Action intentions modulate allocation of visual attention: electrophysiological evidence

In line with the Theory of Event Coding (Hommel et al., 2001), action planning has been shown to affect perceptual processing - an effect that has been attributed to a so-called intentional weighting mechanism (Wykowska et al., 2009; Hommel, 2010). This paper investigates the electrophysiological correlates of action-related modulations of selection mechanisms in visual perception. A paradigm combining a visual search task for size and luminance targets with a movement task (grasping or pointing) was introduced, and the EEG was recorded while participants were performing the tasks. The results showed that the behavioral congruency effects, i.e., better performance in congruent (relative to incongruent) action-perception trials have been reflected by a modulation of the P1 component as well as the N2pc (an ERP marker of spatial attention). These results support the argumentation that action planning modulates already early perceptual processing and attention mechanisms

Recoding between two types of STM representation revealed by the dynamics of memory search

Visual STM (VSTM) is thought to be related to visual attention in several ways. Attention controls access to VSTM during memory encoding and plays a role in the maintenance of stored information by strengthening memorized content. We investigated the involvement of visual attention in recall from VSTM. In two experiments, we measured electrophysiological markers of attention in a memory search task with varying intervals between VSTM encoding and recall, and so we were able to track recoding of representations in memory. Results confirmed the involvement of attention in VSTM recall. However, the amplitude of the N2pc and N3rs components, which mark orienting of attention and search within VSTM, decreased as a function of delay. Conversely, the amplitude of the P3 and sustained posterior contralateral negativity components increased as a function of delay, effectively the opposite of the N2pc and N3rs modulations. These effects were only observed when verbal memory was not taxed. Thus, the results suggested that gradual recoding from visuospatial orienting of attention into verbal recall mechanisms takes place from short to long retention intervals. Interestingly, recall at longer delays was faster than at short delays, indicating that verbal representation is coupled with faster responses. These results extend the orienting-of-attention hypothesis by including an account of representational recoding during short-term consolidation and its consequences for recall from VSTM

A Revised Framework for the Investigation of Expectation Update Versus Maintenance in the Context of Expectation Violations: The ViolEx 2.0 Model

Expectations are probabilistic beliefs about the future that shape and influence our perception, affect, cognition, and behavior in many contexts. This makes expectations a highly relevant concept across basic and applied psychological disciplines. When expectations are confirmed or violated, individuals can respond by either updating or maintaining their prior expectations in light of the new evidence. Moreover, proactive and reactive behavior can change the probability with which individuals encounter expectation confirmations or violations. The investigation of predictors and mechanisms underlying expectation update and maintenance has been approached from many research perspectives. However, in many instances there has been little exchange between different research fields. To further advance research on expectations and expectation violations, collaborative efforts across different disciplines in psychology, cognitive (neuro)science, and other life sciences are warranted. For fostering and facilitating such efforts, we introduce the ViolEx 2.0 model, a revised framework for interdisciplinary research on cognitive and behavioral mechanisms of expectation update and maintenance in the context of expectation violations. To support different goals and stages in interdisciplinary exchange, the ViolEx 2.0 model features three model levels with varying degrees of specificity in order to address questions about the research synopsis, central concepts, or functional processes and relationships, respectively. The framework can be applied to different research fields and has high potential for guiding collaborative research efforts in expectation research

Flexible updating of visual working memory - The joint roles of attention and action

Visual working memory allows us to retain information over short periods of time, thereby enabling the comparison of objects separated in time or space. This ability is critical for various tasks, but it is highly limited in capacity (e.g., Luck & Vogel, 2013). As visual information constantly gains or loses relevance as we interact with our environment, there is a need to update the contents of visual working memory in a flexible manner to ensure that its limited capacity is used efficiently. In five studies, this dissertation examined how this updating is accomplished. The first part of this dissertation (Studies I-III) investigated updating following so-called retrocues presented during visual working memory maintenance, indicating some memorized items as more task-relevant than others and thereby inducing a strategic internal orienting of attention (e.g., Griffin & Nobre, 2003). Results showed that this attentional selection of representations yields a benefit (i.e., better memory) for task-relevant information (Studies I – III), with the magnitude of this benefit being related to the attentional efficiency of an individual (Study I). The consequence of this attentional selection for the other, unselected representations is sensitive to task context: When there are graded differences in the relevance of maintained information, the contents of visual working memory can be weighted to reflect these differences. While the most important information is robustly maintained inside the focus of attention, less important information can be maintained in a more vulnerable state outside the focus of attention, from where it can be accessed to be refocused and retrieved if need be (Study I). Studies II and III established that different visual properties (e.g., location or colour) can be used to guide the selection of relevant representations. A basic distinction can be drawn between mechanisms of spatial and feature-based attentional selection, which can be dissociated in terms of behavioural signatures (Study II) and involved cortical areas (Study III). The second part of the dissertation looked at the effects of more natural indicators of the relevance of specific aspects of our visual surroundings: actions and action-intentions. Instead of presenting retrocues during visual working memory maintenance, Studies IV and V used dual-task paradigms, in which an action was to be executed or prepared. This action rendered some items in a concurrently performed memory task more potentially relevant than others. Results revealed that selective action-related processing continues to influence visual processing beyond the perceptual stage, inducing an updating of visual working memory that reflects differences in the action-relevance of representations. Representations that hold potential action-relevance because they spatially correspond to the location of an action goal (Study IV) or because they contain information that is coded on a feature-dimension that is critical for a particular type of action being prepared (Study V) are preferentially maintained and recalled with higher accuracy than information that is action-irrelevant. The effect of actions on maintenance was found to be particularly pronounced when memory load corresponded to the average visual working memory capacity (Study IV), suggesting that information holding potential relevance for an action is prioritized when demand on the system is high. Furthermore, Study IV provided evidence that action-related enhancement at the mnemonic level is spatially not as precise as it has been shown to be for perception (e.g., Baldauf et al., 2006). Instead, results indicated a graded enhancement spreading out from the representation corresponding to the action goal location. In sum, the present dissertation demonstrates that updating of visual working memory is remarkably flexible. Maintained information can be weighted to reflect graded differences in relevance (Studies I-V), irrespective of whether this relevance is explicitly indicated by external cues (Studies I-III) or more implicitly indicated by action intentions (Studies IV and V). Different representational characteristics can guide the selection of relevant memory contents: Updating is induced when some representations are more important than others because they correspond to relevant locations (Studies I-IV) or because they contain a feature, which is more relevant than other features of the same dimension (Studies II and III) or coded on a feature dimension that is more relevant than other dimensions (Study V). This flexibility highlights the versatile nature of visual working memory, which allows for an efficient use of its highly limited capacity in any given situation

Modulation of visual attention by object affordance

Some objects in our environment are strongly tied to motor actions, a phenomenon called object affordance. A cup, for example, affords us to reach out to it and grasp it by its handle. Studies indicate that merely viewing an affording object triggers motor activations in the brain. The present study investigated whether object affordance would also result in an attention bias, that is, whether observers would rather attend to graspable objects within reach compared to non-graspable but reachable objects or to graspable objects out of reach. To this end, we conducted a combined reaction time and motion tracking study with a table in a virtual three-dimensional space. Two objects were positioned on the table, one near, the other one far from the observer. In each trial, two graspable objects, two non-graspable objects, or a combination of both was presented. Participants were instructed to detect a probe appearing on one of the objects as quickly as possible. Detection times served as indirect measure of attention allocation. The motor association with the graspable object was additionally enhanced by having participants grasp a real object in some of the trials. We hypothesized that visual attention would be preferentially allocated to the near graspable object, which should be reflected in reduced reaction times in this condition. Our results confirm this assumption: probe detection was fastest at the graspable object at the near position compared to the far position or to a non-graspable object. A follow-up experiment revealed that in addition to object affordance per se, immediate graspability of an affording object may also influence this near-space advantage. Our results suggest that visuospatial attention is preferentially allocated to affording objects which are immediately graspable, and thus establish a strong link between an object’ s motor affordance and visual attention