Week 4 Lecture - PSY10007 Brain and Behaviour - Sensation

Flashcards on Sensation, covering definitions, sensory systems, hearing, vision, chemical senses, cutaneous senses, and the vestibular system.

Sense

A system that translates outside information into neural activity.

Sensation

The raw information taken in by the sensory organs (eyes, ears, etc.).

Sensation (as a process)

The process by which the brain organizes and interprets sensations, i.e., raw data from the environment.

Accessory Structures

Structures like ears and eyes that modify stimuli.

Receptors

Structures that transduce energy into neural activity.

Problem of Encoding

The challenge of translating physical properties of environmental stimuli into patterns of nerve cell activities.

Temporal Coding

The timing of impulses which helps in the coding of stimuli.

Spatial Codes

The specific location of neurons firing which is important in encoding information.

Doctrine of Specific Energy (Johann Muller)

The idea that the experience of a neural message as light or sound depends on the specific neurons excited, not the stimulus itself.

Psychophysics

The study of the relationship between physical energy in the environment and the psychological experience of the observer.

Absolute Threshold

The minimum amount of energy that can be detected 50% of the time.

Supraliminal Stimulation

Stimulus strong enough to be detected more than 50% of the time.

Subliminal Stimulation

Stimulus too weak to be perceived.

Signal Detection Theory

The detection of a stimulus involves Sensory processes and Decision-making processes.

Sensitivity

Relies on the intensity of the signal, capacities of sensory systems, and the noise level in the environment.

Response Criterion (Response Bias)

Influenced by willingness to respond to a stimulus, motivations, and expectancies.

Hit (Signal Detection)

Responding to a real signal.

False Alarm (Signal Detection)

Responding when there is no signal.

Miss (Signal Detection)

Failing to respond when a signal is present.

Correct Rejection (Signal Detection)

Ignoring when no signal is present.

Just Noticeable Difference (JND) / Difference Threshold

The amount a stimulus must change for the difference to be noticeable.

Weber's Law

The idea that the just noticeable difference is a constant fraction that varies depending on the individual, stimulus, context, and sensory modality.

Fechner's Law

Constant increases in stimulus strength result in diminishing perceptions of difference; a logarithmic relationship.

Stevens' Power Law

The perceived intensity of a stimulus grows arithmetically, the actual magnitude of the stimulus grows exponentially.

Amplitude (Sound)

Height from the baseline to the peak of a sound wave; relates to loudness, measured in decibels.

Wavelength (Sound)

The distance from peak to peak of a sound wave.

Frequency (Sound)

How frequent the sound waves are progressing; relates to pitch.

Timbre

The quality of sound, from a mixture of frequencies.

Pinna

The outer ear that collects and shapes sound waves.

Middle Ear

Consists of the tympanic membrane and ossicles (malleus, incus, stapes) that vibrate to transduce sounds.

Inner Ear

Made up of the cochlea and semicircular canals.

Cochlea

Where auditory transduction occurs, containing the basilar membrane and hair cells.

Conduction Deafness

Deafness due to the bones of the middle ear being affected; prevents accurate conduction of vibrations.

Nerve Deafness

Deafness resulting from damage to the acoustic nerve or hair cells in the basilar membrane.

Place Theory

Certain hair cells at specific positions on the basilar membrane respond most specifically to certain frequencies.

Frequency Matching (Volley Theory)

Frequencies are matched by the firing rate of neurons or auditory nerve fibers.

Visible Light Spectrum

Small part of the electromagnetic spectrum, from about 400 to 750 nanometers.

Light Intensity

Brightness.

Wavelength (Light)

Color.

Visual Transduction

Converting light energy into neural activity.

Photoreceptors

Specialized cells in the retina that convert light energy into neural activity.

Rods

Photoreceptors highly sensitive to light, but not color.

Cones

Photoreceptors less sensitive to light, but help distinguish colors.

Ganglion Cells

Cells on the surface of the retina that generate action potentials.

Interneurons

Cells that pass signals from photoreceptors to ganglion cells.

Hue

Represents the color or wave length of the light.

Color Saturation

Represents purity.

Brightness (Vision)

Represents intensity.

Trichromatic Theory (Young-Helmholtz)

Theory that any color can be produced by mixing blue, green, and red light; supported by cone activity.

Opponent Process Theory

Theory that all colors are derived from three antagonistic color pairs: red-green, blue-yellow, black-white.

Synesthesia

Unusual mixing of senses or dimensions within senses.

Olfactory Sense

Sense of smell; uses about a thousand different types of receptors.

Pheromones

Chemicals released by one animal that, when detected by another, can shape the second animal's behavior or physiology.

Taste Buds

Located in Papillae on the tongue, roof of the mouth, and back of the throat, allowing us to experience different tastes.

Supertasters

around 25 percent of people, They have a lot more of these papillae on their tongues and in their mouths, which means they can detect taste a bit more so than the average person.

Cutaneous Senses

Information from throughout the body, including touch, temperature, and pain.

Kinesthetic Sense

Tells the brain where parts of the body are.

Van Thunberg's Thermal Illusion

stimulating both warm and cold fibers at the same time, we experience like a searing pain.

A-delta Fibers

Nerve fibers responsible for sharp, prickling pain.

C Fibers

Nerve fibers responsible for dull, aching pain.

Proprioceptive Sensors

Sensing of where our body is, where what what our body position is.

Kinesthetic Perception

where our body parts are located in space and where they are located with respect to each other.