Recent Publications (2018-2019)

Hennesse, J.P., Castel, A.D., & Knowlton, B.J. (2018). The effects of value on context-item associative memory in older adults. Psychology and Aging. 33:46-56.

This paper appears in the special issue of Psychology and Aging on associative memory. The results show that valuable items are remembered better by younger and older adults, but that memory for contextual details associated with these items may be impaired relative to less valuable items. While older adults often show preserved memory for valuable items. this may come at a cost to memory for incidental detail.

Knowlton, B.J. & Patterson, T.K. (2018). Habit formation in the striatum. Current Topics in Behavioral Neurosciences. 37:275-295.

This review article discusses current research in humans and animal models for conditions that favor the shift from actions to habits.

Lee, J., Nuechterlein, K., Knowlton, B., Bearden, C., Cannon, T., Fiske, A., Ghermezi, L., Hayata, J., Hellemann, G., Horan, W., Kee, K., Kern, R., Subotnik, K., Sugar, C., Ventura, J., Yee-Bradbury, C., & Green, M. (2018). Episodic memory for dynamic social interaction across phase of illness in schizophrenia. Schizophrenia Bulletin, 44:620-630.

This was a collaborative study from the UCLA Center for Neurocognition and Emotion in Schizophrenia involving labs at the Greater Los Angeles VA, the Semel Institute at UCLA  and the Dept. of Psychology. We found impaired recollection for elements of social interactions in patients with schizophrenia or those at high risk of developing the disease. It is very possible that such memory difficulties contribute to problems with social interactions that occur in these patients. See the UCLA press release below

Patterson, T.K. & Knowlton B.J. (2018). Specificity in human striatal habit learning: A meta-analytic review. Current Opinion in Behavioral Science. 20:75-82.

This paper will appear in an upcoming issue of Current Opinion in Behavioral Science on “Habits and Skills”. This paper describes a meta-analysis comparing the locus of activation across a number of different habit learning paradigms. The results suggest that activations from tasks that best fit the criteria for habits are centered around the putamen. 

Perugini, A., Ditterich, J., Shaikh, A.G., Knowlton, B.J., & Basso, M.A. (2018). Paradoxical decision-making: A framework for understanding cognitive deficits in Parkinson’s disease. Trends in Neurosciences. 41:512-525

This review paper was a collaborative effort with Michelle Basso in the UCLA Semel Institute. In it, we discuss evidence of an impairment in the integration of memory and sensory information in decision-making in Parkinson’s disease, and that this deficit can lead to the pattern of cognitive deficits displayed by these patients. 

Reggente, N., Cohen, M.S., Zheng, Z.S., Castel, A.D., Knowlton, B.J., Rissman, J. (2018). Memory recall for high reward value items correlates with individual differences in white matter pathways associated with reward processing and fronto-temporal communication. Frontiers in Human Neuroscience. 12:241

This paper resulted from a collaborative effort with the Rissman lab that used diffusion tensor imaging to examine the relationship between memory for high-value items and integrity of tracts related to memory and reward processing. We found that fractional anisotropy of the uncinate fasiculus was related to the number of high value items recalled,. Furthermore, we found that selectivity for high over low value items in memory was related to the number of fibers connecting the nucleus accumbens and ventral tegmental area, implicating reward circuitry.

Lin CJ, Yang HC, Knowlton BJ, Wu AD, Iacoboni M, Ye YL, Huang SL, Chiang MC. (2018). Contextual interference enhances motor learning through increased resting brain connectivity during memory consolidation. Neuroimage, 181:1-15.

This paper resulted from the continued collaboration between UCLA and the National Yang-Ming University in Taipei. The goal of this work is to characterize why interleaved practice of motor skills leads to better learning. The results showed that the advantage of interleaved practice was related to greater functional connectivity between the premotor cortex and cerebellum, medial temporal regions, putamen, and thalamus after initial practice. This enhanced connectivity was related to increased functional activation during subsequent training, and may reflect early consolidation of motor skill.  

Clayson, P. E., Kern, R. S., Nuechterlein, K. H., Knowlton, B. J., Bearden, C. E., Cannon, T. D., Fiske, A. P., Ghermezi, L., Hayata, J. N., Hellemann, G. S., Horan, W. P., Kee, K., Lee, J., Subotnik, K. L., Sugar, C. A., Ventura, J., Yee, C. M., & Green, M. F. (2018). Social vs. non-social measures of learning potential for predicting community functioning across phase of illness in schizophrenia. Schizophrenia Research. 18:30492-30494,

This is another paper from the UCLA Center for Neurocognition and Emotion in Schizophrenia. The main findings were that initial scores on the Wisconsin Card Sorting task and a measure of social cognition were predictive of community functioning in patients with chronic or first-episode schizophrenia. While patients showed a benefit of training on both of these measures, the amount of benefit (learning potential) was not significantly related to community functioning. 

Hennessee, J.P., Reggente, N., Cohen, M.S., Rissman, J., Castel, A.D. & Knowlton, B.J. (2019). White matter integrity in brain structures supporting semantic processing is associated with value-directed remembering in older adults. Neuropsychologia, 129:246-254.

This paper follows from Reggente, et al, (2018) which examined the relationship between white matter tracts in the brain and value-directed remembering. In this paper, similar analyses were done in older adults, who exhibit similar levels of memory selectivity as younger adults. In  older adults, there was a significant relationship between integrity of the left inferior fronto-occipital fasiculus and how many valuable items were recalled. This relationship was not present for memory for low-value items. This tract may play a role in semantic processing, consistent with the idea that older adults engage in more semantic encoding of valuable items. Unlike in younger adults, selectivity was not associated with integrity of white matter in midbrain reward regions.

Hennessee, J.P., Patterson, T.K. Castel, A.D., & Knowlton B.J. (2019). Forget me not: Encoding processes in value-directed remembering. Journal of Memory and Language 106:-29-39.

This paper is from our collaboration with Alan Castel on the mechanisms of value-directed remembering. Here, subjects study words of different values, with some followed by an instruction to forget the word because it will not be tested, and some followed by an instruction to remember them. We found better memory for high value words, even those that subjects were told to forget, suggesting that value can automatically enhance memory. On the other hand, in this paper we also show that we can substantially diminish effects of value by instructing subjects to use one type of encoding (either deep or shallow) for all of the items. Thus, value directed remembering appears to rely on differential encoding of high value items. In this paper, we make the case that both automatic and strategic effects of value can enhance memory. 

Patterson, T.K., Craske, M.G., & Knowlton B.J. (2019) Enhanced avoidance habits in relation to early-life stress. Frontiers in Psychology,10:1876. 

This article appears as part of the Research Topics Section on “On the Nature and Scope of Habits and Model-Free Control” edited by John Bargh, Wendy Wood, and David Ellis Melnikoff. Using an avoidance paradigm in which the subject must make responses to avoid unpleasant sounds, we showed that individuals reporting early life adversity exhibiting a greater number of habitual responses than subjects that do not report significant early life adversity. Habitual responses were defined as the subject continuing to make the avoidance response when the earbud delivering the sound was removed- thus, the response occurs through “force of habit” rather than actually having an effect of preventing the sound. This was the first empirical study supported by our NIDA grant to study early life adversity and instrumental learning.