How Social Are Task Representations?

ABSTRACT— The classical Simon effect shows that actions are carried out faster if they spatially correspond to the stimulus signaling them. Recent studies revealed that this is the case even when the two actions are carried out by different people; this finding has been taken to imply that task representations are socially shared. In work described here, we found that the "interactive" Simon effect occurs only if actor and coactor are involved in a positive relationship (induced by a friendly-acting, cooperative confederate), but not if they are involved in a negative relationship (induced by an intimidating, competitive confederate). This result suggests that agents can represent self-generated and other-generated actions separately, but tend to relate or integrate these representations if the personal relationship between self and other has a positive valence.     

Attentional control of the creation and retrieval of stimulus–response bindings

Two experiments studied the degree to which the creation and retrieval of episodic feature bindings is modulated by attentional control. Experiment 1 showed that the impact of bindings between stimulus and response features varies as a function of the current attentional set: only bindings involving stimulus features that match the current set affect behavior. Experiment 2 varied the time point at which new attentional sets were implemented—either before or after the processing of the to-be-integrated stimuli and responses. The time point did not matter, suggesting that the attentional set has no impact on feature integration proper but controls which features get access to and can thus trigger the retrieval of bindings.     

Increasing self–other integration through divergent thinking

Increasing evidence suggests that people may cognitively represent themselves and others just like any other, nonsocial event. Here, we provide evidence that the degree of self–other integration (as reflected by the joint Simon effect; JSE) is systematically affected by the control characteristics of temporally overlapping but unrelated and nonsocial creativity tasks. In particular, the JSE was found to be larger in the context of a divergent-thinking task (alternate uses task) than in the context of a convergent-thinking task (remote association task). This suggests that self–other integration and action corepresentation are controlled by domain-general cognitive-control parameters that regulate the integrativeness (strong vs. weak top-down control and a resulting narrow vs. broad attentional focus) of information processing irrespective of its social implications.     

Integrating faces, houses, motion, and action: spontaneous binding across ventral and dorsal processing streams

Perceiving an event requires the integration of its features across numerous brain maps and modules. Visual object perception is thought to be mediated by a ventral processing stream running from occipital to inferotemporal cortex, whereas most spatial processing and action control is attributed to the dorsal stream connecting occipital, parietal, and frontal cortex. Here we show that integration operates not only on ventral features and objects, such as faces and houses, but also across ventral and dorsal pathways, binding faces and houses to motion and manual action. Furthermore, these bindings seem to persist over time, as they influenced performance on future task-relevant visual stimuli. This is reflected by longer reaction times for repeating one, but alternating other features in a sequence, compared to complete repetition or alternation of features. Our findings are inconsistent with the notion that the dorsal stream is operating exclusively online and has no access to memory.     

Intelligence and cognitive flexibility: Fluid intelligence correlates with feature “unbinding” across perception and action

People integrate the features of perceived events and of action plans, as well as of episodic stimulus—response relations, intoevent files. We investigated whether the management of event files, and particularly the speed of updating the binding between the task-relevant stimulus feature and the response, correlates with fluid intelligence. Indeed, the performance of participants scoring high on Raven’s Standard Progressive Matrices test was less impaired by a mismatch between the stimulus—response relation in the current and the previous trial. This result suggests that high intelligence is accompanied by a higher degree of flexibility in handling event files—that is, by higher efficiency in updating episodic representations.     

The effect of fMRI (noise) on cognitive control

Stressful situations, the aversiveness of events, or increases in task difficulty (e.g., conflict) have repeatedly been shown to be capable of triggering attentional control adjustments. In the present study we tested whether the particularity of an fMRI testing environment (i.e., EPI noise) might result in such increases of the cognitive control exerted. We found that participants were more effective in controlling episodic retrieval of previous stimulus-response bindings (Experiment 1), in switching to a new task (Experiment 2), and shielding a current goal from distracting response tendencies (Experiment 3) if they were exposed to challenging task situations, such as 70 dB echo planar imaging noise sampled from an fMRI scanner. These findings have considerable theoretical implications in questioning the widespread assumption that people are equally devoted to easy and more challenging tasks, and methodological implications in raising the possibility that experiments carried out in fMRI scanners or under otherwise challenging conditions systematically overestimate contributions from cognitive control processes.     

Variable heart rate and a flexible mind: Higher resting-state heart rate variability predicts better task-switching

The neurovisceral integration model proposes that heart rate variability (HRV) is linked to prefrontal cortex activity via the vagus nerve, which connects the heart and the brain. HRV, an index of cardiac vagal tone, has been found to predict performance on several cognitive control tasks that rely on the prefrontal cortex. However, the link between HRV and the core cognitive control function “shifting” between tasks and mental sets is under-investigated. Therefore, the present study tested the neurovisceral integration model by examining, in 90 participants, the relationship between vagally mediated resting-state HRV and performance in a task-switching paradigm that provides a relatively process-pure measure of cognitive flexibility. As predicted, participants with higher resting-state HRV (indexed both by time domain and frequency domain measures) showed smaller switch costs (i.e., greater flexibility) than individuals with lower resting-state HRV. Our findings support the neurovisceral integration model and indicate that higher levels of vagally mediated resting-state HRV promote cognitive flexibility.     

Symbolic control of visual attention

The present study reports four pairs of experiments that examined the role of nonpredictive (i.e., task-irrelevant) symbolic stimuli on attentional orienting. The experiments involved a simple detection task, an inhibition of return (IOR) task, and choice decision tasks both with and without attentional bias. Each pair of experiments included one experiment in which nonpredictive arrows were presented at the central fixation location and another experiment in which nonpredictive direction words (e.g., "up,""down,""left,""right") were presented. The nonpredictive symbolic stimuli affected responses in all experiments, with the words producing greater effects in the detection task and the arrows producing greater effects in the IOR and choice decision tasks. Overall, the present findings indicate that there is a strong connection between the overlearned representations of the meaning of communicative symbols and the reflexive orienting of visual attention.