Chris Kelland Friesen

The eyes have it! Reflexive orienting is triggered by nonpredictive gaze

Normal subjects were presented with a simple line drawing of a face looking left, right, or straight ahead. A target letter F or T then appeared to the left or the right of the face. All subjects participated in target detection, localization, and identification response conditions. Although subjects were told that the line drawing’s gaze direction (the cue) did not predict where the target would occur, response time in all three conditions was reliably faster when gaze was toward versus away from the target. This study provides evidence for covert, reflexive orienting to peripheral locations in response to uninformative gaze shifts presented at fixation. The implications for theories of social attention and visual orienting are discussed, and the brain mechanisms that may underlie this phenomenon are considered.

Are eyes special? It depends on how you look at it

Recent behavioral data have shown that central nonpredictive gaze direction triggers reflexive shifts of attention toward the gazed-at location (e.g., Friesen & Kingstone, 1998). Friesen and Kingstone suggested that this reflexive orienting effect is unique to biologically relevant stimuli. Three experiments were conducted to test this proposal by comparing the attentional orienting produced by nonpredictive gaze cues (biologically relevant) with the attentional orienting produced by nonpredictive arrow cues (biologically irrelevant). Both types of cues produced reflexive orienting in adults (Experiment 1) and preschoolers (Experiment 2), suggesting that gaze cues are not special. However, Experiment 3 showed that nonpredictive arrows produced reflexive orienting in both hemispheres of a split-brain patient. This contrasts with Kingstone, Friesen, and Gazzanigas (2000) finding that nonpredictive gaze cues produce reflexive orienting only in the face-processing hemisphere of split-brain patients. Therefore, although nonpredictive eyes and arrows may produce similar behavioral effects, they are not subserved by the same brain systems. Together, these data provide important insight into the nature of the representations of directional stimuli involved in reflexive attentional orienting.

Attentional effects of counterpredictive gaze and arrow cues.

The authors used counterpredictive cues to examine reflexive and volitional orienting to eyes and arrows. Experiment 1 investigated the effects of eyes with a novel design that allowed for a comparison of gazed-at (cued) target locations and likely (predicted) target locations against baseline locations that were not cued and not predicted. Attention shifted reflexively to the cued location and volitionally to the predicted location, and these 2 forms of orienting overlapped in time. Experiment 2 discovered that another well-learned directional stimulus, an arrow, produced a different effect: Attention was shifted only volitionally to the predicted location. The authors suggest that because there is a neural architecture specialized for processing eyes, gaze-triggered attention is more strongly reflexive than orienting to arrows.

Attention, Researchers! It Is Time to Take a Look at the Real World:

Theories of attention, too often generated from artificial laboratory experiments, may have limited validity when attention in the natural world is considered. For instance, for more than two decades, conceptualizations of “reflexive” and “volitional” shifts of spatial attention have been grounded in methodologies that do not recognize or utilize the basic fact that people routinely use the eyes of other people as rich and complex attentional cues. This fact was confirmed by our novel discovery that eyes will trigger a reflexive shift of attention even when they are presented centrally and are known to be spatially nonpredictive. This exploration of real-world attention also led to our finding that, contrary to popular wisdom, arrows, like eyes, are capable of producing reflexive shifts of attention—a discovery that brings into question much of the existing attention research. We argue that research needs to be grounded in the real world and not in experimental paradigms. It is time for cognitive psychology to reaffirm the difficult task of studying attention in a manner that has relevance to real-life situations.

Reflexive Joint Attention Depends on Lateralized Cortical Connections

Joint attention, the tendency to spontaneously direct attention to where someone else is looking, has been thought to occur because eye direction provides a reliable cue to the presence of important events in the environment. We have discovered, however, that adults will shift their attention to where a schematic face is looking—even when gaze direction does not predict any events in the environment. Research with 2 split-brain patients revealed that this reflexive joint attention is lateralized to a single hemisphere. Moreover, although this phenomenon could be inhibited by inversion of a face, eyes alone produced reflexive shifts of attention. Consistent with recent functional neuroimaging studies, these results suggest that lateralized cortical connections between (a) temporal lobe subsystems specialized for processing upright faces and gaze and (b) the parietal area specialized for orienting spatial attention underlie human reflexive shifts of attention in response to gaze direction.

Does gaze direction really trigger a reflexive shift of spatial attention

Previous studies have found that the gaze direction of a centrally presented face facilitates response time (RT) to a lone peripheral target. The widely accepted interpretation of this finding is that gaze direction triggers a cortically mediated reflexive shift of spatial attention. In the present study we tested an alternative explanation, that a target appearing abruptly on its own in the visual field triggers a subcortically mediated reflexive shift of spatial attention, which is modulated by compatibility with gaze direction. Using central gaze cues, we compared RT to a single peripheral onset target with RT to a peripheral onset target accompanied by an equivalent distractor at the mirror opposite location. In both cases the facilitation effect was the same, demonstrating conclusively that the observed orienting is attributable to the reflexive effects of the gaze cue.

FMRI of Ventral and Dorsal Processing Streams in Basic Reading Processes: Insular Sensitivity to Phonology

SummaryMost current models of the neurophysiology of basic reading processes agree on a system involving two cortical streams: a ventral stream (occipital-temporal) used when accessing familiar words encoded in lexical memory, and a dorsal stream (occipital-parietal-frontal) used when phonetically decoding words (i.e., mapping sublexical spelling onto sounds). The models diverge, however, on the issue of whether the insular cortex is involved. The present fMRI study required participants to read aloud exception words (e.g., ‘one’, which must be read via lexical memory) and pseudohomophones (e.g., ‘wun’, which must be read via sublexical spelling to sound translation) to examine the processing streams as well as the insular cortex, and their relationship to lexical and sublexical reading processes. The present study supports the notion of independent ventral-lexical and dorsal-sublexical streams, and further suggests the insular cortex to be sensitive to phonological processing (particularly sublexical spelling-sound translation). These latter findings illuminate the nature of insular activity during reading, which must be explored further in future studies, and accounted for in models of the neurophysiology of reading.

Modulation of reflexive orienting to gaze direction by facial expressions

Facial expression and gaze perception are thought to share brain mechanisms but behavioural interactions, especially from gaze-cueing paradigms, are inconsistent. We conducted a series of gaze-cueing studies using dynamic facial cues to examine orienting across different emotional expression and task conditions, including face inversion. Across experiments, at a short stimulus–onset asynchrony (SOA) we observed both an expression effect (i.e., faster responses when the face was emotional versus neutral) and a cue validity effect (i.e., faster responses when the target was gazed-at), but no interaction between validity and emotion. Results from face inversion suggest that the emotion effect may have been due to both facial expression and stimulus motion. At longer SOAs, validity and emotion interacted such that cueing by emotional faces, fearful faces in particular, was enhanced relative to neutral faces. These results converge with a growing body of evidence that suggests that gaze and expression are initially processed independently and interact at later stages to direct attentional orienting.

Modularity and Intersection of “What”, “Where” and “How” Processing of Visual Stimuli: A New Method of fMRI Localization

Summary:Research on the modularity of perceptual and cognitive processes has often pointed to a ventral-dorsal distinction in cortical pathways that depend upon the nature of the stimuli and the task. However, it is not clear whether the dorsal, occipital-parietal stream specializes in locating visual objects (i.e., a “where” stream), or taking action toward objects (i.e., a “how” stream), although there is some consensus for a ventral, occipital-temporal “what” stream that specializes in the identification of visual objects. It is also not clear to what extent word and picture processing are modular along these streams, as functional imaging maps to date have not addressed the modularity question directly. Here we present two types of functional imaging maps that directly show modularity and intersection of processing function for word and picture stimuli in tasks that require decisions about “what is”, “where is”, or “how do you interact with” a stimulus (N=6 participants). Our results reveal a middle dorsal “how” stream with some modular regions of activation that are distinct from activation during “where” processing, and that words and pictures involve several modular regions of activation along these streams.

Gaze-Triggered Orienting as a Tool of the Belongingness Self-Regulation System

Social-psychological theories of belongingness self-regulation suggest that when ones need for interpersonal relationships is not being met, one begins to monitor the social environment more closely. Presumably, this serves to increase awareness of the likelihood of social acceptance versus rejection and to inform later social decision-making processes. The current investigation tested whether low belongingness increases a particular form of social monitoring that has recently been documented in the cognitive literature: gaze-triggered orienting. Low belongingness was operationalized either in terms of low trait self-esteem (Studies 1a and 1b) or in terms of the priming of rejection-related thoughts (Study 2). Across the studies, the normal tendency to orient attention in accordance with another individuals eye gaze was augmented under conditions of low belongingness. However, belongingness had no influence on a nonsocial form of orienting. The results are discussed in terms of their implications for theories of belongingness self-regulation and social attention.