Investigating the Effects of Perceptual Complexity versus Conceptual Meaning on the Neural Correlates of Visual Working Memory

Previous research has demonstrated greater visual working memory (VWM) performance for real-world objects compared to simple features. Greater amplitudes of the contralateral delay activity (CDA) have also been noted for meaningful stimuli, despite being thought of as a neural marker of a fixed working memory capacity. The current study aimed to elucidate the mechanisms underlying improved memory performance for real-world objects by isolating the relative contributions of perceptual complexity (number of features) and conceptual meaning (semantics). Participants (N = 22) performed a lateralized VWM task to test their memory of intact real-world objects, scrambled real-world objects and colours. The CDA was measured during perception and WM retention intervals (600-1000 ms and 1300-1700 ms post-stimulus onset, respectively), and behavioural performance was estimated as capacity (K; number of items correctly remembered in a two-alternative forced choice task). Behavioural performance was significantly greater within-subjects for intact objects relative to scrambled objects and colours, with no difference between colours and scrambled objects. The CDA amplitude was also largest for intact real-world objects, with no difference in magnitude for scrambled objects and colours, during WM maintenance. During perception, both the colours and intact real-world objects had significantly greater amplitudes than scrambled objects and were comparable in magnitude. Overall, findings suggest that conceptual meaning supports the object memory benefit. Comparisons of the CDA across stimulus type during encoding versus WM maintenance may also suggest that the waveform reflects more than purely the storage capacity of VWM.

Name thesis:degree_name

M.A. Psychology

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Faculty of Social Sciences

Department dc:contributor.department

Department of Psychology

Grantor

Brock University

Year dc:date.issued

2023

Author dc:creator

• Thibeault, Alyssa

• visual working memory
• contralateral delay activity
• object memory benefit
• conceptual meaning
• perceptual complexity

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/10464/17935

OAI identifier oai:identifier

oai:brocku.scholaris.ca:10464/17935