Chantal Stern is a neuroscientist who uses techniques including

functional magnetic resonance imaging Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area o ...

(fMRI) to study the brain mechanisms of memory function.

Imaging of hippocampal activation during encoding

Stern published the earliest functional magnetic resonance imaging study showing robust increases in blood flow to the

hippocampus The hippocampus (via Latin from Greek , 'seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, a ...

during

memory encoding Memory has the ability to encode, store and recall information. Memories give an organism the capability to learn and adapt from previous experiences as well as build relationships. Encoding allows a perceived item of use or interest to be conve ...

. Prior to this study, imaging studies did not observe robust changes in hippocampus during verbal memory tasks, but this study demonstrated clear increases in blood flow during

encoding In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...

of complex novel visual scenes. This result was subsequently replicated in numerous studies demonstrating activity in the hippocampus and associated parahippocampal cortical regions during encoding of new information, including work showing that the magnitude of hippocampal activity during encoding of stimuli correlates with

recognition Recognition may refer to: *Award, something given in recognition of an achievement Machine learning *Pattern recognition, a branch of machine learning which encompasses the meanings below Biometric * Recognition of human individuals, or biomet ...

of stimuli in subsequent memory tests.

Medial temporal lobe activity during working memory for novel stimuli

Stern demonstrated that holding novel visual scenes in

working memory Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, ...

involves activation of medial

temporal lobe The temporal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe ...

structures. This activation of medial temporal lobe for novel visual scenes contrasted with activation for familiar visual scenes that primarily appeared in the

prefrontal cortex In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, ...

and

parietal cortex The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integrates sensory informa ...

, which were the focus of most previous fMRI studies of working memory function for familiar stimuli. Subsequent data supports this finding, including work showing impairments of working memory for novel stimuli caused by medial temporal lobe damage. In subsequent work, Stern linked this medial temporal lobe activity to mechanisms of persistent spiking shown in individual neurons.

Hyperactivity in the hippocampus in presymptomatic familial Alzheimer's disease

Research in the Stern laboratory has addressed a range of clinical disorders, including

HIV dementia HIV-associated neurocognitive disorders (HAND) are neurological disorders associated with HIV infection and AIDS. It is a syndrome of progressive deterioration of memory, cognition, behavior, and motor function in HIV-infected individuals during t ...

, Parkinson's dementia and

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

. In research with Yakeel Quiroz, Stern showed higher fMRI signal (hyperactivity) in the hippocampal formation in young subjects with a mutation of the presenilin1 gene that results in familial Alzheimer's disease.

References

{{DEFAULTSORT:Stern, Chantal McGill University Faculty of Science alumni Boston University faculty Year of birth missing (living people) Alumni of the University of Oxford Women neuroscientists Alzheimer's disease researchers