Abstract
Semantic memory refers to the knowledge one possesses through their personal experiences. Knowledge is largely built from conceptual representations which involve a variety of neuronal systems. The present study examined concrete and abstract conceptual representations and their ability to access linguistic and imagistic processing. Concrete concepts refer to tangible entities in the world (Hoffman, 2015). Abstract concepts refer to non-physical referents such as mental states, qualities, and ideals (Paivio, 2014). Most research examining concrete and abstract concepts has found faster response times, greater N400 amplitudes, and greater N700 amplitudes in response to concrete words. The N400 discussed in the present study reflects access to linguistic processing necessary for task completion. This is different from the classical N400 found by Kutas and Van Petten (1988) which reflects the process of integrating current semantic information with the preceding context. The N700 discussed in the present study reflects access to imagistic processing (mental imagery). The present study examined response times and electrophysiological responses to a semantic categorization task. Participants were required to decide if a presented word had a definable meaning or if it was a first name. Stimuli included concrete and abstract words which were divided into eight experimental groups based on concreteness and age of acquisition ratings. The present study found greater N400 amplitudes in response to abstract words compared to concrete words. In addition, greater N400 amplitudes were found in response to high abstract words learned earlier in life, compared to high abstract words learned later in life. Consistent with previous research, greater N700 amplitudes were found for concrete words compared to abstract. The present study also found greater N700 amplitudes for low abstract words learned earlier in life, compared to low abstract words learned later in life. In addition, no difference in reaction time was found in response to concrete and abstract words. These findings help provide support for and against competing theories of semantic processing and conceptual representations..