Brain Oscillatory Correlates of Visual Short-Term Memory Errors

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Mapelli I., ÖZKURT T. E.

FRONTIERS IN HUMAN NEUROSCIENCE, cilt.13, 2019 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 13
  • Basım Tarihi: 2019
  • Doi Numarası: 10.3389/fnhum.2019.00033
  • Dergi Adı: FRONTIERS IN HUMAN NEUROSCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: working memory, false memory, memory errors, neural oscillations, visual, EEG, WORKING-MEMORY, FALSE RECOGNITION, ALPHA OSCILLATIONS, THETA-OSCILLATIONS, GAMMA OSCILLATIONS, EEG ALPHA, EXECUTIVE FUNCTIONS, PREFRONTAL CORTEX, SPATIAL ATTENTION, TASK
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Brain dynamics of memory formation were explored during encoding and retention intervals of a visual working memory task. EEG data were acquired while subjects were exposed to grayscale images of widely known object categories (e.g., "luggage," "chair," and "car"). Following a short delay, two probes were shown to test memory accuracy. Oscillatory portraits of successful and erroneous memories were contrasted. Where significant differences were identified, oscillatory traits of false memories (i.e., when a novel probe item of the same category is recognized as familiar) were compared with those of successful and erroneous memories. Spectral analysis revealed theta (6-8 Hz) power over occipital channels for encoding of successful and false memories that was smaller when compared to other types of memory errors. The reduced theta power indicates successful encoding and reflects the efficient activation of the underlying neural assemblies. Prominent alpha-beta (10-26 Hz) activity belonging to the right parieto-occipital channels was identified during the retention interval. It was found to be larger for false memories and errors than that of correctly answered trials. High levels of alphabeta oscillatory activity for errors correspond to poor maintenance leading to inefficient allocation of WM resources. In case of false memories, this would imply necessary cognitive effort to manage the extra semantic and perceptual load induced by the encoded stimuli.