Research

Past Projects

At the MIT Behavioral Neuroscience Laboratory, we are trying to understand brain mechanisms underlying normal human sensation, perception, cognition, and memory and how these mechanisms change during the process of healthy aging. We incorporate studies of brain activity with functional magnetic resonance imaging (fMRI) into our research to better understand these mechanisms. We also strive to relate the deficits that follow brain injury (including amnesia) or neurological disorders (including Parkinson Disease and Alzheimer Disease) to theories of brain organization and to the interplay of cognitive systems. In order to address questions about human brain function from several vantage points simultaneously, we measure components of behavior and map them onto focal brain areas or systems identified by fMRI, clinical examination, or autopsy studies.

Our research participants include healthy volunteers ranging in age from 18-35 and from 60-85. We also conduct research with patients with amnesia, Alzheimer's Disease, and Parkinson's Disease. We conduct behavioral research at our laboratory at MIT, and all MRI studies are presently conducted at the MGH facilities in Charlestown. If you are interested in becoming a participant in our research studies, click here.

Emotional Memory in Aging Project

Memory is better for material with emotional content in younger adults. There is evidence that the same phenomenon is present in older adults although probably to a lesser degree. This occurs despite older adults showing greater difficulty remembering details of neutral events.

It is likely that these different memory processes rely on different neural circuits: the hippocampal formation (neutral information) and the amygdala, medial temporal and prefrontal cortex (emotional information). However, it is unclear how normal aging affects the cognitive or neural aspects of these emotional memory processes.

The aims of this project are to investigate the cognitive and neural aspects of memory for emotional stimuli compared to neutral stimuli in younger (age 18-30 years) and older (age 60-75 years) education-matched adults. We will also investigate the possible memory benefis of emotional context.

This project comprises two main phases. During the first phase, all participants will be tested on a series of memory tasks (word lists, stories, pictures) comprising neutral and emotional stimuli. They will also undergo high-resolution structural magnetic resonance imaging (MRI). We will then correlate the behavioral and structural data; in other words, we will compare memory performance with brain structures of interest (hippocampus, amygdala, medial temporal region and prefrontal cortex).

In the second phase of the study, participants will undergo the memory tasks as part of functional MRI (fMRI) experiments. We will record brain activation at the time of encoding and retrieval of the various memory stimuli. We will correlate memory performance with brain activation in specific regions of interest. We will also compare patterns of activation between younger and older participants.

Cognition in Aging and Alzheimer's Disease: An fMRI Study

Of the many components of cognition affected in Alzheimer's disease (AD), two particular cognitive domains have special clinical relevance: Tests of episodic memory (delayed recall and recognition) are highly sensitive for detecting AD, and tests of semantic retrieval (naming and fluency) are best for staging the disease and tracking its progression. Documenting the anatomical and physiological correlates of these impairments in the living subject gives insights into the distribution of the underlying anatomical and functional brain lesions that produce AD. To pursue this approach, and thereby extend understanding of brain-behavior relations in aging and AD, we are conducting a series of experiments, relating cognitive test performance in these two domains to hippocampal volume and to patterns of neural activation, measured with functional magnetic resonance imaging. The results of our experiments will have theoretical and clinical applications by providing anatomical and physiological information for aging and AD about the neural substrates of episodic memory and semantic retrieval. We are testing specific hypotheses about the relations between particular neural and cognitive systems, and how these relations are affected in aging and AD.

Theoretical Analysis of Learning in Age-Related Disease

Working memory (WM) comprises multiple specialized components of cognition. The goal of our research is to examine how these components relate to each other and to long-term memory (LTM). The participants include patients with early Alzheimer's disease (AD), early Parkinson's disease (PD), global amnesia, unilateral focal lesions in prefrontal cortex or posterior association cortices, and older normal subjects (ONS).