PSYC 100 - Sensation & Perception

What is sensation?

Sensory organs receive stimulus energies from environment and transduce them into electrical energy of the nervous sytem

What is perception?

Neural processing of electrical signals to form internal mental representation inside brain of what is outside

What is transduction?

Stimulus energy from environment → neural impulses

What is top-down processing?

The brain uses prior knowledge, experiences, and context to interpret new sensory information

What is bottom-up processing?

When we form perceptions by relying solely on sensory input from external stimuli, without using prior knowledge or expectations

What is psychophysics?

The study of the relationship between the physical characteristics of environmental stimuli and our mental experience of them.

What is the figure-ground principle?

a Gestalt principle of visual perception that states humans instinctively separate a visual field into figure, the object of focus, and ground, the background

What is proximity in gestalt psychology?

We perceive features grouped together when they are close together

What is similarity in gestalt psychology?

We group things together that look alike

What is closure in gestalt psychology?

The human tendency to perceive incomplete or fragmented visual elements as a whole, unified object.

What is a good continuation in gestalt psychology?

The human eye tends to see smooth, unbroken lines and forms as a single, continuous object, rather than as separate or interrupted elements.

What is common fate in gestalt psychology?

Humans perceive objects moving together in the same direction and at the same rate as a single, grouped unit.

What is the blindsight phenomenon?

A phenomenon where individuals with damage to the primary visual cortex can still respond to visual stimuli in their blind field without conscious awareness of seeing them

What is visual agnosia?

-Lesion in ventral stream

-Failure to recognize objects despite being capable to see them

What is prosopagnosia?

-Occurs after lesion or is developmental

-Inability to recognize identity of faces despite having normal vision & intelligence

What is the function of rods in the eye?

Support nightime vision

What is the function of cones in the eye?

Responsible for high-resolution

What is the blind spot in the eye?

-Part of eye where there is no photoreceptors

-No information can be received

-Our brain compensates for missing information

What is a feature detector?

A specialized neuron that responds selectively to specific features of a stimulus, such as lines, angles, edges, or motion

What is the trichromatic theory?

-3 types of cone cells work together

-Red, blue, green

What is the opponent process theory?

-Information from comes are separated into 3 sets of opponent channels 

-Green/red, yellow/blue, black/white

What is the somatosensory pathway?

Sensory receptors tuned to detect a specific type of stimulus (pain, touch, temperature, vibration)

What is the sensory homunculus?

Depiction of how the body is represented by the brain

-Proportional to amount of cortex devoted to each body part