Ecological Approach to Perception

Gibson's Ecological Approach to Perception

• Gibson challenged traditional perception studies, criticizing their artificial settings. He proposed a naturalistic approach, emphasizing how people interact with their environment during real-world tasks.
• This approach, termed the ecological approach to perception, focuses on the observer's interaction with the environment and movement.

Optic Flow

• Optic flow describes the changing visual patterns as an observer moves through the environment.
• As one moves, objects and the scene shift in relation to the observer. Examples include seeing roads move towards a car during driving.

Characteristics of Optic Flow

• Gradient of Flow: Optic flow is fastest near the observer and slows down as distance increases. This gradient provides information about the observer's speed and movement direction.
• Focus of Expansion (FOE): The absence of motion at the point toward which the observer is moving. This is a key invariant.
  • For example, the point where a car is headed, if it keeps going in the same direction.

Invariant Information

• Invariant information remains constant despite changes in the observer's position or movement patterns. The FOE, for instance, always occurs at the target destination point.

Practical Applications of Optic Flow

• Driving: Drivers use optic flow to steer, for example.
• Physical Activities: Optic flow helps gymnasts during somersaults and backflips, enabling mid-air corrections. Studies show gymnasts perform these stunts worse with their eyes closed.

Affordances

• Affordances are the potential actions an object provides. A chair, for example, affords sitting. A graspable object affords grasping.
• Affordances suggest that perception is inseparable from intended actions.

Perception and Action

• Visual information interacts with other sensory information (such as balance from inner ear, muscle proprioception) to guide movements. One example is toddlers in a swinging room. If they perceive the room is swinging, they'll sway themselves accordingly; this shows that vision can override other sources of balance information.
• Studies with patient M.P., with temporal lobe damage, showed a specific advantage in object recognition when provided action-based cues (e.g., "something to drink from") compared to object names. This suggests a link between affordances and quick, efficient identification.
• Tools, more than other objects, elicits a stronger response from the brain.

Visual Direction Strategy and Wayfinding

• Visual direction strategy involves maintaining the body's orientation towards the target.
• Wayfinding involves using landmarks, objects that serve as cues for navigation. A study with a maze showed that participants more often looked at landmark decision points in the maze compared to mid-corridor landmarks.
• The brain can distinguish important landmarks from other objects, with the parahippocampal gyrus playing a role in this.

Reaching and Grasping

• The parietal lobe plays a critical role in reaching and grasping.
• Neurons in the parietal reach region (PRR) respond to different types of grips (whole hand or precision grip).
• Other neurons, known as visuomotor grip cells, respond both to seeing an object and to preparing to grasp it.
• Perception and action are linked in this process.

Proprioception

• Proprioception is the sense of body position and movement.

Size-Weight Illusion

• The size-weight illusion highlights how perceived size does influence the perceived weight of an object.

Mirror Neurons

• Mirror neurons fire during an action and when watching someone else perform the same action. Their roles in social interaction and possible connection to disorders like autism are still being explored.
• Similar to mirror neurons, audiovisual mirror neurons fire in response to actions and their associated sounds.

Action-Specific Perception Hypothesis

• This hypothesis proposes that perception is strongly influenced by an individual’s ability to act on the environment

Developmental Aspects of Perception and Affordances

• Baby walkers and crawlers show differences in perception of drop-offs that are related to the affordances connected with locomotion and space perception.