CAS PS 222 Study Guide - Midterm Guide: Absolute Threshold, Absolute Difference, Sensory Neuron
27 Apr 2018
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Study Notes for Midterm Exam 1:
Sensation refers to the initial step of converting of physical features of the environment into
electrochemical signals within specialized nerve cells and sending those signals to the brains for
processing.
Perception refers to the later steps in the process whereby the initial sensory signals are used
to form mental representations of the objects and events in a scene so they can be recognized,
stored in memory and used in thought and action. In many complex organisms, perception also
includes conscious awareness of the objects and events in scene.
Stimuli: The object and events that are perceived and the physical phenomena they produce
Distal Stimuli: A perceived object or event in the world
Proximal Stimuli: A physical phenomenon evoked by a distal stimulus that impinges on the
specialized cells of a sense.
Neurons: The cells of the nervous system that produce and transmit information carrying
electrochemical signals
Sensory receptors: The specialized neurons that convert proximal stimuli into neural signals
Top down information: A oserer’s koledge, epetatios, goals hih a affet
perception.
Bottom up information: The information contained in neural signals from receptors.
Transduction: The transformation of a physical stimulus into neural signals
Neural code: a pattern of neural signals that carries information about a stimulus and can serve
as a representation of that stimulus.
Absolute threshold: The minimum intensity of a physical stimulus that can just be detected by
an observer.
Three methods of detecting absolute/ difference threshold:
- Method of Adjustment
- Method of Constant Stimuli
- Staircase Method
1. Method of Adjustment:
- Simplest and quick
- The participant observes a stimulus and manipulates a control that directly adjusts the
intensity of the stimulus
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Sensation refers to the initial step of converting of physical features of the environment into electrochemical signals within specialized nerve cells and sending those signals to the brains for processing. In many complex organisms, perception also includes conscious awareness of the objects and events in scene. Stimuli: the object and events that are perceived and the physical phenomena they produce. Distal stimuli: a perceived object or event in the world. Proximal stimuli: a physical phenomenon evoked by a distal stimulus that impinges on the specialized cells of a sense. Neurons: the cells of the nervous system that produce and transmit information carrying electrochemical signals. Sensory receptors: the specialized neurons that convert proximal stimuli into neural signals. Top down information: a(cid:374) o(cid:271)ser(cid:448)er"s k(cid:374)o(cid:449)ledge, e(cid:454)pe(cid:272)tatio(cid:374)s, goals (cid:449)hi(cid:272)h (cid:272)a(cid:374) affe(cid:272)t perception. Bottom up information: the information contained in neural signals from receptors. Transduction: the transformation of a physical stimulus into neural signals.
