PerLecture 7 - Motion Perception Practice Flashcards

Vocabulary-style flashcards covering the concepts, theories, and studies of motion perception described in the lecture notes.

Motion Usefulness

Serves functions such as grabbing attention, segmentation or breaking camouflage, structure from motion, and navigation.

JJ Gibson

Argued that perception of motion is direct and that the optic array provides information about motion and the environment.

Apparent Motion

A type of perceived motion where an optical illusion is produced by viewing a rapid succession of still pictures of a moving object; tends to favor the shortest path.

Real Motion

Motion characterized by frames of objects that are infinitely brief.

Induced Motion

An impression of an object having motion relative to objects in motion around it.

Implied Motion

The impression of motion derived from cues like motion streaks and blur.

Motion After-Effect

Perceived opposite motion following adaptation, occurring because adaptation reduces the response to the adaptation direction due to tiring of cells.

Direction-Selective cells

Cells present in the V1 (striate cortex) which are selective to specific directions of motion.

Aperture Problem

The problem where local receptive fields in single neurons cannot provide an accurate perspective of motion without help from neighboring receptors.

Medial Temporal Area (MTA)

The area that solves the Aperture Problem by combining info from direction selective cells and “terminator” cells in V1; characterized by larger receptive fields.

Newsome et al. (1989)

A single cell recording study which found that MTA activity relates to picking out coherence of movement.

Newsome & Pare (1989)

A lesion study on monkeys without an MTA who needed much stronger signals to detect motion, specifically $20x$ more coherence.

Beckers & Zeki (1995)

A TMS study that temporarily disabled the MTA, finding that motion perception of coherence was impaired.

Movshon & Newsome (1992)

A microstimulation study that found a relationship between monkeys' perception of stimulus direction and the direction preference of stimulated MTA neurons.

Kourtzi & Kanwisher (2000)

An fMRI study showing that the MTA is most sensitive to implied motion.

Shiffar & Fred (1993)

Suggested that the interpretation of the structure of motion depends on speed.

Biological Motion

An innate ability to detect if motion comes from a living object, allowing recognition of species, individuals, activity, gender, and mood.

Superior Temporal Sulcus (STS)

The specific area in the brain where biological motion occurs.

Johansson (1973, 1975)

Investigated biological motion and found that information from motion alone allowed people to recognize their friends.

Fox and McDanel (1982)

Found that 4 month old babies preferentially looked at biological stimuli compared to random movement.

Vallortigarta (2005)

Found that newborn chicks possessed biological motion, preferring the light movement of real biological motion.

Thompson et al. (2005)

An fMRI study showing more STS activation to biological motion compared to partially occluded motion.

Grossman (2005)

A TMS study showing that when the STS is disabled, there is less sensitivity to upright biological motion.

Optic Flow

The pattern of motion that provides information about motion speed and heading direction.

Forward Movement Flow Field

The pattern of optic flow that expands outwards.

Backward Movement Flow Field

The pattern of optic flow that expands inwards.

Lee & Aronson (1974)

Found that swaying in a room by as little as $6\,mm$ can cause balancing trouble for children and adults.