Podcast
Questions and Answers
What does an increase in stimulus intensity generally affect in sensory neurons?
What does an increase in stimulus intensity generally affect in sensory neurons?
Which technique measures electrical activity from a subpopulation of neurons in response to specific stimuli?
Which technique measures electrical activity from a subpopulation of neurons in response to specific stimuli?
What is the resting membrane potential of a neuron at rest?
What is the resting membrane potential of a neuron at rest?
Which imaging technique utilizes X-rays to create images of slices through volumes of material?
Which imaging technique utilizes X-rays to create images of slices through volumes of material?
Signup and view all the answers
Which functional imaging method relies on measuring changes in blood flow associated with brain activity?
Which functional imaging method relies on measuring changes in blood flow associated with brain activity?
Signup and view all the answers
Which sensory perception is associated with the detection of harmful stimuli?
Which sensory perception is associated with the detection of harmful stimuli?
Signup and view all the answers
What is the absolute threshold in psychophysics?
What is the absolute threshold in psychophysics?
Signup and view all the answers
Which method involves adjusting the stimulus using a dial until it is perceived?
Which method involves adjusting the stimulus using a dial until it is perceived?
Signup and view all the answers
Which method is likely to yield the most accurate estimate of the absolute threshold?
Which method is likely to yield the most accurate estimate of the absolute threshold?
Signup and view all the answers
In psychophysics, what does the difference threshold refer to?
In psychophysics, what does the difference threshold refer to?
Signup and view all the answers
Which is NOT a part of the perceptual process cycle?
Which is NOT a part of the perceptual process cycle?
Signup and view all the answers
Who invented the science of psychophysics?
Who invented the science of psychophysics?
Signup and view all the answers
What aspect of perception does existing knowledge primarily influence?
What aspect of perception does existing knowledge primarily influence?
Signup and view all the answers
Which technique involves presenting stimuli multiple times to create a psychometric function?
Which technique involves presenting stimuli multiple times to create a psychometric function?
Signup and view all the answers
Balance is a type of which sensory perception?
Balance is a type of which sensory perception?
Signup and view all the answers
The resting membrane potential of a neuron is approximately -70 mV.
The resting membrane potential of a neuron is approximately -70 mV.
Signup and view all the answers
Electroencephalography (EEG) utilizes radioactive substances to measure brain activity.
Electroencephalography (EEG) utilizes radioactive substances to measure brain activity.
Signup and view all the answers
Functional Magnetic Resonance Imaging (fMRI) measures brain activity by detecting changes in blood flow related to local oxygenation levels.
Functional Magnetic Resonance Imaging (fMRI) measures brain activity by detecting changes in blood flow related to local oxygenation levels.
Signup and view all the answers
Blood oxygen level-dependent (BOLD) signal is used to determine the ratio of sodium to potassium ions in neurons.
Blood oxygen level-dependent (BOLD) signal is used to determine the ratio of sodium to potassium ions in neurons.
Signup and view all the answers
Magnetoencephalography (MEG) and Electroencephalography (EEG) both measure changes in magnetic activity across populations of neurons in the brain.
Magnetoencephalography (MEG) and Electroencephalography (EEG) both measure changes in magnetic activity across populations of neurons in the brain.
Signup and view all the answers
Match the following sensory neuroscience terms with their descriptions:
Match the following sensory neuroscience terms with their descriptions:
Signup and view all the answers
Match the following brain imaging techniques with their primary characteristics:
Match the following brain imaging techniques with their primary characteristics:
Signup and view all the answers
Match the following electrophysiological techniques with their functions:
Match the following electrophysiological techniques with their functions:
Signup and view all the answers
Match the following types of sensory modalities with their definitions:
Match the following types of sensory modalities with their definitions:
Signup and view all the answers
Match the following components of the perceptual process with their functions:
Match the following components of the perceptual process with their functions:
Signup and view all the answers
What outcome in a signal detection experiment occurs when a stimulus is present but not detected?
What outcome in a signal detection experiment occurs when a stimulus is present but not detected?
Signup and view all the answers
In signal detection theory, what term refers to the internal threshold set by the observer for making a response?
In signal detection theory, what term refers to the internal threshold set by the observer for making a response?
Signup and view all the answers
How does increasing stimulus intensity generally affect the ROC curve?
How does increasing stimulus intensity generally affect the ROC curve?
Signup and view all the answers
What does the x-axis represent on a receiver operating characteristic (ROC) plot?
What does the x-axis represent on a receiver operating characteristic (ROC) plot?
Signup and view all the answers
What does sensitivity refer to in signal detection theory?
What does sensitivity refer to in signal detection theory?
Signup and view all the answers
Which statement best describes Weber's law?
Which statement best describes Weber's law?
Signup and view all the answers
Fechner's law suggests that lower-intensity stimuli require a lesser increase in intensity to produce the same perceived difference.
Fechner's law suggests that lower-intensity stimuli require a lesser increase in intensity to produce the same perceived difference.
Signup and view all the answers
What does Stevens' power law describe regarding the relationship between stimulus and perceived intensity?
What does Stevens' power law describe regarding the relationship between stimulus and perceived intensity?
Signup and view all the answers
According to Weber's law, the Just Noticeable Difference (JND) increases with the increase in the intensity of the __________ stimulus.
According to Weber's law, the Just Noticeable Difference (JND) increases with the increase in the intensity of the __________ stimulus.
Signup and view all the answers
Match the following laws of psychophysics with their descriptions:
Match the following laws of psychophysics with their descriptions:
Signup and view all the answers
What happens to the firing rate of sensory neurons when stimulus intensity is increased?
What happens to the firing rate of sensory neurons when stimulus intensity is increased?
Signup and view all the answers
How does the blood oxygen level-dependent (BOLD) signal relate to functional MRI (fMRI) results?
How does the blood oxygen level-dependent (BOLD) signal relate to functional MRI (fMRI) results?
Signup and view all the answers
What is the primary function of event-related potentials (ERPs) in sensory neuroscience?
What is the primary function of event-related potentials (ERPs) in sensory neuroscience?
Signup and view all the answers
What distinguishes computerized tomography (CT) from magnetic resonance imaging (MRI)?
What distinguishes computerized tomography (CT) from magnetic resonance imaging (MRI)?
Signup and view all the answers
Describe how sensory modalities interact in the brain.
Describe how sensory modalities interact in the brain.
Signup and view all the answers
What is the role of transduction in the perceptual process?
What is the role of transduction in the perceptual process?
Signup and view all the answers
Explain how the method of limits works in measuring perception.
Explain how the method of limits works in measuring perception.
Signup and view all the answers
Describe the difference threshold and its significance in psychophysics.
Describe the difference threshold and its significance in psychophysics.
Signup and view all the answers
What is the purpose of the psychometric function in psychophysics?
What is the purpose of the psychometric function in psychophysics?
Signup and view all the answers
How does existing knowledge influence perception according to the perceptual process cycle?
How does existing knowledge influence perception according to the perceptual process cycle?
Signup and view all the answers
Study Notes
Scientific Methods in Sensory Neuroscience
- Thresholds define limits of perception for sensory inputs.
- Scaling techniques measure subjective experience of different stimuli.
- Sensory neuroscience studies the biology of sensation and perception.
- Various sensory modalities have dedicated receiving areas; some are polysensory, integrating multiple senses.
Resting Membrane Potential and Firing Rate
- Resting membrane potential is typically -70 mV.
- Sodium (Na+) influx and potassium (K+) efflux lead to depolarization; K+ influx and Na+ efflux lead to repolarization.
- Hypolarization occurs when membrane potential drops below -70 mV.
- Increasing stimulus intensity elevates neuron firing rates.
Brain Electrophysiology Techniques
- Electroencephalography (EEG) measures brain electrical activity via electrodes on the scalp.
- Event-related potentials (ERPs) capture electrical responses from neuronal populations triggered by specific stimuli.
- Visually Evoked Potentials (VEP) assess the activity of visual neurons in response to visual stimuli.
- Magnetoencephalography (MEG) measures magnetic field changes related to neuronal activity.
Brain Imaging Technologies
- Computerized Tomography (CT) uses X-rays for imaging and visualizing brain structures.
- Magnetic Resonance Imaging (MRI) leverages strong magnetic fields to create detailed brain images.
- Positron Emission Tomography (PET) measures blood flow changes associated with brain activity.
- Functional MRI (fMRI) detects changes in blood oxygen levels, providing insights into localized brain activity.
- Functional Near-Infrared Spectroscopy (fNIRS) utilizes near-infrared light to estimate cortical activity linked to neural function.
Perception and Its Processes
- Perception is shaped by evolutionary factors and provides critical information for survival.
- Humans can only sense a limited range of environmental energy.
- Environmental stimulus leads to a series of perceptual stages: attended stimulus, sensory transduction, processing, recognition, and action.
Psychophysics
- Psychophysics examines quantitative relationships between physical stimuli and subjective experience, pioneered by Fechner.
- Absolute threshold: the minimum stimulation level detectable 50% of the time.
- Methods to measure perception include limits, adjustments, constant stimuli, and staircase techniques.
Difference Threshold and Weber's Law
- Difference threshold (just noticeable difference, JND) assesses perceived differences between stimuli.
- Weber's Law states that the JND is proportional to the magnitude of the stimulus, differing across sensory domains.
- Example Weber fractions:
- Taste (Saltiness) 0.083
- Vision (Brightness) 0.079
- Touch (Heaviness) 0.020
Psychophysical Scaling
- Fechner's Law relates perceived intensity to stimulus intensity through logarithmic scales.
- Stevens' Power Law describes non-linear or linear responses to stimuli across various sensory domains, reflecting different exponents for perception.
Neurons and Action Potentials
- Neuron doctrine posits that perception arises from complex interactions among neurons coding various stimulus attributes.
- Action potentials are electrical signals generated by voltage-gated Na+ channels; they follow an all-or-nothing principle.
- Synapses can be excitatory (activating Na+ channels) or inhibitory (activating Cl- channels).
Measuring Neural Activity
- Direct measures include recording from nerves in humans and neurons in animals.
- Indirect measures like EEG and MEG infer activity from groups of neurons.
- Advanced imaging techniques (CT, MRI, PET, fMRI) enhance understanding of brain function and structure.
Signal Detection Theory
- Noise accounts for random variations in how stimuli are processed.
- Outcomes in detection tasks include hits, misses, false alarms, and correct rejections.
- Receiver Operating Characteristic (ROC) plots visualize detection performance, with higher stimulus intensities correlating with increased hit rates.
- Sensitivity measures the ease of stimulus detection, while criterion defines the observer's response threshold. Bias indicates tendencies in reporting responses.
Scientific Methods in Sensory Neuroscience
- Thresholds determine perceptual limitations to sensory stimuli.
- Scaling measures the experience related to sensory perception.
- Sensory modalities are directed to primary receiving areas, sometimes combining multiple senses.
Neuronal Activity
- Resting Membrane Potential: Typically around -70 mV.
- Depolarization occurs with Na+ influx and K+ efflux.
- Repolarization involves K+ influx and Na+ efflux.
- Hyperpolarization happens when the membrane potential drops below -70 mV.
- Firing rate can increase with stimulus intensity, influenced by refractory periods and spontaneous activity.
Modern Brain Electrophysiology Techniques
- Electroencephalography (EEG) captures electrical activity from neuron populations via scalp electrodes.
- Event-Related Potential (ERP) measures the electrical response from specific neurons when exposed to certain stimuli.
- Visually Evoked Potentials (VEP) assess electrical activity in visual pathways following visual stimuli.
- Magnetoencephalography (MEG) detects magnetic changes in brain activity, functioning similarly to EEG.
Brain Imaging Techniques
- Computerized Tomography (CT) utilizes X-rays to generate cross-sectional images of the brain.
- Magnetic Resonance Imaging (MRI) employs strong magnetic fields to produce detailed images of brain structures.
- Positron Emission Tomography (PET) assesses blood flow changes related to brain activity using radioactive tracers.
- Functional Magnetic Resonance Imaging (fMRI) measures localized brain activity via blood flow and its oxygenation levels using BOLD signals.
- Functional Near-Infrared Spectroscopy (fNIRS) uses near-infrared light to evaluate cortical blood flow and activity.
Perceptual Process
- Perception evolved to provide survival information, shaped by the types of energy present in the environment.
- Sensory range is limited, affecting our sense of reality.
- Major sensory modalities include vision, audition, touch, proprioception, nociception, thermoreception, balance, body movement, olfaction, and gustation.
Psychophysics
- Psychophysics focuses on quantifying the relationship between physical stimuli and subjective experiences.
- Absolute threshold indicates the minimum detectable stimulus level at least 50% of the time.
-
Methods of measuring perception include:
- Method of Limits, Adjustment, Constant Stimuli, and Staircase Method, each with differing precision and efficiency.
Thresholds and Sensory Scaling
- Difference threshold (Just Noticeable Difference, JND) calculated through method adjustments based on perceived change detection.
- Weber’s Law states that JND changes across different stimulus intensities, is expressed as k*I, where I is intensity and k is a constant.
- Fechner’s Law relates perceived intensity to physical intensity through logarithmic relationships.
- Stevens’ Law introduces a power law for various sensory modalities indicating linear/non-linear stimulus perception relationships.
Neuron Doctrine
- Perception results from various neurons coding distinct stimulus attributes.
- Ramon y Cajal's discovery on synapse structure laid groundwork for understanding neural communication.
- Action Potentials are generated by the opening of voltage-gated Na+ channels, followed by K+ channel activity leading to repolarization and hyperpolarization.
- Synapses can exhibit either excitatory or inhibitory characteristics.
Measuring Neural Activity
- Direct Measurement involves recording from peripheral nerves and CNS neurons.
- Indirect Measurement refers to techniques like EEG, MEG, fNIRS, CT, MRI, and PET for assessing broader neural activity or blood flow.
- Signal Detection Theory highlights the impact of noise on neural coding and response variability.
Outcomes of Signal Detection Analysis
- Signal detection introduces four potential outcomes: true positive, true negative, false positive, false negative, essential for understanding perceptual decision-making dynamics.
Scientific Methods in Sensory Neuroscience
- Thresholds determine perceptual limitations to sensory stimuli.
- Scaling measures the experience related to sensory perception.
- Sensory modalities are directed to primary receiving areas, sometimes combining multiple senses.
Neuronal Activity
- Resting Membrane Potential: Typically around -70 mV.
- Depolarization occurs with Na+ influx and K+ efflux.
- Repolarization involves K+ influx and Na+ efflux.
- Hyperpolarization happens when the membrane potential drops below -70 mV.
- Firing rate can increase with stimulus intensity, influenced by refractory periods and spontaneous activity.
Modern Brain Electrophysiology Techniques
- Electroencephalography (EEG) captures electrical activity from neuron populations via scalp electrodes.
- Event-Related Potential (ERP) measures the electrical response from specific neurons when exposed to certain stimuli.
- Visually Evoked Potentials (VEP) assess electrical activity in visual pathways following visual stimuli.
- Magnetoencephalography (MEG) detects magnetic changes in brain activity, functioning similarly to EEG.
Brain Imaging Techniques
- Computerized Tomography (CT) utilizes X-rays to generate cross-sectional images of the brain.
- Magnetic Resonance Imaging (MRI) employs strong magnetic fields to produce detailed images of brain structures.
- Positron Emission Tomography (PET) assesses blood flow changes related to brain activity using radioactive tracers.
- Functional Magnetic Resonance Imaging (fMRI) measures localized brain activity via blood flow and its oxygenation levels using BOLD signals.
- Functional Near-Infrared Spectroscopy (fNIRS) uses near-infrared light to evaluate cortical blood flow and activity.
Perceptual Process
- Perception evolved to provide survival information, shaped by the types of energy present in the environment.
- Sensory range is limited, affecting our sense of reality.
- Major sensory modalities include vision, audition, touch, proprioception, nociception, thermoreception, balance, body movement, olfaction, and gustation.
Psychophysics
- Psychophysics focuses on quantifying the relationship between physical stimuli and subjective experiences.
- Absolute threshold indicates the minimum detectable stimulus level at least 50% of the time.
-
Methods of measuring perception include:
- Method of Limits, Adjustment, Constant Stimuli, and Staircase Method, each with differing precision and efficiency.
Thresholds and Sensory Scaling
- Difference threshold (Just Noticeable Difference, JND) calculated through method adjustments based on perceived change detection.
- Weber’s Law states that JND changes across different stimulus intensities, is expressed as k*I, where I is intensity and k is a constant.
- Fechner’s Law relates perceived intensity to physical intensity through logarithmic relationships.
- Stevens’ Law introduces a power law for various sensory modalities indicating linear/non-linear stimulus perception relationships.
Neuron Doctrine
- Perception results from various neurons coding distinct stimulus attributes.
- Ramon y Cajal's discovery on synapse structure laid groundwork for understanding neural communication.
- Action Potentials are generated by the opening of voltage-gated Na+ channels, followed by K+ channel activity leading to repolarization and hyperpolarization.
- Synapses can exhibit either excitatory or inhibitory characteristics.
Measuring Neural Activity
- Direct Measurement involves recording from peripheral nerves and CNS neurons.
- Indirect Measurement refers to techniques like EEG, MEG, fNIRS, CT, MRI, and PET for assessing broader neural activity or blood flow.
- Signal Detection Theory highlights the impact of noise on neural coding and response variability.
Outcomes of Signal Detection Analysis
- Signal detection introduces four potential outcomes: true positive, true negative, false positive, false negative, essential for understanding perceptual decision-making dynamics.
Scientific Methods in Sensory Neuroscience
- Thresholds determine perceptual limitations to sensory stimuli.
- Scaling measures the experience related to sensory perception.
- Sensory modalities are directed to primary receiving areas, sometimes combining multiple senses.
Neuronal Activity
- Resting Membrane Potential: Typically around -70 mV.
- Depolarization occurs with Na+ influx and K+ efflux.
- Repolarization involves K+ influx and Na+ efflux.
- Hyperpolarization happens when the membrane potential drops below -70 mV.
- Firing rate can increase with stimulus intensity, influenced by refractory periods and spontaneous activity.
Modern Brain Electrophysiology Techniques
- Electroencephalography (EEG) captures electrical activity from neuron populations via scalp electrodes.
- Event-Related Potential (ERP) measures the electrical response from specific neurons when exposed to certain stimuli.
- Visually Evoked Potentials (VEP) assess electrical activity in visual pathways following visual stimuli.
- Magnetoencephalography (MEG) detects magnetic changes in brain activity, functioning similarly to EEG.
Brain Imaging Techniques
- Computerized Tomography (CT) utilizes X-rays to generate cross-sectional images of the brain.
- Magnetic Resonance Imaging (MRI) employs strong magnetic fields to produce detailed images of brain structures.
- Positron Emission Tomography (PET) assesses blood flow changes related to brain activity using radioactive tracers.
- Functional Magnetic Resonance Imaging (fMRI) measures localized brain activity via blood flow and its oxygenation levels using BOLD signals.
- Functional Near-Infrared Spectroscopy (fNIRS) uses near-infrared light to evaluate cortical blood flow and activity.
Perceptual Process
- Perception evolved to provide survival information, shaped by the types of energy present in the environment.
- Sensory range is limited, affecting our sense of reality.
- Major sensory modalities include vision, audition, touch, proprioception, nociception, thermoreception, balance, body movement, olfaction, and gustation.
Psychophysics
- Psychophysics focuses on quantifying the relationship between physical stimuli and subjective experiences.
- Absolute threshold indicates the minimum detectable stimulus level at least 50% of the time.
-
Methods of measuring perception include:
- Method of Limits, Adjustment, Constant Stimuli, and Staircase Method, each with differing precision and efficiency.
Thresholds and Sensory Scaling
- Difference threshold (Just Noticeable Difference, JND) calculated through method adjustments based on perceived change detection.
- Weber’s Law states that JND changes across different stimulus intensities, is expressed as k*I, where I is intensity and k is a constant.
- Fechner’s Law relates perceived intensity to physical intensity through logarithmic relationships.
- Stevens’ Law introduces a power law for various sensory modalities indicating linear/non-linear stimulus perception relationships.
Neuron Doctrine
- Perception results from various neurons coding distinct stimulus attributes.
- Ramon y Cajal's discovery on synapse structure laid groundwork for understanding neural communication.
- Action Potentials are generated by the opening of voltage-gated Na+ channels, followed by K+ channel activity leading to repolarization and hyperpolarization.
- Synapses can exhibit either excitatory or inhibitory characteristics.
Measuring Neural Activity
- Direct Measurement involves recording from peripheral nerves and CNS neurons.
- Indirect Measurement refers to techniques like EEG, MEG, fNIRS, CT, MRI, and PET for assessing broader neural activity or blood flow.
- Signal Detection Theory highlights the impact of noise on neural coding and response variability.
Outcomes of Signal Detection Analysis
- Signal detection introduces four potential outcomes: true positive, true negative, false positive, false negative, essential for understanding perceptual decision-making dynamics.
Noise in Neural Coding
- Noise refers to random variations in the neural response to the same stimulus, leading to inconsistent neural activity during sensory transduction.
Outcomes in Signal Detection Experiment
- Four possible outcomes:
- Hit: Correctly identifying a stimulus
- False Alarm: Incorrectly identifying a stimulus when it is not present (Type 1 error)
- Miss: Failing to identify a stimulus when it is present (Type 2 error)
- Correct Rejection: Correctly identifying no stimulus when it is absent
Receiver Operating Characteristic (ROC) Plot
- ROC plots graphically represent the trade-off between hit rate and false alarm rate.
- X-axis: False alarm rate
- Y-axis: Hit rate
- The point on the plot indicates actual performance rates of hits and false alarms.
- Chance performance equates to a 50/50 probability.
Stimulus Intensity and ROC
- Different intensities of stimuli result in various ROC curves.
- Higher stimulus intensity correlates with a higher hit rate, improving detection reliability.
Signal Detection Theory
- This theory differentiates between an observer's capability to detect a stimulus and their willingness to report it.
Sensitivity in Detection
- Sensitivity measures the ease of detecting a stimulus (absolute threshold) or distinguishing between two stimuli (just noticeable difference, JND).
- The sensitivity can vary among observers due to different internal criteria.
Criterion in Signal Detection
- Criterion represents the internal threshold defined by the observer, influencing how they respond to stimuli.
Observer Bias
- Bias refers to the observer's natural tendency to favor certain responses, classified as either liberal or conservative, and is represented by the criterion value.
Psychophysical Laws
-
Weber's Law:
- Just Noticeable Difference (JND) expands with higher standard stimulus intensity.
- Suggests perception of changes in stimulus is relative to initial intensity.
-
Fechner's Law:
- Requires a considerable increase in stimulus intensity for high-intensity situations to yield similar perceived differences.
- Reveals the logarithmic relationship between the actual stimulus intensity and perceived sensation.
-
Stevens' Power Law:
- Describes a relationship between the magnitude of stimuli and corresponding perceived intensity.
- Can be either linear or non-linear depending on the type of stimulus and context, providing a broader understanding of perception.
Scientific Methods in Sensory Neuroscience
- Sensory neuroscience studies the biology of sensation and perception (S&P)
- Thresholds determine limits of perception; scaling measures subjective experience
- Primary receiving areas exist for different sensory modalities, some integrate multiple senses
- Resting membrane potential of neurons measures -70 mV; depolarization occurs with Na+ influx, and repolarization with K+ efflux
- Firing rates correlate with stimulus intensity; spontaneous action potentials can occur without external stimuli
Brain Electrophysiology Techniques
- Electroencephalography (EEG): Measures brain electrical activity via scalp electrodes
- Event-related potential (ERP): Averages EEG responses to specific stimuli to assess brain activity
- Visually Evoked Potentials (VEP): Focuses on electrical activity in visual neurons in response to visual stimuli
- Magnetoencephalography (MEG): Similar to EEG but measures magnetic activity linked to neuron populations
Brain Imaging Technologies
- Computed Tomography (CT): Uses X-rays for imaging slices of brain structures
- Magnetic Resonance Imaging (MRI): Produces images through atomic responses to magnetic fields
- Positron Emission Tomography (PET): Assesses blood flow changes linked to brain activity using a radioactive tracer
- Functional Magnetic Resonance Imaging (fMRI): Measures brain activity by tracking blood flow changes using BOLD signals
- Functional near-infrared spectroscopy (fNIRS): Uses near-infrared light to estimate cortical activity linked to neural function
Perceptual Processes
- Perception evolves to enhance survival, influenced by energy types in the environment
- Sensory modalities are limited to specific energy ranges, impacting our sense of reality
- Categories of senses include vision, audition, tactile perception, proprioception, nociception, thermoreception, balance, body movement, olfaction, and gustation
Psychophysics and Measurement Techniques
- Psychophysics: Examines quantitative relationships between physical stimuli and experiences, pioneered by Fechner
- Absolute threshold: Minimal stimulus needed for 50% detection; measured through various methods
- Method of Limits: Adjusts volume to find detection boundary
- Method of Adjustment: Participant manually tunes stimulus for perception
- Method of Constant Stimuli: Uses a range of stimuli presented multiple times to find thresholds
- Staircase Method: Adjusts intensity based on participant responses to estimate thresholds accurately
Difference Threshold and Weber's Law
- Difference threshold (JND): Smallest detectable change; found through adjustment and constant stimuli
- Weber's Law describes the relationship between stimulus intensity and JND, showing varying perceptual sensitivity across different intensities
- Notable Weber's fractions for various sensory domains illustrate different sensitivity levels
Psychophysical Scaling Laws
- Fechner's Law: Relates perception to stimulus intensity through logarithmic scaling
- Stevens' Power Law: Flexible model accounting for both linear and non-linear stimulus-perception relationships, depending on sensory domain
Neuron and Action Potential Fundamentals
- Neurons have a high concentration of K+ inside and Na+ outside, with a resting potential around -70 mV
- Action potentials occur when voltage-gated Na+ channels open, causing depolarization followed by repolarization through K+ channels
- The all-or-nothing principle dictates that a neuron will only fire if the threshold is met
Synapses and Neural Activity Measurement
- Synapses can be excitatory or inhibitory, affecting neuron firing rates based on channel states
- Direct measurement includes recording neuronal activity in humans and animals; indirect techniques (EEG, MEG, fNIRS) assess broader neural activity
- Different imaging technologies (CT, MRI, PET, fMRI) provide insights into brain structure and function through various underlying mechanisms
Signal Detection Theory
- Noise represents random variations in neural responses, complicating the sensory transduction process
- In signal detection experiments, four possible outcomes can occur based on stimulus detection capabilities
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores key concepts in sensory neuroscience, including scientific methods like thresholds and scaling, as well as the biological underpinnings of sensory perception. It covers the role of primary receiving areas and polysensory integration, as well as fundamental neuronal principles such as resting membrane potential and firing rate.
