Senses and Perception - Psychology

The process by which our sensory receptors and nervous system receive information from external and internal environments

Sensation

Sensory nerve endings that respond to stimuli

Sensory receptors

The process of selecting, organizing, and interpreting sensory information. How we decide what is important or meaningful

Perception

Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information

Bottom-Up Processing

Information processing guided by higher-level mental processes, as we construct perceptions drawing on our experience and expectations

Top-Down Processing

Focusing of conscious awareness on a particular stimulus

Selective Attention

Ability to hear one specific voice amongst many other voices

Cocktail Party Effect

The failure to perceive the existence of an unexpected item

Inattentional Blindness

Failing to notice changes in the environment

Change Blindness

The process of turning one form of energy (sound wave, light, smells) into neural impulses our brain can interpret.

Transduction

Transduction

Rods and cones are responsible for this

1. Stimulus energy (light, sound, smell, taste, touch, etc)

2. Sensory receptors (eyes, ears, nose, tongue, skin)

3. Neural impulses

4. Brain (Visual, auditory, olfactory area, etc)

What is the process of transduction?

The study of the relationships between physical energy we can detect and its effects on our psychological experiences

Psychophysics

The minimum stimulus energy needed to detect a particular stimulus 50% of the time

Absolute Threshold

Predicts how and when we will detect the presence of a faint stimulus. Depends on a person’s expectations, motivation, and alertness

Signal Detection Theory

Below one’s absolute threshold

Subliminal

Minimum difference required to notice a difference between two stimulus

Difference Threshold (JND: Just Noticeable Difference)

In order for someone to perceive a difference, two stimuli must differ by a constant minimum percentage, not amount

Weber’s Law

Lowered sensitivity to a stimulus as a consequence of continuous stimulation. This is caused by our nerve cells firing less frequently

Sensory Adaptation

A phenomenon in which exposure to one stimulus influences how a person responds to a subsequent, related stimulus

Priming

The processing of information by the brain without conscious awareness. The unconscious mind still processes what is going on

Subliminal Perception

Determined by wavelength, the color we experience

Hue

Determined by amplitude of the wave, brightness of color

Intensity

Eye’s outer protective layer

Cornea

The adjustable opening of the eye, first thing to allow light in

Pupil

Colored muscle that controls the size of the pupil

Iris

Behind pupil, changes shape to help focus light on the retina

Lens

The process by which the lens changes its shape to focus on the light of the retina, depending on if you are trying to focus on something close or something far away

Accommodation

Back of eye, contains rods, cones, and neurons that allow for visual perception

Retina

Retinal receptor that detect black/white/grey, and movement

Rods

Retinal receptors that detect color and fine details

Cones

Receive impulses from rods and cones

Bipolar cells

Carry neural impulses and stand together to create the optic nerve

Ganglion Cells

Carry neural impulses to the thalamus, which then is sent to the visual cortex in the occipital lobe

Optic Nerve

Theory that states our retina contains three different types of color receptors that can be stimulated in combination to create any color (Red, Green, Blue)

Young-Helmholtz Trichromatic Theory (Three Color Theory)

Theory that states our retina contains three different types of color receptors that can be stimulated in combination to create any color

(Red-green, blue-yellow, white-black)

Opponent-Process Theory

The lingering image that remains after looking at something bright

Afterimages

Our ability to process multiple aspects of a stimulus or problem simultaneously

Parellel Processing

Nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement

Feature Detectors

Sound volume, measured in decibels

Amplitude

Measured in hertz

Frequency

1. Auditory

2. Canal

3. Eardrum

4. Ossicles

5. (Has)- Hammer, anvil, stirrup

6. Oval

7. Window

8. Cochlea

9. Hair cells

10. Auditory

11. Cortex

What is the process of hearing?

Caused by damage to the cochlea, hair cells, or auditory nerve

Sensorineural hearing loss

Caused by damage to the mechanical system (eardrum, middle ear bones

Conduction deafness

For people with a damaged/underdeveloped cochlea, can implant this to manually turn sound waves into neural impulses

Cochlear implant

The theory that we hear different pitches because different sound waves trigger different parts of our cochlea. Best explains how we hear high pitched sounds

Place theory

The theory that the brain perceives sounds by monitoring the amount of neural impulses coming up the auditory nerve. Best explains how we hear low pitched sounds

Frequency theory

Theory that impulses can alternate firing to have combined frequency higher than 1,000 impulses/second

Volley Principle

• Pressure

• Pain

• Cold

• Warmth

Sense of touch

In the somatosensory cortex (Parietal lobe)

Where is sense of touch processed?

Pain sensory receptors

Nociceptors

Spinal cord contains a “gate” that controls the transmission of pain messages to the brain

Gate control theory

• Sweet

• Salty

• Sour

• Bitter

• Umami

• Oleogustus

Chemical senses

Involved with memory and emotion, memories are associated with smell

Limbic system

Our movement sense, responsible for sensing the position and movement of individual body parts

Kinesthetic Sense

Enables the maintenance of balance in part controlled by the semicircular canals, which contains receptors that detect motions of the head

Vestibular Sense

One sense influences another

Sensory interaction

Bodily sensation influences another

Embodied Cognition

Rare phenomenon where two senses become conjoined

Synesthesia

A mental predisposition to perceive one thing and not another

Perceptual Set

The motivation and emotion we bring to a situation affects our interpretations

Context

Motive gives us energy as we work towards a goal. They can bias our interpretations of neutral stimuli

Motivation

Our mood affects the way in which we perceive the outside world.

Emotion

An organized whole. These psychologists emphasized humans’ tendency to organize pieces of information into a meaningful whole

Gestalt

Organizing the visual field into objects (figures) that stand out from their surroundings (the ground)

Figure-Ground

Organizing stimuli into coherent groups

• Proximity: Grouping nearby figures together

• Continuity: Perception of patterns as smooth and continuous

• Closure: Perceptually filling gaps to create a complete project

Grouping

The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance

Depth Perception

A binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance

Retinal Disparity

A cue to nearby objects’ distance, enabled by the brain combining retinal images

Convergence

Because more light passes through objects that are farther away, we perceive these objects as hazy, blurry, or unclear. Nearby objects appear sharp and clear

Relative Clarity

If we assume two objects are similar in size, most people perceive the one that casts the smaller retinal images as far away

Relative Size

Moving towards or away from an object changes our perception of its smoothness or texture

Texture Gradient

If one object partially blocks our view of another, we perceive it as closer

Interposition

The sharper the angle of convergence, the greater the perceived distance

Linear Perspective

An illusion of continuous movement experienced when viewing a rapid series of varying still images

Stroboscopic Effect

An illusion of movement created when two or more adjacent lights blink on and off in quick succession

Phi Phenomenon

The ability to adjust to changes sensory input, including an artificially displaced or even inverted visual field

Perceptual Adaptation

Depth cues available to both eyes separately

Monocular depth cues

Near objects are low in the visual field, more distant objects are higher up

Relative height

If separate objects are expected to be of the same size, the larger ones are seen as closer

Relative Size

Parellel lines appear to meet in the distance

Linear Perspective

Shading produces a sense of depth consistent with our assumption that light comes from above

Light and Shadow

As we move, still objects may appear to move as well

Relative Motion

Perceiving familiar objects as having consistent color, even if the illumination is changed

Color Constancy

We perceive an object as having an unchanging size, even while our distance from it varies

Size Constancy

We perceive the form of familiar objects as constant even when you are looking at an altered angle of them

Shape Constancy