A rapid, neural measure of implicit recognition memory using fast periodic visual stimulation Abstract   Fast periodic visual stimulation (FPVS) has recently emerged as a powerful new tool in cognitive neuroscience. Capable of measuring a range of cognitive functions in single subjects in just minutes of recording time, it has been adapted to measure visual, semantic and linguistic processing. We present a new adaptation of the FPVS approach to measure recognition memory via oldnew contrasts. Twenty one subjects (23 (xc2xb16) yrs, 7 males) completed an FPVSoddball paradigm that assessed their spontaneous ability to differentiate between rapidly presented images on the basis of a preFPVS encoding task, i.e. oddball stimuli were only defined by the subjectu0027s experimentally induced memory of them. A clear oddball detection response reflecting recognition memory was observed within one minute of EEG recording time, simply through the passive viewing of stimuli, i.e. subjects received no task instructions and provided no behavioural response. Performance on a subsequent behavioural recognition task showed high levels of recognition of the oddball stimuli. As such, the FPVS approach returned an objective, nonverbal measure of recognition memory in just one minute of recording time, free from the confounds of behavioural recognition tasks. This finding reinforces the adaptability of the FPVS approach for the examination of higherlevel cognition and provides a new method for the neural measurement of recognition memory.

Precuneus stimulation alters the neural dynamics of autobiographical memory retrieval Abstract   Autobiographical memory (AM) unfolds over time, but little is known about the dynamics of its retrieval. Spacebased models of memory implicate the hippocampus, retrosplenial cortex, and precuneus in early memory computations. Here we used transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) to investigate the causal role of the precuneus in the dynamics of AM retrieval. During early memory search and construction, precuneus stimulation compared to vertex stimulation led to delayed evoked neural activity within 1000xc2xa0xe2x80x8bms after cue presentation. During later memory elaboration, stimulation led to decreased sustained positivity. We further identified a parietal late positive component during memory elaboration, the amplitude of which was associated with spatial perspective during recollection. This association was disrupted following precuneus stimulation, suggesting that this region plays an important role in the neural representation of spatial perspective during AM. These findings demonstrate a causal role for the precuneus in early AM retrieval, during memory search before a specific memory is accessed, and in spatial context reinstatement during the initial stages of memory elaboration and reexperiencing. By utilizing the high temporal resolution of MEG and the causality of TMS, this study helps clarify the neural correlates of early naturalistic memory retrieval.