Research
Object recognition is ubiquitous in our interactions with the environment, is performed with extreme efficiency, and forms the basis for many of our routine daily decisions. A pervasive idea in cognitive science is that perceptual decisions (like object categorization) are the result of a comparison of sensory evidence that is accumulated over time. Findings from both neurophysiology and neuroimaging now suggest that the brain solves the problem of perceptual decision-making using an accumulator architecture. Using the accumulator model as a framework, the PANLab seeks to understand the neural processing of sensory evidence and how it contributes to perceptual decision-making.
Research involves a combination of experimental techniques, including functional MRI and psychophysics to explore these questions. Object representations are seen as multi-sensory; in other words, object representations are sensory in nature, as opposed to being amodal constructs, and object representations are not uni-sensory (e.g., purely visual). Multi-sensory object representations are conceived as an ecological solution for various cognitive phenomena such as object perception and memory, and the storage and retrieval of semantic knowledge.
PANLab Research Programs:
Neural Substrates of Perceptual Decision-Making
Neural Substrates of Multisensory Integration
Accumulation Models of Object Processing
PANLab Collaborations:
Heather Rupp, Julia Heiman, Erick Janssen, Dale Sengelaub, and Ellen Ketterson
Kinsey Institute for Research in Sex, Gender, and Reproduction
Department of Psychological and Brain Sciences
Department of Biology
- Neural mechanisms of reward involved with alcohol abuse and risky sexual behavior
- Neural mechanisms of reward involved with post-partum depression
Annie Lang, and Robert Potter
Institute for Communication Research
Department of Telecommunications
- Neural mechanisms of motivation and emotion involved with watching public service announcements
Statements from former PANLab members
Jerry S. Fisher (undergraduate RA)
Psychology by definition is "the science that deals with mental processes and behavior" (American Heritage Dictionary). As a cognitive neuroimaging lab, we hope to contribute to this discipline through a greater understanding of the neural substrates that support our mind and mental processes. The human brain is perhaps one of the most fascinating all of evolution's orchestrations. Through its complex bundles of neurons, fibers, and structures, rests the mysterious underpinnings for all of our thoughts, emotions, and memories. It would be no great stretch to say the brain is the house of our selves. And yet for all this, we know so little about it. What is the true relationship between our minds and the world around us? In what ways do we come to know and recognize the outside world? How is this knowledge shaped and integrated by our biological framework? How is it preserved? Endless questions exist and as of now we have breached only the top tip of the ice burg. Our motivation in this lab is to scratch the surface a little further. With the advent of noninvasive functional magnetic resonance imaging, this unseen realm of the human brain in action can be explored a little further. It is a fascinating venture, and we are proud to be a part of it.
Current Projects
“Degrading audio-visual stimuli inversely affects super additive multi-sensory enhancement in the BOLD signal”
This study is investigating the super additive multi-sensory integration of parametrically degraded audio-visual stimuli in a healthy population compared with audio or visual stimuli alone. One more subject is planned to be run and analysis for the collected data is complete. This study is led by Ryan Stevenson (Graduate Student) and he is being assisted by Jennifer Willington (Undergraduate Student).
“Characterization of International Affective Digitalized Sounds (IADS) by discrete emotional categories”
This study normalizes reactions to IADS along discrete emotional categories (such as happy and sad) in a healthy population. All of the data has been collected and the results are expected to be used to define stimuli in a future fMRI experiment. This study is led by Ryan Stevenson (Graduate Student).
“Characterization of pictures of facial affect by discrete emotional categories and dimensions”
This study is a companion to earlier study involving IADS. It expands on the normalization of emotional stimuli to include both categorical and dimensional reaction of a healthy population to the visual stimuli. All of the data has been collected and the results are expected to assist in the stimuli selection of a future fMRI study. The leader of this study is Ryan Stevenson (Graduate Student).
“Synchronicity and multi-sensory speech processing: a parametric design”
This study will test the BOLD response to audio-visual stimuli whose audio component is not synchronized with the visual component in a healthy population. The study is still in the planning stages. The study is led by Ryan Stevenson (Graduate Student) and he is collaborating with Nick Altieri* (Graduate Student) and David Pisoni* (faculty).
“Methods in invoking a super additive signal”
This study is a block design for the super additive response to multi-sensory stimuli in a healthy population. This study is still in the planning stage. The study is led by Ryan Stevenson (Graduate Student).
“Duel pathways for auditory object recognition: shape and composition”
This study will test the ability of healthy subjects to recognize an object’s shape and composition from auditory cues. This study is still in the planning stage. The lead of this project is Ryan Stevenson (Graduate Student) and he is collaborating with Andrew Butler* (Graduate Student) and Karin James* (Faculty).
“Effects of familiarity, training, and configuration on tactile object recognition”
This study tests the ability of healthy subjects to recognize everyday stimuli that have been reconstructed in an unusual to form an unusual new object. The subjects will have to recognize the stimulus by the object’s arbitrary, conditioned name using only touch. All of the data has been collected and it is being analyzed. This study is led by Sunah Kim (Graduate Student) with assistance from Ryan Stevenson (Graduate Student) and Evan Boggs (Undergraduate).
“Effects of touch on perception of ambiguous visual motion stimuli”
This study tests the beneficial influence of touch when deciding the direction and speed of an ambiguous visual stimulus in a healthy population of subjects. The stimuli are currently being generated. The leader for this study is Sunah Kim (Graduate Student).
“Neural substrates of multi-sensory shape and texture recognition and touch”
This study explores the neural components involved in tactile perception, visual perception, and a multi-sensory perception (involving both tactile and visual perception) in a healthy population of subjects. The stimuli for this project are still being generated. This study is led by Sunah Kim (Graduate Student) and she is being assisted by Jerry Fisher (Research Assistant)
“Ideal pulse sequence on orbitofrontal cortex”
This study will use a range of stimuli to determine the best scan protocol to capture BOLD responses in the orbitofrontal cortex of healthy subjects. This project is still in the planning phase. Sunah Kim (Graduate Student) is leading this study and she is collaborating with Luiz Pessoa (Faculty).
“The influence of sequential integration on neural activation in the fusiform gyrus”
This study uses visual stimuli presented behind a digital aperture and tests healthy subjects on object recognition for faces and greebles. All of the data is collected and it is being analyzed before being included in an Undergraduate Senior Thesis. This study is being led by Eun Ji Huh (Undergraduate Student) and she is being assisted by Sunah Kim (Graduate Student).
“Neural mechanism of repetition priming of faces and objects”
This study tests the neurological effects in subjects from healthy populations of being presented with redundant visual stimuli multiple times. Pilot runs are being run in the scanner. This experiment is being led by Lin-Yu Wang (Graduate Student).
“Effects of object recognition difficulty on BOLD activation rate”
This study shows the relation between the lag in recognition decision time due to difficulty and BOLD activation peak times. Data has been collected and analyzed but a revised version of the experiment is planned to conducted before data is published. Peter Cole (Research Assistant) is leading this study.
“Evaluating evidence for the dissociation between implicit and explicit category learning”
This study investigates the neural basis of category learning behavior in healthy populations. In particular, the study investigates the possibility of a difference in neural activation between implicit and explicit categorical induction. Data collection is almost complete and analysis has already begun. This study is led by Todd Gureckis* (Post Doc) and he is collaborating with Rob Nosofsky* (faculty) and Shilling Choo (Undergraduate).
* connotes that the researcher was from an outside lab and graciously agreed to collaborate with us.
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