James Enns

Professor

Research Classification

Cognition
Sensation and Perception

Research Interests

attention
action kinematics
social perception

Relevant Degree Programs

 

Research Methodology

psychophysics
eye, limb, body tracking

Recruitment

Complete these steps before you reach out to a faculty member!

Check requirements
  • Familiarize yourself with program requirements. You want to learn as much as possible from the information available to you before you reach out to a faculty member. Be sure to visit the graduate degree program listing and program-specific websites.
  • Check whether the program requires you to seek commitment from a supervisor prior to submitting an application. For some programs this is an essential step while others match successful applicants with faculty members within the first year of study. This is either indicated in the program profile under "Requirements" or on the program website.
Focus your search
  • Identify specific faculty members who are conducting research in your specific area of interest.
  • Establish that your research interests align with the faculty member’s research interests.
    • Read up on the faculty members in the program and the research being conducted in the department.
    • Familiarize yourself with their work, read their recent publications and past theses/dissertations that they supervised. Be certain that their research is indeed what you are hoping to study.
Make a good impression
  • Compose an error-free and grammatically correct email addressed to your specifically targeted faculty member, and remember to use their correct titles.
    • Do not send non-specific, mass emails to everyone in the department hoping for a match.
    • Address the faculty members by name. Your contact should be genuine rather than generic.
  • Include a brief outline of your academic background, why you are interested in working with the faculty member, and what experience you could bring to the department. The supervision enquiry form guides you with targeted questions. Ensure to craft compelling answers to these questions.
  • Highlight your achievements and why you are a top student. Faculty members receive dozens of requests from prospective students and you may have less than 30 seconds to pique someone’s interest.
  • Demonstrate that you are familiar with their research:
    • Convey the specific ways you are a good fit for the program.
    • Convey the specific ways the program/lab/faculty member is a good fit for the research you are interested in/already conducting.
  • Be enthusiastic, but don’t overdo it.
Attend an information session

G+PS regularly provides virtual sessions that focus on admission requirements and procedures and tips how to improve your application.

 

Master's students
Doctoral students
Postdoctoral Fellows
2020
2021

social cognition, joint action, collaborative cognition, emotional and social attention

I support experiential learning experiences, such as internships and work placements, for my graduate students and Postdocs.

Graduate Student Supervision

Doctoral Student Supervision (Jan 2008 - May 2019)
The social is predictive : human sensitivity to attention control in action prediction (2016)

Observing others is predicting others. Humans have a natural tendency to make predictions about other people’s future behavior. This predisposition sits at the basis of social cognition: others become accessible to us because we are able to simulate their internal states, and in this way make predictions about their future behavior (Blakemore & Decety, 2001). In this thesis, I examine prediction in the social realm through three main contributions. The first contribution is of a theoretical nature, the second is methodological, and the third contribution is empirical. On the theoretical plane, I present a new framework for cooperative social interactions – the predictive joint-action model, which extends previous models of social interaction (Wolpert, Doya, & Kawato, 2003) to include the higher level goals of joint action and planning (Vesper, Butterfill, Knoblich, & Sebanz, 2010). Action prediction is central to joint-action. A recent theory proposes that social awareness to someone else’s attentional states underlies our ability to predict their future actions (Graziano, 2013). In the methodological realm, I developed a procedure for investigating the role of sensitivity to other’s attention control states in action prediction. This method offers a way to test the hypothesis that humans are sensitive to whether someone’s spatial attention was endogenously controlled (as in the case of choosing to attend towards a particular event) or exogenously controlled (as in the case of attention being prompted by an external event), independent of their sensitivity to the spatial location of that person’s attentional focus. On the empirical front, I present new evidence supporting the hypothesis that social cognition involves the predictive modeling of other’s attentional states. In particular, a series of experiments showed that observers are sensitive to someone else’s attention control and that this sensitivity occurs through an implicit kinematic process linked to social aptitude. In conclusion, I bring these contributions together. I do this by offering an interpretation of the empirical findings through the lens of the theoretical framework, by discussing several limitations of the present work, and by pointing to several questions that emerge from the new findings, thereby outlining avenues for future research on social cognition.

View record

When two heads are better than one : the independent versus interactive benefits of collaborative cognition (2014)

Previous research has shown that two heads working together can outperform one working alone, but whether such benefits result from social interaction or the statistical facilitation of independent performance is not clear. Here I apply Miller’s (1982; Ulrich, Miller & Schröter, 2007) race model inequality (RMI) model to distinguish between these two possibilities. This model was developed to test whether response times to two signals compared to one were especially fast because the observer could detect a signal in either of two ways (i.e., separate activation models) or because both signals contributed to a common pool of activation (i.e., coactivation models). I explored the independent versus interactive benefits of social collaboration in four experiments. In a first experiment I replicated Miller’s classic finding that coactivation underlies the faster responses to two targets than one during simple visual search by a single individual. However I found that two-person team performance was no faster than the performance of two independent individuals. Reasoning that the division of the cognitive load between collaborators was important to achieving collaborative performance gains, I employed a more complex enumeration visual search task in three subsequent experiments. With this task I found that performance by two-person teams exceeded the fastest possible performance of two independent individuals. This violated Miller’s RMI and indicated that interpersonal interaction produced the collaborative cognition performance gains. I then linked the magnitude of these collaborative gains to features of the interpersonal interaction between team members, including verbal communication, affiliation, and non-verbal communication such as posture, gesture, and body movement. Together these experiments serve as an important proof of concept that Miller’s RMI can be applied to differentiate between the independent and interactive benefits of collaborative cognition. In addition they demonstrate that the interactive benefits of collaborative cognition are influenced by features of the social interaction between collaborators.

View record

Synaesthesia and learning : a bidirectional relationship (2013)

I present new evidence about the relationships between learning and synaesthesia, particularly grapheme-colour synaesthesia, in which individuals experience letters and numbers as coloured. As part of the largest survey of synaesthetic tendencies ever performed, I show that second language acquisition can act as a trigger for the development of synaesthesia, such that children who learn a second language in grade school are three times more likely to develop synaesthesia as native bilinguals. I also demonstrate that previous reports of a sex bias in synaesthesia are almost certainly due to response and compliance biases, rather than any real differences in the prevalence of synaesthesia between men and women. In a detailed examination of the influences of learning on synaesthetic experiences, I show that synaesthetic colours are influenced by knowledge about letters’ shapes, frequencies, alphabetical order, phonology, and categorical qualities. Finally, I demonstrate that synaesthesia can itself be exploited in learning. All these results are presented as supporting a developmental learning hypothesis of synaesthesia, in which synaesthesia develops, at least in part, because it is useful.

View record

Attentional spatial selection and identity extraction are separable cognitive processes (2009)

While searching for objects in a cluttered environment, observers confront two tasks: selecting where to search, and identifying the targets. Chapter 1 reviews major theories of visual search, and highlights their approaches to these two functions. While anatomical, neurological, and behavioural evidence suggests dissociation between spatial selection and identity extraction, there is a vast controversy about this issue among visual-search accounts. This review demonstrates that none of these theories has adopted the right tool to independently manipulate the two functions. A new methodology is suggested in which the two functions are manipulated independently using spatial cueing to manipulate localization, and the attentional blink – AB - to manipulate identification (AB: impaired identification of the second of two briefly-displayed sequential targets). In examining the separability of spatial selection and identity extraction, additive-factors logic is adopted: if two factors (here: spatial cueing and AB) influence independent stages of processing, they will have additive effects on the dependent measure. Conversely, whenever additivity occurs, the underlying mechanisms can be assumed to be independent. Experiments in Chapter 2 show that cueing and the AB have additive effects, confirming the hypothesis that the two functions are separable. The results are accounted for by relating them to two major parallel pathways in the visual system: the dorsal and ventral pathways. Based on the characteristics of each pathway, it is plausible to assume that spatial cues (indexing spatial selection) are processed along the dorsal pathway while identification is processed along the ventral pathway. The two functions are therefore separable because they are mediated by mechanisms that are anatomically and functionally distinct.The experiment in Chapter 3 was designed to address contrary evidence regarding the separability of location and identity processing. It shows that those results were due to a procedural, artefactual ceiling. In Chapter 4, a prediction is tested based on the interpretation of results in the first study: if cueing involves both the dorsal and ventral pathways it should interfere with the AB; the results support this prediction. Chapter 5 discusses how these results collectively support the separability of spatial and identity processing, and also discusses future directions.

View record

Tracking attention in space and time : the dynamics of human visual attention (2009)

Attention is essential to everyday life: without some selective function to guide and limit the processing of incoming information, our visual system would be overwhelmed. A description of the spatiotemporal dynamics of attention is critical to our understanding of this basic human cognitive function and is the primary goal of this dissertation. In particular, the research reported here is aimed at examining two aspects of the spatiotemporal dynamics of attention: a) the rate at which the focus of attention is shrunk and expanded along with the factors that influence this rate, and b) the factorsgoverning whether attention is deployed as either a unitary or a divided focus. The present research examines the spatiotemporal dynamics of focal attention by monitoring the pattern of accuracy that occurs when participants attempt to identify two targets embedded in simultaneously presented streams of items. By asking participants to monitor these streams simultaneously, with the spatial and temporal positions of the two targets in the streams being varied incrementally, it is possible to index the extent of focal attention in both space and time. Chapter 2 develops this behavioural procedure and assesses the rate at which the focus of attention is contracted. A qualitative model is put forward and tested. Chapter 3 examines factors that modulate the temporal course of attentional narrowing in young adults who presumably can exercise efficient control of attentional processes. In contrast, Chapter 4 examines the effect of reduced attentional control by examining the same process in older adults. The second goal of this thesis was to examine whether focal attention is deployed as a unitary or a divided focus. These two perspectives are generally viewed as mutually exclusive. The alternative hypothesis pursued in Chapter 5 is that focal attention can be deployed as either a single, unitary focus or divided into multiple foci, depending on the observers mental set and on the task demands. The final chapter then combines and compares the findings across all experiments and evaluates how they fit in with current theories of visual attention.

View record

Master's Student Supervision (2010 - 2018)
Performance of impressionist visualizations on measures of recognition and trend identification (2015)

Experimental aesthetics, one of the oldest branches of research psychology, empirically examines what elements of an image associate with beauty and preference. Drawing on this research the current paper hypothesizes that by applying the painterly techniques of impressionist era artists a modern applied problem of information visualization may be addressed, namely how to create effective and aesthetically pleasing depictions of data. To do so a series of weather maps obtained from the International Panel of Climate Change were rendered into four data visualization styles: industry standard glyphs, and three impressionism inspired styles titled interpretational complexity, indication and detail, and visual complexity. Two separate experiments were then conducted, each aimed at testing a key feature of effective data visualization, image recognition and the ability to communicate data trends. The first experiment found visual complexity visualizations to be comparable to glyphs on a new-old recognition task, and better than the styles interpretational complexity, and indication and detail. The second experiment found that visual complexity visualizations were more effective than glyphs at depicting and communicating data trends to the viewer. Incidental eye tracking data during both experiments suggests that impressionist visualizations were more engaging and aesthetically pleasing than glyphs as evident by a higher fixation count and greater pupil dilation. Individually experiments 1 and 2 demonstrate that the painterly techniques of visual complexity may be applied to create highly recognizable and communicative data visualizations. Collectively the two experiments support the broader hypothesis that by modelling the knowledge and expertise of artists we may create aesthetically pleasing and functional depictions of data. Following these results the thesis concludes with a discussion of future research and potential limitations, and how the present results relate to aesthetics research more broadly.

View record

Take a hike! : the cognitive effects of exposure to natural and urban environments (2015)

The purpose of this study was to investigate links between attention restoration theory and executive function. A series of four experiments, each using a pre- versus post-test design, studied the influence of various interventions on executive function, as assessed by a backward digit span task and Raven’s progressive matrices. Experiment 1 began by testing the influence of cognitive strategy as manipulated through task instructions. Experiment 2 tested the influence of viewing slides of nature versus urban scenes, as predicted by attention restoration theory (Berman, et al., 2008). Experiment 3 repeated these procedures, using more engaging 10-min video tours of nature versus urban environments. Experiment 4 combined the successful instructional manipulations of Experiment 1 and the video manipulation of Experiment 3 to examine interactions between strategy and environment on executive function. The results showed that the nature video intervention reduced the influence of task instructions relative to the urban intervention. This supports Berman et al. (2008), who claim that exposure to nature has a restorative influence on executive function.

View record

Motion enhances or reduces target visibility, depending on prediction and postdiction of shape (2011)

Motion masking refers to the finding that objects are less visible when they appear as part of an apparent motion sequence than when they appear for the same duration in isolation. Against this backdrop of generally impaired visibility, there are reports of a relative visibility benefit when a target on the motion path is spatiotemporally predictable versus when it is unpredictable. The present study investigates whether prediction based on the shape of the originating stimulus in the motion sequence, and postdiction based on the terminating shape, is an aid to the visibility of a target in motion. In Experiment 1 these factors are examined separately for originating and terminating stimuli; in Experiment 2 they are examined in combination. The results show that both factors influence target discriminability in an additive way, suggesting that the processes of prediction and postdiction have independent influences on visibility. Experiment 3 examines the same display sequences with a different psychophysical task (i.e., detection) in an effort to reconcile the present findings with previous contradictory results. The upshot is that in contrast to the results for discrimination, target detection is influenced little by these factors. Experiments 4 and 5 examine the discrimination of a fine shape detail of the target, in contrast to the crude discrimination of target orientation in Experiments 1 and 2. This design also eliminates the opportunity for decision-biases to influence the results. The results show that predictable motion has a strong positive influence on target shape discrimination, to the extent that it makes a backward-masked target even more visible than when it appears in isolation. These findings are related to the empirical literature on visual masking and interpreted within the theoretical framework of object updating.

View record

Person perception informs understanding of cognition during visual search (2010)

Does person perception – the impressions we form from watching others’ behavior – hold clues to the mental states of people engaged in cognitive tasks? We investigate this with a two-phase method: in Phase 1 participants search on a computer screen (Experiment 1) or in an office (Experiment 2); in Phase 2 other participants rate their video-recorded behavior. We find ratings are sensitive to stable traits (search ability), temporary states (cognitive strategy), and environment (task difficulty). We also find that the visible behaviors critical to success vary between settings (e.g., eye movements are important in search on computer screens; head movements for search in an office). Positive emotions are linked to search success in both settings. These findings demonstrate that person perception can inform cognition beyond traditional measures of performance, and as such, offer great potential for studying cognition in natural settings with measures that are both rich and relatively unobtrusive.

View record

Publications

Current Students & Alumni

This is a small sample of students and/or alumni that have been supervised by this researcher. It is not meant as a comprehensive list.
 
 

If this is your researcher profile you can log in to the Faculty & Staff portal to update your details and provide recruitment preferences.