EXAM CHAPTER 3

Bottom-up process, ex.

processing that starts with info from environment, its conversion into action potentials, and the transmission of these signals to the brain

ex. someone fixating on an area with high stimulus salience

transduction

converting environmental energy into action potentials

beginning of the bottom-up process

top-down processing

using our past experiences, beliefs, goals, knowledge, and expectations to guide and interpret the information that is coming in through our senses

likelihood principle

part of Helmholtz’s theory of unconscious inference: we perceive the object that is most likely to have caused the pattern of stimuli we are receiving (we perceive things to be whatever it’s most logical for them to be)

Gestalt grouping principles

proximity, similarity, good continuation, connectedness, common fate, pragnanz, past experiences, symmetry

proximity

we group things together that are close to each other

similarity

we group things together that are similar to each other

good continuation

we group things together whose contours form a continuous straight or curved line

connectedness

we group things or parts of things together that are connected

common fate

we group things together that move together

pragnanz

of all possible ways to interpret our environment, we tend to perceive the pattern in the simplest way possible

physical regularities, ex.

regularly occurring physical properties of environment, we can use our knowledge about regularities in the environment to help us build a representation of our environment

Light comes from above (sun), we use this fact to help build a three-dimensional representation of the world around us

semantic regularities, ex.

functional regularities in different scenes

ex. Food preparation and cooking occur in a kitchen

what pathway

aka ventral stream, neural pathway, extending from occipital lobe to temporal lobe, associated with perceiving or recognizing objects, corresponds to perception pathway

where stream

neural pathway, extending from occipital lobe to parietal lobe, associated with neural processing that occurs when people locate objects in space, roughly corresponds to action pathway

Ungerleider & Mishkin study (1982)

trained monkeys on two types of tasks. 

-1: monkeys had to recognize an object based on previous experience (object discrimination task). If correct, it was rewarded with food. 

-2: monkeys had to choose the location that was closest to a tall cylinder (landmark discrimination task). If correct, it was again rewarded with food. 

-they could successfully do both

-the researchers then selectively damaged parts (either temporal lobe / ventral stream or parietal lobe/ dorsal stream) of the monkeys' brains to determine the effect on performance. When the ventral stream was damaged, the animals struggled with the object discrimination task and the opposite happened when the parietal lobe was damaged. These results suggested that each of these areas of the brain are responsible for different functions, and the researchers termed these pathways the "what" and "where" pathways.

brain ablation

procedure in which a specific area is removed from an animal’s brain, usually done to determine function of this area by assessing effect on animal’s behavior