Jessica Watson is a fourth-year Clinical Psychology PhD student at Palo Alto University with an emphasis in Neuropsychology. She is currently a neuropsychological assessor through Stanford's Brain Development Project, conducting behavioral and cognitive testing for research projects. Prior to this, Jessica was a Research Assistant at the Stanford Center for Neuroscience in Women's Health. Jessica belongs to the BRAIN lab at Palo Alto University. Her most recent research involves the lab’s pediatric sport concussion program, examining the frequency of “abnormal” (i.e., low) scores in baseline tests of healthy youth to differentiate between statistical and clinical significance. She is working towards completing her dissertation, which examines the level of consensus across psychologists regarding assessment practices.

Honors & Awards

  • Edith Kaplan Scholarship recipient, National Academy of Neuropsychology, Women in Leadership Committee (2018)

Education & Certifications

  • MS, Palo Alto University, Clinical Psychology (2018)
  • BS, Cal Poly, San Luis Obispo, Statistics (2015)

All Publications

  • Perceptions of the cognitive effects of cannabis use: A survey of neuropsychologists' beliefs JOURNAL OF CLINICAL AND EXPERIMENTAL NEUROPSYCHOLOGY Hirst, R. B., Watson, J., Rosen, A. S., Quittner, Z. 2019; 41 (2): 133–46


    Research evaluating the neuropsychological effects of cannabis has yielded mixed findings, with some studies finding cognitive deficits in cannabis users (primarily in learning and memory) and others finding no significant effects. It is important to understand how clinicians perceive this discrepancy in the empirical literature. However, no studies have assessed neuropsychologists' beliefs regarding the effects of cannabis on cognitive functioning. Thus, this study sought to evaluate how patient and cannabis-use factors influence neuropsychologists' perceptions of cannabis's cognitive effects.Neuropsychologists (N = 261) read eight vignettes, each depicting cannabis users varying in age, gender, and cannabis-use history (frequency, duration, and recreational/medicinal use). Respondents rated the anticipated effects of cannabis in each vignette on nine cognitive domains. Mixed effects linear regression modeled the ratings of cognitive abilities as a function of neuropsychologist, neuropsychologists' training, vignette, patient age, gender, and frequency/duration/type of cannabis use, and treated neuropsychologist and vignette as random effects.Duration of use had the most notable effect on neuropsychologists' ratings, with a small (0.1 to 0.2 SDs) yet statistically significant (p < .001) negative effect on each cognitive domain. Male gender and medicinal use also predicted lower cognitive ratings. Differences in ratings between neuropsychologists accounted for 73% of the total variability in each domain, whereas variability due to vignette alone was negligible (<1%).Results suggest that neuropsychologists believe that cannabis use results in broad but mild cognitive deficits, consistent with meta-analytic findings of active chronic cannabis users, particularly for males and for individuals using cannabis for medicinal purposes. Interestingly, neuropsychologists expected fewer cognitive effects in recreational cannabis users. Further, duration of use (rather than frequency) was believed to be the primary factor contributing to cognitive deficits.

    View details for DOI 10.1080/13803395.2018.1503644

    View details for Web of Science ID 000454590400003

    View details for PubMedID 30124369

  • Don't Judge a Book by its Cover: Examiner Expectancy Effects Predict Neuropsychological Performance for Individuals Judged as Chronic Cannabis Users ARCHIVES OF CLINICAL NEUROPSYCHOLOGY Sodos, L. M., Hirst, R. B., Watson, J., Vaughn, D. 2018; 33 (7): 821–31


    The experimenter expectancy effect confound remains largely unexplored in neuropsychological research and has never been investigated among cannabis users. This study investigated whether examiner expectancies of cannabis user status affected examinees' neuropsychological performance.Participants included 41 cannabis users and 20 non-users. Before testing, examiners who were blind to participant user status privately rated whether they believed the examinee was a cannabis user or non-user. Examiners then administered a battery of neuropsychological and performance validity measures. Multiple regression analyses compared performance between examinees judged as cannabis users (n = 37) and those judged as non-users (n = 24).Examiners' judgments of cannabis users were 75% accurate; judgments of non-users were at chance. After controlling for age, gender, and actual user status, examiner judgments of cannabis user status predicted performance on two measures (California Verbal Learning Test-II, and Trail Making Test B; p < .05), as individuals judged as cannabis users obtained lower scores than those judged as non-users.Examiners' judgments of cannabis user status predicted performance even after controlling for actual user status, indicating vulnerability to examiner expectancy effects. These findings have important implications for both research and clinical settings, as scores may partially reflect examiners' expectations regarding cannabis effects rather than participants' cognitive abilities. These results demonstrate the need for expectancy effect research in the neuropsychological assessment of all populations, not just cannabis users.

    View details for DOI 10.1093/arclin/acx114

    View details for Web of Science ID 000455325500003

    View details for PubMedID 29342226