Department of Psychology

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https://hdl.handle.net/20.500.14078/12

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Striking gold: navigating the education massification maze for work readiness
(2024) Enstroem, Rickard; Schmaltz, Rodney
Purpose This study investigates the impact of large-scale teaching in higher education on students’ preparedness for the workforce within the context of evolving labour market demands, the expansion of higher education and the application of high-impact teaching strategies. It synthesizes perspectives on employer work readiness, the challenges and opportunities of large-scale teaching and strategies for fostering a dynamic academia-industry feedback loop. This multifaceted approach ensures the relevance of curricula and graduates’ preparedness while addressing the skills gap through practical recommendations for aligning teaching methodologies with employer expectations. Design/methodology/approach The research methodically examines the multifaceted challenges and opportunities inherent in large-scale teaching. It focuses on sustaining student engagement, maintaining educational quality, personalizing learning experiences and cultivating essential soft skills in extensive student cohorts. Findings This study highlights the critical role of transversal skills in work readiness. It also uncovers that despite its challenges, large-scale teaching presents unique opportunities. The diversity of large student groups mirrors modern workplace complexities, and technological tools aid in personalizing learning experiences. Approaches like peer networking, innovative teaching methods, real-world simulations and collaborative resource utilization enrich education. The importance of experiential learning for augmenting large-scale teaching in honing soft skills is emphasized. Originality/value This manuscript contributes to the discourse on large-scale teaching, aligning it with employer expectations and the dynamic requirements of the job market. It offers a nuanced perspective on the challenges and opportunities this educational approach presents, providing insights for crafting engaging and effective learning experiences in large cohorts. The study uniquely integrates experiential learning, co-creation in education and industry-academia feedback loops, underscoring their importance in enhancing student work readiness in large-scale teaching.
Prism adaptation speeds reach initiation in the direction of the prism after-effect
(2017) Striemer, Christopher; Borza, Carley A.
Damage to the temporal-parietal cortex in the right hemisphere often leads to spatial neglect – a disorder in which patients are unable to attend to sensory input from their contralesional (left) side. Neglect has been associated with both attentional and premotor deficits. That is, in addition to having difficulty with attending to the left side, patients are often slower to initiate leftward vs. rightward movements (i.e., directional hypokinesia). Previous research has indicated that a brief period of adaptation to rightward shifting prisms can reduce symptoms of neglect by adjusting the patient’s movements leftward, towards the neglected field. Although prism adaptation has been shown to reduce spatial attention deficits in patients with neglect, very little work has examined the effects of prisms on premotor symptoms. In the current study, we examined this in healthy individuals using leftward shifting prisms to induce a rightward shift in the egocentric reference frame, similar to neglect patients prior to prism adaptation. Specifically, we examined the speed with which healthy participants initiated leftward and rightward reaches (without visual feedback) prior to and following adaptation to either 17° leftward (n=16) or 17° rightward (n=15) shifting prisms. Our results indicated that, following adaptation, participants were significantly faster to initiate reaches towards targets located in the direction opposite the prism shift. That is, participants were faster to initiate reaches to right targets following leftward prism adaptation, and were faster to initiate reaches to left targets following rightward prism adaptation. Overall these results are consistent with the idea that prism adaptation can influence the speed with which a reach can be planned toward a target in the direction opposite the prism shift, possibly through altering activity in neural circuits involved in reach planning.
Direction of visual shift and hand congruency enhance spatial realignment during visuomotor adaptation
(2023) Striemer, Christopher; Morrill, Adam
Although prism adaptation has been studied extensively for over 100 years to better understand how the motor system adapts to sensory perturbations, very few studies have systematically studied how the combination of the hand used to adapt, and the direction of visual shift, might influence adaptation. Given that sensory inputs and motor outputs from the same side are processed (at least initially) in the same hemisphere, we wondered whether there might be differences in how people adapt when the hand used and the direction of visual shift were congruent (e.g., adapting to rightward shifting prisms with the right hand),compared to incongruent (e.g., adapting to rightward shifting prisms with the left hand). In Experiment 1we re-analyzed a previously published dataset (Striemer, Enns, & Whitwell, 2019)in which healthy adults (n=17) adapted to 17° leftward or rightward optically displacing prisms using their left or right hand (tested in separate sessions, counterbalanced). Our results revealed a “congruency effect” such that adaptation aftereffects were significantly larger for reaches performed without visual feedback (i.e., straight-ahead pointing) when the direction of prism shift and the hand used were congruent, compared to incongruent. We replicated this same congruency effect in Experiment 2 in a new group of participants(n=25). We suggest that a better understanding of the cognitive and neural mechanisms underlying the congruency effect will allow researchers to build more precise models of visuomotor learning, and may lead to the development of more effective applications of prism adaptation for the treatment of attentional disorders following brain damage.
Left cerebellar lesions may be associated with an increase in spatial neglect-like symptoms
(2023) Verbitsky, Ryan; Anderson, Britt; Danckert, James; Dukelow, Sean; Striemer, Christopher
Each cerebellar hemisphere projects to the contralateral cerebral hemisphere. Previous research suggests a lateralization of cognitive functions in the cerebellum that mirrors the cerebral cortex, with attention/visuospatial functions represented in the left cerebellar hemisphere, and language functions in the right cerebellar hemisphere. Although there is good evidence supporting the role of the right cerebellum with language functions, the evidence supporting the notion that attention and visuospatial functions are left lateralized is less clear. Given that spatial neglect is one of the most common disorders arising from right cortical damage, we reasoned that damage to the left cerebellum would result in increased spatial neglect-like symptoms, without necessarily leading to an official diagnosis of spatial neglect. To examine this disconnection hypothesis, we analyzed neglect screening data (line bisection, cancellation, figure copying) from 20 patients with isolated unilateral cerebellar stroke. Results indicated that left cerebellar patients (n=9) missed significantly more targets on the left side of cancellation tasks compared to a normative sample. No significant effects were observed for right cerebellar patients (n=11). A lesion overlap analysis indicated that Crus II (78% overlap), and lobules VII and IX (66% overlap) were the regions most commonly damaged in left cerebellar patients. Our results are consistent with the notion that the left cerebellum may be important for attention and visuospatial functions. Given the poor prognosis typically associated with neglect, we suggest that screening for neglect symptoms, and visuospatial deficits more generally, may be important for tailoring rehabilitative efforts to help maximize recovery in cerebellar patients.
Assessment and recovery of visually guided reaching deficits following cerebellar stroke
(2023) Robles, Chella M.; Anderson, Britt; Dukelow, Sean P.; Striemer, Christopher
The cerebellum is known to play an important role in the coordination and timing of limb movements. The present study focused on how reach kinematics are affected by cerebellar lesions to quantify both the presence of motor impairment, and recovery of motor function over time. In the current study, 12 patients with isolated cerebellar stroke completed clinical measures of cognitive and motor function, as well as a visually guided reaching (VGR) task using the Kinarm exoskeleton at baseline (~2 weeks), as well as 6, 12, and 24-weeks post-stroke. During the VGR task, patients made unassisted reaches with visual feedback from a central ‘start’ position to one of eight targets arranged in a circle. At baseline, 6/12 patients were impaired across several parameters of the VGR task compared to a Kinarm normative sample (n=307), revealing deficits in both feed-forward and feedback control. The only clinical measures that consistently demonstrated impairment were the Purdue Pegboard Task (PPT; 9/12 patients) and the Montreal Cognitive Assessment (6/11 patients). Overall, patients who were impaired at baseline showed significant recovery by the 24-week follow-up for both VGR and the PPT. A lesion overlap analysis indicated that the regions most commonly damaged in 5/12 patients (42% overlap) were lobule IX and Crus II of the right cerebellum. A lesion subtraction analysis comparing patients who were impaired (n=6) vs. unimpaired (n=6) on the VGR task at baseline showed that the region most commonly damaged in impaired patients was lobule VIII of the right cerebellum (40% overlap). Our results lend further support to the notion that the cerebellum is involved in both feedforward and feedback control during reaching, and that cerebellar patients tend to recover relatively quickly overall. In addition, we argue that future research should study the effects of cerebellar damage on visuomotor control from a perception-action theoretical framework to better understand how the cerebellum works with the dorsal stream to control visually guided action.
Psychological flexibility, non-attachment and materialism
(2023) Watson, David; Howell, Andrew J.
Psychological flexibility, or the ability to flexibly respond to psychological events, may be associated with peoples' preferences for material versus experiential purchases, their attachment to objects and experiences, and their motivation for non-material purchases. The present research tested predictions that greater psychological flexibility and lesser psychological inflexibility are associated with lower materialism and non-attachment (Study 1) and with a greater preference for, and internal motivation toward, experiential versus material purchases (Study 2). Study 1 (N = 298 undergraduates) revealed relationships between psychological inflexibility, high materialism, and attachment, and between psychological flexibility, low materialism, and non-attachment. Non-attachment was a meditator in the relationships between both flexibility and inflexibility and materialism. Study 2 (N = 299 undergraduates) revealed that psychological flexibility was correlated with both experiential buying and autonomous reasons for experiential buying, whereas inflexibility was related to controlled and amotivated reasons for experiential buying. We discuss the research and practice implications of the current findings.
COVID-19 anxiety and its relation to anxiety-related disorder symptoms and mechanisms
(2024) Byam, Layton; Penney, Alexander
The COVID-19 pandemic had a significant impact on the mental health of individuals, particularly in the area of anxiety-related disorders. Anxiety regarding COVID-19 has been associated with health anxiety, panic disorder, and obsessive-compulsive disorder symptoms. Additionally, COVID-19 anxiety has been associated with anxiety sensitivity, disgust, maladaptive metacognitions, and intolerance of uncertainty. While researchers have established that anxiety disorders and anxiety-related mechanisms were associated with COVID-19 anxiety, which specific anxiety-related symptoms and mechanisms are primarily associated with COVID-19 anxiety needs to be more extensively explored. The current study sought to further this area by examining which particular anxiety related disorder symptoms and mechanisms were uniquely associated with COVID-19 anxiety. A non-clinical sample of 593 Canadian undergraduate participants (Mage = 21.13 years; 67.7 % female) completed this cross-sectional study between September 2020 and February 2021. Participants completed online questionaries assessing anxiety-related disorder symptoms and mechanisms in addition to multiple scales of COVID-19 anxiety. When examining symptoms, health anxiety (prs = 0.17–0.29) and obsessive-compulsive disorder (prs = 0.16–0.35) symptoms had the strongest unique associations with COVID-19 anxiety. Among the anxiety-related mechanisms, disgust sensitivity (prs = 0.14–0.16) and health anxiety-specific intolerance of uncertainty (prs = 0.12–0.30) had the strongest unique associations with COVID-19 anxiety. Individuals experiencing these disorders and anxiety-related mechanisms may be at a heightened vulnerability to experiencing heightened anxiety during future pandemics. Mental health professionals should discuss COVID-19 anxiety with individuals experiencing health anxiety or obsessive-compulsive disorder symptoms. Lastly, the study highlights the significance of considering a variety of specific anxiety-related disorder symptoms and mechanisms when working to understand pandemic anxiety.
Situational materialism: an extension and replication
(2023) Watson, David; Schmaltz, Rodney
Materialistic thoughts have been associated with poorer life-satisfaction, increased incidence of depression, and lowered self-control. Invoking materialistic thoughts seem to impact health behaviours, such as consuming unhealthy snacks. Kim (2013) found that when materialistic thoughts are activated, participants are more likely to engage in unhealthy behaviours, such as increasing consumption of candy. Kim proposed that the mechanism for this behaviour is that materialistic thoughts lower self-control, which then leads to an increase in consumption of unhealthy food. In the current study, the role of envy on self-control, using a similar experimental paradigm as Kim was investigated. Over the course of three studies, replication of the finding that inducing materialistic thoughts has an impact on eating behaviour was unfounded as none of the differences between experimental conditions were significant. Possible explanations for this failure to replicate are presented.
Research recast(ed): S1E3 - A conversation with Dr. Trevor Hamilton
(2021-09) Ekelund, Brittany; Cave, Dylan; Hamilton, Trevor
Today we go under the sea and get a crash course in Zebrafish with Dr. Trevor Hamilton, a neuroscientist and psychologist at MacEwan University. With a PhD in Neuroscience from the University of Alberta and a Bachelor of Science in Psychology from McGill University, Trevor has a broad body of research involving Zebrafish, and how different substances and pharmacological compounds, like LSD or alcohol, modifies their behaviour. A visiting scholar from the Scripps Institution of Oceanography at the University of San Diego, Dr. Hamilton has also been studying the effects of increasing acidification of the oceans on fish behaviour.
Carotenoid availability and tradeoffs in female convict cichlids, a reverse sexually-dichromatic fish
(2020) Earley, Ryan L.; Anderson, Caleb; Moscicki, Michele; Norton, Benjamin B.; Brown, Alexandria C.; Clotfelter, Ethan D.
Carotenoid pigments have myriad functions in fish, including coloration and immunity. The “carotenoid trade-off hypothesis” posits that dietary limitation of carotenoids imposes constraints on animals to allocate to one function at the expense of another. This hypothesis rarely has been tested in fish. We quantified tissue carotenoids in breeding and non-breeding female convict cichlids in Lake Xiloá, Nicaragua. This species is reverse sexually dichromatic such that females possess carotenoid-based coloration that males lack. We also collected algae samples near nest sites to assess carotenoid availability, recorded water depth, and examined cichlids’ behavioral interactions with pair mates, conspecifics, heterospecific competitors, and predators. Each of these, we predicted, would mediate potential carotenoid trade-offs. We found that non-breeding females had significantly higher levels of carotenoids in their integument, liver, and gonads compared to breeding fish. We found that algae and total carotenoids declined with depth across our study transects at 9, 11, 13, and 15 m, but the concentration of carotenoids (ng carotenoid g−1 algae, or algal quality) did not vary with depth. Furthermore, relationships among carotenoid concentrations of the three tissue types did not vary with depth, and female color status (orange or not) was not affected by behavioral interactions with other community members, reproductive status, or water depth. Our results support previous studies showing that carotenoid pigmentation may serve a signal function that facilitates the establishment of non-breeding females within the breeding population. Our study also uncovered no evidence indicating that carotenoids are limiting in the diet of breeding female convict cichlids.
Canadian undergraduates’ perspectives on medical assistance in dying (MAiD): a quantitative study
(2022) Hawrelak, Erin; Harper, Lori; Reddon, John R.; Powell, Russell A.
Background and Objectives: In 2016, Medical Assistance in Dying (MAiD) became legal in Canada for those suffering a grievous and untreatable medical condition. Currently, it is not available to minors or to those with an untreatable mental illness, although it is likely the scope of MAiD will be widened to include persons with severe and untreatable mental illnesses. However, little is known about the factors predicting acceptance or rejection of MAiD for persons with either a grievous medical condition or an untreatable mental illness. Methods: A survey was administered to 438 undergraduate students to examine factors associated with their acceptance or rejection of MAiD. The survey included four different scenarios: a young or old person with an untreatable medical condition, and a young or old person with an untreatable mental illness. Demographic questions (age, sex, religion, etc), personality measures, and an attitude towards euthanasia scale were also administered, as well as questions assessing participants’ general understanding of MAiD and their life experiences with death and suicide. Results/Conclusion: Overall, most of the Canadian undergraduate participants accepted MAiD for both terminally ill and mentally ill patients; however, different variables, such as age, religion, and ethnicity, predicted the acceptance or rejection of MAiD for each scenario.
The HEXACO model of personality: factors related to gossip & friendship
(2022) Watson, David
In this study, the relationship between gossip, friendship, and the HEXACO model of personality was investigated in a sample of 419 undergraduate participants with three different gossip questionnaires. The results confirmed the hypothesis that emotionality mediates the relationship between friendship and gossip with intimate friendship. With personality and gossip, honesty-humility was the strongest correlate of gossip in a negative direction. The HEXACO facet of sentimentality was found to be a significant indirect mediator of the gossip-friendship relationship rather than the withdrawal facet. With regard to motivation and the tendency to gossip, the subscale-level predictors had a negative relationship with sincerity and fairness. With gossip functions, greed avoidance, sincerity, and modesty were the negatively related predictors. In addition, some sex differences were noted in the relationship between friendship and gossip. Overall gossip scale scores, and the social information and physical appearance gossip subscale scores were correlated with friendship intimacy with females. Achievement gossip was negatively related to friendship intimacy with males. The information function and social motive to gossip were associated with male friendship intimacy. The findings add to the understanding of the relationship between friendship and gossip in terms of personality factors, different elements of gossip, and aspects of friendship. These findings could be used to help individuals deepen the understanding of their friendships and enhance the quality and level of intimacy in these relationships. Particularly useful are the findings that sentimentality rather than withdrawal was related to friendship and gossip.
A juggler's manifesto: elevating creativity to stay productive amid uncertainty
(2023) Enstroem, Rickard; Schmaltz, Rodney
Purpose The Industry 4.0 environment is characterized by fast data, vertically and horizontally interconnected systems, and human–machine interfaces. In the middle stands the manager, whose sustained performance is critical to the organization's success. Business disturbances—such as supply chain disruptions during the pandemic—can quickly test the manager's resiliency. While creativity and flexibility are critical for success in these situations, these skills are often not promoted directly. This paper will discuss strategies for enhancing managers' creativity and resiliency and give suggestions for improving professional development training and post-secondary business education. Design/methodology/approach A synthesis of the literature in business and psychology provides a foundation for creating a conceptual model incorporating strategies to promote managerial creativity and resiliency. While the model focuses on managerial performance under adverse conditions, the tenets of the model also apply during times of relative stability. Findings Findings based on a synthesis of the literature on creativity in business and psychology provide the foundation for a conceptual model to identify potential elements in training and curriculum design to further managers' creativity and resiliency. This model recommends clear, actionable training and program-level curriculum design suggestions for improved managerial performance. Originality/value This paper identifies a conceptual model to enhance managerial creativity leading to increased resiliency through professional development programs and suggestions for educators in post-secondary business education. This model provides tools for managers to deal with adverse and rapidly changing conditions flexibly, promoting employee productivity and satisfaction.
Effects of ocean acidification on dopamine-mediated behavioral responses of a coral reef damselfish
(2023) Hamilton, Trevor; Tresguerres, Martin; Kwan, Garfield T.; Szaszkiewicz, Joshua; Franczak, Brian C.; Cyronak, Tyler; Andersson, Andreas J.; Kline, David I.
We investigated whether CO2-induced ocean acidification (OA) affects dopamine receptor-dependent behavior in bicolor damselfish (Stegastes partitus). Damselfish were kept in aquaria receiving flow through control (pH ~ 8.03; pCO2 ~ 384 μatm) or OA (pH ~ 7.64; CO2 ~ 1100 μatm) seawater at a rate of 1 L min−1. Despite this relatively fast flow rate, fish respiration further acidified the seawater in both control (pH ~7.88; pCO2 ~ 595 μatm) and OA (pH ~7.55; pCO2 ~ 1450 μatm) fish-holding aquaria. After five days of exposure, damselfish locomotion, boldness, anxiety, and aggression were assessed using a battery of behavioral tests using automated video analysis. Two days later, these tests were repeated following application of the dopamine D1 receptor agonist SKF 38393. OA-exposure induced ceiling anxiety levels that were significantly higher than in control damselfish, and SKF 38393 increased anxiety in control damselfish to a level not significantly different than that of OA-exposed damselfish. Additionally, SKF 38393 decreased locomotion and increased boldness in control damselfish but had no effect in OA-exposed damselfish, suggesting an alteration in activity of dopaminergic pathways that regulate behavior under OA conditions. These results indicate that changes in dopamine D1 receptor function affects fish behavior during exposure to OA. However, subsequent measurements of seawater sampled using syringes during the daytime (~3–4 pm local time) from crevasses in coral reef colonies, which are used as shelter by damselfish, revealed an average pH of 7.73 ± 0.03 and pCO2 of 925.8 ± 62.2 μatm; levels which are comparable to Representative Concentration Pathway (RCP) 8.5 predicted end-of-century mean OA levels in the open ocean. Further studies considering the immediate environmental conditions experienced by fish as well as individual variability and effect size are required to understand potential implications of the observed OA-induced behavioral effects on damselfish fitness in the wild.
Zebrafish (danio rerio) shoaling in light and dark conditions involves a complex interplay between vision and lateral line
(2023) Chaput, Shayna; Burggren, Warren; Hurd, Peter L.; Hamilton, Trevor
We know little about how - or even if in some species – fish shoal in darkness. We hypothesized that ‘dark shoaling’ occurs in zebrafish and therefore must depend upon lateral line sensory input. Shoaling in groups of five adult zebrafish was analyzed with motion tracking software. We measured average inter-individual distance, time near the arena wall (thigmotaxis zone) and total distance traveled under normal room light, and in near-complete darkness (infrared light at 850 nm). These observations were repeated in fish treated with cobalt chloride (CoCl2), which ablates lateral line function. In untreated controls, dark shoaling was reduced compared to in light, but nonetheless still present. Elimination of lateral line sensory input by CoCl2 treatment similarly reduced, but did not eliminate, shoaling under both light and dark. Our findings indicate that normal zebrafish shoaling in light or dark requires both visual and lateral line inputs, with neither alone sufficient for normal shoaling.
Continuous light (relative to a 12:12 photoperiod) has no effect on anxiety-like behaviour, boldness, and locomotion in coho salmon (Oncorhynchus kisutch) post-smolts in recirculating aquaculture systems at a salinity of either 2.5 or 10 ppt
(2022) Hamilton, Trevor; Szaszkiewicz, Joshua; Krook, Jeffrey T.; Richards, Jeffrey G.; Stiller, Kevin; Brauner, Colin J.
There is increased interest in rearing salmon in Recirculating Aquaculture Systems (RAS), where environmental conditions can be tightly controlled to optimize growth. Photoperiod and salinity are two important parameters that can be manipulated in RAS. A longer photoperiod permits more time for feeding, while intermediate salinities may reduce the energetic costs of ionoregulation, both of which may enhance growth. However, little is known about how rearing at different photoperiods and salinity affect behaviour, an understudied but important research topic for intensive fish rearing. To address this, we examined the behavioural effects of two salinities and two photoperiod regimes in coho salmon (Oncorhynchus kisutch) post-smolts reared continuously for 120 days in a RAS. Fish were reared on a photoperiod of either 12 h light:12 h dark (12:12), or 24 h light (24:0) at salinities of 2.5 and 10 ppt. To investigate behavioural differences associated with these treatments, we quantified: i) movement in an open-field test, ii) exploratory behaviour/boldness using a novel object approach test, and iii) anxiety-like behaviour with a light/dark test. The 24:0 groups displayed no differences in boldness/anxiety-like behaviour and locomotion relative to the 12:12 groups at their respective salinities. Taken together, fish reared under continuous light (24:0) show negligible behavioural alterations compared to fish reared under normal light dark conditions (12:12).
Zebrafish aversion to infrasound in an open field test
(2023) Scatterty, Kale R.; Pitman, Taylor; Eckersley, Tristan; Schmaltz, Rodney; Hamilton, Trevor
Aquatic species are capable of detecting infrasound (sub-20 Hz frequencies) which may be a source of anthropogenic pollution and have a detrimental impact on the environmental fitness of fish. Infrasound is generated by infrastructure, producing acoustic frequency peaks that are not discernible by humans. The presence of these frequencies may therefore impact the environmental wellbeing of aquatic laboratory animals, which are often housed in spaces adjacent to facilities producing infrasound. To investigate the potential impact of infrasound, we used wild-type zebrafish (Danio rerio) and exposed them to short periods of infrasound at either 5, 10, 15, or 20 Hz, or 0 Hz as a control group. A motion-tracking software system was used to monitor fish movement in an open field test and arena location, distance moved, and immobility were quantified. There was a significant effect of 15 Hz which caused the fish to spend more time away from the infrasound source. The 20 Hz group also spent significantly less time in the zone closest to the speaker. There were no differences in distance moved or immobility between infrasound and control groups. These findings demonstrate that 15 Hz infrasound has aversive effects on zebrafish, causing them to move away from the sound source. To enhance environmental enrichment and wellbeing of aquatic laboratory animals, sources of infrasound pollution should be investigated and mitigated.
Examining behavioural test sensitivity and locomotor proxies of anxiety-like behaviour in zebrafish
(2023) Johnson, Andrea; Loh, Erica; Slessor, Jordan; Verbitsky, Ryan; Franczak, Brian C.; Schalomon, Melike; Hamilton, Trevor
This study assessed the sensitivity of four anxiety-like behaviour paradigms in zebrafish: the novel tank dive test, shoaling test, light/dark test, and the less common shoal with novel object test. A second goal was to measure the extent to which the main effect measures are related to locomotor behaviours to determine whether swimming velocity and freezing (immobility) are indicative of anxiety-like behaviour. Using the well-established anxiolytic, chlordiazepoxide, we found the novel tank dive to be most sensitive followed by the shoaling test. The light/dark test and shoaling plus novel object test were the least sensitive. A principal component analysis and a correlational analysis also showed the locomotor variables, velocity and immobility, did not predict the anxiety-like behaviours across all behaviour tests.
Effects of super-class cannabis terpenes beta-caryophyllene and alpha-pinene on zebrafish behavioural biomarkers
(2022) Johnson, Andrea; Stewart, Alycia; El-Hakim, Ismaeel; Hamilton, Trevor
Terpenes possess a wide range of medicinal properties and are potential therapeutics for a variety of pathological conditions. This study investigated the acute effects of two cannabis terpenes, β-caryophyllene and α-pinene, on zebrafish locomotion, anxiety-like, and boldness behaviour using the open field exploration and novel object approach tests. β-caryophyllene was administered in 0.02%, 0.2%, 2.0%, and 4% doses. α-pinene was administered in 0.01%, 0.02%, and 0.1% doses. As α-pinene is a racemic compound, we also tested its (+) and (−) enantiomers to observe any differential effects. β-caryophyllene had only a sedative effect at the highest dose tested. α-pinene had differing dose-dependent effects on anxiety-like and motor variables. Specifically, (+)-α-pinene and (−)-α-pinene had significant effects on anxiety measures, time spent in the thigmotaxis (outer) or center zone, in the open field test, as well as locomotor variables, swimming velocity and immobility. (+ /−)-α-pinene showed only a small effect on the open field test on immobility at the 0.1% dose. This study demonstrates that α-pinene can have a sedative or anxiolytic effect in zebrafish and may have different medicinal properties when isolated into its (+) or (−) enantiomers.
Robust behavioural effects in response to acute, but not repeated, terpene administration in Zebrafish (Danio rerio)
(2021) Hamilton, Trevor; Leigh, Shannon; Hamilton, Trevor
Terpenes are fragrant aromatic compounds produced by a variety of plants, most notably cannabis and hops. With increasing legalization of cannabis there is a need to better understand the behavioural effects of terpenes and ultimately their therapeutic value. Our study investigated the dose-dependent impact of three terpenes (limonene 0.25, 0.5, 0.75%; β-myrcene 0.001, 0.01, 0.1%; and 0.0001, 0.001, 0.00125% linalool) on zebrafish (Danio rerio) behaviour when exposed both acutely and repeatedly over a 7-day period. Anxiety-like behaviour, boldness, and locomotion were assessed using the open field test and the novel object approach test. In the acute dosing experiment, limonene and β-myrcene exposed groups demonstrated a significant decrease in locomotion, a decrease in anxiety-like behaviour, and an increase in boldness, while linalool treatment groups demonstrated only minor alterations in locomotion. Moreover, repeated exposure to limonene (0.39%) or β-myrcene (0.0083%) for a seven day period did not result in any significant behavioural effects. In conclusion, our study provides support for an anxiolytic and sedative effect in zebrafish in response to acute limonene and β-myrcene exposure that is no longer present after one week of repeated exposure.

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