~Chapter #1 - Lectures Flashcards
What is the distal stimulus?
The distal stimulus is the environmental stimulus, it is “distant”—out there in the environment.
What is the proximal stimulus?
The image on the retina
How do we get from the distal stimulus to the proximal stimulus?
To get from the distal to the proximal stimulus, this covers the Principles of transformation and representation.
What is the principle of transformation?
Stimuli and responses created by stimuli are transformed, or changed, between the distal stimulus and perception.
What is the principle of representation?
The principle of representation states that everything a person perceives is based not on direct contact with stimuli but on representations of stimuli that are formed on the receptors and the resulting activity in the person’s nervous system.
What is transduction?
The receptor processes stage
What is neural transduction?
Neural transduction is the transformation of one kind of energy into neural activity
Which process shapes our perceptual experience?
Transduction. If we don’t have the correct detectors as part of our nervous system, we don’t have access to specific types of information.
We have to have the right kind of receptors which are transducing stimuli into neural activity in order to affect perception.
What is processing?
Processing means to collect, send, change, and calculate information.
Where does transduction occur?
Transduction occurs at the primary receptors on the eyes, on the retina.
What is the primary receiving area for vision?
The Occipital Lobe
What is the primary receiving area for hearing?
The Temporal Lobe
What is the primary receiving area for touch?
The Parietal Lobe
Where are the primary receiving areas?
The Cortex
Can you have perception without recognition?
Yes, but it is not usually the case.
For example; Visual-form agnosia, a condition where the person cannot recognize objects.
What is Bottom-Up (Data-Based) Processing?
Processing based on incoming stimuli from the environment.
What is Top-Down Processing?
- Processing based on the perceiver’s previous knowledge or memory
- Also called knowledge-based processing
- Almost always involved in “real-life perception”
- Almost always available to us.
- Critical for normal perception
What is the Stimulus-Perception question?
- How do we use information from the environment to create perceptions?
- The link between the perception and the environment stimuli.
What kind of experiment would be used for the Stimulus-perception question?
- A Color recognition or colour perception task
- Psychophysics
What is the Stimulus-Physiological question?
- How are the properties of physical stimuli represented by the activity of neurons?
- The link between the environmental stimulus and nervous system activity.
What kind of experiment would be used for the Stimulus-Physiological question?
Neural Recordings
What is the Physiological-Perception question?
What is the brain doing during perception?
What kind of experiment would be used for the Physiological-perception question?
fMRI, PET, EEG, NIRS
What are Qualitative Methods?
Qualitative Methods (Quality) Non-numeric descriptive-type methods:
- Introspection
- Describing
- Recognizing
What are Quantitative Methods?
Quantitative Methods (Quantity) Numbers are associated with some measurements of perception:
- Detecting - Judging Magnitude - Response Measures
What is introspection?
Questioning yourself
What is the link between philosophy and psychology?
Introspective questions
What is a Descriptive (Phenomenological Method) question?
How do I describe what is out there?
What is a Recognition (Categorization) question?
What is the identity of the stimulus?
What is Psychophysics?
The study of the relationship between the physical qualities of stimuli and the subjective perceptions of those stimuli.
Who introduced Psychophysics?
Gustav Fechner
What are the 3 methods of measuring thresholds in Psychophysics?
- Method of Limits
- Method of Adjustment
- Method of Constant Stimuli
How does a Method of Limits experiment work?
- In the method of limits, the intensity of the stimulus is changed one step at a time.
- In the first block of trials, the intensity of the stimulus is decreased very gradually.
- To get the threshold, you take the average of all the crossover values.
How does a Method of Adjustment experiment work?
- Stimulus intensity is adjusted continuously by the observer until the observer detects it
- The fastest of the methods, but is the least accurate.
- To help with accuracy, repeated trials are done.
- Repeated trials averaged for threshold
How does a Method of Constant Stimuli experiment work?
- Several stimuli of different intensities are presented in random order
- Is slightly different from the method of limits because the stimuli are presented in random order.
- Anticipation and guessing are eliminated by randomizing the order of trials.
- Multiple trials are presented
- Threshold is the intensity that results in detection in 50% of trials
- This method is the most complex, involves randomizing trials and theres lots of trials that have to be averaged, but it is generally considered to be the most accurate.
What is the Just Noticeable Difference/Difference Threshold (DL)?
The smallest difference between two stimuli a person can detect.
Who came up with the JND/Difference Threshold (DL)?
Ernst Weber
Who came up with Magnitude Estimation?
S.S. Stevens
How is a Magnitude Estimation experiment done?
- Observer is given a standard stimulus and a value for its intensity
- Observer compares the standard stimulus to test stimuli by assigning numbers relative to the standard
- Example: The standard stimulus is a light at 10 brightness, you are shown another light that looks half as bright as the standard stimulus, so that is 5 brightness. You are shown a light that is twice as bright as the standard stimulus, so that is 20 brightness.
What are Response Measure questions?
Perceptual Question: How quickly can I react to it?
-E.g. Measure Reaction Time in a SEARCH TASK
- Perceptual Question: How do I interact with it?
- E.g. Measure Grip Aperture Behavior when interacting with an Ebbinghaus array
What route does the stimulus info take?
Transduction at the primary receptor –> Neuroprocessing that is pretty close to the receptors –> that info is sent to the thalamus –> then gets sent to a primary receiving area in the cortex.
True or False: Processing happens at many stages
True
True or False: Processing occurs with many layers of feedback
True
Can you have perception without action?
Yes, but it is not usually the case
Which question contains all three chunks of the perceptual process?
The Physiological-Perception Question
Many of the initial investigations into perception started as ___________.
introspective questions
What is the threshold?
In psychophysics, sensory threshold is the weakest stimulus that an organism can sense. Threshold is the intensity that results in detection in 50% of trials
What method is the most complex?
Method of Constant Stimuli
What is Response Compression?
As intensity increases, the perceived magnitude increases more slowly than the intensity. (0
What is the Perceived Magnitude?
Constant multiplied by Stimulus Intensity raised to an exponent.
What is Response expansion?
As intensity increases, the perceived magnitude increases more quickly than the intensity. (n>1)
