Flexible establishment of functional brain networks supports attentional modulation of unconscious cognition

Abstract

In classical theories of attention, unconscious automatic processes are thought to be independent of higher-level attentional influences. Here, we propose that unconscious processing depends on attentional enhancement of task-congruent processing pathways implemented by a dynamic modulation of the functional communication between brain regions. Using functional magnetic resonance imaging, we tested our model with a subliminally primed lexical decision task preceded by an induction task preparing either a semantic or a perceptual task set. Subliminal semantic priming was significantly greater after semantic compared to perceptual induction in ventral occipito-temporal (vOT) and inferior frontal cortex, brain areas known to be involved in semantic processing. The functional connectivity pattern of vOT varied depending on the induction task and successfully predicted the magnitude of behavioral and neural priming. Together, these findings support the proposal that dynamic establishment of functional networks by task sets is an important mechanism in the attentional control of unconscious processing.

Depressive Emotionality Moderates the Influence of the BDNF Val66Met Polymorphism on Executive Functions and on Unconscious Semantic Priming

“…In healthy participants, individuals with low digit span backward performance as a measure of EF of working memory exhibited larger priming for visible indirectly (e.g., lemon-sweet) associated primes (Kiefer et al 2005). Furthermore, semantic processing and EF have a partially overlapping neural substrate in prefrontal cortex, rendering an interaction between both cognitive functions likely (Norman and Shallice 1986;Ulrich et al 2014;Ulrich et al 2013;Wagner et al 2001). Taken together, these findings suggest an overlapping neural substrate and a negative association between EF and semantic priming.…”

“…As we did not assess the neural correlates of priming with neuroimaging techniques, we cannot specify differences in brain structure and function between BDNF Val66Met genotype groups in our study. Given the known functional neuroanatomy of semantic priming (Norman and Shallice 1986;Ulrich et al 2013Ulrich et al , 2014Wagner et al 2001), we speculate that functional neuroanatomical differences mainly concern prefrontal and temporal areas. It must of course also remain open whether the putative difference in processing styles between BDNF Val66Met genotype groups is the consequence of possible differences in functional neuroanatomy or vice versa.…”

“…We assessed the capacity of verbal working memory as well as the ability to manipulate stored information using two digit span tasks adapted from the "Hamburg Wechsler Intelligenztest für Erwachsene" (HAWIE-R) (Tewes 1994). Working memory capacity was defined as the maximum number of digits the participant was able to recall correctly (range three to nine digits).…”

Neurobiological Mechanisms for Semantic Feature Extraction and Conceptual Flexibility

“…The mechanisms of semantic priming between circuits and activity reverberation in the semantic kernel can accommodate a range of experimental results about “flexible” semantic or conceptual brain activations. In semantic priming experiments, Ulrich and colleagues showed priming‐related modulation of neurophysiological activity in a range of areas known to contribute to semantic processing (Ulrich, Adams, & Kiefer, ), and Grisoni et al. found that semantic priming between meaningful sounds and action‐related words significantly reduced semantic activation in similar areas.…”

Exploring the visual (un)conscious

“…Evidence for such an attentional modulation of unconscious stimulus processing comes from masked priming studies: Facilitation effects of masked prime stimuli on subsequently presented visible targets are selectivity enhanced or attenuated depending on the specific attentional task set, which was active during masked prime presentation (Kiefer & Martens, 2010;Martens et al, 2011;Ulrich, Adams, & Kiefer, 2014. In an extension of this line of research, Kiefer, Sim and Wentura (2015) investigated the role of task sets for masked evaluative priming effects elicited by unfamiliar primes. In evaluative priming, primes and targets (words or pictures) either share the same emotional valence (e.g., both positive: baby -rabbit) in the congruent condition or exhibit a different valence (e.g., positive vs. negative: baby -shark) in the incongruent condition (Fazio, 2001;Fazio, Sanbonmatsu, Powell, & Kardes, 1986).…”