Toward a taxonomy of attention shifting: Individual differences in fMRI during multiple shift types

Abstract

Although task switching is often considered one of the fundamental abilities underlying executive functioning and general intelligence, there is little evidence that switching is a unitary construct and little evidence regarding the relationship between brain activity and switching performance. We examined individual differences in multiple types of attention shifting in order to determine whether behavioral performance and fMRI activity are correlated across different types of shifting. The participants (nϭ 39) switched between objects and attributes both when stimuli were perceptually available (external) and when stimuli were stored in memory (internal). We found that there were more switchrelated activations in many regions associated with executive control-including the dorsolateral and medial prefrontal and parietal cortices-when behavioral switch costs were higher (poor performance). Conversely, activation in the ventromedial prefrontal cortex (VMPFC) and the rostral anterior cingulate was consistently correlated with good performance, suggesting a general role for these areas in efficient attention shifting. We discuss these findings in terms of a model of cognitive-emotional interaction in attention shifting, in which reward-related signals in the VMPFC guide efficient selection of tasks in the lateral prefrontal and parietal cortices. WAGER, JONIDES, SMITH, AND NICHOLStasks can be dissociated on the basis of three factors: (1) Among what representations is attention shifted? (2) In what locus are the items between which attention is shifted stored-in WM or in perceptual buffers? (3) And finally, when does the shift occur-when an actual stimulus is presented and a behavioral response is required, or in advance of stimulus presentation and response selection? What Representations and What Locus of Storage?Theories of switching have combined evidence on switch costs from studies varying the cue type (Coull, Frith, Buchel, & Nobre, 2000), the target tasks (Allport, Styles, & Hsieh, 1994;Rubinstein, Meyer, & Evans, 2001), and whether switching occurs among the tasks themselves (i.e., both stimulus and response sets), operations (Spector & Biederman, 1976), stimulus-response mapping rules (Rubinstein et al., 2001), objects stored in WM (Garavan, 1998), object attributes (Owen, Roberts, Polkey, Sahakian, & Robbins, 1991;Rogers & Monsell, 1995), or combinations of these. The question of consistency across types is critical if particular shifting tasks are used as measures of an executive ability.In this study, we combined two types of evidence that have been considered for understanding the relationships between types of shifting: individual differences in performance and brain-imaging activation. In individualdifferences studies, the basic measures of performance are the reaction time (RT) and error rate costs for trials in which a shift of attention is required, as compared with trials with no shift (i.e., shift-no shift; see, e.g., Garavan, 1998;Gopher, Armony, & Greenshpan, 2000;Meiran, Chorev, & Sapir, 2...

Recruitment of the left hemispheric emotional attention neural network in risk for and protection from depression

“…In contrast, vulnerability to MDD is characterized by a stronger activation in sensory and attention managing areas 18,[44][45][46]48,[53][54][55][64][65][66][67][68][69][70] during evaluation of negative stimuli. A similar pattern is observed in the course of attention shifting from negative information with a more notable increase in the attention network.…”

“…18,48,[53][54][55][64][65][66][67][68][69][70] Observed overactivation suggests the aforementioned mechanism of compensation, which characterizes the HC-FHP group. Having strong sensory reactions to external emotional cues when there is a requirement to focus on external nonemotional information puts more demand on the attention control system.…”

“…In the course of shifting attention from negative stimuli, relative resilience is characterized by greater activation in areas managing attention 18,48,[53][54][55][64][65][66][67][68][69][70] and decreased activation in regions of emotional arousal. 34 These changes suggest that relative resilience to MDD is associated with better reactivity to positive emotional cues and stronger control of attention in the face of negative information.…”

“…The behavioural data suggest that the key skills impaired in individuals with a family history of MDD are emotion processing [12][13][14] and attention shifting from emotional content, 15,16 neural correlates of which have been previously verified in healthy individuals. [17][18][19] These 2 processes are crucial components of emotional regulation 20,21 and represent its 2 basic functions: an ability to explore emotional meaning of the environment and a potential to withdraw from the exploration in accordance with one's goals. The disturbance of emotional regulation is, according to some models, [22][23][24][25][26][27] a key feature of MDD and involves interplay of cognitive and emotional functions.…”

“…Therefore, examining neural correlates in these comparison groups is of high clinical relevance and seems to be crucial for targeting vulnerable individuals and developing strategies for prevention of depression. We assumed that the HC-FHP group experienced alterations in neural activation in the areas associated with emotion processing and attention switching in healthy controls (e.g., frontal and cingulate gyri, parietal cortex, insula, premotor cortex, subcortical areas [17][18][19]34 ). We hypothesized that the HC-FHP group had elevated neural activation relative to the MDD-FHP group in frontal, premotor and parietal areas as markers for relative resilience and elevated activation compared with the HC-FHN group in the cingulate cortex and subcortical areas based on our previous study.…”