The D'Esposito Lab is a cognitive neuroscience research laboratory within the
Helen Wills Neuroscience Institute
and the Department of Psychology.

Recent Publications

Sreenivasan, KK, D'Esposito M.  2019.  The what, where and how of delay activity., 2019 May 13. Nature reviews. Neuroscience. Abstract

Working memory is characterized by neural activity that persists during the retention interval of delay tasks. Despite the ubiquity of this delay activity across tasks, species and experimental techniques, our understanding of this phenomenon remains incomplete. Although initially there was a narrow focus on sustained activation in a small number of brain regions, methodological and analytical advances have allowed researchers to uncover previously unobserved forms of delay activity various parts of the brain. In light of these new findings, this Review reconsiders what delay activity is, where in the brain it is found, what roles it serves and how it may be generated.

Baniqued, PL, Gallen CL, Kranz MB, Kramer AF, D'Esposito M.  2019.  Brain network modularity predicts cognitive training-related gains in young adults., 2019 May 24. Neuropsychologia. Abstract

The brain operates via networked activity in separable groups of regions called modules. The quantification of modularity compares the number of connections within and between modules, with high modularity indicating greater segregation, or dense connections within sub-networks and sparse connections between sub-networks. Previous work has demonstrated that baseline brain network modularity predicts executive function outcomes in older adults and patients with traumatic brain injury after cognitive and exercise interventions. In healthy young adults, however, the functional significance of brain modularity in predicting training-related cognitive improvements is not fully understood. Here, we quantified brain network modularity in young adults who underwent cognitive training with casual video games that engaged working memory and reasoning processes. Network modularity assessed at baseline was positively correlated with training-related improvements on untrained tasks. The relationship between baseline modularity and training gain was especially evident in initially lower performing individuals and was not present in a group of control participants that did not show training-related gains. These results suggest that a more modular brain network organization may allow for greater training responsiveness. On a broader scale, these findings suggest that, particularly in low-performing individuals, global network properties can capture aspects of brain function that are important in understanding individual differences in learning.

Hwang, K, Shine JM, Cellier D, D'Esposito M.  2019.  The Human Intraparietal Sulcus Modulates Task-Evoked Functional Connectivity., 2019 Jul 29. Cerebral cortex (New York, N.Y. : 1991). Abstract

Past studies have demonstrated that flexible interactions between brain regions support a wide range of goal-directed behaviors. However, the neural mechanisms that underlie adaptive communication between brain regions are not well understood. In this study, we combined theta-burst transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging to investigate the sources of top-down biasing signals that influence task-evoked functional connectivity. Subjects viewed sequences of images of faces and buildings and were required to detect repetitions (2-back vs. 1-back) of the attended stimuli category (faces or buildings). We found that functional connectivity between ventral temporal cortex and the primary visual cortex (VC) increased during processing of task-relevant stimuli, especially during higher memory loads. Furthermore, the strength of functional connectivity was greater for correct trials. Increases in task-evoked functional connectivity strength were correlated with increases in activity in multiple frontal, parietal, and subcortical (caudate and thalamus) regions. Finally, we found that TMS to superior intraparietal sulcus (IPS), but not to primary somatosensory cortex, decreased task-specific modulation in connectivity patterns between the primary VC and the parahippocampal place area. These findings demonstrate that the human IPS is a source of top-down biasing signals that modulate task-evoked functional connectivity among task-relevant cortical regions.

Novakovic-Agopian, T, Kornblith E, Abrams G, McQuaid JR, Posecion L, Burciaga J, D'Esposito M, Chen AJW.  2019.  Long-term effects of executive function training among veterans with chronic TBI., 2019 Aug 19. Brain injury. :1-9. Abstract

: To investigate long-term effects of GOALS executive function training in Veterans with chronic TBI. In a recently completed study Veterans with chronic TBI showed improvement immediately post-GOALS but not control training on measures of executive function, functional task performance, and emotion regulation. We now examine the long-term maintenance of post-GOALS training changes in the same sample. : San Francisco VA Health Care System (SFVAHCS), and VA Northern California Health-Care System (VANCHS) in Martinez. : 24 Veterans with chronic TBI were assessed at baseline, post-GOALS training, and long-term follow-up 6+ months following completion of training with a structured telephone interview, neuropsychological and complex functional performance measures, and self-report measures of daily and emotional functioning. : Participants reported an increased likelihood of involvement in competitive employment/volunteering at follow-up (61%) compared to baseline (26%; χ2 = 5.66, < .01, ѱ = .35). Repeated measures MANOVAS indicated improvement on attention/executive function (F = 13.85, < .01, partial η2 = .42), complex functional task performance (GPS Total: F = 9.12, < .01, partial η2 = .38) and daily functioning (MPAI Total: F = 3.23, < .05, partial η2 = .21), and reduction in overall mood disturbance (POMS Total: F = 3.42, < .05, partial η2 = .22) at follow-up relative to baseline. : Training in attention regulation applied to participant-defined goals is associated with meaningful long-term improvement in cognitive skills, emotion regulation, and daily functioning in Veterans with chronic TBI.

Kornblith, E, Posecion L, Abrams G, Chen AJ-W, Burciaga J, D'Esposito M, Novakovic-Agopian T.  2019.  Long-Term Effect of Cognitive Rehabilitation Regardless of Prerehabilitation Cognitive Status for Veterans with TBI., 2019 Aug 28. Applied neuropsychology. Adult. :1-13. Abstract

Persisting difficulties in executive functioning (EF) are common after traumatic brain injury (TBI). Cognitive rehabilitation can be effective, but the impact of pretreatment neurocognitive functioning on long term effects of rehabilitation is unknown. Because this information can impact treatment planning, we examined the relationship between prerehabilitation neurocognitive status and long-term effects of EF training. Archival data were drawn from a trial of Goal-Oriented Attentional Self-Regulation group-format EF training for Veterans with TBI [mild-severe; 11 years postinjury; 96% male, 32% nonwhite, 14.21 years education ( 1.72), 41.13 years old ( 11.39)]. Using prerehabilitation neurocognitive performance, participants were clustered into cognitive difficulty (CD) and cognitively normal (CN) groups. Six-plus months after EF rehabilitation training, participants completed a structured telephone interview and/or in-person cognitive/functional/emotional assessment using standardized measures of cognitive, daily, and emotional functioning frequently employed in TBI research. At 6+ months post-EF training compared to prerehabilitation, CD and CN improved in multiple cognitive (Overall Attention/EF: (1,18) = 26.17, partial  = .59; Total Memory: (1,18) = 6.82, partial  = .28) and functional domains (Goal Processing Scale [GPS] total score: (1,15) = 6.71, partial  = .31). CD improved more than CN on Learning and Memory functional domain [F(1,15) = 6.10, partial  = .29]. Results of our small archival analysis raise the possibility that Veterans with chronic TBI may demonstrate long-term effects of EF training.