Emotional arousal and lexical specificity modulate response times differently depending on ear of presentation in a dichotic listening task

We investigated possible hemispheric differences in the processing of four different lexical semantic categories: SPECIFIC (e.g. bird), GENERAL (e.g. animal), ABSTRACT (e.g. advice), and EMOTIONAL (e.g. love). These wordtypes were compared using a dichotic listening paradigm and a semantic category classification task. Response times (RTs) were measured when participants classified testwords as concrete or abstract. In line with previous findings, words were expected to be processed faster following right-ear presentation. However, lexical specificity and emotional arousal were predicted to modulate response times differently depending on the ear of presentation. For left-ear presentation, relatively faster RTs were predicted for SPECIFIC and EMOTIONAL words as opposed to GENERAL and ABSTRACT words. An interaction of ear and wordtype was found. For right-ear presentation, RTs increased as testwords’ imageability decreased along the span SPECIFIC–GENERAL–EMOTIONAL–ABSTRACT. In contrast, for left ear presentation, EMOTIONAL words were processed fastest, while SPECIFIC words gave rise to long RTs on par with those for ABSTRACT words. Thus, the prediction for EMOTIONAL words presented in the left ear was borne out, whereas the prediction for SPECIFIC words was not. This might be related to previously found differences in processing of stimuli at a global or local level.