We shift our gaze even when we orient attention internally to visual representations in working memory. Here, we show the bodily orienting response associated with internal selective attention is widespread as it also includes the head. In three virtual reality experiments, participants remembered 2 visual items. After a working memory delay, a central color cue indicated which item needed to be reproduced from memory. After the cue, head movements became biased in the direction of the memorized location of the cued memory item—despite there being no items to orient toward in the external environment. The heading-direction bias had a distinct temporal profile from the gaze bias. Our findings reveal that directing attention within the spatial layout of visual working memory bears a strong relation to the overt head orienting response we engage when directing attention to sensory information in the external environment. The heading-direction bias further demonstrates common neural circuitry is engaged during external and internal orienting of attention.

In this reflective piece on visual working memory, I depart from the laboriously honed skills of writing a review. Instead of integrating approaches, synthesizing evidence, and building a cohesive perspective, I scratch my head and share niggles and puzzlements. I expose where my scholarship and understanding are stumped by findings and standard views in the literature.

Working memory enables us to retain past sensations in service of anticipated task demands. How we prepare for anticipated task demands during working memory retention remains poorly understood. Here, we focused on the role of time—asking how temporal expectations help prepare for ensuing memory-guided behavior. We manipulated the expected probe time in a delayed change-detection task and report that temporal expectation can have a profound influence on memory-guided behavioral performance. EEG measurements corroborated the utilization of temporal expectations: demonstrating the involvement of a classic EEG signature of temporal expectation—the contingent negative variation—in the context of working memory. We also report the influence of temporal expectations on 2 EEG signatures associated with visual working memory—the lateralization of 8- to 12-Hz alpha activity, and the contralateral delay activity. We observed a dissociation between these signatures, whereby alpha lateralization (but not the contralateral delay activity) adapted to the time of expected memory utilization. These data show how temporal expectations prepare visual working memory for behavior and shed new light on the electrophysiological markers of both temporal expectation and working memory.

The fundamental role that our long-term memories play in guiding perception is increasingly recognized, but the functional and neural mechanisms are just beginning to be explored. Although experimental approaches are being developed to investigate the influence of long-term memories on perception, these remain mostly static and neglect their temporal and dynamic nature. Here, we show that our long-term memories can guide attention proactively and dynamically based on learned temporal associations. Across two experiments, we found that detection and discrimination of targets appearing within previously learned contexts are enhanced when the timing of target appearance matches the learned temporal contingency. Neural markers of temporal preparation revealed that the learned temporal associations trigger specific temporal predictions. Our findings emphasize the ecological role that memories play in predicting and preparing perception of anticipated events, calling for revision of the usual conceptualization of contextual associative memory as a reflective and retroactive function.

Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8–14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.

Selective attention biases the encoding and maintenance of representations in visual STM (VSTM). However, precise attentional mechanisms gating encoding and maintenance in VSTM and across development remain less well understood. We recorded EEG while adults and 10-year-olds used cues to guide attention before encoding or while maintaining items in VSTM. Known neural markers of spatial orienting to incoming percepts, that is, Early Directing Attention Negativity, Anterior Directing Attention Negativity, and Late Directing Attention Positivity, were examined in the context of orienting within VSTM. Adults elicited a set of neural markers that were broadly similar in preparation for encoding and during maintenance. In contrast, in children these processes dissociated. Furthermore, in children, individual differences in the amplitude of neural markers of prospective orienting related to individual differences in VSTM capacity, suggesting that children with high capacity are more efficient at selecting information for encoding into VSTM. Finally, retrospective, but not prospective, orienting in both age groups elicited the well-known marker of visual search (N2pc), indicating the recruitment of additional neural circuits when orienting during maintenance. Developmental and individual differences differentiate seemingly similar processes of orienting to perceptually available representations and to representations held in VSTM.

Cognitive control can be triggered in reaction to previous conflict, as suggested by the finding of sequential effects in conflict tasks. Can control also be triggered proactively by presenting cues predicting conflict (“proactive control”)? We exploited the high temporal resolution of ERPs and controlled for sequential effects to ask whether proactive control based on anticipating conflict modulates neural activity related to cognitive control, as may be predicted from the conflict-monitoring model. ERPs associated with conflict detection (N2) were measured during a cued flanker task. Symbolic cues were either informative or neutral with respect to whether the target involved conflicting or congruent responses. Sequential effects were controlled by analyzing the congruency of the previous trial. The results showed that cueing conflict facilitated conflict resolution and reduced the N2 latency. Other potentials (frontal N1 and P3) were also modulated by cueing conflict. Cueing effects were most evident after congruent than after incongruent trials. This interaction between cueing and sequential effects suggests neural overlap between the control networks triggered by proactive and reactive signals. This finding clarifies why previous neuroimaging studies, in which reactive sequential effects were not controlled, have rarely found anticipatory effects upon conflict-related activity. Finally, the high temporal resolution of ERPs was critical to reveal a temporal modulation of conflict detection by proactive control. This novel finding suggests that anticipating conflict speeds up conflict detection and resolution. Recent research suggests that this anticipatory mechanism may be mediated by preactivation of ACC during the preparatory interval.

Selective attention has the potential to enhance the initial processing of objects, their spatial locations, or their constituent features. The present study shows that this capacity to modulate initial stages of processing also applies to linguistic attributes. A cueing paradigm focused attention at different levels of word representations on a trial-by-trial basis to study the time course of attentional modulation on visual word processing by means of a high-density electrophysiology recording system. Attention to different linguistic attributes modulated components related to semantic, phonological, and orthographic stages of word processing. Crucially, the N200, associated with initial stages of orthographic decoding, was enhanced by attention to the letter pattern of words. These results suggest that top-down attention has the capacity to enhance initial perceptual stages of visual word processing and support the flexibility of attention in modulating different levels of information processing depending on task goals.

Links between attention and emotion were investigated by obtaining electrophysiological measures of attentional selectivity together with behavioral measures of affective evaluation. Participants were asked to rate faces that had just been presented as targets or distractors in a visual search task. Distractors were rated as less trustworthy than targets. To study the association between the efficiency of selective attention during visual search and subsequent emotional responses, the N2pc component was quantified as a function of evaluative judgments. Evaluation of distractor faces (but not target faces) covaried with selective attention. On trials where distractors were later judged negatively, the N2pc emerged earlier, demonstrating that attention was strongly biased toward target events, and distractors were effectively inhibited. When previous distractors were judged positively, the N2pc was delayed, indicating unfocused attention to the target and less distractor suppression. Variations in attentional selectivity across trials can predict subsequent emotional responses, strongly suggesting that attention is closely associated with subsequent affective evaluation.

Three experiments investigated whether it is possible to orient selective spatial attention to internal representations held in working memory in a similar fashion to orienting to perceptual stimuli. In the first experiment, subjects were either cued to orient to a spatial location before a stimulus array was presented (pre-cue), cued to orient to a spatial location in working memory after the array was presented (retro-cue), or given no cueing information (neutral cue). The stimulus array consisted of four differently colored crosses, one in each quadrant. At the end of a trial, a colored cross (probe) was presented centrally, and subjects responded according to whether it had occurred in the array. There were equivalent patterns of behavioral costs and benefits of cueing for both pre-cues and retro-cues. A follow-up experiment used a peripheral probe stimulus requiring a decision about whether its color matched that of the item presented at the same location in the array. Replication of the behavioral costs and benefits of pre-cues and retro-cues in this experiment ruled out changes in response criteria as the only explanation for the effects. The third experiment used event-related potentials (ERPs) to compare the neural processes involved in orienting attention to a spatial location in an external versus an internal spatial representation. In this task, subjects responded according to whether a central probe stimulus occurred at the cued location in the array. There were both similarities and differences between ERPs to spatial cues toward a perception versus an internal spatial representation. Lateralized early posterior and later frontal negativities were observed for both preand retro-cues. Retro-cues also showed additional neural processes to be involved in orienting to an internal representation, including early effects over frontal electrodes.

Event-related potentials (ERPs) were recorded from the scalp to investigate the processing of word stimuli. Three tasks were used: (1) a task comparing words that provided an anomalous or normal sentence ending, (2) a word-list task in which different word types were examined, and (3) a word-list task in which semantic priming was examined. ERPs were recorded from a 50-channel montage in an attempt to dissociate overlapping ERP features by their scalp distributions. The focus of these studies was the N400, an ERP previously associated with language processing (Kutas & Hillyard, 1980). The temporal interval typically associated with N400 (250–500 msec) was found to contain overlapping ERP features. Two of these features were common to both sentence and word-list tasks—but one appeared different. Anomalous sentence endings and words with semantic content in lists both showed coincident negative left frontotemporal and midline-anterior ERP foci, peaking at 332 msec for sentences and 316 msec for word lists. The most negative voltage obtained in the sentence task peaked at 386 msec and had a midline-posterior focus. A right frontotemporal focus developed after the midline-posterior focus and outlasted its duration. The most negative voltage for content words in lists was reached at 364 msec. The distribution of this ERP was extensive over the midline and appeared to differ from that observed in the sentence task. Modulation of language-related ERPs by word type and semantic priming was investigated using the word-list tasks, which required category-detection responses. Two novel findings were obtained: (1) The ERP distributions for words serving grammatical function and content words differed substantially in word lists. Even when devoid of any sentence context, function words presented significantly attenuated measures of N400 compared to content words. These findings support hypotheses that suggest a differential processing of content and function words. (2) Semantic priming functionally dissociated two ERP features in the 250–500 msec range. The later and most negative midline ERP feature (peaking at 364 msec) was attenuated by semantic priming. However, the earlier left frontotemporal feature (peaking at 316 msec) was enhanced by semantic priming. The isolation of this novel language-related ERF' that is sensitive to semantic manipulations has important consequences for temporal and mechanistic aspects of theories of language processing.