Week 4 Lecture - PSY10007 Brain and Behaviour - Sensation
Concise Version
Sensation vs. Perception
Sensation: Raw sensory information taken in by sense organs (eyes, ears). Initial intake of raw data from the environment.
Perception: The process by which the brain organizes and interprets sensations, turning raw data into a meaningful picture.
Example: Black and white image. Initially, sensation involves seeing black and white patterns. Highlighting the dog turns the sensation into perception.
Definitions
Sense: A system that translates outside information into neural activity.
Sensations: Raw information taken in by sensors or sense organs.
Sensation (process): The process by which the brain organizes and interprets sensations.
Process of Sensing
Stimulus: Energy from the environment.
Accessory Structures: Structures (e.g., ears, eyes) that modify the stimulus.
Receptors: Structures that transduce energy into neural activity. Converts environmental energy into a form the brain can understand.
Sensory Nerves: Transfer neural activity from sense organs to the central nervous system.
Thalamus: Initial processing for all senses except smell.
Cortex: Further processing that leads to perception.
Encoding
Encoding: Translating physical properties of stimuli into patterns of nerve cell activity.
Temporal Coding: Timing of impulses; faster impulses represent brighter light.
Spatial Codes: Specific location of firing neurons.
Doctrine of Specific Energy (Johann Muller, 1826):
The sensation experienced (e.g., light, sound) depends on the specific neurons excited, not the type of stimulus.
Example: Rubbing eyes elicits the sensation of seeing light (stars).
Psychophysics
Psychophysics: The study of the relationship between physical energy in the environment and psychological experience.
Absolute Threshold:
The minimum amount of energy that can be detected 50% of the time.
Not truly absolute; detection involves judgment.
Supraliminal Stimulation: Stimulus strong enough to be detected more than 50% of the time.
Subliminal Stimulation: Stimulus too weak to be perceived.
Signal Detection
Two Processes:
Sensory Process: Depends on signal intensity, sensory system capacity, and environmental noise.
Decision-Making Process: Influenced by willingness to respond, motivation, and expectancies (response bias).
Outcomes:
Hit: Responding to a real signal.
False Alarm: Responding when there is no signal.
Miss: Failing to respond to a signal.
Correct Rejection: Ignoring when there is no signal.
Difference Thresholds and Laws
Just Noticeable Difference (JND) / Difference Threshold: The amount a stimulus must change for the difference to be noticeable.
Weber's Law:
The JND is a fraction that varies based on the individual, stimulus, context, and sensory modality.
Deals with the proportional change required to notice a difference.
Fechner's Law:
Constant increases in stimulus strength result in diminishing perceptions of difference.
Expressed as a logarithmic function: S = k \cdot log(I), where S is the subjective sensation, I is the stimulus intensity, and k is a constant.
Stevens's Power Law:
Expanded version of Fechner's Law that covers a wider array of stimuli.
Perceived intensity grows arithmetically (1, 2, 3, 4, 5), while the actual magnitude grows exponentially (by a power).
Expressed as a power function: S = k \cdot I^a, where S is the subjective sensation, I is the stimulus intensity, k is a constant, and a is an exponent.
Hearing
Physical Characteristics of Sound (Waveform):
Amplitude: Height of the wave (relates to loudness, measured in decibels).
Wavelength: Distance from peak to peak.
Frequency: How frequent the waves are (relates to pitch).
Psychological Dimensions of Sound:
Loudness: Related to amplitude.
Pitch: Related to frequency (high or low tones).
Timbre: Quality of sound, from a mixture of frequencies.
Ear Structure:
Outer Ear:
Pinna: Collects and shapes sounds.
Middle Ear:
Tympanic Membrane (eardrum).
Ossicles (Malleus, Incus, Stapes): Vibrate to transduce sounds.
Inner Ear:
Cochlea: Where transduction occurs.
Basilar Membrane: Floor of the cochlea; contains hair cells.
Hair Cells: Stimulate the auditory nerve.
Deafness:
Conduction Deafness: Middle ear bones are affected, preventing accurate vibration conduction; often due to ossicle fusion.
Nerve Deafness: Damage to the acoustic nerve or hair cells in the basilar membrane; often caused by loud noise exposure.
Auditory Processing:
Information goes through the thalamus.
Then passes to the auditory cortex.
Different regions process different frequencies and locate sounds.
Encoding in the Auditory System:
Intensity: Encoded by the firing rate of neurons; more intense = more rapid firing.
Frequency: Place theory (location on basilar membrane) and frequency matching/volley theory (firing rate of auditory nerve fibers).
Vision
Light: Electromagnetic energy; humans can only sense a small portion (400-750 nanometers).
Light intensity = brightness
Wavelength = color
Eye Structure:
Accessory structure that converts electromagnetic light energy to images (visual transduction)
Photoreceptors (in the retina):
Rods: Sensitive to light but not color.
Cones: Less sensitive to light, but help distinguish colors.
Ganglion cells: Generate action potentials.
Interneurons: Pass signals from photoreceptors to ganglion cells.
Color Vision:
Hue: The color itself.
Color Saturation: Purity of the color.
Brightness: Intensity of the color.
Theories of Color Vision:
Trichromatic Theory (Young-Helmholtz):
Any color can be produced by mixing blue, green, and red light.
Supported by cone activity (short, medium, and long wavelengths).
Opponent Process Theory:
Colors are derived from three antagonistic pairs: red-green, blue-yellow, black-white.
Explains afterimages.
Sensory Interaction and Synesthesia
Sensory Interaction: Senses can influence each other (e.g., hearing alters touch sensitivity).
Synesthesia: Unusual mixing of senses (e.g., feeling colors, tasting shapes).
Chemical Senses
Smell (Olfaction):
Employs about 1,000 receptor types.
Olfactory neurons are replaced every two months.
Bypasses thalamus; strongly linked to emotional memory systems.
Loss of smell can lead to memory problems, emotional issues, and depression.
Pheromones:
Chemicals released by one animal that affect another's behavior or physiology.
Detected by the vomeronasal system.
May influence moods and menstrual synchrony in humans, but evidence for attraction is unclear.
Taste:
Humans have about 10,000 taste buds grouped in papillae.
Tastes: Sweet, sour, bitter, salty, umami, astringent.
Supertasters: Around 25% of people with more papillae, thus, elevated taste sensitivity.
Cutaneous Senses and Vestibular System
Cutaneous Senses: Information from throughout the body.
Skin sensors: Touch, temperature, pain.
Kinesthetic sense: Body position.
Encoding Touch Information:
Intensity: Firing rate and number of neurons stimulated.
Location: Stimulated nerves.
Changes: Most important sensory information.
Temperature Sensing:
Warm and cold fibers; some respond to both touch and temperature.
Thunberg's thermal illusion (stimulating warm and cold fibers simultaneously causes searing pain).
Pain:
Provides information about the world's impact on the body.
Closely associated with emotions.
Pain signals can be interrupted by other inputs (e.g., rubbing an injury).
A delta fibers: Sharp, prickling pain.
C fibers: Dull, aching pain.
Acupuncture:
Alternative therapy for pain relief.
May release endorphins.
Naloxone blocks acupuncture's pain-relieving effects.
Proprioceptive Senses:
Sense of balance, head position, and movement.
Involves vestibular sacs, otoliths, and semicircular canals.
Connected to the cerebellum, autonomic nervous system, and eye muscles.
Kinesthetic Perception:
Awareness of body part locations in space and in relation to each other.
Necessary to guide movement.
Comes from proprioceptors in joints and muscles.
Detailed Version
Sensation vs. Perception
Sensation:
Raw sensory information is detected by sense organs (eyes, ears, skin, nose, taste buds).
Involves the detection of stimuli and transmission of this information to the brain.
Provides initial, basic data about the environment.
Sensory receptors respond to physical energy or chemical compounds. Examples include:
Photoreceptors: Detect light in the eyes.
Hair cells: Detect sound vibrations in the ears.
Mechanoreceptors: Detect pressure and touch on the skin.
Chemoreceptors: Detect chemicals for taste and smell.
Perception:
The process by which the brain organizes, interprets, and gives meaning to sensations.
Transforms raw sensory input into a coherent and understandable representation of the world.
Influenced by past experiences, expectations, and context.
Higher-level cognitive processes involved:
Attention: Selective focus on certain stimuli.
Organization: Structuring sensory inputs into meaningful patterns.
Identification: Recognizing and categorizing objects and events.
Interpretation: Assigning meaning based on context and prior knowledge.
Example:
A black and white image involves seeing patterns of black and white during sensation.
When the brain recognizes a dog in the image, this recognition transforms the sensation into perception, adding meaning and context to the raw visual data.
Definitions
Sense:
A sensory system comprising sensory receptors that respond to specific stimuli.
Includes neural pathways that transmit information to the brain and brain areas that process the information, translating external information into neural activity.
Examples of senses include:
Vision: The sense of sight, using photoreceptors in the eyes.
Audition: The sense of hearing, using hair cells in the ears.
Touch: The sense of tactile sensation, using mechanoreceptors in the skin.
Taste: The sense of gustation, using chemoreceptors in taste buds.
Smell: The sense of olfaction, using chemoreceptors in the nasal cavity.
Sensations:
Raw sensory information is detected by sensory receptors or sense organs.
Basic sensory experiences like detecting light, sound, touch, taste, and smell.
Sensory adaptation: Reduction in sensitivity to a stimulus after constant exposure to it. For example, the ability to smell something decreases over time.
Perception (process):
The set of processes by which the brain organizes and interprets sensations, allowing us to understand and interact with the world around us.
Perceptual constancy: Perceiving objects as unchanging even as illumination and retinal images change. E.g., color constancy, size constancy.
Process of Sensing
Stimulus:
Any form of energy from the environment to which an organism can respond, such as light waves, sound waves, pressure, or chemicals.
Stimulus modality: Type of energy a receptor is most sensitive to (e.g., light for photoreceptors, sound for hair cells).
Accessory Structures:
Structures that modify stimuli before they are processed by receptors.
They enhance or filter the stimulus to make it more accessible to the receptors.
Examples:
Lens of the eye: Focuses light onto the retina.
Outer ear (pinna): Collects and funnels sound waves toward the auditory canal.
Skin layers: Modulate pressure and temperature on the skin.
Receptors:
Specialized cells that transduce (convert) environmental energy into neural signals that the brain can understand.
Receptor potential: Change in electrical potential of a receptor cell in response to stimulation.
Examples:
Photoreceptors (rods and cones) in the retina transduce light into neural signals.
Hair cells in the cochlea transduce sound vibrations into neural signals.
Thermoreceptors in the skin transduce temperature changes into neural signals.
Sensory Nerves:
Nerves that transmit neural activity from sensory receptors in sense organs to the central nervous system (spinal cord and brain).
Afferent neurons: Carry sensory information from receptors to the CNS.
Examples:
Optic nerve: Transmits visual information from the retina to the brain.
Auditory nerve: Transmits auditory information from the cochlea to the brain.
Spinal nerves: Transmit tactile and pain information from the skin to the spinal cord.
Thalamus:
A brain structure that serves as an initial processing center for sensory information from all senses except smell.
It filters and relays sensory signals to the cortex.
Sensory relay nuclei: Specific regions of the thalamus that process and transmit information for different senses.
Examples:
Lateral geniculate nucleus (LGN): Relays visual information to the visual cortex.
Medial geniculate nucleus (MGN): Relays auditory information to the auditory cortex.
Ventral posterior nucleus (VPN): Relays tactile information to the somatosensory cortex.
Cortex:
The outer layer of the brain is responsible for higher-level processing of sensory information, leading to conscious perception and interpretation of stimuli.
Sensory areas: Regions of the cortex dedicated to processing specific types of sensory information.
Examples:
Visual cortex: Processes visual information in the occipital lobe.
Auditory cortex: Processes auditory information in the temporal lobe.
Somatosensory cortex: Processes tactile information in the parietal lobe.
Encoding
Encoding:
The process of translating physical properties of stimuli into patterns of neural activity that can be interpreted by the brain.
It involves converting stimulus characteristics into action potentials or other neural signals.
Different coding methods include temporal coding and spatial coding.
Temporal Coding:
Encoding stimulus intensity or other features by varying the timing of neural impulses.
Brighter light may be represented by faster firing rates, while dimmer light may be represented by slower firing rates.
Burst coding: Encoding information through the number of spikes within a short time window.
Spatial Codes:
Encoding stimulus information based on the specific location of firing neurons.
Different locations on the retina correspond to different parts of the visual field.
Topographic maps: Ordered representation of sensory information in the brain.
Doctrine of Specific Nerve Energies (Johann Muller, 1826):
The sensation experienced depends on which specific neurons are excited rather than the nature of the stimulus.
Different sensory qualities are signaled by different neurons.
Example: Rubbing eyes elicits the sensation of seeing light (stars) because it stimulates the optic nerve, which the brain interprets as visual input, regardless of the source of stimulation.
Psychophysics
Psychophysics:
The branch of psychology studies the relationship between the physical energy of environmental stimuli and our psychological experiences of them.
Key concepts in psychophysics include absolute threshold, supraliminal stimulation, and subliminal stimulation.
Absolute Threshold:
The minimum amount of stimulus energy that can be detected 50% of the time.
It is the point at which a stimulus becomes detectable.
Quantifying minimal detectable stimulus intensity.
Varies depending on the individual and conditions.
Not truly absolute; detection involves judgment. Factors such as attention, motivation, and expectation can influence the detection process.
Method of limits: Presenting stimuli in ascending and descending order to determine the threshold.
Method of constant stimuli: Presenting stimuli at different intensities in random order.
Supraliminal Stimulation:
A stimulus that is strong enough to be detected more than 50% of the time.
It is consciously perceived.
Affects behavior and conscious awareness.
Subliminal Stimulation:
A stimulus that is too weak to be perceived consciously:
It falls below the absolute threshold of detection but may still influence behavior.
Priming: Exposure to a stimulus influences a response to a later stimulus.
Signal Detection Theory
Signal Detection Theory:
A framework for understanding how we make decisions about the presence or absence of a stimulus when there is uncertainty.
Takes into account both sensory sensitivity and decision-making processes.
Two Processes:
Sensory Process:
Reflects the observer’s sensitivity to the signal and is influenced by signal intensity, the capacity of the sensory system, and environmental noise.
Sensory adaptation and habituation affect the process.
Decision-Making Process:
Influenced by the observer’s willingness to respond, motivation, and expectancies (response bias).
It involves setting a criterion for what counts as a signal.
Influenced by rewards, punishments, and prior experiences.
Outcomes:
Hit: Correctly responding to a real signal when it is present.
False Alarm: Responding as if a signal is present when it is not (false positive).
Miss: Failing to respond to a signal when it is present (false negative).
Correct Rejection: Correctly not responding when there is no signal.
Difference Thresholds and Laws
Just Noticeable Difference (JND) / Difference Threshold:
The minimum amount of change in a stimulus required for a person to detect a difference between the original stimulus and the altered one.
Thresholds vary across sensory modalities and individuals.
Weber's Law:
The JND is a constant fraction of the intensity of the original stimulus.
States that the greater the magnitude of the stimulus, the larger the difference must be to be noticed.
Deals with the proportional change required to notice a difference.
The formula is \frac{\Delta I}{I} = k, where \Delta I is the increment threshold, I is the initial stimulus intensity, and k is the Weber fraction.
Applies to various sensory modalities (e.g., weight, brightness, loudness).
Fechner's Law:
States that the subjective experience of the intensity of a sensation increases proportionally to the logarithm of the stimulus intensity.
Equal increases in stimulus intensity produce smaller increases in the perceived magnitude.
A logarithmic relationship between actual and perceived intensity.
Derived from Weber's Law, integrating small JNDs.
Expressed as a logarithmic function: S = k \cdot log(I), where S is the subjective sensation, I is the stimulus intensity, and k is a constant.
Stevens's Power Law:
A psychophysical law that suggests the perceived magnitude of a stimulus is related to its actual physical intensity raised to some power.
Modification of Fechner’s law that applies to a wider range of sensations.
Extends to pain, temperature, and other sensory modalities.
Perceived intensity grows arithmetically (1, 2, 3, 4, 5), while the actual magnitude grows exponentially (by a power).
Expressed as a power function: S = k \cdot I^a, where S is the subjective sensation, I is the stimulus intensity, k is a constant, and a is an exponent. Different sensory modalities have different exponents.
Hearing
Physical Characteristics of Sound (Waveform):
Sound waves are characterized by amplitude, wavelength, and frequency.
Amplitude:
The height of the sound wave, which corresponds to loudness.
Measured in decibels (dB).
Higher amplitude waves are perceived as louder sounds; related to the intensity of sound.
Wavelength:
The distance from one peak of a sound wave to the next.
Related to the frequency or pitch of the sound.
Frequency:
The number of complete wavelengths that pass a point in a given time.
Measured in Hertz (Hz).
High frequency corresponds to high pitch; indicates how many cycles occur per second.
Psychological Dimensions of Sound:
The subjective perception of sound includes loudness, pitch, and timbre.
Loudness:
The subjective perception of the intensity or amplitude of a sound.
Influenced by amplitude and frequency.
Pitch:
The subjective perception of the highness or lowness of a sound.
Determined by the frequency of the sound waves (high frequency = high pitch).
Timbre:
The quality of sound distinguishes different sounds with the same pitch and loudness.
Determined by the combination of frequencies present in the sound; relates to complexity of the sound.
Ear Structure:
The ear is divided into three main parts: outer ear, middle ear, and inner ear.
Outer Ear:
Pinna:
The visible part of the ear that collects and shapes the sound waves.
Funnels them toward the auditory canal.
Middle Ear:
Tympanic Membrane (eardrum):
A thin membrane vibrates in response to sound waves.
Transmits the vibrations to the ossicles.
Ossicles (Malleus, Incus, Stapes):
Three small bones amplify and transmit vibrations from the tympanic membrane to the oval window of the cochlea.
Act as levers to increase pressure.
Inner Ear:
Cochlea:
A spiral-shaped, fluid-filled structure contains the sensory receptors (hair cells) for hearing.
Conducts auditory transduction.
Basilar Membrane:
A membrane inside the cochlea that vibrates in response to sound, supporting the organ of Corti, which contains hair cells.
Hair Cells:
Sensory receptors located on the basilar membrane that transduce mechanical vibrations into electrical signals, stimulating the auditory nerve.
Deafness:
Hearing loss can occur due to various factors affecting different parts of the ear.
Conduction Deafness:
Hearing loss caused by damage or blockage in the outer or middle ear.
Prevents sound waves from reaching the inner ear properly (e.g., ossicle fusion).
Nerve Deafness (Sensorineural Hearing Loss):
Hearing loss caused by damage to the hair cells in the cochlea or auditory nerve.
Common causes include loud noise exposure and aging.
Auditory Processing:
The brain processes auditory information through several stages.
Information goes through the thalamus, where initial processing occurs.
Then passes to the auditory cortex in the temporal lobe for further processing, including sound localization and recognition.
Encoding in the Auditory System:
The auditory system encodes the intensity and frequency of sound.
Intensity:
Encoded by the firing rate of neurons.
More intense sounds cause more rapid firing of auditory nerve fibers.
Frequency:
Encoded by place theory (different locations on the basilar membrane respond to different frequencies).
Encoded by frequency matching/volley theory (auditory nerve fibers fire in synchrony with the sound waves).
Vision
Light:
Electromagnetic energy; humans can only sense a small portion of the electromagnetic spectrum (400-750 nanometers), known as visible light.
Light intensity = brightness. The amplitude of light waves determines how bright the light appears.
Wavelength = color. The distance between peaks of light waves determines the color we perceive.
Eye Structure:
The eye converts electromagnetic light energy to images through visual transduction.
Structures such as the cornea, lens, and retina work together to focus light and convert images.
Photoreceptors (in the retina):
Rods:
Photoreceptor cells in the retina are highly sensitive to light but do not distinguish colors.
Responsible for vision in low-light conditions; more abundant in the periphery of the retina.
Cones:
Photoreceptor cells in the retina are less sensitive to light than rods but can distinguish colors.
Responsible for color vision and visual acuity in bright-light conditions; concentrated in the fovea.
Ganglion cells:
Neurons in the retina collect signals from photoreceptors and transmit them to the brain via the optic nerve.
Generate action potentials.
Interneurons:
Neurons in the retina (e.g., bipolar cells, amacrine cells, and horizontal cells) pass signals from photoreceptors to ganglion cells.
Modify and integrate the signals.
Color Vision:
Hue: The actual color we perceive, such as red, green, or blue.
Determined by the dominant wavelength of the light.
Color Saturation: The purity of the color. Highly saturated colors appear vivid, while less saturated colors appear faded or washed out.
Brightness: The intensity of the color. Determined by the amplitude of the light waves.
Theories of Color Vision:
Trichromatic Theory (Young-Helmholtz):
Any color can be produced by mixing blue, green, and red light. The theory suggests that there are three types of cone receptors in the retina that are sensitive to these three colors.
Supported by cone activity (short, medium, and long wavelengths): These cones respond maximally to blue, green, and red light, respectively.
Opponent Process Theory:
Colors are derived from three antagonistic pairs: red-green, blue-yellow, black-white. Activation of one member of the pair inhibits the other.
Explains afterimages. After prolonged exposure to one color, its opposing color is seen when looking at a neutral surface because the neural response to the original color is fatigued, and the opposing response is enhanced.
Sensory Interaction and Synesthesia
Sensory Interaction:
The principle that senses can influence each other, leading to integrated sensory experiences.
Taste is influenced by smell; vision can affect touch sensitivity.
The McGurk effect: A perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception. It occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.
Synesthesia:
A neurological phenomenon where stimulation of one sensory pathway leads to involuntary experiences in a second sensory pathway.
Seeing colors when hearing music, tasting shapes.
Types of synesthesia include grapheme-color synesthesia, where letters or numbers are associated with colors, and sound-color synesthesia, where sounds evoke color perceptions.
Chemical Senses
Smell (Olfaction):
Employs about 1,000 receptor types:
Allows humans to detect a wide range of odors.
Olfactory neurons are replaced every two months:
Allows for continuous adaptation and sensitivity to new smells.
Bypasses thalamus:
Olfactory information is directly linked to emotional memory systems in the limbic system, explaining why smells can evoke strong emotions and memories.
Loss of smell (anosmia) can lead to memory problems, emotional issues, and depression because of the close link between olfaction and emotional processing.
Pheromones:
Chemicals released by one animal that affect the behavior or physiology of another animal of the same species.
Detected by the vomeronasal system (VNO): A separate olfactory structure.
May influence moods and menstrual synchrony in humans.
Pheromones play a more significant role in animal behavior, affecting mating and social interactions.
Taste:
Humans have about 10,000 taste buds grouped in papillae on the tongue, palate, and throat.
Tastes: The primary tastes include sweet, sour, bitter, salty, umami (savory), and astringent (puckering).
Supertasters: Around 25% of people have more papillae, resulting in elevated taste sensitivity. They tend to experience tastes more intensely.
Cutaneous Senses and Vestibular System
Cutaneous Senses:
Sensory information from throughout the body, including touch, temperature, and pain.
Skin sensors: Touch, temperature, and pain. These receptors detect mechanical, thermal, and chemical stimuli.
Kinesthetic sense: Provides information about body position and movement. Allows us to sense where our body parts are in space.
Encoding Touch Information:
Intensity: Encoded by the firing rate and number of neurons stimulated. Stronger stimuli activate more neurons and cause them to fire more rapidly.
Location: Determined by which stimulated nerves send signals to the brain. Specific areas of the skin correspond to specific areas of the somatosensory cortex.
Changes: The most important sensory information involves detecting changes in stimulation. Sensory adaptation reduces our awareness of constant stimuli.
Temperature Sensing:
Warm and cold fibers in the skin respond to changes in temperature. Some fibers respond to both touch and temperature.
Thunberg's thermal illusion: Simultaneously stimulating warm and cold fibers can cause a sensation of searing pain, as the brain misinterprets the conflicting signals.
Pain:
Provides information about the world's impact on the body, signaling potential harm and triggering protective responses.
Closely associated with emotions. Pain can evoke strong emotional responses, such as fear, anxiety, and anger.
Pain signals can be interrupted by other inputs. Rubbing an injury stimulates touch receptors, which can inhibit pain signals.
A delta fibers: Transmit sharp, prickling pain signals quickly. Associated with immediate, acute pain.
C fibers: - Transmit dull, aching pain signals more slowly. Associated with chronic, lingering pain.
Acupuncture:
Alternative therapy for pain relief that involves inserting thin needles into specific points on the body.
May release endorphins, the body's natural pain relievers, reducing the perception of pain.
Naloxone blocks acupuncture's pain-relieving effects. Indicates that endorphins are involved in the process.
Proprioceptive Senses:
Sense of balance, head position, and movement. Allows us to maintain equilibrium and coordinate movements.
Involves vestibular sacs detect linear acceleration, otoliths detect gravity and tilt, and semicircular canals detect rotational movements.
Connected to the cerebellum coordinates movement, the autonomic nervous system regulates balance-related reflexes, and eye muscles stabilize gaze during movement.
Kinesthetic Perception:
Awareness of body part locations in space and in relation to each other. allows us to perform coordinated movements.
Necessary to guide movement. Essential for fine motor skills and spatial awareness.
Comes from proprioceptors in joints and muscles. Provides information about muscle length, tension, and joint position.
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