Can Facilitation Imagery Alter the Effects of Semantic Priming?

This study examined if task motivational imagery suggestions could facilitate a semantic priming effect, relative to general relaxation suggestions and no specific suggestions; and if the participants’ hypnotizablity moderated the effects of the three types of instructions. Participants (n = 127) were assigned randomly in groups to one of the three instructional conditions (imagery, relaxation, or control) and two versions of a stimulus list for counterbalancing. A 3-way analysis of variance suggested that the semantic priming effect was found to be stronger for stimulus list version 2 than for version 1. A stronger semantic priming effect was found for the high, relative to the low and medium, hypnotizable groups. When medium hypnotizable participants were excluded, an instructional group X hypnotizability group interaction was found for list 1 suggesting that while the low hypnotizable participants benefited more from the relaxation suggestion, the high hypnotizables benefited more from the imagery instruction. The results suggest that imagery instructions may moderate automatic processes for highly hypnotizable individuals.     

On the existence of semantic working memory: evidence for direct semantic maintenance

Despite widespread acknowledgment of the importance of online semantic maintenance, there has been astonishingly little work that clearly establishes this construct. We review the extant work relevant to short-term retention of meaning and show that, although consistent with semantic working memory, most data can be accommodated in other ways. Using a new concurrent probe paradigm, we then report experiments that implicate a semantic maintenance capacity that is independent of phonological or visual maintenance that may build on a mechanism of direct semantic maintenance. Experiments 1 through 5 established that while subjects maintain the meaning of a word, a novel delay-period marker of semantic retention, the semantic relatedness effect, is observed on a concurrent lexical decision task. The semantic relatedness effect refers to slowed response times when subjects make a lexical decision to a probe that is associatively related to the idea they are maintaining, compared to when the probe is unrelated. The semantic relatedness effect occurred for semantic but not for phonological or visual word-form maintenance, dissipated quickly after maintenance ends, and survived concurrent articulatory suppression. The effect disappeared when subjects performed our immediate memory task with a long-term memory strategy rather than with active maintenance. Experiment 6 demonstrated a parallel phonological relatedness effect that occurs for phonological but not semantic maintenance, establishing a full double dissociation between the effects of semantic and phonological maintenance. These findings support a distinct semantic maintenance capacity and provide a behavioral marker through which semantic working memory can be studied.     

Dissociating semantic and phonological maintenance using fMRI

Functional magnetic resonance imaging (fMRI) distinguished regions of neural activity associated with active maintenance of semantic and phonological information. Subjects saw a single word for 2 sec, and following a 10-sec delay, made a judgment about that word. In the semantic task, subjects focused on the meaning of the word and decided whether a second word was synonymous with it. In the phonological task, subjects repeated the word silently and decided whether it shared a vowel sound with a nonsense word. Analyses allowed for isolation of neural activity during the maintenance delay. Semantic maintenance elicited greater activity in bilateral inferior frontal gyrus and left middle temporal gyrus regions of interest (ROI). In contrast, there was greater activity for phonological maintenance in the left superior parietal ROI. These results show a frontal-temporal network involved in actively maintaining the meanings of words, and they indicate that semantic and phonological maintenance processes are dissociable within working memory.