The nature and organization of object concepts : behavioral evidence for grounded cognition

The theory of modality grounded cognition is steadily gaining in popularity as the explanation for the nature and organization of object concepts. This theory, also known as embodied cognition, states that object memories are encoded within the same neural networks that were active during the perception of, or interaction with, that object. Certain aspects of this modality grounding remain unexplained, limiting its widespread acceptance. In particular, it is unknown whether memories are grounded according to all relevant perceptual features, or if only the most diagnostic features are used. Also, the current version of the theory cannot account for abstract concepts, which are those with no inherent perceptual or motion information. The current thesis addresses these issues by way of four independently conducted studies using varied behavioral techniques. The first study shows that associative links can form between mental imagery and perceptual stimuli. This finding demonstrates that imagery and perception are largely interchangeable within associative learning, indicating that similar patterns of neural activity are likely involved for both kinds of stimuli. The second study shows that color imagery can bias color perception. This finding indicates that the previously demonstrated processing similarity between mental imagery and perception can also involve perceptual color areas. The third study shows that the recognition of highly color-diagnostic objects can be facilitated through the prior presentation of their known color associates. Along with the previous study, this finding provides strong evidence that color plays an important role in the perceptual grounding of memories for certain objects. The fourth study shows evidence suggesting that the recognition of specific tools may be facilitated through the prior presentation of tool-use pantomimes. While this facilitation was only observed when the prime stimuli contained real visual motion information, not implied motion, this finding indicates that motion is a very important aspect of the grounding of manipulable object concepts. Together these four studies provide novel and diverse behavioral support for the theory of modality grounded cognition by addressing its major criticisms