Document Type


Degree Name

Master of Science (MSc)



Program Name/Specialization

Behavioural Neuroscience


Faculty of Science

First Advisor

Roelof (Rudy) Eikelboom

Advisor Role

My advisor provided support and helped edit my thesis.


Nondeprived rats receiving every 3rd day access (E3DA) to 4% sucrose solution consume more sucrose on access days compared to rats with everyday access (EDA). Rats receiving EDA or E3DA to 16% sucrose do not consume different amounts, but if placed on every 2nd day access (E2DA) to 4% sucrose E3DA-group rats consume more than EDA rats (Eikelboom, Hewitt, & Adams, 2022). E3DA affects rats’ value of sucrose but effects appear hidden with high sucrose concentrations. Valyear and Eikelboom (2021) suggested that calorie ceilings limit E3DA-induced consumption with high sucrose, but this ceiling could also be caused by increased sweetness. Are rats increasing consumption for calories, or taste?

Experiment 1 found two highly sweet but calorically different solutions that were similarly preferred in rats: 4% sucrose solution sweetened with calorie-free 0.2% saccharin, and 12% sucrose. Experiment 2 placed rats on EDA or E3DA to 4% sucrose, 4% sucrose + 0.1% saccharin (4S solution), or 12% sucrose for 34 days followed by 16 days of E2DA to 4% sucrose. Rats receiving E3DA to 4% sucrose or 4S solution consumed more than their respective EDA counterparts, but rats receiving E3DA to 12% sucrose did not. All E3DA rats consumed large amounts of 4% sucrose in the E2DA phase despite decreases in solution sweetness for rats that received 4S solution and 12% sucrose earlier. Placing rats on E3DA to calorically and hedonically different solutions induced similar lasting effects. Thus, intermittency increases rats’ consumption, but effects can be masked by caloric limits; not taste.

Convocation Year


Convocation Season