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CNL Project Team: Elizabeth Castro ('22), Dr. Ledwidge
Default Mode Network Project
Previous research has identified that a history of diagnosed mTBI is associated with alterations to different brain networks (Arciniega et al., 2021, Hristopulos et al., 2019, Tao et al, 2015, Wang et al., 2017). One network in particular is the default mode network, which is a resting state network. This means that it is active or “on” in mind wandering, self-referential processing, daydreaming, etc. (Raichle, 2011). The default mode network is “off” when engaged in active tasks (Raichle, 2011). It remains to be investigated how the default mode network is influenced by a history of mTBI in college athletes who participate in contact sports, including football, rugby, soccer, lacrosse, basketball, baseball, softball, and wrestling (Meehan et al., 2015).
The focus of this project is to investigate how alpha and theta brain frequencies are altered in the default mode network and whether these alterations may be influenced by a history of diagnosed mTBI. Alpha and theta frequencies have been cited in previous literature as being hallmarks of baseline default mode network function in resting state electroencephalography (RS-EEG) research (Bowman et al., 2017, Laufs et al., 2003, Prestel et al., 2018, Sheeringa et al., 2007). Therefore, we will be recording 10 minutes of eyes open RS-EEG (participants will fixate on a cross) in order to look indirectly at the default mode network through the
Cognitive and Emotional Responses in Children and Adolescents Project
In this study we recorded event-related brain potentials (ERPs) in children and adolescents 7-17 years of age to examine typically developing cognitive and emotional processing. The findings from this study will guide our future work in investigating how these brain responses may change after pediatric concussion. As shown in the picture to the left, we recorded EEG while children/adolescents viewed pictures to examine how the Late Positive Potential (LPP) ERP varied based on the valence of the pictures (negative, neutral, positive)
Neural Correlates of Contextual Ambiguity Resolution
Cognitive-Linguistic Brain Function after Concussion
In this study we examined the association between concussion and EEG/ERP brain activity involved in lexical-semantics and impulse control. We tested 40 students and student-athletes within 1-month after experiencing a concussion. Testing included two EEG tasks, including one which examined semantic elements of language comprehension (see illustration) and an assessment of cognitive-linguistic function. Our goal is to successfully chart the time course of recovery of cognition and language in this population to better inform clinical best practices for concussion management and intervention. Click on the links for preliminary findings. Peer-reviewed publications will be added when in press!
Our understanding of the meaning being portrayed within a conversation or discourse changes to each instance of a new semantic item. However, when the topic of a conversation is ambiguous, we must actively search for and identify the meaning/purpose that interlocultors or narrators are attempting to portray. This ambiguity extends beyond single words but rather encompasses the broader discourse context. We used ERPs to study how the brain resolves this contextual ambiguity. Furthermore, we examined if this process was distinct from that which involves the change/update of an existing context?
Preliminary results from this study suggest that the Late Anterior Positivity ("Frontal post-N400 positivity") fluctuates to coherent words that partially resolve contextual ambiguity. In contrast, greater P600 amplitudes are recorded to coherent, but unexpected words within a known, existing context.
Smartphone Induced Divided Attention Project
The literature is rich in its demonstrations of the distracting properties of your cell-phone when used while driving. It turns out that humans are not as good at multi-tasking as we think. In fact, the term "multi-tasking" is a misnomer, as we instead switch between tasks with the performance on each task decreasing as a function of the number of tasks being performed.
The social aspects of smartphones (e.g., texting, notifications) have the capacity to provide us with potentially limitless positive reinforcement. The Motivated Cognition Model (Lang, 2006) demonstrates that we allocate greater attentional resources to stimuli we are motivated to engage in, such as those which provide positive reinforcement (e.g., cell phones). And as long our phones are turned on, there is always the opportunity to receive this gratification. This study is the first to examine if and how the mere presence of a smartphones alters ERP markers of attention.