PSY 324 - Units 3-4 - Exam 1

Perception - Spring 2025

monocular cues

a depth cue where just one functional eye is needed

binocular cues

a depth cue where both eyes are needed

interposition

When one object interrupts the form of another object, the first object is perceived to be in front of the second

linear perspective

As straight lines gradually converge, they may be perceived as parallel; greater distance at convergence

relative size

Objects appearing to be different sizes are perceived to be the same size, but at different distances; does not involve motion 

size constancy

As an object moves further away and its retinal image becomes smaller, observers perceive it to be the same size throughout; involves motion

texture gradients

Distant objects appear more “packed” than close objects

motion parallax

When in motion, an observer can distinguish distance by the apparent “speed” of other objects in view; nearby objects seem to move faster than distant objects

stereopsis

how we see 3D; everything would be flat like a picture without it

retinal disparity

the slight difference between what each of your eyes sees because they’re spaced apart

convergence

the angle formed between a stimulus and both eyes impacts our impression of its distance from the self

feature detection theory

all objects are composed of distinct parts (features); object recognition requires decomposing it into its features

weakness of feature detection theory

they only consider the features themselves and not the relationships between the features

geons

36 basic shapes describing the spatial relations of components in the world

weaknesses of geons

more than 36 basic shapes are needed to form objects

gestalt psychology/principles

asks how we organize low level visual information to form a whole image

figure ground principle

observers separate objects between foreground and background

similarity principle

observers tend to group like objects together

proximity principle

observers tend to group objects that are close together

common region principle

observers tend to group objects that are enclosed in the same space

good continuation principle

observers tend to perceive contours and lines as continuous instead of favoring angles and joints 

closure principle

observers tend to look for a discernible pattern, and if necessary, the mind will fill in the gaps 

good gestalt principle

a stimulus that is orderly, complete, coherent, balanced, and clear while being regular as possible

global precedence effect

people tend to process the overall structure or pattern of a visual stimulus faster than the smaller details within it, meaning the big picture is perceived before the individual components

marr’s low level vision

involves extracting immediate information from light on the retina; notices edges, motion, depth

marr’s high level vision

requires integrating details to form a full image; like objects, faces

edge detection

how are we able to tell when one object ends and another begins? we must be able to determine the boundaries between separate components of one object 

steven’s power law

explains how we feel changes in things like brightness, sound, weight, or pain compared to how much they actually change in the real world

structural theory

how our minds process and organize information; claims that we do this in a structured way

template matching theory

explains basic pattern recognition like how we know that a letter ‘A’ is the letter ‘A’; when we see something new we compare it to the template we have in our brain of that stimulus

weaknesses of template matching theory

additional steps are required to explain how observers can identify objects that have been rotated, resized, or otherwise transformed 

weber’s law

states that the just noticeable difference of stimulus intensity is proportional to the original intensity

just noticeable difference

describes the minimum change in intensity that a human can notice