Theta oscillatory power decreases in humans are associated with spatial learning in a virtual water maze task

• Published in: The European journal of neuroscience 2023-12, Vol.58 (11), p.4341-4356
• Main Authors: Thornberry, Conor, Caffrey, Michelle, Commins, Sean
• Format: Article
• Language: English
• Subjects: EEG; efficiency; Electroencephalography; Humans; learning; Maze Learning; navigation; Parietal Lobe; Sensorimotor integration; Spatial discrimination learning; Spatial Learning; spatial memory; theta oscillations; Theta Rhythm; Theta rhythms
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.16185

Theta oscillations (4–8 Hz) in humans play a role in navigation processes, including spatial encoding, retrieval and sensorimotor integration. Increased theta power at frontal and parietal midline regions is known to contribute to successful navigation. However, the dynamics of cortical theta and its role in spatial learning are not fully understood. This study aimed to investigate theta oscillations via electroencephalogram (EEG) during spatial learning in a virtual water maze. Participants were separated into a learning group (n = 25) who learned the location of a hidden goal across 12 trials, or a time‐matched non‐learning group (n = 25) who were required to simply navigate the same arena, but without a goal. We compared all trials, at two phases of learning, the trial start and the goal approach. We also compared the first six trials with the last six trials within‐groups. The learning group showed reduced low‐frequency theta power at the frontal and parietal midline during the start phase and largely reduced theta combined with a short increase at both midlines during the goal‐approach phase. These patterns were not found in the non‐learning group, who instead displayed extensive increases in low‐frequency oscillations at both regions during the trial start and at the parietal midline during goal approach. Our results support the theory that theta plays a crucial role in spatial encoding during exploration, as opposed to sensorimotor integration. We suggest our findings provide evidence for a link between learning and a reduction of theta oscillations in humans. This study investigated the role of theta oscillations (4–8 Hz) in human spatial learning using EEG recordings during a virtual water maze task. Participants were divided into two groups: one group learning the location of a hidden goal and the other simply navigating the maze. Results showed the learning group had reduced theta power at the parietal midline during the start phase and task‐related decreases during learning at parietal and frontal sites during the goal approach phase. Our results suggest a link between efficient learning and theta oscillations in humans and supporting the idea that theta plays a crucial role in spatial encoding during exploration.