MRRI Scientists Awarded Albert Einstein Society Research Grants

MRRI is pleased to announce the recent receipt of new grants from the Albert Einstein Society to support research studies led by two of the Institute’s postdoctoral fellows.

One of the grant awards will fund a project led by Anna Krason, PhD, with MRRI Institute Scientist Erica Middleton, PhD, as co-investigator. This study will examine the process of conflict adaptation in people with post-stroke aphasia, a language and communication disorder that affects their ability to produce and understand language. While language production deficits have been extensively studied, language comprehension deficits have received limited attention in research and treatment. Moreover, comprehension deficits are multi-determined in that difficulties in comprehension frequently stem from impairments in other modalities, including executive functions. Understanding the underlying mechanisms and factors involved in comprehension deficits is therefore crucial for effective interventions to improve language comprehension.

It has been established that cognitive control, an executive function that enables the detection, revision, and resolution of conflicts between mental representations, plays a pivotal role in language comprehension. Dr. Krason’s study will provide important preliminary knowledge regarding conflict adaptation and whether particular individuals with aphasia could benefit from this potential treatment approach. Specifically, the study will address the question of whether upregulating cognitive control can optimize comprehension in at least some people with aphasia. Drs. Krason and Middleton will also conduct thorough background testing, providing initial observations into linguistic, cognitive control, and neurophysiological traits of individuals who show (or do not show) conflict adaptation. Together, the findings from this study will lay the groundwork for future research to inform patient selection and the development of a new theory-grounded conflict adaptation training for neurorehabilitation of individuals with aphasia after stroke.

As principal investigator of a separate grant award, Simon Thibault, PhD, will work with MRRI Institute Scientist co-investigators Aaron Wong, PhD, and Laurel Buxbaum, PsyD, on a study to clarify the mechanism underlying errors commonly seen in the performance of naturalistic actions (i.e., preparing breakfast and packing a lunchbox) in people with left-hemisphere stroke. Impairments in the ability to perform activities of daily living, such as preparing a meal, have been widely reported after stroke. These impairments are unrelated to underlying motor impairments, such as hemiparesis, as they can be observed when individuals are required to only use their ipsilesional, non-paretic (less-affected) arm.

Although such errors are frequently attributed to an underlying sequencing deficit – i.e., an inability to represent sequential orderings of events – other findings suggest that individuals with left-hemisphere stroke may not be impaired at learning simple finger-tapping sequences. In contrast, individuals with left-hemisphere stroke also frequently exhibit limb apraxia (30-50% of individuals), a disorder characterized by slowed or failed retrieval of single tool-use actions (e.g., stirring with a spoon). To identify the mechanism giving rise to ordering errors in naturalistic actions, the study team will first examine the pattern of impairments across a series of sequencing tasks of increasing complexity. They will then correlate those impairments with performance in naturalistic actions within the same group of individuals with left-hemisphere stroke. This research will address a critical gap in the understanding of impairments in naturalistic actions in individuals following left-hemisphere stroke. It will also bring together two lines of study that have thus far largely been examined separately: naturalistic actions and action sequencing. Ultimately, research in this area will aid in developing rehabilitation techniques that better target the deficits underlying the inability to perform activities of daily living in individuals after stroke, particularly for those who have limb apraxia.