaging Techniques: ● Perceptual Set: How expectations influence perception.
○ EEG: Measures electrical activity. ● Illusions: Demonstrate the brain’s interpretation of sensory input (e.g., McGurk Effe
○ MRI: Visualizes brain structure. Rubber Hand Illusion).
○ fMRI: Visualizes brain activity.
○ PET: Measures glucose consumption to show neural activity. Research Designs
○ TMS: Applies magnetic fields to stimulate or interrupt brain function. ● Experimental Research: Random assignment, manipulation of independent variables
5. Research Methods measurement of dependent variables.
● Experimental Research: Manipulates variables to establish cause-and-effect. ● Correlational Designs: No manipulation of variables; examines relationships betwee
● Correlational Research: Examines relationships between variables without manipulation. variables.
● Qualitative Research: Observes behaviors in natural settings. ○ Types of correlations: Positive, Negative, Zero.
● Longitudinal Studies: Track changes over time. ○ Correlation coefficients measure strength and direction of relationships.
Key Concepts: ● Qualitative Designs: Observes behaviors/mental processes in natural settings or thro
● Neuroplasticity: Brain's ability to reorganize itself. interviews; expressed in words/language.
● Action Potential: Electrical impulse that allows neurons to communicate. ● Quasi-experimental Designs: No random assignment; different independent variable
● Neurotransmitters: Chemicals that facilitate communication between neurons. ● Longitudinal Designs: Tracks participants over time to study long-term effects.
● Brain Structures: Different regions control various functions (e.g., cortex for thinking, ● Trade-offs: No perfect design; consider resources, ethics, cost, time, and equipment.
brainstem for survival). What is Research?
● Neuroimaging: Tools like MRI and EEG help study brain structure and function. ● Systematic observation and investigation of the natural world.
● Provides empirical evidence to support or refute hypotheses.
1. Sensation vs. Perception Psychological Research
● Sensation: ● Quantitative Research: Numeric data collected through tests, scales, or questionnaire
○ The stimulation of sense organs by external stimuli (light, sound, chemicals, analyzed statistically.
etc.). ● Qualitative Research: Non-numeric data (e.g., observations, interviews); expressed i
○ Detection of physical energy by sense organs, which send information to the words.
brain.
○ Transduction: The process of converting external stimuli into neural activity.
● Perception:
○ The brain’s interpretation of raw sensory data.
○ Involves selection, organization, and interpretation of sensory input.
● Neurons: Specialized cells for communication via electrical and chemical signals. interpretation of those stimuli.
○ ~100 billion neurons in the brain, ~160 trillion connections. 2. Visual Processing
○ Neuroplasticity: Ability to change size, shape, and connections in response ● Light:
to environmental input. ○ Stimulus for visual sensation.
● Parts of a Neuron: ○ Travels in waves as photons.
○ Soma (Cell Body): Contains nucleus and organelles. ○ Visible light ranges from 400nm (purple) to 700nm (red).
○ Axon: Sends signals away from the cell body. ● Eye Structure:
○ Dendrites: Receive signals from other neurons. ○ Light enters through the pupil, is focused by the cornea and lens, and la
○ Synapse: Space between neurons where communication occurs. on the retina.
○ Neurotransmitters: Chemical messengers released at synapses. ○ Retina: Contains photoreceptors (rods and cones) that detect light and
● Types of Neurons: convert it into electrical signals.
○ Sensory (Afferent): Carry information to the spinal cord. ● Visual Pathways:
○ Motor (Efferent): Send information to muscles/glands. ○ Optic Nerve: Transmits information from the retina to the brain.
○ Interneurons: Connect sensory and motor neurons. ○ Optic Chiasm: Point where optic nerves from both eyes cross, sending
information to the opposite hemisphere of the brain.
●
Glial Cells: Support neurons by providing nutrients, insulation (myelin), and removing ○ Left visual field → Right hemisphere; Right visual field → Left hemisp
waste. 3. Theories of Color Vision
● Types of Glial Cells: ● Trichromatic Theory:
○ Astrocytes: Support and synchronize neuron activity. ○ Suggests humans have three types of receptors sensitive to red, blue, an
○ Microglia: Remove waste and damaged neurons. green.
○ Oligodendrocytes & Schwann Cells: Produce myelin. ○ These colors combine to create all visible colors.
○ Radial Glia: Guide neuron migration during development. ● Opponent Process Theory:
2. Neuronal Communication ○ Receptors respond to color pairs (red vs. green, yellow vs. blue, black v
● Action Potential: Electrical signal that travels down the axon. white).
● Steps: ○ One color suppresses the other in each pair.
○ Resting potential (-70mV). ● Both Theories:
○ Depolarization (Na+ enters, making the cell more positive). ○ Trichromatic theory explains the first stage of processing (cones in the
○ Repolarization (K+ leaves, restoring negative charge). retina).
○ Hyperpolarization (temporary increase in polarity). ○ Opponent process theory explains later stages (ganglion cells, thalamus
● All-or-Nothing Law: Action potentials either fire fully or not at all. visual cortex).
○ Synapse: Junction where neurons communicate. 4. Visual Perception:
● Chemical Synapse: Neurotransmitters released into the synaptic cleft. ● Outcome: Seeing color, edges, texture, and parts of a whole.
● Electrical Synapse: Direct flow of ions through gap junctions. ● Afterimages: Visual images that persist after the stimulus is removed, explained by
○ Neurotransmitters: opponent process theory.
● Excitatory: Increase likelihood of action potential (e.g., Glutamate, ● Parallel Processing: The brain processes multiple aspects of a visual scene simultane
Acetylcholine). (e.g., color, motion, depth).
● Inhibitory: Decrease likelihood of action potential (e.g., GABA). 5. Perceptual Set & Illusions
● Examples: ● Perceptual Set: A bias toward interpreting sensory information based on expectation
○ Dopamine: Motivation, addiction, motor control. ● Illusions:
○ Serotonin: Mood, sleep, hunger. ○ McGurk Effect: Demonstrates how visual information can influence aud
○ Norepinephrine/Epinephrine: Arousal, fight-or-flight response. perception.
○ Endorphins: Pain relief, pleasure. ○ Rubber Hand Illusion: Shows how tactile and visual information can cr
3. The Nervous System false sense of body ownership.
● Central Nervous System (CNS): Brain and spinal cord. ● Cross-Modal Effects: Interaction between different senses (e.g., synesthesia, where o
● Peripheral Nervous System (PNS): Nerves outside the CNS. sense triggers another, like hearing colors).
● Brain Structures: 6. Attention:
○ Cerebral Cortex: Responsible for higher-order functions (e.g., planning, ● Plays a crucial role in perception by filtering and prioritizing sensory information.
speech). Key Concepts:
○ Limbic System: Emotion, motivation, memory (includes amygdala, ● Sensation: Detection of stimuli by sense organs.
hippocampus, thalamus, hypothalamus). ● Perception: Brain’s interpretation of sensory input.
○ Brainstem: Controls survival functions (e.g., breathing, heart rate). ● Transduction: Conversion of sensory stimuli into neural signals.
○ Cerebellum: Coordination and balance. ● Visual Pathways: Light → Retina → Optic Nerve → Optic Chiasm → Brain.
4. Brain Mapping ● Color Vision: Explained by both trichromatic and opponent process theories.
● Neuroimaging Techniques: ● Perceptual Set: How expectations influence perception.
○ EEG: Measures electrical activity. ● Illusions: Demonstrate the brain’s interpretation of sensory input (e.g., McGurk Effe
○ MRI: Visualizes brain structure. Rubber Hand Illusion).
○ fMRI: Visualizes brain activity.
○ PET: Measures glucose consumption to show neural activity. Research Designs
○ TMS: Applies magnetic fields to stimulate or interrupt brain function. ● Experimental Research: Random assignment, manipulation of independent variables
5. Research Methods measurement of dependent variables.
● Experimental Research: Manipulates variables to establish cause-and-effect. ● Correlational Designs: No manipulation of variables; examines relationships betwee
● Correlational Research: Examines relationships between variables without manipulation. variables.
● Qualitative Research: Observes behaviors in natural settings. ○ Types of correlations: Positive, Negative, Zero.
● Longitudinal Studies: Track changes over time. ○ Correlation coefficients measure strength and direction of relationships.
Key Concepts: ● Qualitative Designs: Observes behaviors/mental processes in natural settings or thro
● Neuroplasticity: Brain's ability to reorganize itself. interviews; expressed in words/language.
● Action Potential: Electrical impulse that allows neurons to communicate. ● Quasi-experimental Designs: No random assignment; different independent variable
● Neurotransmitters: Chemicals that facilitate communication between neurons. ● Longitudinal Designs: Tracks participants over time to study long-term effects.
● Brain Structures: Different regions control various functions (e.g., cortex for thinking, ● Trade-offs: No perfect design; consider resources, ethics, cost, time, and equipment.
brainstem for survival). What is Research?
● Neuroimaging: Tools like MRI and EEG help study brain structure and function. ● Systematic observation and investigation of the natural world.
● Provides empirical evidence to support or refute hypotheses.
1. Sensation vs. Perception Psychological Research
● Sensation: ● Quantitative Research: Numeric data collected through tests, scales, or questionnaire
○ The stimulation of sense organs by external stimuli (light, sound, chemicals, analyzed statistically.
etc.). ● Qualitative Research: Non-numeric data (e.g., observations, interviews); expressed i
○ Detection of physical energy by sense organs, which send information to the words.
brain.
○ Transduction: The process of converting external stimuli into neural activity.
● Perception:
○ The brain’s interpretation of raw sensory data.
○ Involves selection, organization, and interpretation of sensory input.
